Activities of daily living (ADL) are important for quality of life. They are indicators of cognitive health status and their assessment is a measure of independence in everyday living. ADL are difficult to reliably assess using questionnaires due to self-reporting biases. Various sensor-based  systems have been proposed to successfully recognize and quantify ADL without relying on self-reporting. New classifiers required to classify sensor data are on the rise. We propose two ad-hoc classifiers that are based only on non-intrusive sensor data.A wireless sensor system with ten sensor boxes was installed in the home of ten healthy subjects to collect ambient data over a duration of 20 consecutive days. A handheld protocol device and a paper logbook were also provided to the subjects. Eight ADL were selected for recognition. We developed two ad-hoc ADL classifiers, namely the rule based forward chaining inference engine (RBI) classifier and the circadian activity rhythm (CAR) classifier. The RBI classifier finds facts in data and matches them against the rules. The CAR classifier works within a framework to automatically rate routine activities to detect regular repeating patterns of behavior. For comparison, two state-of-the-art  classifiers have also been used. All classifiers were validated with the collected data sets for classification and recognition of the eight specific ADL.Out of a total of 1,373 ADL, the RBI classifier correctly determined 1,264, while missing 109 and the CAR determined 1,305 while missing 68 ADL. The RBI and CAR classifier recognized activities with an average sensitivity of 91.27 and 94.36%, respectively, outperforming both RF and NB.The performance of the classifiers varied significantly and shows that the classifier plays an important role in ADL recognition. Both RBI and CAR classifier performed better than existing state-of-the-art  on all ADL. Of the two ad-hoc classifiers, the CAR classifier was more accurate and is likely to be better suited than the RBI for distinguishing and recognizing complex ADL.The online version of this article (doi:10.1186/s12938-015-0050-4) contains supplementary material, which is available to authorized users. Activities of daily living (ADL) is an umbrella term that refers to self-care, comprising activities or tasks that people undertake routinely in their everyday life. ADL are the essential activities a person needs to perform to be able to live independently. Existing literature identified the importance of ADL such as bathing, toileting, eating  as indicActivities of daily living assessment measures individuals’ ability to formulate and plan goals in interaction with the environment in which they live and are routinely used by physicians/clinicians. Decline in ADL performance was shown to reflect cognitive impairment, neurobehavioral dysfunction or other neurological disorder/injury . MeasuriActivities of daily living are traditionally assessed with questionnaires like the Katz Index of Independence in Activities of Daily Living (Katz ADL) , StanforThe automatic assessment of ADL is a fundamental problem in elderly care. Several groups have proposed sensor-based systems to recognize and quantify ADL –11 in thIrrespective of the sensor-type, all sensor systems require processing and classification of the massive amount of collected data to derive information regarding the ADL. Different algorithms have been used to classify and recognize ADL from sensor streams, such as probabilistic based , rule baThis paper describes the two ad-hoc classifier algorithms  we developed and evaluates them using wireless sensor data collected from the homes of ten healthy subjects. The performance of the ad-hoc classifiers is also validated using the NB and RF classifiers. The choice of the state-of-the-art classifiers was based on common practice of first data assessment with the NB, and on novelty and resistance to over-fitting performance, shown by many data mining and machine learning researchers, for RF . FirstlySecondly, we introduce the circadian activity rhythm (CAR) classifier, which works within a framework to automatically rate routine activities and detect regular patterns of behavior. The human body keeps track of time in a section of the brain called the suprachiasmatic nucleus . Clinica3) , luminescence (l×) , passive infrared radiation (V)  and acceleration (m/s2) ] are assembled within one sensor box . A commercially available laptop, running customized Microsoft Windows 7 software, serves as the CCU and acts as a local data server. The ad-hoc classifiers implemented in Matlab R2007b  and state-of-the-art classifier implemented in KNIME (https://www.knime.org/knime.org) run on the CCU too. A receiver unit attached to the CCU collects the data packets transmitted from the ten sensor boxes. Besides the five ambient sensor values, each data packet includes a date, timestamp, sensor node number, supply voltage, status word with even-parity error handling and a handshake word to detect frame collision as shown in Figure The wireless sensor system  compriseThe data collection was carried out in accordance with the latest version of the Declaration of Helsinki and was approved by the Ethics Committee of the Canton of Bern, Switzerland. All procedures related to the study were explained to the participants and a written informed consent was obtained prior to participation. No compensation for participation was provided. Healthy subjects were recruited via advertisement in the local newspaper and in the Senior University of Bern. Demographic details were collected using standard questionnaires. Subjects were assessed for neuropsychological details with standardized paper–pencil test battery, which included the Montreal Cognitive Assessment (MoCA) , 25, theActivities of daily living such as sleeping, grooming, toileting, getting ready for bed, cooking, eating, watching TV and seated activity were chosen for this study. The eight ADL Table  and theiThe sensor boxes and the CCU were installed in the home of the ten healthy subjects. For each room, one sensor box was fixed at a height of approximately 2 m, facing towards the middle of the room. Additional sensor boxes were placed in the kitchen (on the fridge door) and in the bathroom (on the flush handle). Once the sensor system was set up and initialized, it recorded the five ambient environmental values autonomously at a rate of 0.2 Hz and continuously for a duration of 20 days in the participant’s home. For validation, the subjects were instructed to protocol their ADL using the wireless protocol device and a paper–pencil log book.Prior to classification, the collected data were stratified by rooms in the apartment  using a Data analysis was based both on existing classification (NB and RF) algorithms and two ad-hoc (RBI and CAR), in-house developed algorithms. The goal of classification is to assign the sorted ambient sensor values to a given set of ADL. The supervised training approach based classifiers such as the NB and RF use a training-set data to predict the classification. Our ad-hoc classification algorithm is based on the assumption that irrespective of the daily routine of the subject, specific patterns with specific duration and timing occur every day .This classifier is based on Bayes theorem , which aThe RF  belongs The RBI classifier is built on (1) a database of facts, 2) a rule-repository and (3) a forward chaining inference engine . The dat a rule-rSi) is composed from the sorted raw data. Each ambient value matrix, Si is then compared to a set of rules For each potential ADL, an ambient value matrix . Figure Biological circadian rhythms are mainly based on daylight and are characterized by their amplitude, period and phase . The daiSt) are composed into ambient value matrices (Si). This is done by summing up the St chronologically as long as the next sample is not null.After sortation, the ambient values samples  successfully captured 33,939,441 data packets . A small percentage  of the captured data packets were lost due to transmission errors, hence leading to an overall transmission reliability of 99.53%.For the ad-hoc classifiers, the sorting and analysis of the captured data packets retrieved a total of 1,373 ADL. The RBI classifier correctly determined 1,264 ADL and missed 109 ADL, while the CAR classifier determined 1,305 ADL and missed 68 ADL. Additional file The difference in sensitivity and specificity for the individual ADL between the classifiers are shown in Table The activity map of a healthy female subject  shown in Figure Ambient assisted living applications are on the rise  and hencSome ADL are not exclusively room related and evoke only slightly different ambient values as reported earlier , 17, 39.Specificity and accuracy of ADL recognition have been reported before and our results are in line with them , 17. TheAccurate models of ADL require labelled examples of ADL for training, however comparable ADL inevitably vary between households and between individuals. The protocol box and log book provided ADL labels for cross-validation and were used for training in the NB and RF classifiers, though not for training for the ad-hoc classifiers. However, we should not rule out the possibility of subjects reporting a wrong activity or missing an activity. This compliance in logging ADL negatively affects the performance of ADL recognition and may be one of the reason that performance for some ADL are low.The majority of the algorithms reported earlier are usually embedded in other algorithms and make up only part of the final results, which makes a comparison of the different algorithms difficult. It is possible that one classifier can obtain very high accuracy for one ADL and average accuracy for another ADL, while the other classifier obtains moderate accuracy for both ADL. When such a condition arises it is difficult to predict the best classifier. In our case, the CAR classifier performed better than RBI for all ADL which makes the comparison easier. The RBI classifier can handle unusual data by adding another rule. But with the manual implementation of a rule-based algorithm there is a risk for over fitting and the performance on new data is non-predictable. The CAR classifier uses the fact that a person’s behavior during the daily cycle tends to fall into regular patterns and variation in these circadian patterns can be pre-markers of upcoming diseases. CAR based approaches have great potential in monitoring activity using ambient sensor systems and are expected to make “aging in place” a possibility for elderly people and patients with dementia , 11.Activity maps can provide information about the variations or transitions in ADL patterns. This may help to benchmark the physical and cognitive abilities of patients . The difThe advantages of our wireless sensor system lie in its low maintenance, quick and easy installation, small discrete shape, non-intrusiveness into privacy of subjects and model-independent data collection. The sensor system further does not draw attention from the user and can be used discreetly. The classification performance in our study relied on the protocol compliance (wireless protocol box and paper–pencil log book) of the subjects. One possible downfall of this approach is that subjects might have forgotten to protocol an activity or logged a wrong ADL, which in turn may have affected the classification performance. While using the log book approach is far from flawless, it seems that the classifier performances reported in this paper actually represent a worst case scenario. Moreover, the ADL recognized and reported here are activities performed by subjects in a free-living context, where subjects made natural transitions between activities. We have classified a wide range of activities ranging from static “sleeping” to the more dynamic “cooking” compared to most studies which limit themselves to two or three ADL. The accuracies obtained with the wide range of ADL in our study is promising. State-of-the-art classifiers as well as custom built algorithms can be used with our wireless sensor system. As for limitations, we collected data using a small sample of participants. Future studies would benefit from using multiple demographic participant designs, as daily activity patterns vary with individuals.The non-intrusive wireless sensor system can be used to acquire environmental data essential for the classification of ADL. Both the ad-hoc classifiers performed better than the state-of-art classifiers. The pattern recognition based CAR classifier performed better than the RBI and we surmise that it is better suited for complex ADL. Variations in regular circadian patterns are thus measurable by monitoring activity and hold great promise in early detection of disorders.


Objectives: We propose a novel approach to examine vulnerability in the relationship between heat and years of life lost and apply to neighborhood social disparities in Montreal and Paris. Methods: We used historical data from the summers of 1990 through 2007 for Montreal and from 2004 through 2009 for Paris to estimate daily years of life lost social disparities (DYLLD), summarizing social inequalities across groups. We used Generalized Linear Models to separately estimate relative risks (RR) for DYLLD in association with daily mean temperatures in both cities. We used 30 climate scenarios of daily mean temperature to estimate future temperature distributions (2021–2050). We performed random effect meta-analyses to assess the impact of climate change by climate scenario for each city and compared the impact of climate change for the two cities using a meta-regression analysis. Results: We show that an increase in ambient temperature leads to an increase in social disparities in daily years of life lost. The impact of climate change on DYLLD attributable to temperature was of 2.06  in Montreal and 1.77  in Paris. The city explained a difference of 0.31  on the impact of climate change. Conclusion: We propose a new analytical approach for estimating vulnerability in the relationship between heat and health. Our results suggest that in Paris and Montreal, health disparities related to heat impacts exist today and will increase in the future. It is well known that rising ambient temperatures are associated with increased heat related health impacts, namely increases in mortality or years of life lost ,2. This Assessing effect modification in the relationship between heat and health in order to identify heat-vulnerability factors is essential in the development of specific policies included in heat action plans . In addiTimes series studies are the most commonly used type of study when assessing the association between temperature and health outcomes ,11,12,13i.e., vulnerability) in the relationship between heat and years of life lost. The main idea of this approach is to address the association between temperature and the intra-population disparities directly, instead of assessing if the heat-mortality association differs across two or more strata. This approach would prevent the loss of statistical power, and provide a comprehensive interpretation about vulnerability to heat related mortality.Here, we propose a novel approach to obtain a single index to represent effect modification (We labeled this index Daily Years of Life Lost Disparities (DYLLD). As a case study, we compared neighborhood SES (measured through neighborhood level of education) potential vulnerability between Montreal and Paris. We also used this estimate to assess such disparities projections under climate change using a large ensemble of climate scenarios.We included all residents of the island of Montreal, Canada who died in the city in the summers  of 1990 to 2007 and the residents of the city of Paris, France in the summers of 2004–2009. For Montreal, we included all underlying non-accidental causes of death. It was not possible to exclude accidental causes of death in Paris, because we did not have access to underlying causes of mortality. Therefore we only included Paris subjects older than 35 years old at the time of death to minimize this bias, because accidental causes of death are dominant in subjects younger than 35 years . To calcWe attributed the following neighborhood SES indicators to each death at the smallest census unit area available. For Montreal, we used the percentage of the population of a dissemination area aged >20 years without a high school diploma from the 2006 census , and fordYLL is the total daily years of life lost, j indexes each of the J neighborhood SES groups , and refdYLL is the daily total dYLL estimate for the reference group (here the highest neighborhood SES group). Using this index allowed us to obtain a single daily estimate of dYLL social disparities between the different neighborhood SES strata. This index thus represents a daily average difference between all groups and the most advantaged neighborhood SES group.We first stratified the total daily YLL (as described above) by terciles of the indicator of neighborhood SES vulnerability. We then used a modified “Index of Disparity” , to summThe relationship between DYLLD and daily mean temperatures in both cities separately was modeled with a non-parametric approach, with adjustments for trend, season, and daily humidity. Details about the statistical modeling are provided in supplementary material. We calculated Relative Risks (RR) for the relation between DYLLD and daily temperature relative to the average DYLLD for the entire period . We estin = 30). We computed pooled estimates for each city and compared them (using a t-test). We compared historical and future DYLLD rates  attributable to temperature between Montreal and Paris . We then conducted a meta regression analysis on the 60 future rates  where the dependent variable was the ln (DYLLD rates) and the independent variable was the city. Different sensitivity analyses were conducted and are presented in supplementary Material.We defined the historical period as 1981–2010 and the future period as 2021–2050. Thirty climate scenarios of daily mean temperature were used (details in Each year an average of 3408 and 3235 deaths (representing 188 and 145 deaths per 100 000 persons) during the summer months (June–August) occurred in Montreal and Paris, respectively, during the study periods . The average summer daily mean observed temperatures were 20.4 °C (SD = 3.24 °C) for Montreal and 19.63 °C (SD = 3.21 °C) for Paris for the study observation periods. The daily YLL ranged from 1076 years to 6739 years in Montreal (mean = 2660 years) and from 633 years to 2991 years in Paris (mean = 1483 years). p < 0.01) in Montreal than in Paris according to the climate scenarios included in our analysis.The pooled estimate of the averaged difference between historical and future scenario daily mean temperatures was 1.35 °C  for Montreal and 1.12 °C  for Paris suggesting that daily mean temperature increase will be larger . The summer rate of DYLLD attributable to temperature in historical period was greater in Montreal  than in Paris   to 100.24 years per 100,000 persons  in Montreal and from 9.98 years per 100,000 persons  to 35.23 years per 100,000 persons  in Paris. The future summer rate of DYLLD attributable to temperature was 45.13 years per 100,000 persons  higher in Montreal than in Paris .i.e., the ratio between future and historical DYLLD) was higher in Montreal 2.06    than in 0, 2.25) . The ICC0, 2.25) .In this paper, we showed that an increase in ambient temperature can lead to an increase in daily years of life lost disparities (according to the neighborhood SES) in both Montreal and Paris. We also report these heat-related neighborhood SES disparities to be larger in Montreal than in Paris in both historical (1981–2010) and future (2021–2050) periods. Lastly, we estimate that the increasing years of life lost neighborhood SES disparities associated with climate change will be higher in Montreal than in Paris. This last result can be partly explained by the fact that the impact of climate change on daily mean temperature will be larger in Montreal than in Paris according to the climate scenarios included in our analysis.We propose a new approach to obtain a single index to represent effect modification in the relationship between heat and years of life lost. This index, which is based on the econometric literature  and modii.e., quantile-quantile methods). Indeed, the use of numerous climate scenarios is essential to represent the uncertainty of future mortality impacts [In parallel to the index we propose, other methods deserve mention. We calculated future health impacts, using a large panel of climate scenarios from the most recent IPCC report from global climate modeling centers with modern post-processing analyses  which represents the reach of commuter movement to and from the island of Montreal and its surrounding suburbs, the most socially disadvantaged communities are situated on the island of Montreal , whereasi.e., lag0), which may underestimate our results. However, according to previous studies, the strongest heat effects are from the current day’s temperature [Other limitations of this study deserve mention and could be addressed in further studies. First, we did not consider the effect of heat waves , which cperature , thus thperature  or displperature  for examperature . Yet, byIn this paper, we present a new index that can be used in different settings in time series analyses and will help to achieve future systematic epidemiologic evaluations about heat-related vulnerability and its determinants . This in


Hearing loss has been associated with cognitive decline in the elderly and is considered to be an independent risk factor for dementia. One of the most common causes for acquired sensorineural hearing loss is exposure to excessive noise, which has been found to impair learning ability and cognitive performance in human subjects and animal models. Noise exposure has also been found to depress neurogenesis in the hippocampus. However, the effect is mainly attributed to the oxidant stress of noise on the cognitive brain. In the present study, young adult CBA/CAJ mice (between 1.5 and 2 months of age) were briefly exposed a high sound level to produce moderate-to-severe hearing loss. In both the blood and hippocampus, only transient oxidative stress was observed after noise exposure. However, a deficit in spatial learning/memory was revealed 3 months after noise exposure. Moreover, the deficit was correlated with the degree of hearing loss and was associated with a decrease in neurogenesis in the hippocampus. We believe that the observed effects were likely due to hearing loss rather than the initial oxidant stress, which only lasted for a short period of time. Hearing loss is one of the most common neurological disorders, affecting 10% of the general population267810The mechanisms underlying the decline of cognitive functions after noise exposure are not entirely clear. Animal studies have suggested that noise exposure is likely to impair cognitive functions through two different but closely related approaches. One is due to the oxidative reaction initiated by noise exposure. Many studies have shown that increased oxidative stress is the cause of neuronal degeneration in many auditory nuclei as well as the brain regions critical for cognitive functions6713In the present study, CBA/CAJ mice were exposed to noise at a high level (123 dB SPL) but for a brief period of time (2 h) to produce permanent hearing loss. Cognitive performance and hippocampal neurogenesis were examined 3 months after noise exposure, long after the disappearance of oxidative stress. The long delay between the presence of oxidative stress and cognitive examination allowed for the investigation of the role of NIHL, rather than oxidative stress, in the decline of hippocampal learning/memory function and neurogenesis.ABR audiograms were obtained at the age of 4.5–5 months and compared between the control group and the noise-exposed group to determine differences in hearing sensitivity. t test, t = 2.946, n = 22 in each group, p < 0.05, Spatial learning ability and memory was tested in a Morris water maze (MWM). The first stage of this test involved a five-day training period in which the mice learned to find the hidden platform underwater (measured as escape latency) using spatial cues around the pool. A Pearson correlation analysis was performed to verify whether the degree of NIHL is correlated to the outcome of MWM tests. A significant positive correlation was observed between the frequency-averaged ABR threshold and the averaged escape latency over the 5 days of training for each individual  region using antibodies against DCX (a marker specific to neurons newly generated within the last 2–3 weeks) and Ki67 (a marker of proliferation). The representative images for both DCX  and Ki67In the present study, young adult CBA/CAJ mice were briefly exposed to noise, producing NIHL, which was verified to be of a moderate-severe degree by comparing the ABR threshold between the two groups at three months after noise exposure . BecauseThe adverse impact of noise on learning and memory and hippocampal neurogenesis has been reported by many previous studies591819202122While the role of noise-induced stress in cognitive impairment and neurogenesis is widely recognized, the independent effect of NIHL should also be considered, especially in cases of brief noise exposure. We think that the stress induced by the brief noise exposure in the present study is unlikely the reason for the deteriorated cognitive function and the depressed neurogenesis measured three months after the noise exposure. This argument is based upon several reasons. First of all, it has been recognized that adrenal glucocorticoid hormones are common pathway to the negative impact of stress on neurogenesis and related cognitive functions25262830313335To further confirm the contribution of negative impact of hearing loss, the cognitive functions and neurogenesis should be evaluated by using conditional knockout mouse models in which hearing loss can be produced in adulthood with no or minimal stress. However, this does not devalue the noise model because NIHL impacts a larger population.The possible impact of NIHL (rather than oxidative stress) on cognitive function is also supported by several lines of previous research data. Firstly, recent studies have demonstrated that hearing loss in general is an independent risk factor of dementia3839404445A significant reduction in cell proliferation and neuronal generation was observed in the noise group, similar to that reported by other researchers17363748495354In conclusion, the present report suggested a role of NIHL independent of its oxidative effect on cognitive function and hippocampal neurogenesis. Therefore, NIHL, if appropriately established, can be used as a model of sensorineural hearing loss to study the mechanism through which hearing loss promotes the development of dementia.A total of 96 CBA/CAJ mice were obtained from the Experimental Animal Center of Shanghai Super-B&K Laboratory Animal Corp. Ltd., Shanghai, China. The subjects in the noise group were exposed to an intense broadband noise at 123 dB SPL for 2 hours at the age of 6 and 8 weeks, while the control subjects underwent sham exposure to the environmental change.Blood samples were taken from 8 subjects in each group at 0, 1, 7 and 28 day(s) after noise exposure to examine serum CORT level. They were returned to the colony for further evaluation. Twenty-four subjects in the noise group were sacrificed  for the examination of oxidative stress in the hippocampus, and 8 subjects in the control group were sacrificed at 1 m after the sham exposure for the same evaluation.Three months after the noise/sham exposure, all animals remaining (32 in each group) were examined for hearing threshold by the frequency specific auditory brainstem response (ABR). In each group, the 32 subjects were further divided into trained (n = 22) and non-trained (n = 10) subgroups. The capabilities of spatial learning and memory were measured in each trained subgroup by means of a Morris water maze. Immediately after the functional test, the hippocampus was harvested for the observation of neurogenesis, and the cochleae were harvested from 12 subjects in the noise group for the evaluation of hair cell loss. All animal procedures were performed in accordance with the guidelines in the ethic protocol approved by the University Committee for Laboratory Animals of Southeast University, China (Permit number: SCXK2011-0003).The animals were unrestrained in a cage 60 cm below the horns of two loudspeakers, a low frequency woofer and a high frequency tweeter. Electrical Gaussian noise was delivered to the speakers after power amplification. The acoustic spectrum of the sound was distributed mainly below 20 kHz, as previously reportedFor the ABR recordings, the animal was anesthetized with pentobarbital , and body temperature maintained at 37.5–38 °C with a thermostatic heating pad. Three subdermal needle electrodes were used to record the ABRs. The non-inverting electrode was inserted at the vertex, and the reference and grounding electrodes were placed on the two earlobes.Hardware and software (BioSig and SigGen) from Tucker-Davis Technology  were used for stimulus generation and bio-signal acquisition. The stimuli were played through a broadband speaker (MF1 from TDT), which was placed 10 cm in front of the animal’s head. The evoked responses were amplified 20 times and digitized via a pre-amplifier (RA16PA) with a filter between 100–3000 Hz. The responses were averaged 1,000 times. The thresholds were measured across frequencies from 2 to 32 kHz with tone bursts presented at the rate of 21.1/s. At each frequency, the test was performed in a descending sequence from 90 dB SPL in 5-dB steps until the ABR response disappeared.The MWM setting was identical to that described previously59Blood samples were taken from the tail vein repeatedly from 8 subjects in each group at 0, 1, 7 and 28 day(s) after noise exposure to examine serum CORT level. Each sample was placed in a sodium heparin-coated tube, and 50 μl of supernatant plasma was obtained from each sample after centrifugation for testing. The plasma CORT concentration was measured using a Mouse Corticosterone (CORT) ELISA Kit , strictly following the kit instructions.In Vitro ROS/RNS Assay Kit, STA-347). Total protein concentration was measured before the MDA test using the Pierce® BCA Protein Assay Kit . The ROS/RNS level was tested using a ROS/RNS-sensitive fluorescent dye, DCF , which was generated from the reaction of ROS/RNS with a specific probe: DCFH-DA (dichlorofluorescein diacetate). The compound is hydrolyzed to DCF, which interacts with ROS/RNS to generate fluorescence. The quantity of ROS/RNS was calculated based on the standard obtained using the known ROS/RNS contents.Hippocampal tissue was quickly harvested on ice from mice after decapitation and was immersed in PBS of 9 times the tissue volume for ultrasonication. Supernatant was obtained after ultracentrifugation for the tests of three common indicators of oxidative stress. Commercial test kits from Cell Biolabs  were used for measuring super oxide dismutase (SOD) activity (Superoxide Dismutase Activity Assay kit STA-340), malondialdehyde (MDA) adducts  and reactive oxygen/nitrogen species (ROS/RNS) level  and fixed with open-chest cardiovascular perfusion of 4% paraformaldehyde in PBS buffer followed by post-fixation in the same fixative at 4 °C for 24 h. The brain tissue block was then immersed in 30% sucrose, dehydrated at 4 °C until it sunk to the bottom, embedded in OCT compound and then frozen in a −80 °C freezer. The frozen block was sliced into 25 μm thick sections using a microtome . One section from every 3 was chosen for further processing.Doublecortin (DCX) staining was performed using floating sections. The selected sections were permeabilized with 0.1% Triton X-100 in PBS for 30 min, incubated for 30 min in 10% donkey serum in PBS and then incubated in the primary antibody  overnight at 4 °C. This was followed by treatment with secondary antibodies  for 1 h at room temperature. Ki67 staining was performed on affixed tissue sections. The selected slices were placed onto lysine-treated glass slides, dried at room temperature, dipped in antigen retrieval solution (mixture of citric acid buffer), and then heated in a microwave oven. The slices were then permeabilized with 0.1% Triton X-100 in PBS for 30 min, incubated for 30 min in 10% goat serum and then incubated in the primary antibody  overnight at 4 °C. This was followed by incubation with secondary antibodies  for 1 h at room temperature. The numbers of DCX- and Ki67-positive cells were counted under a fluorescence microscope  and multiplied by 3 to yield the total number of DCX/Ki67-positive cells in the whole DG region in each animal brain.The mouse was anaesthetized  and decapitated. The otocyst was quickly removed, and the round and oval windows were picked under an anatomical microscope. The cochlea was perfused with the succinate dehydrogenase (SDH) staining solution, which contained 0.2 M succinate dibasic hexahydrate  and 0.1% Tetranitro Blue Tetrazolium Chloride  in 0.2 M PBS. Then, the cochlea was immersed in the solution for 45 min at 37 °C before being transferred to 4% paraformaldehyde for 24 h at 4 °C and decalcified with 1N HCl. After that, the organ of Corti was dissected and mounted with 80% glycerin in PBS on a glass slide. It was observed under a light microscope, and the missing hair cells were counted to establish a cochleogramAll statistical analyses were performed using SigmaPlot 12.2 software. The ANOVA tests were performed before the post-hoc tests. All data are presented as the means ± SEM, unless otherwise specified. Significance is accepted at the level of p < 0.05.How to cite this article: Liu, L. et al. Noise induced hearing loss impairs spatial learning/memory and hippocampal neurogenesis in mice. Sci. Rep.6, 20374; doi: 10.1038/srep20374 (2016).


Mycoplasma hyopneumoniae, Mycoplasma flocculare and Mycoplasma hyorhinis. While colonization by M. flocculare is virtually asymptomatic, M. hyopneumoniae and M. hyorhinis infections may cause respiratory disease. Information regarding transcript structure and gene abundance provides valuable insight into gene function and regulation, which has not yet been analyzed on a genome-wide scale in these Mycoplasma species. In this study, we report the construction of transcriptome maps for M. hyopneumoniae, M. flocculare and M. hyorhinis, which represent data for conducting comparative studies on the transcriptional repertory. For each species, three cDNA libraries were generated, yielding averages of 415,265, 695,313 and 93,578 reads for M. hyopneumoniae, M. flocculare and M. hyorhinis, respectively, with an average read length of 274 bp. The reads mapping showed that 92%, 98% and 96% of the predicted genes were transcribed in the M. hyopneumoniae, M. flocculare and M. hyorhinis genomes, respectively. Moreover, we showed that the majority of the genes are co-expressed, confirming the previously predicted transcription units. Finally, our data defined the RNA populations in detail, with the map transcript boundaries and transcription unit structures on a genome-wide scale.The swine respiratory ciliary epithelium is mainly colonized by  Mycoplasma hyopneumoniae, Mycoplasma flocculare and Mycoplasma hyorhinis are the most important species that have been identified in the swine respiratory system M. hyopneumoniae is the etiological agent of porcine enzootic pneumonia, whereas M. hyorhinis, in addition to being present in swine respiratory tracts, may cause swine serofibrinous to fibrinopurulent polyserositis and arthritis M. flocculare is also widespread in swine herds, but no disease has been associated with this species M. hyopneumoniae and M. flocculare are phylogenetically closely related species M. hyopneumoniae can adhere to the cilia of tracheal epithelial cells and cause damage. Although M. flocculare can also adhere to cilia, no important resulting damage has been observed, suggesting that M. hyopneumoniae and M. flocculare may possess different mechanisms of action involving the recognition of different receptor sites on the cilia M. hyorhinis to colonize other host sites M. hyopneumoniae, M. flocculare and M. hyorhinis possess small genomes with limited biosynthetic potentials. Six M. hyopneumoniae genome strains have been sequenced M. hyorhinis strains M. flocculare strain Similar to other mycoplasmas, M. hyopneumoniae 7448 genome M. hyopneumoniae genome by both in silico and in vitro approaches have suggested that the ORFs are continuously transcribed (cotranscribed) in large clusters (TUs). The authors have predicted that each TU is transcribed in the same direction with no intervening gene transcribed in the opposite orientation M. hyopneumoniae genome have also been reported in the M. flocculare and M. hyorhinis genomes Mycoplasma pneumoniaeAnalyses related to transcriptional unit (TU) organization, transcriptional regulation and promoter sequence composition have been performed on the Mycoplasma species that inhabit the swine respiratory tract and the limited knowledge available regarding mycoplasma transcriptional regulation, we aimed to analyze the whole transcriptomes of M. hyopneumoniae, M. flocculare and M. hyorhinis. In this work, we have sequenced, analyzed and constructed single nucleotide resolution transcriptome maps for the three species. A comparative analysis of the whole gene expression profiles between these swine respiratory mycoplasmas was also performed. Furthermore, the organizations of the genomes into large TUs (polycistronic mRNA), as previously predicted, were estimated and compared between the three species.Considering the importance of the three M. hyopneumoniae strain 7448, M. flocculare ATCC 27716 and M. hyorhinis ATCC 17981 were used in this study. The bacteria were grown in 25 ml Friis broth Total RNA was isolated with the RNeasy Mini Kit . For cell lysis, 0.7 ml of RNeasy Lysis Buffer (RLT buffer) in 0.134 M β-mercaptoethanol was used per cultivation flask. The purification was performed according to the manufacturer's instructions, with on-column DNase I digestion using the RNase-Free DNase Set  and a second round of treatment with DNase I . The absence of DNA in the RNA preparations was monitored by PCR. The extracted RNA was analyzed by gel electrophoresis and quantified using the Qubit system . RNA quality and integrity were determined by the evaluation of the RNA Integrity Number (RIN) using the Agilent 2100 Bioanalyzer . Values that were greater than or equal to 9.5 indicated sufficient quality.The ribosomal RNA (rRNA) depletion was performed using Terminator 5′-phosphate-dependent exonuclease , according to the manufacturer's instructions. Briefly, total RNA (10 µg) was combined with TEX 10X Reaction Buffer A, 20 U RiboGuard RNase Inhibitor, 10 U TEX (1 U/µg mRNA) and nuclease-free water in a final volume of 40 µl and incubated at 30°C for 60 minutes. The reaction was stopped with EDTA (0.5 M), and the mRNA was precipitated with 3 M sodium acetate and 2.5 volumes of ethanol. The mRNA was quantified using the Qubit system , and the effectiveness of the reaction was assessed by the Agilent 2100 Bioanalyzer . The absence of 16S and 23S rRNA in the posttreatment sample indicated a successful reaction.cDNA Rapid Library Preparation Method Manual GS FLX Titanium Series . After the library construction, the samples were quantified using the Qubit system , and average fragment sizes were determined using the Agilent 2100 Bioanalyzer . Three cDNA libraries for each strain were generated, totaling nine libraries, which were sequenced using the Roche/454 GS-FLX system. Following the analyses of the reads, each of the triplicate sets of libraries was pooled.The cDNA library preparation and pyrosequencing were performed using GS-FLX Titanium series reagents following the manufacturer's instructions . An equal amount of mRNA (200 ng) from each strain was used to synthesize the first and second strands of the cDNA, according to the http://www.bioinformatics.babraham.ac.uk/projects/fastqc/) was used for the read quality assessments, and the FASTX-Toolkit v0.0.13 (http://hannonlab.cshl.edu/fastx_toolkit/) was employed for trimming. Reads were aligned with Bowtie2 v2.1.0 M. hyopneumoniae 7448, M. flocculare ATCC 27716 and M. hyorhinis HUB-1 genomic sequences were used as references, and the rRNA sequences were filtered. The results were parsed, and GenBank (gb) format files were generated for analysis with the Artemis Release 10.5.2 software package For the transcriptome assembly, Newbler v2.8 was used with the default parameters. The FastQC software (The Standard Flowgram Format (SFF) files of the sequence data generated in this study have been deposited in the Short Read Archive (SRA) database at NCBI under the accession number PRJNA255516.M. hyopneumoniae 7448 (NC_007332), M. flocculare ATCC 27716 (NZ_AFCG00000000.1) and M. hyorhinis HUB-1 (NC_014448.1).Expressed reads with coverage above background were mapped onto the annotated genes of M. hyopneumoniae 7448 M. flocculare and M. hyorhinis TUs were predicted The operon assessment was based on published experimental data from de novo assembly. The cDNA libraries were constructed with total mRNA from M. hyopneumoniae 7448, M. flocculare ATCC 27716 and M. hyorhinis ATCC 17981. The RNA preparations from the three species were obtained from bacteria grown under the same culture conditions. M. hyopneumoniae 7448, M. flocculare ATCC 27716 and M. hyorhinis ATCC 17981 genomes. The sequence coverage per base was subsequently plotted and visualized using the genome browsers Artemis and DNAplotter A total of 1,204,156 raw sequencing reads with an average length of 274 bp were generated using the Roche GS FLX Sequencing Platform. After cleaning and removing the adapters from each sequence in addition to low-quality sequences  and rRNA sequences, a total of 683,385 high-quality reads were obtained and used for the M. hyopneumoniae library allowed for the generation of 415,265 reads, of which approximately 94% mapped to the reference genome sequences of M. hyopneumoniae strain 7448. Most of the 695,313 reads (93%) from the M. flocculare library also mapped to the reference genome sequences of M. flocculare strain ATCC 27716. Similarly, 86% of the 93,578 reads from the M. hyorhinis library mapped to the reference genome sequences of M. hyorhinis strain HUB-1. The mapped M. hyopneumoniae, M. flocculare and M. hyorhinis genes represented 92%, 98% and 96% of the total predicted ORFs in these genomes, respectively  to genes from M. hyopneumoniae and other mycoplasma species. Three of these genes encoded hypothetical proteins, with the gene IDs MHP7448_0560, MHP7448_0709 and MHP7448_0138 in the M. hyopneumoniae 7448 genome, to which 127, 10 and 146 reads, respectively, were mapped in the M. flocculare transcriptome. Another novel identified gene encoded a lipoprotein with the gene ID MHP7448_0366 in M. hyopneumoniae, to which 31 reads were mapped in the M. flocculare transcriptome. A gene encoding a type III restriction-modification system: DNA methylase with the gene ID MHP7448_0386 in M. hyopneumoniae was also identified, to which 4 reads were mapped in the M. flocculare transcriptome.Genome annotation refinement is an important aspect of a transcriptome analysis. The transcriptome map of M. flocculare genome, the ftsZ gene is located in contig 04 and is positioned from nucleotides 8844–9491, which is located 647 bp downstream of a hypothetical gene (MF01093) in the opposite strand. However, the transcriptome map constructed in this study allowed for the identification of the incorrect annotation of the start codon of the ftsZ gene. The gene MF01093, with a highly expressed level   in contig 04. This observation was confirmed by BLASTX comparisons against homologous genes in other Mycoplasma sp.According to the current annotation of the 8.8) see , is in fM. hyorhinis allowed for the identification of two novel genes. The first encoded a hypothetical protein, HUB-1, which was positioned from nucleotides 721079–721572 (with 12 associated reads). BLAST comparisons indicated that this gene shared 98% identity  with MYM_0631, which is a hypothetical protein that is positioned from nucleotides 719192–719647 in the M. hyorhinis GDL-1 genome and totals 453 bp in size. The second non-annotated gene was rnpB, to which 7,876 reads were mapped. The BLASTX analysis showed that it shared homologies  with the genomes of other M. hyorhinis strains and other Mycoplasma species.The transcriptome map of M. hyorhinis HUB-1 genome. RNase P, which is encoded by the rnpB gene, is a ribonucleoprotein complex that removes 5′ leader sequences from tRNA precursors during tRNA biosynthesis. RNase P is present in all cells and subcellular compartments that synthesize tRNA, but catalytic activity by the RNA alone has been demonstrated only for bacterial RNase P RNA. Bacterial RNase P RNAs have been separated into two main structural classes. Type A (rnpA) is the most common structural class, and type B (rnpB) is found in low G+C gram-positive bacteria Mycoplasma sp. genomes typically contain both classes of RNase P.Additionally, in this work, we detected the endoribonuclease P (RNase P) ncRNA in the M. hyopneumoniae, M. flocculare and M. hyorhinis now allow for the detection of novel transcripts that have not been previously annotated in these genomes. Such transcripts include noncoding RNAs (ncRNAs), which were shown in other microorganisms to regulate important processes, such as pathogenesis, iron metabolism, and quorum sensing M. hyopneumoniae, M. flocculare and M. hyorhinis transcriptomes, respectively  ribonucleoprotein complex. The SRP RNA belongs to a group of small 4.5S RNAs that are found in bacteria, which direct the traffic of proteins within the cell and allow for their secretion. The SRP RNA, together with one or more SRP proteins, contribute to the binding and release of signal peptides In our M. hyopneumoniae transcriptome showed that 92% of the predicted genes possessed significant alignments with one or more sequences (rnpB), which encodes the RNA component of RNase P. Other genes that were also associated with high RPKM values included those encoding the cell division protein MraZ, S-adenosyl-methyltransferase, cell division protein FtsZ, p216 surface protein and hexosephosphate transport protein.The read distribution of the equences . A detaiM. flocculare genome revealed that 98% of the predicted genes significantly aligned to one or more sequences of the M. flocculare transcriptome , and another four hypothetical genes  with orthologs in the M. hyopneumoniae genome also presented with high RPKM values  presented with a significant amounts of transcripts   , similarM. hyopneumoniae genes encoding MHP7448_0198 (protein p97-copy 1) and MHP7448_0199 (protein p102-copy 1) are the only adhesin genes absent in the M. flocculare genome M. flocculare genome compared with those of the M. hyopneumoniae transcriptome (M. hyopneumoniae ortholog was MHP7448_0108 with RPKM  = 234.7) and MF00475  (the M. hyopneumoniae ortholog was MHP7448_0107 with RPKM  = 51.1). The finding of higher numbers of reads mapping in the M. flocculare adhesins compared with those of the M. hyopneumoniae orthologs was unexpected (see M. flocculare display inversions and rearrangements in contrast with those of M. hyopneumoniaeM. flocculare lacks the R1 domain M. hyopneumoniae adherence M. flocculare p97-like protein and its orthologs from M. hyopneumoniae (p97-like adhesin). Thus, even with the high read numbers of some of the adhesins that were observed in the current study, M. flocculare possesses a weak adhesion ability Previous analyses have shown that the orthologs of criptome , and evected see , but accM. flocculare, was elevated, as shown in M. hyopneumoniaeM. hyopneumoniae, compared to the M. flocculare ortholog with 278 reads (RPKM  = 72.5) , which has no ortholog in  = 72.5) . The P21M. hyorhinis was performed with the strain M. hyorhinis ATCC 17981. Because the genome of this strain was not available, the transcriptome assembly and mapping was based on the M. hyorhinis HUB-1 genome. The percentage of reads mapped (86%) was the lowest among the three mycoplasma cDNA libraries    also were aligned by expressive numbers of reads.The transcriptome analysis of ibraries . This recriptome , and app8,637.4) , followe1,456.1) . The genM. hyorhinis contains an exclusive variable lipoprotein (Vlp) system that constitutes its major coat proteins M. hyorhinis strains carry variable numbers of vlp genes M. hyorhinis HUB-1 is characterized by the presence of seven vlp genes displayed in the order 5-vlpD-vlpE-vlpF-insertion sequence (IS)-vlpG-vlpA-IS-vlpB-vlpC-3′ vlp genes were identified in the M. hyorhinis transcriptome map, the transcript numbers mapping to the different vlp genes were variable. vlpF, vlpE and vlpB were mapped by more reads compared with vlpG, vlpD and vlpC  and cell division (mraZ). Notably, the gene ftsZ, which encodes a cell division-related protein, is among the genes mapped with the largest RPKM amounts in the M. hyopneumoniae and M. flocculare transcriptomes (M. hyorhinis (RPKM  = 839.9). Most bacteria produce the tubulin homolog FtsZ ftsZ is non-essential for cell growth and in the absence of the FtsZ protein, M. genitalium can manage feasible cell divisions and cytokinesis using the force generated by its motile machinery M. pneumoniae, very low levels of both ftsZ mRNA and FtsZ protein are present Abundant numbers of transcripts were identified in the three transcriptome maps that aligned to S-adenosyl-methyltransferase-associated genes, that participate in cell wall biosynthesis  . HSPs arM. hyopneumoniae, M. flocculare and M. hyorhinis has been recently described M. hyopneumoniae and M. flocculare. These two closely related mycoplasma species M. hyopneumoniae is considered to be pathogenic, and M. flocculare is considered to be a commensal species. This genome comparison showed many differences that may help to explain their differing behaviors. However, they were not able to identify specific virulence determinants that could explain the differences in their pathogenicities M. hyorhinis genome also shares significant numbers of genes with both M. hyopneumoniae and M. flocculare. The differences in M. hyorhinis gene composition seem to be related mainly to the ability of M. hyorhinis to colonize different hosts and sites.A comparative genome analysis between M. hyopneumoniae, M. flocculare and M. hyorhinis. The RNA-Seq data enabled us to determine the structures of the TUs on a genome-wide scale, which is important for the identification of co-expressed genes and for the understanding of the coordinated regulation of the mycoplasma transcriptome. Our results support previous predictions that the genes are preferably transcribed in polycistronic mRNA, forming TUs, in the mycoplasma genomes M. hyopneumoniae, M. flocculare and M. hyorhinis was described in silico prediction revealed that they are present in similar numbers in these three mycoplasmas genomes M. flocculare and M. hyorhinis similar to M. hyopneumoniaeM. hyopneumoniae, the overall gene distributions within the TUs in M. flocculare and M. hyorhinis are highly variable with respect to gene number and the functional categories of the encoded products in silico and in vitro approaches in M. hyopneumoniae in addition to the computationally predicted TUs in the M. flocculare and M. hyorhinis genomes were confirmed in the three transcriptomes analyzed here.We have constructed transcriptome maps of M. hyopneumoniae and M. hyorhinisM. flocculare transcriptome, all of the TUs predicted by the previous in silico analysis Over 80% of the TUs predicted for the three species were either confirmed or partially confirmed by our transcriptome analysis . Table 1M. hyopneumoniae 7448. The M. hyorhinis map has the largest mRNA contig mapped, with a size reaching of 13,000 bp (locations: 485595–498603 bp and 779997–788652 bp). M. pneumoniae transcriptome data showed a natural polarity with respect to the TU, in which the first gene of the TU exhibits the most prominent level of transcription, and levels progressively decreased for each successive gene in the TU The overlapping reads mapping to each reference genome generated a surprisingly large number of long contigs . Some exM. hyopneumoniae TUs are preceded by putative promoter sequences M. hyopneumoniae genomes M. hyopneumoniae TUs possess internal promoter sites, which is in agreement with the high variations in expression levels that were observed within the TUs. These findings are also similar to others that have been described in many bacterial species, including those in the M. pneumoniae transcriptome, which has been characterized by the frequent occurrence of polycistronic operons with alternative transcripts Bacillus subtilis transcriptome, in which 20% of the genes in polycistronic operons are transcribed from more than one promoter Halobacterium salinarum, 40% of the operons are expressed in condition-dependent manners Mycoplasmas are characterized by the presence of long TUs containing genes that encode highly functionally variable products. Moreover, all the Mycoplasma species that inhabit the respiratory tract of swine. We have analyzed the RNA populations present in M. hyopneumoniae, M. flocculare and M. hyorhinis in detail and used the data to map transcript boundaries and operon structures on a genome-wide scale. Moreover, we showed that almost all of the genes in these mycoplasma genomes are expressed at some basal level and that the majority of the genes are co-expressed, confirming the previously predicted TUs. Our results expand upon current knowledge regarding the coordination of transcription in swine respiratory mycoplasmas, in which genes are preferably transcribed in TUs. The determinations of all of the functional elements in the M. hyopneumoniae, M. flocculare and M. hyorhinis is a prerequisite for formulating holistic approaches to delineating the complex transcriptional regulation that occurs in these mycoplasma species.Overall, we provided comprehensive assessments of the transcriptomes of three important Figure S1Genome wide assessment. Circular plot of the reads mapping to the (A) M. hyopneumoniae 7448, (B) M. flocculare ATCC 27716 and (C) M. hyorhinis HUB-1 genomes. The outer circle (black) is marked in basepairs. The outermost circles represent CDS on the forward (outermost) and reverse (second outermost) strand (blue). Coding regions are illustrated by intermediate gray circle. The green inner circle represents the mapped sequence reads with a minimum quality score of 20. Visualization by DNAplotter.(TIF)Click here for additional data file.Figure S2Length distribution of contigs from M. hyopneumoniae (MHP), M. flocculare (MFL) and M. hyorhinis (MHR) transcriptome assembly.(JPG)Click here for additional data file.Table S1Transcriptome mapping from Mycoplasma hyopneumoniae.(XLSX)Click here for additional data file.Table S2Transcriptome mapping from Mycoplasma flocculare.(XLSX)Click here for additional data file.Table S3Transcriptome mapping from Mycoplasma hyrhinis.(XLSX)Click here for additional data file.Table S4Probably noncoding RNA detected in the three transcriptome studied.(XLSX)Click here for additional data file.Table S5Mycoplasma hyopneumoniae 7448 trancriptional units and cotranscription analysis.(XLS)Click here for additional data file.Table S6Mycoplasma flocculare trancriptional units and cotranscription analysis.(XLS)Click here for additional data file.Table S7Mycoplasma hyorhinis trancriptional units and cotranscription analysis.(XLS)Click here for additional data file.


They are known to play an important role in various processes, including metabolic regulation, craving, pain, anxiety, and immune function. In the last decade, there has been a growing interest for endocannabinoids in the retina and their role in visual processing. The purpose of this review is to characterize the expression and physiological functions of the endocannabinoid system in the visual system, from the retina to the primary visual cortex, with a main interest regarding the retina, which is the best-described area in this system so far. It will show that the endocannabinoid system is widely present in the retina, mostly in the through pathway where it can modulate neurotransmitter release and ion channel activity, although some evidence also indicates possible mechanisms via amacrine, horizontal, and Müller cells. The presence of multiple endocannabinoid ligands, synthesizing and catabolizing enzymes, and receptors highlights various pharmacological targets for novel therapeutic application to retinal diseases.Endocannabinoids are important retrograde modulators of synaptic transmission throughout the nervous system. Cannabinoid receptors are seven transmembrane G-protein coupled receptors favoring G N-arachidonoyl ethanolamide, also known as anandamide (AEA), and 2-arachidonoyl glycerol (2-AG), are then quickly degraded, mostly via fatty acid amide hydrolase (FAAH) activity for AEA and monoacylglycerol lipase (MAGL) for 2-AG. This retrograde release can also act on CB2R in large part situated on glial cells in the adult nervous system -noradrenaline and [3H]-dopamine in the guinea pig [i/o-dependent mechanism [3H]-D-aspartate (a substitute of L-glutamate for high-affinity uptake sites) release following ischemia or K+ channel activation in isolated bovine retina [A receptor-mediated inward currents from WIN55,212-2, a synthetic cannabinoid with similar affinity to both CB1R and CB2R, on low spontaneous transmission in embryonic chick amacrine cells [ in vivo electrophysiological studies, only CB2R, not CB1R, appears to cause changes to light responses in the mouse retina: in vivo recording of electroretinogram responses indicates that cnr2-KO animals exhibit increased a-wave amplitude under scotopic conditions and different light adaptation pattern in photopic conditions [In the retina, cannabinoids inhibit the release of various neurotransmitters. Indeed, CB1R agonists decrease the release of [inea pig  via a Giechanism , 62. In echanism . A firste retina . Some evne cells . It is inditions . As this3 K/AKT) activation, a fundamental signaling pathway for cellular apoptosis [e , has reiew, see . Abn-CBDiew, see , 71. Var, see [α , althougdiabetes . It woulIK) were suppressed by WIN55,212-2 in cones and rods, whereas Ca2+ currents (ICa) were enhanced in rods and suppressed in cones [IK is mediated by Ca2+ dependent release of 2-AG from bipolar cell dendrites. Cannabinoids also preserved cone and rod structure, as well as function and synaptic connectivity with postsynaptic neurons in a transgenic model for autosomal dominant retinitis pigmentosa. Indeed, HU-210, a more potent and longer lasting synthetic analogue of THC, increased the scotopic a- and b-wave amplitudes in treated animals and preserved photoreceptor degeneration and synaptic contacts between photoreceptors and bipolar or horizontal cells [Different effects on rod and cone photoreceptors have been reported for the salamander and goldfish following WIN55,212-2 addition, with a potential biphasic response based on concentration for the goldfish. Delayed rectifier currents  afforded partial recovery following the AMPA-induced excitotoxicity of both bNOS-positive and cholinergic amacrine cells [1/2 signaling pathways, but not CB2R.The neuroprotective effects of endogenous and synthetic cannabinoids on the viability of amacrine cells were studied using anne cells . This neIK via the tetraethylammonium (TEA)-sensitive K(+) current component in rat RGCs. These effects could not be reversed either by the CB1R inverse agonists AM251/SR141716A or by the CB2R inverse agonist AM630 [ in vitro study showed a partial inhibition of high-voltage activated Ca2+ channels with WIN55,212-2 that could be reversed by both SR141716A and AM281 in cultured rat RGCs [It has been reported that WIN55,212-2, AEA, the selective CB1R agonist arachidonoyl-2-chloroethylamide (ACEA), and the CB2R agonist CB65 inhibit st AM630  althoughst AM630 , 82. An rat RGCs . A recenrat RGCs . This efα release, and iNOS expression. But it is not confirmed experimentally. Thus, cannabinoid agonists, such as WIN55,212-2, could be relevant targets to prevent degeneration of RGC cells for intraocular pressure induced ischemia [In addition to their effect at the level of ionic channels, eCBs, via CB1R, have neuroprotective properties. In fact, blockade of FAAH produces neuroprotective effects on RGCs in a rat model of optic nerve axotomy through a CB1R-mediated mechanism, which was gradually lost in aging animals . Neuroprischemia . Overallischemia . Furtherischemia . Furtherischemia –89. Addi in vitro. This activation causes an increase in intracellular Ca2+ and leads to cell apoptosis and could be partially prevented by using a nonspecific antagonist, iodoresiniferatoxin [Various TRP channels can be activated by tactile and pressure stimuli, including TRPV channels –93. In Reratoxin . Ligandseratoxin . It woul cnr1-KO mice [ cnr1-KO animals. These results suggest that visually stimulated endocannabinoid-mediated long-term depression of GABAergic neurotransmission (iLTD) happens in the extragranular layer of the mouse visual cortex [So far, few studies have looked at the effects of eCBs on central visual areas processing. CB1R activation alters spontaneous and visual activity in the rat dLGN, increasing the spontaneous bursting and oscillatory activity , 96. For-KO mice , 98. GABl cortex . In anotl cortex . Moreovel cortex . The sysl cortex . FinallyAs shown in other systems, eCBs are well known modulators of synaptic transmission and neuronal plasticity, mostly via presynaptic inhibitory mechanisms. The impact of the eCB system during CNS development has been documented in the last decade. The eCB system regulates the proliferation, migration, specification, and survival of neural progenitors , dictateα, and MAGL were also detected during postnatal development of the rat retina [α is expressed early in retinal development as its presence at P1 is observed in cone and rod photoreceptors, horizontal, amacrine, and ganglion cells [α combined with the absence of MAGL expression in early postnatal development of the retina suggests that 2-AG levels could be elevated and thus play an active role in retinal development. Despite an important body of literature currently available on the involvement of eCBs in developmental functions, only few studies focused on the impact of cannabinoids in retinal development , which is a good indicator of its possible developmental implication . By E15 t retina , 52, 56.on cells . MAGL exon cells . MAGL isment see . It is t animals . For theThe TRPV1 receptor is also present in the rat retina from E19 onto adulthood . From E1No studies have yet reported the expression of GPR18 in the developing retina. Ongoing projects from our group have so far shown that GPR55 mRNA and protein are expressed in the retina of newly born mice, more specifically in RGCs .β-D-glucoside, in glial-neuron communication in the developing spinal cord [ gpr55−/− mice revealed a decreased branching in the dorsal terminal nucleus and a lower level of eye-specific segregation of retinal projections in the superior colliculus and in the dLGN. Altogether, these studies identify a mechanism by which the eCB system modulates retinothalamic development and offer a potential model to explain why cannabinoid agonists affect CNS development.Only two studies reported the functional impact of cannabinoids on retinal development. CB1R and CB2R specific agonists induce a collapse of the growth cone of RGC axon and decrease axon growth , 115. Conal cord . GPR55 anal cord . FurtherAs we have reported in this review, CB1R and CB2R are both present in various retinal tissue where they modulate, in the most part via retrograde signaling, neurotransmitter release and where they inhibit potassium and calcium currents. These effects can thus modulate visual activity as early as the retina level. More studies are obviously needed to assess to what extent a cannabinoid-mediated modulation in the retina could impact visual perception. This is especially true given that cannabinoid receptors are present in most retinal cell types. As cannabinoids are also present in the visual cortex (including areas beyond V1 and V2), as well as subcortical regions such as the LGN, it may well be that cannabinoids modulate visual perception at each level of visual system hierarchy.The ability of the eCB system to induce various changes in plasticity in central visual areas is now well described , and soEndocannabinoids constitute one of the newest neuromodulators found in neural and nonneural tissues throughout the body. Their wide expression in the nervous system and peripheral organ systems highlights the range of their actions and their potential in therapeutic applications. Strong evidence now suggests a wide distribution of eCBs, receptors, and enzymatic machinery in key structures of the visual system, including a strong presence in the retina. Although no clear picture can ascertain the specific effects cannabinoids can have in the retina itself, or the visual system as a whole, various mechanisms in specific cellular structures of the retina have now been reported. The cannabinoid system also appears to have several roles in neuronal survival and apoptosis in the retina and could be linked with many other ocular disorders. However, their specific mechanisms in retinal development, neuroplasticity, and neuroprotection need to be more thoroughly investigated.


Questionnaire studies suggest that hearing is declining among young adults. However, few studies have examined the reliability of hearing questionnaires among young adult subjects. This study examined the associations between pure tone audiometrically assessed (PTA) hearing loss and questionnaire responses in young to middle aged adults.A cross-sectional study using questionnaire and screening PTA (500 through 6000 Hz) data from 15322 Swedish subjects (62% women) aged 18 through 50 years. PTA hearing loss was defined as a hearing threshold above 20 dB in both ears at one or more frequencies. Data were analysed with chi-square tests, nonlinear regression, binary logistic regression, and the generalized estimating equation (GEE) approach.p < 0.001). Slight hearing impairment was reported by 18.5% of the men and 14.8% of the women (p < 0.001), whereas 0.5% of men and women reported very impaired hearing. Using multivariate GEE modelling, the odds ratio of PTA hearing loss was 30.4  in men and 36.5 (17.2-77.3) in women reporting very impaired hearing. The corresponding figures in those reporting slightly impaired hearing were 7.06 (5.25-9.49) in men and 8.99 (6.38-12.7) in women. These values depended on the sound stimulus frequency (p = 0.001). The area under the ROC curve was 0.904 (0.892-0.915) in men and 0.886 (0.872-0.900) in women.The prevalence of PTA hearing loss was 6.0% in men and 2.9% in women (Subjective hearing impairment predicted clinically assessed hearing loss, suggesting that there is cause for concern as regards the future development of hearing in young to middle-aged people. Recent large-scale questionnaire studies have reported an increasing prevalence of subjective hearing impairment in young and middle-aged people . QuestioThe available data on hearing loss prevalence are also conflicting. Several studies found a successive increase in the prevalence of pure tone audiometrically assessed (PTA) hearing loss during the past 30 years , 8 and wIn this cross-sectional study, we aimed to determine the relation between PTA and subjective hearing impairment in young and middle aged subjects. We found that subjective hearing impairment predicted PTA hearing loss, provided that age, sex, tinnitus, and sound stimulus frequency were included in the models. Thus, should the increase in self-reported hearing problems continue , there iA cross-sectional study was conducted, using data from LifeGene, a Swedish national resource for research on the relationships among heredity, environment, and lifestyle. LifeGene, which included its first participant in 2009, collects data via a comprehensive web-based questionnaire and also performs extensive physiological testing along with blood and urine sampling. A random sample of Swedish inhabitants aged 18 through 50 years is invited to participate, but it is also possible to enroll without an invitation, through LifeGene’s web site. Further details can be found elsewhere .Included in the present investigation were all subjects that answered the question “How is your hearing?” in any of the years 2009 through 2012, had their hearing measured with screening audiometry, and were between 18 and 50 years of age at the time of the PTA assessment (n = 5809 men and 9513 women), which were 84% of all subjects that had enrolled in LifeGene.Frequency-specific screening PTA measurements were performed by a special-trained nurse at one of LifeGene’s test centers, using SA 202 audiometers  and sound-isolating headphones , according to procedures established by the International Standards Organization (ISO 8253–1). In short, air conduction hearing thresholds were determined by presenting pure tones at 0 dB or 10 dB, at the ordered frequencies 1000, 2000, 3000, 4000, 6000, and 500 Hz. If no response was obtained, the stimulus level was increased in 5-dB steps, until the subject heard the tone or the maximum level of the audiometer, 110 dB, was reached. Masking of the opposite ear was not performed. In the present study, a hearing threshold below 10 dB and above 110 dB was assigned the value 10 dB and 111 dB, respectively. A pure tone hearing threshold above 20 dB in both ears at one or several frequencies was defined as PTA hearing loss.Multifaceted data on phenotypes and exposures is gathered through LifeGene’s questionnaire, which includes several queries related to hearing. In the present study, the following items were used ?”“No”;”Yes, sometimes, but the sound does not disturb me”;”All the time, the sound is very disturbing”;”Do not know/Do not want to answer”.All included subjects had answered Q1, whereas there were 27% missing answers on each of Q2 and Q3. Only one subject had not answered Q4.LifeGene’s questionnaire also contains one query on educational level,”What is the highest educational level you have achieved or are currently studying for?” There are five possible answers:”Compulsory school”;”Upper secondary school”;”University”;”Other”;”Do not know/Do not want to answer”. In the present study, educational data were used for descriptive statistics and were missing in 0.5% of subjects.Information on residence was based on the postal code reported by the participant when answering LifeGene’s questionnaire. If this information was lacking, the postal code of subjects actively invited to participate in LifeGene was obtained from a computerized register. Considering the localities of the numbers and the classification systems used by Statistics Sweden , the folStatistical calculations were performed with IBM SPSS Statistics version 21 using the chi-square test, nonlinear regression, binary logistic regression, or the generalized estimating equation (GEE) approach, as appropriate.p < 0.05.The results of binary logistic regression are presented as odds ratios (ORs) followed by p-values within parentheses. Whenever age was a statistically significant predictor of the dependent variable, age adjustment was performed with age as a continuous variable. The adequacy of the models was evaluated with goodness-of-fit statistics based on the Hosmer-Lemeshow decile-of-risk test , and a mROC) [GEEs was used to investigate the associations between PTA and subjective hearing. The GEE approach allows for analysis of clustered data , which iROC) , which wWhen performing calculations, the response categories of the hearing questions were in some instances reduced in order to increase the statistical power. In these cases, the tinnitus category”Yes, sometimes, but the sound does not disturb me” of Q4 was fused with”No”. All subjects that had answered”Do not know/Do not want to answer” or not answered at all on Q2, Q3, and Q4 were assigned to the same category as those reporting no problems on that specific question. This seemed as a reasonable strategy as almost all of them  had reported good hearing on question Q1.The data on which our study is based can be found in The study was approved by the Regional Ethics Board of Stockholm, Sweden (protocol no 2011/1827-31/1). Data were obtained from the Swedish national research project LifeGene. To participate in LifeGene, writted informed consent must be provided.The median age of the study population was 32 years in men and 31 years in women. The age distribution stratified by sex is shown in 76% of the men and 78% of the women lived in metropolitan areas. These figures are considerably larger than the fraction of metropolitan inhabitants in the Swedish population at large .The highest self-reported educational level was university in 64% of the men and 70% of the women and upper secondary school in 27% of the men and 21% of the women. Again, these figures are higher than those found in the general population, where 33% of men and 43% of women had a university education, whereas 50% of Swedish men and 43% of women had an upper secondary school education at the end of 2012 . Hence, p < 0.001; chi-square test). Its dependence on age could be described with 2 = 0.885 in men and 0.764 in women; weighted least square):p < 0.001; binary logistic regression) at 3000 Hz, 3.44 (p < 0.001) at 4000 Hz, and 2.35 (p < 0.001) at 6000 Hz. At all other frequencies, the difference between men and women was non-significant.The prevalence of PTA hearing loss, i.e. a hearing threshold above 20 dB in both ears at one or several frequencies, was 6.0% in men and 2.9% in women  as was sometimes having tinnitus , whereas having slight difficulties to hear when talking with one person in a quiet room (Q2) was most common among women . All other sex differences were non-significant.p < 0.001 in both men and women).The relationship between PTA and subjective hearing was evaluated with the GEE approach. The results of the final model are presented in p = 0.001 in men, p < 0.001 in women), generally contributing to an increased association between PTA and subjective hearing at lower frequencies. The ROC curves given in ROC was 0.904  in men and 0.886 (0.872–0.900) in women.There was a significant interaction between subjective hearing and frequency , they were classified as having no hearing problems with one or several persons, respectively. This may have led to underestimated prevalences of these difficulties.In the young to middle-aged, well-educated, and urban population investigated in this study, the overall prevalence of PTA hearing loss was lower than that of subjective hearing impairment. Still, we found that subjective hearing impairment predicted PTA hearing loss, provided that age, sex, tinnitus, and sound stimulus frequency were included in the models. Our results suggest that there is cause for concern about the future development of hearing problems in this population, since hearing problems generally worsen with age. Future studies should explore the longitudinal relation between subjective and PTA hearing and how it is influenced by factors unrelated to the hearing function, such as a reduced tolerance to hearing problems due to higher health expectations or higher demands of communication skills in modern society.S1 TableOriginal Swedish formulations on hearing items are shown.(PDF)Click here for additional data file.S2 Table(XLSX)Click here for additional data file.S3 Table(PDF)Click here for additional data file.


Background. Patients with unilateral atresia and microtia encounter problems in sound localization and speech understanding in noise. Although there are four implantable hearing devices available, there is little discussion and evidence on the application of these devices on patients with unilateral atresia and microtia problems. Objective. This paper will review the details of these four implantable hearing devices for the treatment of unilateral atresia. They are percuteaneous osseointegrated bone anchored hearing aid, Vibrant Soundbridge middle ear implant, Bonebridge bone conduction system, and Carina fully implantable hearing device. Methods. Four implantable hearing devices were reviewed and compared. The clinical decision process that led to the recommendation of a device was illustrated by using a case study. Conclusions. The selection of appropriate implantable hearing devices should be based on various factors, including radiological findings and patient preferences, possible surgical complications, whether the device is Food and Drug Administration- (FDA-)/CE-approved, and the finances. To ensure the accurate evaluation of candidacy and outcomes, the evaluation methods should be adapted to suite the type of hearing device. Difficulties in sound localization and speech understanding in noise have been underestimated in adults with unilateral atresia . The ampPercutaneous osseointegrated bone anchored hearing aid (p-BAHA), for example, Cochlear BAHA by Cochlear Bone Anchored Solutions AB and Ponto by Oticon Medical AB, Sweden;Vibrant Soundbridge (VSB) middle ear implant system ;BoneBridge bone (BB) conduction system ;Otologics MET Carina fully implantable hearing device (FIHA) .There are four commercially available implantable hearing devices available as rehabilitative options for patients with unilateral microtia and atresia. They areAll of these devices need to be implanted surgically. These devices are expected to benefit patients with moderate to severe hearing, regardless of their type of hearing loss, that is, sensorineural, conductive, or mixed. However, these devices differ in terms of the sound transmission pathway, and some, such as the FIHA, are suitable for adults only.The bone anchored hearing aid (BAHA) was first introduced in 1977 as an alternative hearing rehabilitation option for patients with conductive hearing loss. Later developments expanded the indications to include single-sided deafness and mixed hearing loss. The BAHA hearing system incorporated the concept of osseointegration discovered by Professor Brånemark, enabling improved comfort and fine sound quality. It represented a major milestone in the evolution of bone conduction hearing amplification . Two comThe surgical procedure for the BAHA is relatively simple in comparison with other implantable devices. BAHA is placed in the mastoid bone. Local anesthesia could be used for the majority of the adult cases. The most obvious benefit for the BAHA system is its surgical simplicity; it bypasses the outer and middle ear pathology and stimulates the inner ear effectively via direct bone conduction, which is particularly well suited for patients with aural atresia. However, despite years of technological advancement, the problem of postoperative periabutment wound infection has remained at approximately 5%, which results in a significant negative impact on the clinical application.An alternative to p-BAHA is the Vibrant Soundbridge middle ear implant system (VSB) . The Vibrant Soundbridge (VSB) is a direct-drive, partly implantable middle ear hearing device which was approved by the FDA in 2000. It is intended for patients of the age of 3 and above with a mild to severe degree of hearing loss, with their bone conduction thresholds at or not worse than 65 dBHL across frequencies.The VSB system is comprised of two parts, namely, an internal component of the VSB called the Vibrating Ossicular Prosthesis (VORP) and an external audio processor (AP). The VORP consists of an internal coil, a magnet to hold the Amadé audio processor over the implant, a demodulator, the conductor link, and the floating mass transducer (FMT). The VORP is implanted by a surgical procedure in which the FMT is attached to a vibratory structure in the middle ear either via a round window approach (round window vibroplasty (RWV)) or via ossicular chain coupling . IntraopBenefits from the VSB device include, firstly, the provision of a unilateral stimulation to the atretic ear, which is beneficial for those with unilateral hearing loss. Secondly, there is no pin tract problem as in BAHA. In addition, the patient's satisfaction with the sound quality and the improvement in speech intelligibility are higher and could be sustained even after five to eight years of implant use , 6. HoweThe Bonebridge (BB)  is another feasible option for children at age of 5 years and above who have conductive, mixed hearing loss or single-sided deafness with bone conduction thresholds at 45 dBHL or better at 0.5, 1, 2, and 3 kHz. It is a semi-implantable bone conduction implant hearing device consisting of an external audio processor (AP) worn behind the ear and a bone conduction implant (BCI) positioned surgically under the skin. The acoustic signals are recorded by the microphones of the AP, which converts sounds into electrical signals, and these are then transferred to the BCI. The BCI then converts the electrical signals to mechanical vibrations on the mastoid bone and thus the inner ear is stimulated via bone conduction.Several advantages have been noted with the BB. Firstly, the BB offers a bilateral stimulation that is similar to the BAHA. Thus, it is especially beneficial for those with bilateral hearing loss in that they will need to wear only one device to achieve desirable outcomes. Secondly, the BB does not require a good middle ear structure for the coupling of the device; thus it is suitable for patients with middle ear pathologies and who are not feasible for VSB implantation. Thirdly, the risks associated with the use of MRI are reduced, compared to the VSB. The BB allows MRI to be done up to 1.5 Tesla.Although the BB seems to be a better device in terms of surgical complications and the application of MRI, compared to the VSB, the BB system is still pending FDA approval in the United States' market. Thus, the BB system may not be considered as a reimbursable item by a third party . Other disadvantages of the BB include possible postsurgical displacement of the BCI and extrusion of the implant, although this is uncommon. Lastly, the BB provides bilateral stimulation and thus may not be desirable when hearing in the other ear is normal; this is because there is a possible risk of signal interference to the normal contralateral ear. Careful assessment of individual preferences and preoperative trial on potential candidates with the Apollen bone conduction hearing aid provided by MED-EL could be helpful to determine its suitability before surgery is performed.The Carina implantable hearing aid, developed by Otologics LLC , was initially developed as a semi-implantable middle ear transducer (MET) but is now a fully implantable hearing device. The Carina device consists of the implant, the programming system, the charger, and the remote control. The implant itself contains the electronics which contain the microphone, battery, magnet, digital signal processor, and connector. The system utilizes a microphone located beneath the skin that picks up acoustic signals, which are then amplified and converted into an electrical signal. The signal is sent down the lead and into the transducer and the ossicular stimulator is coupled directly with the ossicular chain or the round window .The Carina is considered to be another viable option for adults with moderate to severe hearing loss of conductive, sensorineural, or mixed etiologies. The device is CE-marked for sale and currently is still in the clinical trial stage, and therefore it has not been cleared for marketing by the FDA in United States. Three advantages of the Carina device include the following: (1) among the four devices discussed in this paper, the Carina is cosmetically the most appealing because no external processor can be seen; (2) it is easy to use; and (3) unilateral stimulation is provided. This device is thus suitable for adults with unilateral hearing loss such as unilateral congenital atresia. Siegert et al. investigated the surgical and audiological outcomes of Carina FIHA on five adults with either unilateral or bilateral congenital aural atresia . All patHowever, there are several drawbacks of using the Carina device as follows: (1) it is not suitable for children and teenagers under 18 years of age; (2) the surgery is difficult to perform and it requires general anesthesia for about three hours; (3) revision surgery is required for battery change and future upgrade; (4) it is MRI-incompatible; (5) it is the most costly of all the MEIs; and (6) postoperative deterioration in hearing thresholds has been reported. Local experience in Hong Kong, with the application of the Carina device on five adults with sensorineural hearing loss, indicates a general drop of pure tone air conduction thresholds in all subjects postoperatively, at an average of 9 dB across the 250–8,000 Hz frequencies. A few cases also indicated a drop in bone conduction thresholds of about 10–15 dBHL [A candidate who has unilateral atresia must meet various criteria in order to be considered for implantation. In general, three types of considerations should be given: (1) the nature of the hearing loss, (2) patient preferences, and (3) issues related to practical usage.The air conduction hearing thresholds must fall within the manufacturer's suggested criteria, that is, not more than a moderate to severe degree of hearing loss, except for the FIHA, where bone conduction thresholds are used as one of the selection criteria. While the BAHA and the BB would allow hearing loss up to 45 to 55 dB HL, the VSB and the Carina would fit a hearing loss of up to 70 to 80 dB HL.The bone conduction threshold should be stable.Whether the middle ear structure would allow the coupling of the transducer.There should be an absence of retrocochlear pathology and auditory processing disorders.The unaided speech intelligibility should be better than 50% to 60%. However, there is no speech discrimination requirement for the BB device.In terms of the nature of the hearing loss, the patient should be selected according to the following criteria .While local anesthesia is used for implanting the BAHA, general anesthesia surgical procedures are recommended for other devices and there are risks associated with the surgery.At the moment, the fact is only the BAHA and BB is MRI conditional, BB can have MRI up to 1.5 Tesla, while as long as the Baha sound processor is removed for the MRI procedure, a patient can have MRI up to 3 Tesla. The use of MRI is contraindicated with the VSB and Carina. The patient should understand that there could be issues with MRI assessment in the future.In regard to patient preferences, patient should understand the following factors see .The deviDue to normal hearing in the good ear, the benefits from amplification may be limited .Due to bilateral stimulation by the implant, there could be a distortion of hearing.There could be implications related to long-term reliability of the device and other complications .Cosmetic appearance could be a concern with the BAHA.In regard to the usage of implantable devices, the patient should be informed about the following.3. However, this assumption cannot be made in cases of malformed external ear structures. Difficulties in establishing valid air conduction thresholds would also mean that we are not able to establish posttreatment advantages in air conduction thresholds. Thus, other types of outcome measures, such as soundfield thresholds measures, should be used.The consideration of an appropriate hearing device involves the examination of hearing thresholds. However, there are issues in regard to the measurement of air conduction thresholds in an ear with microtia and atresia because the calibration of the earphone is based on a normal physiologic pathway of air conduction. The volume of the ear under a supra-aural earphone is estimated to be about 6 cmWhen evaluating soundfield thresholds, the involvement of the good contralateral ear should be minimized, in order to obtain the true thresholds. When speech intelligibility is measured, the clinician should also consider whether the objective is to demonstrate the effects of implantation on hearing in the poor ear only (implant ear) or binaural hearing. In the former case, the good ear should be plugged and muffed to prevent its participation so that whether appropriate amplification has been provided to the poor ear can be verified. However, if the latter objective is desired, then the individual should be tested binaurally, without the good ear being plugged and muffed. Because of the good ear, it is likely that benefits in speech intelligibility will not be demonstrated if both speech and noise are being presented from the front loudspeaker. In other words, the effects of amplification may not be readily observable unless there is a spatial separation of speech and noise.With the other ear having normal hearing, the benefits from an implant in the atretic ear are expected to be minimal. Thus, the above objective measures  might not be effective in demonstrating benefits. Self-reports of aided benefit and satisfaction should be obtained to evaluate the outcomes.Background. K.C. is a 23-year-old man presenting with a unilateral microtia with congenital complete bony external auditory canal atresia on the right side, as confirmed by using a computer tomography (CT) scan. The malleus and incus had fused together and were found attached to the bony atretic plate. The stapes, oval window, and round window appeared normal on a CT scan. His major complaints were poor sound localization and speech understanding difficulties on the right side, especially in the presence of background noise. The unaided audiogram for K.C. was indicated in While both the VSB and Carina would be good choices, the VSB was chosen because K.C. was worried about possible future revision surgery in the case of a battery recharge problem. The VSB was an appropriate option for his right ear because CT scan findings showed that his stapes, oval window, and round window were normal and that therefore VSB could provide a unilateral stimulation to his right ear. Y.H. was counseled regarding the risks and benefits of the VSB . The surSurgical Monitoring. The operation was done under general anesthesia with facial nerve monitoring. The skin incision and soft tissue handling were such that the patient may need to undergo plastic reconstruction of the pinna at a later stage. Mastoidectomy was performed and access to the round window was achieved by removing atretic plate, malformed malleus and incus. The round window membrane needed to be fully exposed and this was performed by careful removal of bony overhang at the round window niche by a diamond burr. To ensure that the round window membrane will not be damaged by the FMT, a layer of perichondrium was placed on the round window membrane. To allow placement of the FMT in the round window niche, the titanium clip was removed. The FMT was carefully orientated and rested on the round window area. An extra perichondrium was put onto the FMT body to provide further stability.Facial nerve monitoring is essential in this surgery for identifying any abnormal course of facial nerves and for avoiding facial nerve injury. Compound action potential (CAP) thresholds were examined during electrocochleography (ECochG) intraoperatively to determine the best site of the FMT placement as well as to evaluate the function of the implant system. With the electrodes placed on the promontory (active), vertex (reference), and forehead (ground), an increased CAP amplitude was observed with the FMT, and the goal was to achieve the best CAP thresholds possible. Device Fitting. The device was activated eight weeks after the surgery. This wait was required for wound healing both internally and externally. Based on the unaided soundfield hearing thresholds obtained from the implanted ear, the Amadé audio processor  was programmed with the Connexx 6.11 software equipped with the Symfit database Rev.5.0. The default desired sensation level (DSL I/O) fitting formula was applied. Although the NAL/NL1 fitting formula is also available, it has not been modified to yield gain targets appropriate for a direct-drive device. When the aid was first switched on, the patient was not able to tolerate the prescribed gain. However, verification of the VSB device gain was difficult because the VSB is not an acoustic device. It is not possible to perform real ear measurements; soundfield aided thresholds, sentence reception thresholds (SRTs), and self-reports were obtained to evaluate the outcomes. K.C. returned for a fine-tuning session two weeks after device activation to ensure that he was listening at most comfortable levels as well as obtaining benefits from the device. Informal feedback on sound tolerance was obtained.Results. Change in residual hearing was evaluated by comparing the preoperative unaided bone conduction thresholds to the postoperative bone conduction thresholds. The results revealed no obvious change at any frequency. Verification of the Implantable Hearing Device Performance. One of K.C.'s chief preimplant complaints was his difficulty in picking up the signals from the right ear. In order to assess the aided benefits with the implant, aided soundfield thresholds were measured with warble tone signals presented at 90 degree azimuths, with the left ear both plugged and muffed. With the VSB set at the most comfortable listening level, it was also shown that VSB offered functional gains of 5 to 20 dB across the frequencies from 500 Hz to 4 kHz, when compared with the unaided thresholds  were measured 3 months after implantation, when acclimatization, if any, would have been completed. With the good ear plugged and muffed, the SRT of the poor ear improved to 50.8 dB (A) in quiet, suggesting that although the VSB implant improved understanding of moderately soft speech, the benefit has not been optimized for soft speech. These results are consistent with findings in aided soundfield thresholds. SRT was −0.4 dB (A) in noise, thereby suggesting no improvement from the unaided condition. Thus, the implant improved the audibility of signals but not the S/N for 50% intelligibility when listening in noise.With binaural hearing in quiet, there was a slight elevation of SRT (0.8 to 3.8 dB) when compared to the unaided conditions . HoweverIn noise, as shown in Self-reported aided benefit and satisfaction were measured with the two Chinese versions of the abbreviated profile of hearing aid benefit (APHAB) and the satisfaction with amplification in daily life (SADL) , 13. TheOverall, there are many practical concerns when making clinical decisions on the selection of an appropriate implantable device for an adult with unilateral atresia. One of the most important questions to ask is the age of the patient see . The secFor microtia patient with pure conductive hearing loss, the underlying cause is likely due to malformed ossicles; then the option of VSB surgery should only be considered after radiological studies where an appropriate coupling is possible. The options of BAHA and BB do not have this constraint. However, the clinician should be aware that both the BAHA and BB provide bilateral stimulations and thus they may introduce interference to the contralateral ear. In contrast, the VSB and Carina FIHA provide a unilateral stimulation of the worse ear. Skin tract problem of BAHA must be thoroughly discussed. Also the VSB and FIHA are neither MRI-incompatible nor FDA-approved, and the potential candidates should be well informed of the risks including worsening of hearing loss and implant failure before they opt for a relatively difficult operating procedure in VSB and FIHA.Regarding the cost, the FIHA is the most expensive in comparison with the VSB and BB. Thus, preoperative counseling of the risks and benefits of each device is important.Despite the lack of high-level evidence about these devices, the selection of appropriate implantable hearing devices should be based on various factors, including radiological findings and patient preferences. In addition, surgical complications, whether the device is FDA-/CE-approved, and the finances should be considered. To ensure the accurate evaluation of candidacy and outcomes, the evaluation methods should be adapted to suit the type of hearing device.