The absence of auditory input, particularly during development, causes widespread changes in the structure and function of the auditory system, extending from peripheral structures into auditory cortex. In humans, the consequences of these changes are far-reaching and often include detriments to language acquisition, and associated psychosocial issues. Much of what is currently known about the nature of deafness-related changes to auditory structures comes from studies of congenitally deaf or early-deafened animal models. Fortunately, the mammalian auditory system shows a high degree of preservation among species, allowing for generalization from these models to the human auditory system. This review begins with a comparison of common methods used to obtain deaf animal models, highlighting the specific advantages and anatomical consequences of each. Some consideration is also given to the effectiveness of methods used to measure hearing loss during and following deafening procedures. The structural and functional consequences of congenital and early-onset deafness have been examined across a variety of mammals. This review attempts to summarize these changes, which often involve alteration of hair cells and supporting cells in the cochleae, and anatomical and physiological changes that extend through subcortical structures and into cortex. The nature of these changes is discussed, and the impacts to neural processing are addressed. Finally, long-term changes in cortical structures are discussed, with a focus on the presence or absence of cross-modal plasticity. In addition to being of interest to our understanding of multisensory processing, these changes also have important implications for the use of assistive devices such as cochlear implants. A profound childhood hearing loss can have widespread, devastating consequences that impact a child and their family for a lifetime. Perhaps most importantly, hearing loss can prevent a child from acquiring spoken language, which has a number of subsequent developmental and psychosocial consequences . However, it is important to note that changes in the anatomy and function of peripheral and central auditory structures depend highly upon a number of factors, including the time of onset of hearing loss and the specific nature of the impairment. This review aims to address changes that occur in response to bilateral, congenital or early-onset deafness. Other forms of deafness  are associated with a wide variety of highly specific changes that are beyond the scope of this paper. Here we address the most common methods for acquiring deaf animal models, including some discussion surrounding whether the methods currently used to evaluate hearing impairment are sufficient. We then describe anatomical and physiological changes that occur following deafness, including structures within the cochlea, subcortical nuclei, and within auditory cortex. Finally, we discuss cross-modal reorganization that appears to follow hearing impairment with some consideration of potential mechanisms.Much of what we know about the changes to auditory structures that result from deafness, and how these changes have informed the design of cochlear prostheses, has come from studies in animal models. Fortunately, the subcortical auditory system is highly conserved among mammals  cause hereditary auditory-pigmentary disorders that mimic Waardenburg syndrome in humans  to define the endpoint of, or to measure the success of their deafening procedure. ABRs can be evoked using a variety of auditory stimuli. However, researchers typically rely on click-evoked ABRs to measure deafness in animal models , and a descending branch caudally into the posterior division (PVCN) of the ventral nucleus, which ultimately innervates the dorsal nucleus. These branches terminate in a variety of structures including endbulbs of Held, modified endbulbs, and terminal boutons which may be accompanied by a series of en passant swellings. In normal hearing animals, endbulbs of Held typically exhibit a complex arborization, with multiple branches that stem from a single, thick trunk. These endings typically contact up to half of the soma of a spherical bushy cell  cover the somata of bushy cells. These PSDs are punctate and tend to present as distinct convexities that indent the presynaptic membrane , lateral superior olive (LSO), and the medial nucleus of the geniculate body (MNTB), along with several smaller periolivary nuclei. In hearing animals, the MSO, LSO, and MNTB contribute to sound localization in the azimuth, and are tonotopically organized. Rough frequency gradients in these nuclei are established by the differential expression of ion channels  is comprised of dorsal and lateral cortices that collectively form a “rind” surrounding the central core Winer, . This ceWhile the number of projections to the IC appears unaffected by hearing loss, there appear to be substantial qualitative differences between IC neurons in hearing-deprived and normal hearing animals. The somata of IC neurons in bilaterally deafened animals undergo some degree of atrophy, resulting in a slight but significant decrease in soma area relative to normal hearing controls  is the auditory thalamic processing station between the inferior colliculus and the auditory cortex. Across species, the MGB is typically subdivided into multiple subsections, each of which contains several nuclei that process both afferent and efferent neural activity Winer, . DespiteThe primary auditory cortex (A1) is the most extensively studied area of auditory cortex. In congenitally deaf animals, A1 has a similar laminar structure to that of hearing animals  of the auditory cortex, which lies adjacent to the visual motion processing regions of the middle suprasylvian sulcus  underlying cross-modal plasticity are not yet fully understood. Thus, research using animal models will continue to inform our understanding of the far-reaching consequences of deafness as the field moves forward.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Purpose. The aim of this study is the investigation of the effectiveness of intratympanic steroids therapy (IST) in patients with idiopathic sudden sensorineural hearing loss (ISSHL) who had not responded to intravenous treatment, evaluating the overall hearing recovery and comparing the results with different variables. Materials and Methods. Our study consisted of 55 patients with refractory ISSHL who, at the end of 10 days of therapy with intravenous steroids, had puretone 4-frequency average (PTA) of worse than 30 dB. The patients received 0.5 mL of methylprednisolone by direct intratympanic injection. The procedure was carried out up to 7 times within a 20-days period. Statistical analysis was carried out. Results. Overall 29 patients (52.7%) showed improvement in PTA, 24 (43.8%) had no change in hearing, and 2 (3.5%) worsened. There was a significant statistical correlation between hearing recovery and time to onset of symptoms, severity of hearing loss and frequency of hearing loss. Conclusions. IST is an effective and safe therapy in sudden sensorineural hearing loss cases that are refractory to standard treatment. The earlier IST, the hearing losses less than 90 dB and the involvement of the low frequencies seem to influence positively the hearing recovery. Nearly 60 years after the first report of idiopathic sudden sensorineural hearing loss (ISSHL) , the otoMany treatments for ISSHL have been tested and found ineffective. These include hyperbaric oxygen, agents that decrease blood viscosity , vasodilator drugs , free radical scavenging vitamins, gingko biloba, and magnesium. At this time, the only treatment for ISSHL shown effective in controlled clinical trials is systemic corticosteroid therapy with high dose of prednisone taper. The reported success rate is around 50 to 80%, whereas the spontaneous recovery rate is approximately 30 to 60% . DespiteAlthough the safety and efficacy of intratympanic steroids therapy (IST) have not been studied in a randomized clinical trial, there are many evidences to suggest that IST improves treatment success by increasing intracochlear corticosteroid and reducing the incidence of toxic side effects. The optimal drug, the dosage, the treatment schedule, the duration of treatment, and the standard protocol universally accepted are not known yet.The aim of this study is the investigation of the safety and effectiveness of IST in the treatment of ISSHL after failure of intravenous steroid therapy, with special attention for the correlations between hearing recovery and time to onset of therapy, severity and frequencial range of hearing loss, age of the patient, and status of the contralateral ear.Between January 2005 and December 2008, a nonrandomized prospective clinical trial was conducted on 158 patients with a diagnosis of ISSHL. The study was approved by the local Institutional Review Board, and each patient provided informed consent. The patients were hospitalized at the Otosurgery and Audiology Units of General Hospital of Dolo (Venice) and San Bortolo Hospital of Vicenza. Physical examination, pure-tone and speech response audiometry, tympanometry, syphilis serology, autoimmune antibody tests, auditory brainstem response (ABR), and temporal bone high-resolution computed tomography (CT) were performed. Cerebral magnetic resonance imaging (MRI) was performed only if a retrocochlear lesion was suspected by means of ABR and high-resolution CT.All patients were treated intravenously with 4–8 mg of intravenous betamethasone for 10 days.Auditory function was determined by pure-tone audiometry; the mean hearing levels were expressed as the average of hearing thresholds at 0.5, 1, 2, and 3 kHz (4-tone average) (PTA), according to the guidelines of the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery. Auditory measurements were performed before, during, and 3-month after treatment, according to Siegel's criteria for hearing improvement . “CompleAfter intravenous steroid therapy, if the patients showed a recovery less than 50%, they were enrolled for IST as salvage treatment.Patients with ISSHL were enrolled and treated with IST if they:had a sudden unilateral hearing loss of at least 30 dB across 3 contiguous frequencies occurring in less than 72 hours or progressively over several days, but with an onset within 30 days;had begun steroid treatment (4–8 mg of intravenous betamethasone for 10 days) within 10 days of hearing loss onset;recovered less than 50% of their preloss hearing during steroid treatment and presented for IST within 1 month of onset;had no retrocochlear pathology as demonstrated by negative MRI scan;were age 18 years or older.Patients with ISSHL were excluded when they presented hearing loss history with onset over 30 days, oncologic history with recent chemotherapy or radiation therapy, autoimmune diseases, congenital cochlear malformations, Ménière's disease, acute or subacute otitis media with abnormal tympanometry, neurological disorders, recent use of ototoxic medications, severe liver or renal dysfunction, pregnancy, recent trauma.The operative procedure of intratympanic steroid injection was performed under a microscope and with patient in supine position. After the surgeon confirmed intact tympanic membrane and middle ear status, local anaesthesia was administered with a cotton ball soaked with lidocaine 10% pump spray (Xylocaine), which was applied on the tympanic membrane for 20 minutes. While the patient tilted the head 45° to the healthy side, a 25-gauge spinal needle was introduced into the posteroinferior portion of membrane and 0.4-0.5 mL of methylprednisolone (40 mg/mL) was instilled through this site. The patient was instructed to avoid swallowing or moving for 30 minutes, remaining in the same position. IST was performed on the 1st, 3rd, 5th day up to 7 total injections, one every two or three days.t-test for continuous variables and Fisher's test for categorical variables. A P value of less than  .05 was considered statistically significant.Statistical analysis was carried out using the Student's After inclusion and exclusion criteria were applied, 55 patients were available for the study.There were 24 men (43.6%) and 31 women (56.4%). The mean age at enrolment for all patients was 49.7 years and ranged from 18 to 83 years. The mean age for the men was 53.2 years and for the women was 46.1 years.Overall, 29 patients (52.7%) showed improvement in PTA, 24 (43.8%) had no change in hearing, and 2 (3.5%) worsened . Accordin = 7), the median was 12 days; for the group that responded to IST with a “partial or slight recovery” (n = 22), the median was 23 days; for the group that did not respond (n = 26), the mean was 34 days. Statistical analysis shows that there is a significant correlation between hearing recovery and time to onset of symptoms; patients that started IST soon after failures of systemic therapy was detected had an evident advantage (P = .007 Fisher's test).The average number of days from onset of symptoms to IST was 33 days with a range of 5 days to 96 days. For the group that responded to IST with a “complete recovery” (P = 0.06 Fisher's test).A total of 16 patients (29.1%) had hearing loss greater than 90 dB with an improvement rate of 7.2%; a total of 29 patients (52.7%) had hearing loss of 90 dB or less and greater than to 50 dB with improvement rate of 21.2%; a total of 10 patients (18.2%) had hearing loss less than 50 dB and greater than 30 dB with an improvement rate of 47.6% . PatientP = .08 Fisher's test).Hearing recovery related to patient's age was studied. Fifty-seven percent of patients were under 60 years of age and had an overall recovery rate of 26%. Forty-three percent of patients were 60 years of age or older and had an overall recovery of 32%. Statistical analysis shows no significant correlations between age and improvement after IST (P = 1.2 Fisher's test).A total of 76.5% of patients had normal hearing in the contralateral ear. The recovery rate in this group was 31.5%. Only 23.5% of patients had abnormal hearing in the opposite ear. The recovery rate in this group was 22.5%. Statistical analysis shows no significant correlations between recovery and situation of the contralateral ear (P = .06 Fisher's test).We have analyzed the hearing recovery for each frequency  of hearing threshold. A total of 37 patients (67.2%) showed improvement over 30 dB on hearing gain for the frequency of 0.25 and 0.5 kHz. The same result was obtained with 1 kHz frequency in 27 patients (49.1%), with 2 kHz frequency in 23 patients (41.8%), with 4 kHz frequency in 14 patients (25.4%), and with 8 kHz frequency in 9 patients (16.3%) . StatistThe ISSHL is a very frightening and incapacitating event, and it severely impairs patient's life quality and social interaction. Considering the high rate of spontaneous recovery, it is difficult to determine if any therapeutic intervention actually improves the hearing. The natural history of untreated patients with ISSHL states that the recovery rates varies from 31% to 65% , 13, 15,κB. This is a molecular transcription factor that plays a key role in the normal cellular physiology and in mediating the cellular responses to a pathogenic stress , with stimulation of synthesis of cytokines and alterations of homeostatic balance of the inner ear. The transient activation of this system might be related to a spontaneous recovery, whereas a prolonged stimulation should lead to an irreversible damage of cochlear cells  [In 2002 Gloddek et al. demonstrated the immunologically mediated vasculitis relation with ISSHL pathogenesis. The role of endothelial cells in this mechanism is inferred, and these cells are thought to promote vasculitis by secreting cytokines . Moreoves organ) .α and NF-κB) and cytokines (interleukin 1 and 6), which is elevated in infection and flogosis [The precise mechanism through which steroids may improve hearing remains unknown; both glucocorticoid and mineralcorticoid receptors may be found in the inner ear . The maiflogosis , 19;  aflogosis ; (iv) reflogosis . There tflogosis . Systemiflogosis .The first report of IST in the treatment of ISSHL was by Silverstein in 1996  followedUsually, intratympanic steroids are used in three main protocols, as initial treatment, as adjunctive treatment given concomitantly with systemic steroids, and as salvage treatment after failure of standard therapy.The different criteria of hearing improvement and the wide variability of treatment protocols hinder the interpretation of the results. However, according to both randomized –30, 34 aAlthough the reports about the combination of topical and systemic therapy are controversial , 31, theDifficulty in proving safety and efficacy of a single modality of IST is present in all studies on ISSH, due to a multiple treatment protocols, a variable rate of recovery, and a high rate of spontaneous recovery. Moreover, the hearing losses less than 90 dB, the involvement of the low frequencies, and the earlier IST seem to influence positively the hearing recovery, although the success could be attributed to the natural history of the disease.More well-controlled clinical trials and standard criteria of hearing recovery are required to document the real efficacy of this option in the treatment of ISSHL and to determine the most appropriate use and the correct timing and dosage of this therapeutic modality in the emerging field of inner ear medicine delivery.


Given that hearing loss occurs in 1 to 3 of 1,000 live births and approximately 90 to 95 percent of them are born into hearing families, it is of importance and necessity to get better understanding about the carrier rate and mutation spectrum of genes associated with hearing impairment in the general population.7,263 unrelated women of childbearing age with normal hearing and without family history of hearing loss were tested with allele-specific PCR-based universal array. Further genetic testing were provided to the spouses of the screened carriers. For those couples at risk, multiple choices were provided, including prenatal diagnosis.Among the 7,263 normal hearing participants, 303 subjects carried pathogenic mutations included in the screening chip, which made the carrier rate 4.17%. Of the 303 screened carriers, 282 harbored heterozygous mutated genes associated with autosomal recessive hearing loss, and 95 spouses took further genetic tests. 8 out of the 9 couples harbored deafness-causing mutations in the same gene received prenatal diagnosis.Given that nearly 90 to 95 percent of deaf and hard-of-hearing babies are born into hearing families, better understanding about the carrier rate and mutation spectrum of genes associated with hearing impairment in the female population of childbearing age may be of importance in carrier screening and genetic counseling. In China, approximately 30,000 infants are born with congenital hearing loss per 20 million live births every year ,2. MoreoDespite a great number of mutations in many genes may contribute to hearing loss, the patterns of high frequency mutations in certain populations and their population-wide distributions make it meaningful to initially select hotspot mutations for carrier screening ,11. A miA total of 7,263 unrelated women of childbearing age with normal hearing and without family history of hearing loss were enrolled in the study under an institutional review board-approved protocol of informed consent at the Guangdong Women and Children Hospital Institutional Review Board and Ethics Committee of Guangzhou Medical College, China. The study cohort was recruited from women came for (pre-)pregnancy examination at the Clinic of Guangdong Women and Children Hospital, China. The majority of the participants were from Guangdong Province, and a small portion of them were from Hunan, Guangxi and Jiangxi Provinces. The study cohort was of a significant characteristic of South China origins. A comprehensive history and physical examination record for each participating subjects was obtained, including clinical history, infaust gravidity, infection, aminoglycoside antibiotics exposure, as well as genetic factors related to the hearing loss. Blood samples were obtained from all participants and genomic DNA was isolated from the whole blood by standard procedures using Fuji DNA Blood Minikit.Allele-specific PCR-based universal array was applied to screen mutation carriers of deafness-associated genes in the study cohort . The DetFor the mutation carriers of genes associated with hearing loss, elaborate genetic counseling were provided, concerning the nature of the disease, the implications of being carriers and the reproductive choices ,21. FurtAs for those couples at risk and may need prenatal diagnosis, detailed information was offered, regarding to the fetal DNA sampling procedure, the risk of fetal mortality, the chance of misdiagnosis, and the mortality and morbidity of an abortion in case of affected fetus . Fetal DAmong the 7,263 normal hearing participants enrolled in this study, 303 subjects carried pathogenic mutations included in the screening chip, which made the carrier rate 4.17% in the population under investigate. As shown in Table Of the 303 screened carriers, 282 were found out to be carrying heterozygous mutated genes associated with autosomal recessive hearing loss. After the genetic counseling, with regard to the nature of the disease, the implications of being carriers and the reproductive choices, were provided to the carriers and their families, 95 spouses were willing to take further genetic tests, including the allele-specific PCR-based universal array to detect high frequency deafness-associated mutations in Chinese population, and DNA sequencing to analyze the mutated gene of the wife. As shown in Additional file In the present study, eight out of the nine couples harbored deafness-causing mutations in the same gene received prenatal diagnosis Table . The preIn the present study, a cohort of 7,263 unrelated women of childbearing age were investigated for the carrier rate of genes associated with hearing loss in the South China hearing female population. In the study cohort, 303 subjects carried pathogenic mutations associated with hearing loss, which made the carrier rate 4.17% in the population. Based on a comparatively large study population, the figure could be reliable and representative, and could be of importance in carrier screening and genetic counseling of hearing loss, the most common birth defect and the most prevalent sensorineural disorder in China.Besides of the carrier rate, the mutation spectrum of genes associated with hearing loss in South China hearing population was also a core concern in the present study. As previous reports suggested, variants of GJB2 gene could account for the molecular etiology of 8 to 72 percents of non-syndromic hearing impairment. In the study cohort, GJB2 gene mutations accounted for 54.12% of the mutant alleles. The most common mutation in Caucasians, c. 35 del G, accounted for only 0.33% of mutant alleles in the South China hearing population. Instead, c. 235 del C accounted for 42.24% of mutant alleles in the study population. c. 235 del C was also at the highest rate in the Asian deaf populations .The patterns of high frequency mutations in populations and their population-wide distributions made it meaningful to initially select hotspot mutations for carrier screening. Yet the genetic heterogeneity of hearing loss has proved a challenge for genetic testing using conventional methods. Fortunately, the parallelism offered by the microarray platform makes it ideally suited for genotyping of genetically heterogeneous conditions such as hearing loss. The allele-specific PCR-based universal array allowed the parallel analysis of nine common variations in GJB2, GJB3, SLC26A4, and mitochondrial DNA 12S rRNA genes, and could easily be expanded or modified, according to further epidemiologic survey on the carrier rate and mutation spectrum of genes associated with hearing loss under certain ethnic background.Previous researches mainly focused on molecular etiology of hearing loss, which provided valuable data of deafness-causing mutations and their prevalences. However, without the implementation of carrier screening and intervention programs, the average age at diagnosis was 1.5 to 3 years, which was well beyond the beginning of the critical interval for speech and language acquisition . DiagnosThe authors declare that they have no competing interests.XZ Zhang, AH Yin and C Liu defined the research theme. AH Yin, C Liu, Y Zhang, J Wu, MQ Mai, HK Ding and JX Yang performed the experimental work and organized the data. AH Yin and C Liu designed experiments, interpreted data and drafted the manuscript. XZ Zhang critically reviewed the manuscript and provided concepts. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2350/14/57/prepubGenetic test results for the spouses of screened carriers.Click here for file


Geotria australis during the downstream migration of the young, recently-metamorphosed juveniles to the sea and during the upstream migration of the fully-grown and sexually-maturing adults to their spawning areas. Glutamate and taurine were distributed throughout the retina, whilst GABA and glycine were confined to neurons of the inner retina matching patterns seen in most other vertebrates. Glutamine and aspartate immunoreactivity was closely matched to Müller cell morphology. Between the migratory phases, few differences were observed in the distribution of major neurotransmitters i.e. glutamate, GABA and glycine, but changes in amino acids associated with retinal metabolism i.e. glutamine and aspartate, were evident. Taurine immunoreactivity was mostly conserved between migrant stages, consistent with its role in primary cell functions such as osmoregulation. Further investigation of glutamate signalling using the probe agmatine (AGB) to map cation channel permeability revealed entry of AGB into photoreceptors and horizontal cells followed by accumulation in inner retinal neurons. Similarities in AGB profiles between upstream and downstream migrant of G. australis confirmed the conservation of glutamate neurotransmission. Finally, calcium binding proteins, calbindin and calretinin were localized to the inner retina whilst recoverin was localized to photoreceptors. Overall, conservation of major amino acid neurotransmitters and calcium-associated proteins in the lamprey retina confirms these elements as essential features of the vertebrate visual system. On the other hand, metabolic elements of the retina such as neurotransmitter precursor amino acids and Müller cells are more sensitive to environmental changes associated with migration.Lampreys are one of the two surviving groups of the agnathan (jawless) stages in vertebrate evolution and are thus ideal candidates for elucidating the evolution of visual systems. This study investigated the retinal amino acid neurochemistry of the southern hemisphere lamprey  Lampreys, together with the hagfishes, are the sole survivors of the early agnathan (jawless) stages in vertebrate evolution Beyond anatomical similarities, the expression of key phototransduction proteins including transducin, phosphodiesterase 6 and recoverin in the lamprey retina indicates the presence of a characteristic vertebrate visual system Petromyzon marinus, Lampetra fluviatilis and Ichthyomyzon unicuspis. These animals have two structurally and spectrally distinct photoreceptor types, proposed as a rod-like and a cone-like photoreceptor although this classification is still subject to debate  visual system, which may provide greater insight into the neurochemistry of colour vision than the dichromatic visual system of its northern hemisphere counterparts G. australis  possess a short and densely packed photoreceptor layer, likely to reflect its highly photopic habitat of shallow fresh water rivers G. australis with a large unpigmented ellipsosome, resulting in a shift in the peak spectral sensitivity (λmax) from 492 nm to 552 nm G. australis using immunocytochemical techniques and determine if their distribution is associated with the anatomical differences found in the retina of downstream and upstream migrants. We will also investigate glutamate signalling by analysing cation channel permeability using the small organic cation, agmatine (AGB) and briefly assess the role of calcium, based on the distribution of calcium binding proteins.Here, we seek to further understand the neurochemistry of the lamprey retina by investigating the amino acid distribution in the retina of ustralis  providesThis study was carried out in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. Animals were killed with an overdose of methane tricaine sulfonate salt in concordance with ethical guidelines of the National Health and Medical Research Council of Australia, and all efforts were made to minimize suffering. All experimental protocols were approved by The University of Queensland Animal Ethics Committee.G. australis were collected as young, downstream migrants  or upstream migrants  from streams and rivers in south-western Australia using an electric fish shocker as described previously Adult The procedures for post-embedding immunocytochemistry have been previously described Primary antibodies for glutamate, glycine, glutamine, GABA, taurine and aspartate were diluted with 1% (v/v) goat serum in phosphate buffered saline (GSPBS) and incubated with tissues overnight. Specifications and working dilutions for these antibodies are described in Images were acquired using a LEICA DC500 camera, version 4.1.0.0 attached to a LEICA microscope . All images were captured using fixed parameters of exposure time, intensity, contrast, gamma, brightness and eight-bit channel.camera lucida to determine the morphology of major glycine interplexiform cell dendrites.Toluidine blue stained upstream and downstream specimens were used in the drawing of schematics of the retina . For putCell identification was based on anatomical classification described in previous studies of the lamprey retina 3, 1.25 mM NaH2PO4, 10 mM dextrose, 2 mM CaCl2, 1 mM MgCl2, pH 7.4) bubbled with 95% O2/5% CO2Isolated eye cup pieces were mounted on 0.8 µm pore metrical membrane filters  and the sclera/retinal pigment epithelium removed by gently pulling it away from the retina. Retinal pieces were then incubated for 5–60 min at room temperature (∼20°C) under normal room lighting (300–400 lux) in a modified Edwards medium  paraformaldehyde, 0.01% (w/v) glutaraldehyde in PB for 30 min and then cryoprotected in 30% (w/v) sucrose overnight. Frozen vertical sections were collected on positively charged slides . Tissues were blocked with 6% (v/v) goat serum, 1% (v/v) bovine serum albumin and 0.5% (v/v) Triton X-100 in PB for 1 h at room temperature followed by incubation with primary antibodies, diluted in 3% (v/v) goat serum, 1% (v/v) bovine serum albumin and 0.5% (v/v) Triton X-100 in PB overnight at 4°C. Details and dilutions of the primary antibodies used for indirect immunocytochemistry are provided in Primary antibodies were detected with an anti-goat secondary antibody conjugated to AlexaFluor488  diluted in 1∶500 in 3% (v/v) goat serum, 1% (v/v) bovine serum albumin and 0.5% (v/v) Triton X-100 in PB. The specificity of secondary antibodies was confirmed by omitting the primary antibody and using a secondary antibody from a different species. Fluorescence images were captured using a confocal laser scanning microscope (LEICA Microsystems TCS 4D). Image brightness and contrast was adjusted using Adobe Photoshop .For the amino acid antibodies, the specificity of the glutamate antibody was previously shown in dot immunoassays where a positive signal for the glutamate antibody was obtained against an artificial glutamate antigen coupled to bovine serum albumin (BSA) via glutaraldehyde cross-linking The specificity of the calbindin antibody was established in immunoblots yielding a single 28 kDa band corresponding to the expected calbindin protein (manufacturer’s data sheet). Specificity of the calretinin antibody has been confirmed by Western blots of mouse brain lysate which show the antibody reacting with a single 31 kDa band corresponding to the expected size for the calretinin protein (manufacturer’s data sheet). The specificity of the glutamine synthetase (GS) antibody was confirmed with a Western blot using rat cerebellum lysate where it reacted with a 45 kDa band which corresponds to the expected size of the GS protein, amino acids 1–373 . The specificity of protein kinase C-α (PKCα) antibody was confirmed in a Western Blot of rat glioma extract and NIH 3T3 mouse fibroblast lysate where the antibody reacted with a single 80 kDa band corresponding the expected size for PKCα. Finally, the specificity of the recoverin antibody was confirmed as the presence of single 26 kDa band in Western blots of human adult retina tissue homogenate G. australis retina features 5 different cone-like photoreceptors and densely packed INL with over 10 layers of cells including at least three, possibly four layers of horizontal cells . The upstream G. australis retina is much thicker; dominated by large photoreceptors, some with an altered morphology (e.g. the C2 photoreceptor replaces a photostable pigment with an unpigmented ellipsosome). The number of cell layers in the INL appears reduced but four layers of horizontal cells are visible. Similar to other vertebrates, the lamprey retina has a pigmented epithelium.G. australis , calretinin  and the calcium sensitive protein, recoverin, to analyse calcium associated protein distribution in the retina of eceptors .G. australis was found in the outer segment/inner segment of photoreceptors, horizontal cells and in the inner INL  suggesting conservation across species L. fluviatilis are CalB immunonegative), these differences probably reflect acquired species-specific variations rather than stages in evolutionary development. Unique to G. australis was the presence of CalB in photoreceptors. Although absent in other lampreys, CalB is present specifically in the cones of jawed vertebrates including pig, sheep, chick, cat and salamander G. australis are cone-like, whilst those of other lamprey species are less defined, which may explain the discrepancies in CalB immunoreactivity G. australis IPL. ChAT and serotonin immunoreactive striations in the IPL have also been observed Recoverin immunoreactivity was confined to photoreceptors, corresponding to patterns observed in other species of lamprey G. australis metabolic requirements during migration. This was supported by glutamine synthetase labelling, which demonstrated extensive changes in Müller cells between downstream and upstream migrants. Overall, this suggests retinal anatomical changes associated with adaptation of the G. australis retina to ocean environments is coupled with changes in metabolic elements including supporting glia and amino acids involved in glutamate production.We found the distribution of key amino acid neurotransmitters, including glutamate, GABA and glycine were conserved throughout different phases of the lamprey lifecycle. Functional analysis of glutamate channels with AGB also suggests amino acid signalling is a plesiomorphic feature of the vertebrate retina. Calcium protein cell markers including recoverin, CalB and CalR were highly conserved supporting an essential role for calcium in the retina. On the other hand, increase levels of neurotransmitter precursors, glutamine and aspartate were observed between the two migrant phases suggesting alterations in the Figure S1Distribution of protein kinase C-α (PKCα) in the retina of G. australis. PKCα immunoreactivity in the A: downstream (DS) migrating and B: upstream (US) migrating G. australis. Abbreviations are as in (TIF)Click here for additional data file.


GJB2 sequencing was carried out for the probands of all 103 families. The prevalence of the p.V37I variant was compared between the subtle, mild or moderate hearing loss (group I) and the severe or profound hearing loss (group II) groups. Where possible, a targeted next generation sequencing of 82 deafness genes was performed from the p.V37I carrier to exclude the existence of other pathogenic genes. Five (4.8%) of 103 probands were found to carry p.V37I. The carrier frequency of p.V37I among group I (18.2%) was significantly higher than that of group II (1.2%) or the reported Korean normal hearing control group (1.0%). Detection of the p.V37I variant of GJB2 in 18.2% of Koreans with mild hearing loss strongly suggests its contribution to the pathogenesis of milder hearing loss, which might justify sequencing of GJB2 from these subjects in the Korean population.A p.V37I variant of GJB2 has been reported from subjects with moderate or slight hearing loss especially in East Asian populations. This study aimed to estimate the prevalence of the p.V37I variant among such subjects and prove, epidemiologically, its pathogenic potential to cause mild hearing loss. A total of 380 subjects from 201 families with hearing loss were enrolled. From them, 103 families were selected who had autosomal recessive inheritance or sporadic occurrence of hearing loss and who were younger than 15 years old.  GJB2  causes more than 50% of autosomal recessive nonsyndromic deafness in many populations GJB2 gene (http://davinci.crg.es/deafness/) GJB2 mutant alleles Despite significant heterogeneity of genetic deafness, GJB2 variant that is frequently found in East Asian populations The p.V37I is another trans configuration with other pathogenic mutation of GJB2, the possibility of a pathogenic role of the variant has been raised GJB2 mutations The p.V37I variant was originally described as an innocent polymorphism because it was identified in unaffected heterozygous control subjects GJB2 or in homozygosity, may cause subclinical subtle hearing loss at birth, and this hearing loss may progress and become apparent at later age. In that paper, they showed that the genotype is present in a substantial portion (20%) of post natal permanent childhood hearing impairment (PCHI) Recently, an epidemiological study of a Chinese population by Li et al. (2012) demonstrated that the p.V37I variant, either in compound heterozygosity with other truncating mutations of To the best of our knowledge, there has been no study estimating the prevalence of the p.V37I variant according to the degree of hearing loss. Therefore, we conducted a genetic test to estimate genetic loads of the p.V37I variants according to the degree of sensorineural hearing loss.The Institutional Review Boards (IRBs) at the Seoul National University Bundang Hospital (SNUBH) (IRB-B-1007-105-402) and the Seoul National University Hospital (SNUH) (IRBY-H-0905-041-281) approved the study. We obtained a written informed consent from all the participants in this study. In case of children participants, the written informed consent was obtained from the parents or guardians on behalf of them.Clinical phenotype evaluations included medical and developmental history interviews, physical examinations, pure tone audiometry and imaging studies , whenever possible. An initial cohort of 380 subjects from 201 families with varying degrees of hearing loss were collected at the otolaryngology clinics of SNUH and SNUBH from September 2010 through though March 2012. The 380 subjects were subjected to preselection based upon the presence of autosomal recessive inheritance or sporadic occurrence of hearing loss. Ten milliliters of whole blood was obtained from all probands in the 201 families and, if possible, their siblings and parents for the segregation study. Families segregating hearing loss in an autosomal dominant, a maternally transmitted or X-linked manner were excluded. To exclude any bias resulting from presbycusis, subjects were excluded if they were older than 15 years of age at their initial visit. Individuals with syndromic, unilateral hearing loss, or with inner ear anomalies, such as enlarged vestibular aqueduct or incomplete partition type III, were also excluded from this study. This preselection resulted in the number of study families being reduced to 103.The following demographic data were collected for each patient: sex, birth date, date of initial otolaryngological consultation, and major comorbidities or syndromic features. The ethnicity of all subjects was Korean. Where available, the temporal bone CT or magnetic resonance imaging findings were also taken. For example, anomalies in the seventh nerve, cochlear anomaly or enlarged vestibular aqueduct syndromes were all recorded.All subjects underwent audiological evaluation. Hearing levels were determined by pure-tone audiometry. We performed serial audiograms regularly to detect any noticeable aggravation of hearing after their participation in this study and to provide timely auditory rehabilitation. In addition, if necessary, we traced back the previous hearing status by obtaining the clinical information from the private practitioner who referred patients to our center. Initial audiograms conducted in our center were reviewed, and the pure-tone average (PTA) was calculated for each ear. The pure-tone thresholds at 0.5, 1, 2, and 4 kHz were recorded, and the pure-tone average across these frequencies was calculated and reported as decibels of hearing loss. In six cases where pure-tone audiometry was not performed because of the subjects’ young age, auditory brainstem response threshold (ABRT) evaluations and/or auditory Steady-State Response(ASSR) were recorded, and mean thresholds at frequencies in the 0.5-to 4-kHz range were averaged to approximate the PTA. The hearing level of the better ear calculated by four-tone average  was labeled as subtle (16–25 dB), mild (26–40 dB), moderate (41–70 dB), severe (71–95 dB), or profound (>95 dB). This cohort was then screened by visual examination of audiometric data and classified into two groups: Subtle, mild or moderate sensorineural hearing loss (SNHL) (group I) versus severe or profound SNHL (group II) .GJB2 (GenBank Accession NM_004004.5). The two exons and flanking sequences of GJB2 were PCR-amplified and sequenced as previously described GJB2. The names of all variants were checked using Mutalyzer . Novel splice site variants and synonymous changes were considered non-pathogenic when they were detected in the normal Korean population or BDGP (http://www.fruitfly.org/seq_tools/splice.html) and ESEfinder (http://rulai.cshl.edu/cgi-bin/tools/ESE3/esefinder.cgi?process=home) software did not predict a change that creates or eliminates a splicing acceptor or donor site. We have submitted our novel variants of GJB2 to the LSDB database (https://research.cchmc.org/LOVD2/variants.php?select_db=GJB2&action=view&view=0000808).As a first step toward molecular genetic diagnosis of the 103 families, we performed bidirectional nucleotide sequence analysis of the two exons of GJB2 as one of two mutant alleles, they were further evaluated by targeted capture of exons and flanking sequences of 82 deafness genes, followed by massively parallel sequencing of DNA libraries, as previously described TRIBOP, TMC1 and DSPP that we detected by next generation sequencing to the LSDB databases .For two subjects (SH42-94 and SB51-95) carrying the p.V37I variant of trans configuration with p.V37I, we conducted a multiplex breakpoint PCR assay for the single heterozygous carriers of the p.V37I allele designed to detect known reported large genomic deletions (del(GJB6-D13S1830) and del(GJB6-D13S1854)) To exclude the possibility of large genomic deletions that may be in a The SPSS15 statistical package was used for the analysis . Fisher’s exact test and logistic regression analysis were used to compare the prevalence of the p.V37I variant among different subject groups. For control groups, we assembled a composite cohort of 3418 ethnically matched Korean normal hearing subjects from three independent studies .Odds ratios and confidence intervals were calculated by logistic regression analysis; p-values ≤0.05 were considered statistically significant.GJB2. The variant was detected in a trans configuration with a known pathogenic variant in three subjects and as a mono-allelic variant in two subjects.One hundred and three families satisfied our inclusion criteria by showing either autosomal recessive inheritance pattern or sporadic occurrence of the hearing loss . Twenty-GJB2, either as one of two mutant alleles (three subjects) or as a single heterozygote (one subject). In contrast, only one (1.2%) of the 81 probands from group II with a severe hearing loss carried the p.V37I variant (as a single heterozygote)  carried the p.V37I variant of ozygote) . The preozygote) . Howevertrans configuration with another mutant allele of GJB2 in the other homologous chromosome, as a compound heterozygote. SB80-141 carried the p.V37I allele as the only variant (trans configuration with the p.V37I in the other homologous chromosome for two compound heterozygotes (SB51-95 and SHJ12), while c.235delC was in a trans configuration with p.V37I in one subject (SH42-94) with subtle hearing loss. Rapid progression of hearing loss over a 5 month period was noted from SHJ12 carrying the p.V37I and p.R143W mutant alleles  who carried the p.V37I variant, three subjects  carried the p.V37I allele in a  variant . The p.R alleles . Hearing alleles .GJB2, and not by other known deafness genes by targeted next generation sequencing (panel sequencing) of 82 known deafness genes . For two subjects (SH42-94 and SB51-95), the other 81 known deafness genes were excluded as causes of the observed hearing loss  carrying a single heterozygous p.V37I allele from group II was a monozygotic twin. The monozygotic twin brother of SHJ1 carried the same p.V37I allele but had completely normal hearing, indicating that detection of the p.V37I allele in this subject with profound deafness is probably incidental .GJB2 was present in 20% of postnatal permanent childhood hearing impairment subjects To the best of our knowledge, the frequency of the p.V37I allele has never been reported in an exclusive group with only mild hearing loss. The carrier frequency of the p.V37I allele was calculated as 18.2% among Korean subjects with moderate or slight hearing loss in this study. This figure is strikingly high, considering that the carrier frequency of the p.V37I variant from Korean normal hearing control populations ranged from 0.88 to 1.25% GJB2 in the mild hearing loss group compared with the severe hearing loss group and the reported Korean normal hearing control group, provides strong genetic evidence of its contribution to the pathogenesis of mild hearing loss, rather than more severe or profound hearing loss. This agrees with previous descriptive reports where p.V37I homozygotes and c.235delc/p.V37I compound heterozygotes had mild to moderate nonsyndromic hearing loss The significantly higher prevalence of the p.V37I variant of GJB2 variants, but none of the variants were compatible with a recessive inheritance pattern. More specifically, p.D1143E in DSPP and p.D498E in TRIOBP  in group II was not significantly different from that of the reported Korean normal hearing control group.Two single heterozygotes (SB80-141 from group I and SHJ1 from group II) of p.V37I were detected in our cohort. We suggest a different interpretation of the genotype depending upon the degree of hearing loss. Based upon our data, p.V37I detected as a single heterozygote is most likely to contribute to the phenotype if hearing loss is mild or moderate. It is not surprising that a substantial portion of DFNB1 patients carry only one detectable mutation of GJB2 in a trans configuration. Our subject SHJ12, carrying p.V37I and p.R143W, showed a rapid progression of hearing loss over 5 months (GJB2. Some researchers advocate newborn genetic screening (NGS) GJB2 in children with mild to moderate hearing impairment that segregates in a manner compatible with autosomal recessive inheritance. Further study is needed to elucidate the function of the p.V37I mutation, not only the p.V37I phenotype, but also any genetic interaction with other pathogenic or causative variants.Occasionally, the p.V37I variant can be expressed as progressive hearing loss, especially in combination with other pathogenic mutations of 5 months , eventuaGJB2 contributes to the pathogenesis of milder hearing loss and may justify sequencing of GJB2 from subjects with mild to moderate degree of hearing loss in the Korean population.Our study strongly suggests that the p.V37I variant of Table S1Statistics for targeted next generation sequencing from the two subjects with p.V37I variant.(DOCX)Click here for additional data file.


Objective: We explored the relationship between audiogram shape and tinnitus pitch to answer questions arising from neurophysiological models of tinnitus: ‘Is the dominant tinnitus pitch associated with the edge of hearing loss?’ and ‘Is such a relationship more robust in people with narrow tinnitus bandwidth or steep sloping hearing loss?’ Design: A broken-stick fitting objectively quantified slope, degree and edge of hearing loss up to 16 kHz. Tinnitus pitch was characterized up to 12 kHz. We used correlation and multiple regression analyses for examining relationships with many potentially predictive audiometric variables. Study Sample: 67 people with chronic bilateral tinnitus . Results: In this ample of 67 subjects correlation failed to reveal any relationship between the tinnitus pitch and the edge frequency. The tinnitus pitch generally fell within the area of hearing loss. The pitch of the tinnitus in a subset of subjects with a narrow tinnitus bandwidth (n = 23) was associated with the audiometric edge. Conclusions: Our findings concerning subjects with narrow tinnitus bandwidth suggest that this can be used as an a priori inclusion criterion. A large group of such subjects should be tested to confirm these results. The prevalence of tinnitus is high. In the general population, it is estimated at around 10–15% , while fRecent neurophysiological models of tinnitus predict one of two relationships between the audiometric profile and the dominant tinnitus pitch. The ‘tonotopic expansion’ model suggests that tinnitus is the perceptual consequence of a plastic transformation of the orderly representation of single frequencies within central auditory structures see . As a resome individuals did exhibit a pitch at the low-frequency edge of the hearing loss. From these observations, they postulated that a relationship between pitch and audiometric profile might be present in a certain subgroup of people with tinnitus. However, they were unable to identify what might be the important defining characteristics. A number of authors highlight their finding that a majority of people with tinnitus report a dominant tinnitus pitch that falls within the area of hearing loss  we specify objective criteria for quantifying the shape of the audiogram and we consider a larger part of the audible range (up to 16 kHz), (2) we use a psychophysical method to estimate tinnitus pitch in a way that does not rely on obtaining a pitch match to a single-frequency and that attempts to separate loudness and pitch similarity ratings, (3) we apply a rigorous statistical method for testing the relationships, and (4) we try to account for the heterogeneity of tinnitus by using two While the pure-tone audiogram indicates portions of the basi-lar membrane with reduced sensitivity for detecting sound energy at low levels, it does not determining the physical integrity of the inner and outer hair cells in those regions . NeverthA second challenge in interpreting current findings concerns the method that has been used to estimate the dominant tinnitus pitch, as described above. Tinnitus pitch is most often estimated using a pitch-matching procedure whereby an external sound  is selected that best matches the dominant tinnitus pitch . The chopost-hoc testing inflates the likelihood of a false positive result. Here we report adjusted significance levels where appropriate and also the corresponding confidence intervals for r, which define the likely range of the true value in the population from which the sample was drawn. Equally important, correlational statistics do not lend themselves to accurately characterizing complex relationships when two or more of the audiometric variables are correlated with one another and when two or more audiometric variables contribute to the tinnitus pitch. While we report correlation statistics for comparison with previous studies, we also apply principal component analysis and multiple regression. These methods overcome the problem of colinearity between audiometric variables and the problem of multiple comparisons.The third limitation concerns the statistical methods applied to examine the relationship between the shape of hearing loss and the tinnitus pitch. Studies to date have typically examined this relationship using correlation statistics (e.g. a Pearson two-tailed correlation) . For exaGiven the heterogeneity of tinnitus, most authors would agree that it is probably inappropriate to pool all tinnitus participants into a single group for statistical analysis. In the present study, we therefore not only investigate potential relationships across the whole cohort, but we specifically test our hypotheses in subgroups of patients chosen according to a narrow tinnitus bandwidth c.f.  and a stAudiometry and tinnitus data were collected from 67 volunteers with bilateral tinnitus  tested at one of three research sites. These sites were McMaster University in Hamilton, Canada (47 subjects), the University of British Columbia in Vancouver, Canada (12 subjects) and MRC Institute of Hearing Research, Nottingham, UK (8 subjects). Subjects were recruited from the ENT clinic at McMaster University Medical Center (Hamilton cohort), ENT clinics at hospitals affiliated with the University of British Columbia (Vancouver cohort), Nottingham Audiology Services (Nottingham cohort), as well as advertisements in the local newspapers (Hamilton and Vancouver cohorts). Out of the cohort, 40 people reported tonal tinnitus, 15 people reported ringing tinnitus, and 12 people had hissing tinnitus (see later for definitions). For most subjects (N = 55), their tinnitus was steady over time, although some (N = 12) reported a pulsing sensation.Hearing levels for the two ears were measured up to 16 kHz (Hamilton cohort) or 12 kHz (Vancouver and Nottingham cohorts) using standard audiometric procedures see . An autoThe choice of tinnitus spectral property determined the bandwidth of the target frequencies in the loudness and frequency stages of the test battery. Loudness was first quantified using a visual-analogue rating scale, and second by asking people to adjust the level of each frequency (in dB SPL) so that it matched the loudness of their tinnitus. Eleven different centre frequencies (from 0.5 kHz to 12.0 kHz) were presented and the adjustment was capped at a maximum of 95 dB SPL. The frequency spectrum was quantified by asking people to indicate the similarity of their tinnitus to each presented frequency. Each of the frequencies was presented three times and the mean value of three judgements was taken to represent the similarity value for that frequency. In this phase the tones were presented at the same loudness that was chosen to match their tinnitus loudness in the previous phase. Loudness and pitch ratings were performed using a Borg CR100 scale . LoudnesThe audiometric profile was used to quantify a number of different aspects of the hearing loss; namely the audiometric edge, slope, degree of hearing loss, frequency of the worst hearing level, and the ear with the steeper hearing loss . To imprThe frequency at which the break of the function occurred was taken as the edge of the hearing loss. In the case of 1- and 2-break fits, the edge was constrained to correspond to the break point of the portion of the regression line that passed from clinically normal (<20 dB HL) to impaired , a group with a moderate slope (20.5-36.4 dB/octave), and a group with a shallow slope (4.0-20.4 dB/octave).A standardized clinical procedure defines the degree of hearing loss as the mean hearing level across 0.25, 0.5, 1, 2, 4 kHz . This method fails to account for higher frequencies which might be relevant for tinnitus generation . In the This variable was the frequency at which the hearing loss reached a maximum value. Whenever there were two or more frequencies with the maximum loss, the lowest frequency was recorded for further analysis.The dominant pitch was taken from the pitch-similarity ratings (i.e. the frequency that was rated as the most similar to the tinnitus pitch). Three of 67 participants rated more than one frequency equally to be ‘most like’ their tinnitus. In these cases, we selected the frequency closest to the edge of the hearing loss to represent the dominant tinnitus pitch. One rationale for selecting the frequency closest to the edge was that this choice represents the ‘best’ evidence to support the theory of tinnitus as an over-representation of the lesion edge in the tonotopic map. If the subsequent analysis failed to support a relationship between tinnitus pitch and edge frequency then this could be due to a bias in our data selection. Secondly, when several tones were rated as ‘most like’ the tinnitus they were often far apart on the frequency axis. In these cases, the alternative geometric mean estimate would seem inappropriate.The width of the tinnitus spectrum was also derived from the pitch-similarity ratings. To derive a single measure of bandwidth that was independent of the obtained similarity scores, bandwidth was calculated as the standard deviation of the weighted frequencies, where large weights were given to those frequencies rated as most similar to the tinnitus. The Borg scale was used to assess similarity  and the http://www.informahealthcare.com/doi/abs/10.3109/14992027.2010.551221). In fact, 17 out of the 28 pairs were significantly correlated. While correlational analysis is usually used to explore the relationship between two variables, multiple regression analysis allows us to assess the relationship between several audiometric variables and tinnitus pitch. However, including predictor variables that are highly correlated with other predictor variables is not recommended as the new predictor variable is associated with variance which has already been explained by the model. As a more rigorous alternative strategy for examining our hypotheses, we have therefore implemented a multiple regression analysis using a set of predictor variables that are not intercorrelated. These variables were derived from a principal components analysis: a mathematical procedure that transforms a number of potentially correlated variables into a smaller number of uncorrelated variables.Many of the variables were not normally distributed and so these were transformed by taking a natural logarithmic transform of the values. The measure of tinnitus bandwidth satisfied a normal distribution and so was not transformed. For direct comparison with previous literature, we first report the results of simple correlation statistics. However, we interpret these results with caution, most notably because the audiometric variables  were highly inter-correlated (see Appendix at From the broken-stick fitting procedure that was applied to the 134 ears (67 participants), a 0-break fit best described the audiogram for 19 ears, a 1-break fit best described the audiogram for 81 ears, and a 2-break fit was chosen for 34 ears. From the 1- and 2-break solutions, our criterion for defining the edge of the hearing loss was met in the majority of cases (106 out of 115 ears). There appeared to be a large amount of inter-subject variability in the values obtained. For those ears in which an edge was identified, it ranged from 0.13 to 14.33 kHz (mean = 2.74 and SD = 2.72). Across all 134 ears, the slope of the hearing loss ranged from 0.09 to 214.38 dB/octave , and degree of hearing loss ranged from 2.46 to 105.73 dB/octave .Likewise, there was a large amount of inter-subject variability in the observed tinnitus characteristics. The dominant tinnitus pitch ranged from 0.5 to 12 kHz  and bandwidth varied from 0.13 to 0.44 . A one-way ANOVA revealed that the participant's choice about the spectral property of their tinnitus  was unrelated to the subsequent numerical estimate of bandwidth . The associations between subjective classification and the bandwidth estimate are plotted in 2) demonstrated that only 6.5% and 8.1% of variance in the tinnitus pitch could be accounted for by degree of hearing loss .For comparison with previous studies, a series of correlations explored the degree of association between the dominant tinnitus pitch and the audiometric variables, separately for each ear . The resIn the Introduction, we outlined a planned comparison between the edge ofthe hearing loss and tinnitus pitch, specifically in those 23 participants who reported a narrow numerical tinnitus bandwidth . SignifiThis result is certainly intriguing because it supports the observation reported previously by König and colleagues  that thoIn the Introduction, we outlined a planned comparison between the edge of the hearing loss and tinnitus pitch in those 22 participants who had a steep-sloping hearing loss, (defined for the steeper ear). Even in this selected subject group there was no significant relationship, r = .05, p (one-tailed) < .42 see . Only abWe also found null results for the other two subgroups with a moderate and shallow slopes of hearing loss (p > .3). From these findings, we conclude that the slope of hearing loss does not appear to drive individual tinnitus pitch.To generate a set of independent predictor variables describing a participant's audiometric profile, all the data were first subjected to a principal component analysis. From the original set of eight variables, eight factors were generated and these are reported in The multiple regression model specified the dominant tinnitus pitch as the criterion variable with the three selected principal components as predictor variables. Given the evidence that tinnitus bandwidth plays an important role in modulating the relationship between tinnitus pitch and audiometric profile, bandwidth categories were included in the model as a fixed between-subjects factor. The interactions between each of the three principal components were also included as predictor variables in the model. The model was not successful in predicting tinnitus pitch across the whole cohort . If only people with a tonal tinnitus experience a tinnitus pitch that is determined by their audiometric edge, then including data from people whose tinnitus has a moderate or broad bandwidth might weaken the overall relationship, despite including it as a moderator variable in the model. However, analysing only those data for people with a narrow tinnitus bandwidth would be too lacking in statistical power. In the discussion we propose a way to deal with this issue.correspond to the edge frequency. Although significant, these correlation coefficients had large confidence intervals suggesting some degree of uncertainty about whether the observed r value truly represents the population. We suggest that more substantial evidence to refute or support alternative neurophysiological models for tinnitus will be best obtained by using appropriate a priori inclusion criteria , and to recruit a large sample of such participants. This would generate a reasonably homogenous sample of people with tinnitus in sufficient numbers to yield a high degree of statistical certainty in the outcome.The present study set out to explore the relationship between audiometric profile and tinnitus pitch in a large cohort of participants. The data broadly support the view that tinnitus is associated with the degree of hearing loss, and that the tinnitus pitch more typically falls within the region of hearing loss than at (or close to) the edge of hearing loss. No further systematic relationships were found between audiometric variables and tinnitus pitch when all the participants were considered as a single group. The strongest positive correlations emerged when the analysis was limited to the subgroup reporting a narrow tinnitus bandwidth. For these subj ects, their dominant tinnitus pitch was about an octave above the edge in the area of hearing loss - a result that is inconsistent with the tonotopic expansion model of tinnitus which predicts that the pitch should Our data demonstrated some discrepancy between the participant's classification of their tinnitus spectral properties and their subsequent psychoacoustical ratings of tinnitus bandwidth shown in . Two pos2). Confidence intervals on the other hand give us information about likely value of the correlation coefficient (r) in the population. If two samples have confidence intervals that do not overlap it can indicate that samples were taken from different populations. If they do overlap, the sample was probably taken from the same population. We can apply this logic to compare our results with those of other studies even though the actual correlation coefficients obtained were very different. A positive finding from our correlation analysis was a significant relationship between dominant tinnitus pitch and edge of hearing loss in people with narrowest tinnitus bandwidth, somewhat consistent with Given that correlation analyses are more useful for data exploration than for hypothesis testing, it is informative to seek convergent support for our main findings through comparison with other studies. In this section, we therefore compare our results with those of An important issue for future experimental design concerns sample size. To reliably estimate the strength of an association we need to obtain narrower confidence intervals. Based on the above observations, we therefore recommend that future studies should aim to reduce the confidence intervals by at least half. Halving the confidence intervals can be achieved by quadrupling the sample size. Hence, a sample of 100 tinnitus subjects is needed to reliably evaluate the association between tinnitus pitch and the edge of hearing loss.Simply increasing the sample size is probably unlikely to be sufficient for improving reliability, since it does not address the issue of heterogeneity. This point can be illustrated by considering the strength of the association between tinnitus pitch and degree of hearing loss, comparing our data (n = 67) with those of


Fabry disease is an X-linked lysosomal storage disorder resulting in a multiple-system disorder with a wide spectrum of physical signs and symptoms, predominantly affecting the central and peripheral nervous systems, skin, heart, kidneys, and eyes.We describe the case of a 26-year-old European Caucasian man who had Fabry disease and who presented with episodic sudden unilateral hearing loss and was treated with glucocorticoids, pentoxifylline, hyperbaric oxygen, and fluoride because of concomitant audiometric evidence of otosclerosis. This case demonstrates the partial and transient beneficial effect of standard treatment for sudden hearing loss not related to Fabry disease and analyzes the possible connection between typical Fabry disease inner-ear lesions and otosclerosis. Whereas hearing loss has been described in connection with Fabry disease, otosclerosis-associated hearing loss in Fabry disease has not yet been described.Although progressive hearing loss in patients with Fabry disease seems to be influenced by replacement therapy, few data concerning treatment of sudden hearing loss are available. The lack of literature concerning the pathogenesis of the otological involvement in Fabry disease makes it impossible to identify a connection between the latter and otosclerosis. Therefore, this report may help to reinforce the importance of a thorough evaluation of hearing in patients with Fabry disease and may be of help with therapeutic decision-making. GLA gene; EC 3.2.1.22) [Fabry disease (FD) is an X-linked lysosomal storage disorder that is due to the deficient activity of the enzyme alpha-galactosidase A (GLA enzyme), a lysosomal hydrolase encoded by the alpha-galactosidase gene (.2.1.22) .Otosclerosis (incidence of 0.3% to 0.4% in Caucasians)  is a bonWe describe the case of a 26-year-old Caucasian man who had FD and who presented after two episodes of unilateral sudden hearing loss (SHL) and who was treated with glucocorticoids, pentoxifylline, and hyperbaric oxygen without complete recovery of right ear function. The case was associated with the audiometric characteristics of otosclerosis.®; Genzyme Corporation, Cambridge, MA, USA), at a dosage of 1 mg/kg intravenously every 2 weeks, was started in 2001 after approval of the drug in Italy. Since then, his renal function has been stable. Before the start of ERT, the brain , fundus oculi, cardiac function and morphology, hearing, and kidney function were evaluated, and all were normal.A 26-year-old Caucasian man tested positive for FD when he was nine years old. At presentation, his main manifestations were fatigue, hypohydrosis, and painful acroparesthesias correlated with fever and physical effort.. The dosage of GLA activity in lymphocytes was 2.4 nmol/hour per mg, which was well below normal values (24 to 56 nmol/hour per mg protein), and a molecular genetic analysis confirmed the diagnosis (R100K mutation in exon 2). Our patient was in good health until 18 years of age, when he had three episodes of severe nephrotic syndrome and acute renal failure requiring hospitalization and corticotherapy. Enzyme replacement therapy (ERT) with agalsidase-β  and tinWe then performed an audiometric test, which showed a left SNHL associated with a mild conductive component at low frequencies Figure  and a noAn otological investigation revealed normal tympanic membranes. The brainstem auditory evoked response was consistent with the auditory impairment, showing increased latencies for the central pathways of the left ear, and an augmented I-V interval was on the left side.Our patient presented no other associated symptoms.Oral corticosteroid therapy with prednisone (50 mg/day for two days decreased to 25 mg every two days for eight days) along with hyperbaric oxygen therapy was administered for eight days; our patient underwent eight sessions of 80 minutes each at 1.5 bars of pressure with 100% oxygen. Audiometry was performed after eight days and showed mild recovery of both the bone and air conduction. However, our patient continued to complain of left-ear hearing loss associated with intense tinnitus. This prompted us to continue therapy by performing a second cycle of hyperbaric oxygen treatment with the addition of oral pentoxifylline (400 mg twice per day for 15 days) as an anti-aggregant. Our patient reported subjective improvement of the tinnitus after the fifth session. An ear, nose, and throat evaluation after the completion of therapy showed an almost complete normalization of bone conduction and only a mild deficit, whereas a conductive gap on low frequencies remained  and hyperoxygen therapy with the addition of sodium fluoride  for two months to slow down the evolution of the suspected otosclerosis.Repeated audiograms performed after five days and one month showed no significant recovery, whereas the audiogram performed three months after the onset of the hearing loss showed partial recovery of high-frequency hearing Figure . HoweverGiven the increased risk of stroke and microvascular disease, our patient began permanent therapy with acetyl salicylic acid at a dosage of 300 mg/day. Brainstem auditory evoked potentials performed during and three months after the second episode showed mild suffering of the central auditory pathway on the left. Minor SNHL with associated conductive hearing loss remained at the two-year follow-up.This case of FD presents the unusual association of two different complex audiological diseases: otosclerosis combined with SHL. Otosclerosis is a well-defined entity and presents two different treatment options. Medical therapy for otosclerosis can slow down the progression of hearing loss, but the only possible cure to restore hearing is a surgical stapedotomy . As statSeveral studies have indicated that progressive hearing loss in patients with FD comprises 50% of the morbidity, but only one study showed an SHL incidence of 11.8% in men with FD  reportedMore recently, two large studies on hearing loss in patients with FD and on the effect of ERT have been published. Hegemann and colleagues  analyzedHearing loss in patients with FD typically involves all frequencies and appears to be more rapidly progressing than the hearing loss associated with normal aging. In men, residual enzyme activity of greater than 1.5% appears to have a protective function, and ERT can stabilize and possibly improve progressive hearing loss but has no proven effect on preventing SHL . Ries anERT was successful for improving and stabilizing renal function in our patient. Consistent with what is stated in the literature, areas not responsive to ERT were the central nervous system and the auditory apparatus.As this case report demonstrates, there is only a partial and transient beneficial effect of ERT and hyperbaric oxygen treatment combined with corticotherapy and pentoxifylline for hearing loss in patients with FD. As there is no international consensus on treatment of SHL  (particuThe mechanism of progressive SHL in patients with FD remains unclear. It has been suggested that globotriaosylceramide accumulation in vascular endothelium, decreased numbers of spiral ganglion cells , long-tein vivo. Patients with recurrent SHL usually present with punctiform cerebral white matter lesions representing microvascular brain damage, as is the case in patients with FD.Also, the etiology of SHL is difficult to demonstrate even in otherwise healthy patients because the involved anatomical structures may be evaluated only partially To the best of our knowledge, no previous description of otosclerosis in association with FD is available. We could not find an obvious link between otosclerosis and FD, as hypervascularization has been described for otosclerosis in contrast to the microvascular damage seen in FD. However, the involved structures are the same and the spiral ligament has been described in both otosclerosis and FD atrophy of the stria vascularis ,15.Further structured studies are necessary to identify the underlying mechanism of inner-ear involvement in patients with FD. Also, a careful follow-up is essential to evaluate the degree of cochlear involvement, understand the fundamental pathophysiological mechanisms, and prevent SHL and the irreversible progression of hearing damage in patients who have already undergone ERT.ERT: enzyme replacement therapy; FD: Fabry disease; GLA: alpha-galactosidase A; SHL: sudden hearing loss; SNHL: sensorineural hearing loss.Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of the journal.The authors declare that they have no competing interests.MG established the pharmacological and therapeutic approaches to the metabolic disease and reviewed the manuscript. ER assessed the overall condition of the patient and contributed the pediatric part of the manuscript. ES was involved in the follow-up of the patient and critically revised the manuscript. GF was involved in the therapeutic approach of the sudden hearing loss and provided a major review of the ear, nose, and throat part of the manuscript. SP performed the audiograms and the otological follow-up and contributed to the writing of the manuscript. CP performed the literature search and wrote the manuscript. All authors read and approved the final manuscript.


Background. Functioning of nonlinear hearing aids varies with characteristics of input stimuli. In the past decade, aided speech evoked cortical auditory evoked potentials (CAEPs) have been proposed for validation of hearing aid fittings. However, unlike in running speech, phonemes presented as stimuli during CAEP testing are preceded by silent intervals of over one second. Hence, the present study aimed to compare if hearing aids process phonemes similarly in running speech and in CAEP testing contexts. Method. A sample of ten hearing aids was used. Overall phoneme level and phoneme onset level of eight phonemes in both contexts were compared at three input levels representing conversational speech levels. Results. Differences of over 3 dB between the two contexts were noted in one-fourth of the observations measuring overall phoneme levels and in one-third of the observations measuring phoneme onset level. In a majority of these differences, output levels of phonemes were higher in the running speech context. These differences varied across hearing aids. Conclusion. Lower output levels in the isolation context may have implications for calibration and estimation of audibility based on CAEPs. The variability across hearing aids observed could make it challenging to predict differences on an individual basis. Hearing aid validation using aided speech evoked auditory evoked potentials is of research and clinical interest. Such measurements involve elicitation of an evoked potential using a speech stimulus that has been processed through a hearing aid. Hearing aids, being mostly nonlinear, may have implications for the nature of speech stimulus used as input. The present study focuses on the effect of nonlinear hearing aid processing on speech stimuli used for measurement of cortical auditory evoked potentials (CAEPs). Nonlinear hearing aids are sensitive to the characteristics of input stimuli. Factors such as input level, duration, crest factor (ratio of peak to root mean square (RMS) amplitude), modulation depth, and modulation frequency of the input signal may affect the gain applied by the hearing aid, in ways that would not occur with a linear system –4. TheseNonlinear hearing aids, being sensitive to features of the input signal, process speech or speech-like stimuli differently from nonspeech stimuli , 10, 15.Aided auditory evoked potentials are objective and electrophysiological  but historically have not used speech stimuli. Of these, one of the reasons CAEPs have been of interest in the validation of hearing aid fittings is because natural speech sounds can be used as stimuli , 23–27. Phonemes presented in isolation for CAEP protocols may differ in several important ways from phonemes presented within running speech. In CAEP protocols, the target phoneme is preceded by an ISI (a silence period) whereas the same phoneme in running speech is likely to be preceded by other phonemes. Since nonlinear hearing aids continuously and rapidly adjust band-specific gains based on the acoustic input, there is a possibility that the hearing aids may react differently to the same phoneme when presented during aided CAEP testing as compared to when they occur in running speech. With 1-2 seconds of ISI preceding every repetition of the stimulus, nonlinear hearing aids may demonstrate an overshoot at the onset of the stimulus consistent with compression circuitry . Also, hThe effects of CAEP protocols on the gain achieved while processing tone bursts have been reported elsewhere in this issue , 41. TheThe purpose of this study was to understand if hearing aids process CAEP phonemes presented in isolation differently to phonemes presented in running speech. The primary outcome measure of interest in this study was the output level of phonemes in both contexts. Findings from this study may provide some insights into the design of hearing aid validation protocols that employ aided CAEP measures, because large differences in hearing aid output arising due to stimulus context may influence interpretation of audibility based on aided CAEPs.Ten hearing aids sampled across various manufacturers were chosen. A list of the hearing aids used is provided in ∫/, /m/, /t/, and /g/) were identified within a recording of the Rainbow passage. The passage was spoken by a male talker and lasted 2 minutes and 14 seconds. Aided recordings of this passage were made for each hearing aid, and the level of each phoneme was measured from within the aided passage. For the isolated context, the same phonemes and phoneme boundaries were used, but were excised from the passage for use as individual stimuli. Boundaries of these phonemes were chosen such that any transitions preceding and following these phonemes due to coarticulation were excluded. The duration of each of the phonemes are as follows: /a/—87 ms, /i/—84 ms, /u/—124 ms, /s/—133 ms, /∫/—116 ms, /m/—64 ms, /t/—26 ms, and /g/—19 ms. The durations of these phonemes differed naturally and were not modified in order to allow direct comparisons between the two contexts. These specific phonemes were chosen as the first six of these phonemes are a part of the commonly used Ling 5 or 6 sounds test , P = 0.013), input level , and phoneme . Interactions between input level and context , phoneme and context , and input level and phoneme  were also significant. The three-way interaction between input level, context, and phoneme was not significant . Paired contrasts comparing overall phoneme levels between contexts at each input level showed significant differences at the 55 and 65 dB SPL input levels but not at the 75 dB SPL input level. At input levels of 55 and 65 dB SPL, the levels of phonemes were significantly higher when they appeared in running speech compared to when they occurred in isolation , input level , and phoneme . Interactions between input level and context , and phoneme and context  were significant. Interaction between input level and phoneme  and the three-way interaction between input level, context, and phoneme were not significant . Paired contrasts between phoneme onset levels of both contexts at each input level showed significant differences between contexts at 55 and 65 dB SPL but not at the 75 dB SPL input level. At input levels of 55 and 65 dB SPL, the onset levels of phonemes were significantly higher when they appeared in running speech compared to when they occurred in isolation  for measures of overall level of phoneme, and in fewer cases (66%) for measures of phoneme onset level. When differences existed, they typically manifested as the hearing aid producing a lower output for the phoneme in isolation than it did for the phoneme in running speech. Differences reduced with increases in input level and varied across phonemes and hearing aids. Similar trends were observed in overall phoneme level and phoneme onset level. Results from the present study are similar to the findings from other reports in this issue , 41. SpeThe decrease in differences in overall and onset level of phonemes between contexts with increase in input level could indicate an effect of output limiting. As the output levels of phonemes come close to the maximum power output of the hearing aids, they are subject to compression limiting , 5. CompAnalyses revealed that differences across contexts varied across phonemes. We did not perform a direct comparison across phonemes because the individual phonemes occur at different levels relative to, the overall RMS level of running speech. Compression, being a level-dependent nonlinear factor in the hearing aid, may therefore vary the gain applied for each of these phonemes, especially when they are presented in isolation. In addition, compression features such as compression ratio and time constants were likely different across different frequencies due to the slightly sloping configurations of audiograms chosen and the presence of multiple channels in our hearing aid sample. Since phonemes varied in their spectral composition and position of spectral peaks, they could have been subject to different compression features in different channels. One stimulus characteristic that could have been influential in determining overall phoneme output levels is the duration of phonemes. Tables CAEPs are level dependent , 52, 53.Since the experimental conditions used in this study were limited to one duration of ISI and one naturally occurring preceding context per phoneme, generalization to other instances and variation across durations or levels of phonemes may require further investigation. Investigation of the effects of hearing aid signal processing on spectral characteristics such as formant transitions may also be possible, but these effects were not evaluated in this study. The effects of other aspects of hearing aid signal processing, such as digital noise reduction, may also be relevant and were not explored in this study. Based on this study, we conclude that significant differences in hearing aid functioning between running speech and isolated phoneme contexts occur, along with considerable interhearing aid variability. In over a fourth of aided phonemes, the magnitude of these differences was large enough to impact calibration, or interpretation of group data. This may indicate the need to perform acoustic calibration for individual hearing aids for the purpose of well-defined CAEP stimuli. In 7%–13% of phonemes, the differences exceeded that of an audiometric step size and therefore may be clinically important.


AbstractGastropoda were most species rich 50 species followed by Bivalvia (37), Aplacophora (5), Scaphopoda (3) and one from each of Polyplacophora and Monoplacophora.Information regarding the molluscs in this dataset is based on the epibenthic sledge (EBS) samples collected during the cruise BIOPEARL II / JR179 RRS James Clark Ross in the austral summer 2008. A total of 35 epibenthic sledge deployments have been performed at five locations in the Amundsen Sea at Pine Island Bay (PIB) and the Amundsen Sea Embayment (ASE) at depths ranging from 476 to 3501m. This presents a unique and important collection for the Antarctic benthic biodiversity assessment as the Amundsen Sea remains one of the least known regions in Antarctica. Indeed the work presented in this dataset is based on the first benthic samples collected with an EBS in the Amundsen Sea. However we assume that the data represented are an underestimation of the real fauna present in the Amundsen Sea. In total 9261 specimens belonging to 6 classes 55 families and 97 morphospecies were collected. The species richness per station varied between 6 and 43.  Project title: BIOPEARL II-JR 179 RRS James Clark Ross 2008Personnel: Camille Moreau, Katrin Linse, Huw Griffiths, Peter Enderlein and David BarnesFunding: This study is part of the British Antarctic Survey Polar Science for Planet Earth Programme funded by the Natural Environment Research Council.Study extent description: The study area of this dataset was set in the eastern Amundsen Sea and focused on the continental shelf, upper slope and over-deepened shelf basins of the Amundsen Sea Embayment (ASE) and Pine Island Bay (PIB). This dataset presents species occurrences and species richness of the individual epibenthic sledge (EBS) deployments. PIB appears to be the third largest drainage outlet of the West Antarctic Ice Sheet . BIOPEARL , a core project at the British Antarctic Survey, studied the southern Bellingshausen and eastern Amundsen seas to assess the biodiversity at local and regional scales (comparable to the BIOPEARL 2006 cruise to the Scotia Sea) and investigate the phylogenetic relationships of selected marine invertebrate taxa and their biogeography in reference to the climatological, oceanographical and geological history of the Bellingshausen/Amundsen Seas. The results are used to determine of the role of Antarctica and extreme environments in general in evolutionary innovation and generation of global biodiversity. The species presence data are added to SOMBASE (Southern Ocean Mollusc Database www.antarctica.ac.uk/sombase). SOMBASE generated initial core data system upon which SCAR’s Marine Biodiversity Information Network (SCAR-MarBIN) was built. As SCAR-MarBIN is the Antarctic Node of the international OBIS network, the SOMBASE data system was designed to comply with the Darwin Core standards. Regarding the dataset, the existing Data Toolkit from SCAR-MarBIN was used (http://www.scarmarbin.be/documents/SM-FATv1.zip), following PageBreakthe OBIS schema (http://iobis.org/data/schema-and-metadata). The dataset was uploaded in the ANTOBIS database , and the taxonomy was matched against the Register of Antarctic Marine Species, using the Taxon Match tool (http://www.scarmarbin.be/rams.php?p=match). The dataset meets the Darwin Core requirements and was designed around this data schema.Sampling description: Five locations in the Pine Island Bay (PIB) and Amundsen Sea Embayment (ASE) at different depths ranging from 476 to 3501m have been sampled using an epibenthic sledge (EBS). Most deployments were made along depth transects from shallow to overdeepened continental shelf and to deeper slope (https://www.bodc.ac.uk/data/information_and_inventories/cruise_inventory/report/8277/).er slope  and 2. AThis dataset presents 34 EBS deployments: 21 of which were performed at a depth of 500m at four different sites  , six at a 1000m depth in three areas , five at a depth of 1500m at three different sites , and two replicates at site BIO8-3500 in 3500m depth. For three of the five locations, sites were positioned along vertical transects sampling at 500m, 1000m and 1500m with repeat deployments of the EBS. The sites BIO4-1, BIO4-2 and BIO4-3 and BIO6-1, BIO6-2 and BIO6-3 were situated in the same local area; while the sites BIO5-1, BIO5-2 and BIO5-3 were dispersed over a wider area because of ice cover. The EBS consist of on an epi-(below) and a supra-(above) net. Each of these nets has a mesh size of 500μm and an opening of 100x33cm. The cod end of both nets is equipped with net-buckets containing a 300μm mesh window . The EBSQuality control description: A species name was given to each specimen when it was possible. Individuals not corresponding to described species have been included in the analyses with the family or genus name and a letter or numerical code (e.g. Turbinidae gen. sp.), however they represent a single morphospecies.For these specimens, further morphological and genetic analyses are necessary to give them a species name but they can be included in this dataset as different species. Finally, specimens too badly damaged for species identification have not been taken in account here.This dataset presents species occurrences and species richness of the individual EBS deployments.PageBreakPageBreakGeneral taxonomic coverage description: The present dataset focus on six molluscs classes . It includes respectively for each class:Class:AplacophoraSpecies:Aplacophora sp. 1, Aplacophora sp. 2, Aplacophora sp. 3, Aplacophora sp. 4, Aplacophora sp. 5Class:PolyplacophoraFamily:LeptochitonidaeGenus:LeptochitonSpecies:Leptochiton sp.Class:MonoplacophoraFamily:MicropilinidaeGenus:MicropilinaSpecies:Micropilina sp.Class:GastropodaFamily:Scissurellidae, Ataphridae, Mangeliidae, Capulidae, Calliotropidae, Seguenzioidea, Turbinidae, Turridae, Eulimidae, Limacinidae, Eatoniellidae, Cancellarioidea, Naticidae, Rissoidae, Diaphinidae, Fissurellidae, Raphitomidae, Cylichnidae, Lepetidae, Orbitestellidae, Buccinidae, Mathildidae, Newtoniellidae, Marginellidae, CavoloniidaeGenus:Anatoma, Trochaclis, Lorabela, Belalora, Torellia, Capulus, Calliotropis, Brookula, Brookula, Lissotesta, Liotella, Cirsonella, Balcis, Onoba, Hemiaclis, Limacina, Eatoniella, Cancellaridae gen., Falsilunatia, Pseudomauropsis, Sinuber, Powellisetia, Rissoid, Toledonia, Fissurellidae gen., Cornisepta, Zeidora, Pleurotomella, Cylichna, Iothia, Microdiscula, Pareuthria, Turritellopsis, Cerithiella, Eumetula, Marginella, ClioSpecies:Anatoma euglypta, Trochaclis antarctica, Lorabela pelseneeri, Belalora cf striatula, Torellia insignis, Capulus sp., Calliotropis pelseneeri, Brookula cf charleenae, Brookula sp. b, Lissotesta sp., Liotella sp., Liotella cf endeavourensis, Cirsonellaextrema, Turbinid sp. Turrid sp. 1, Turrid sp. 2, Balcis sp. Onoba cf gelida, Hemiaclis incolorata, Limacina helicina, Eatoniella cf kerguelenensis regularis, Cancellarid sp. Falsilunatia sp. Pseudomauropsis anderssoni, Sinuber microstriatum, Powellisetia cf deserta, Rissoid sp. Toledonia sp. 1, Toledonia sp. 2, Toledonia cf elata, Fissurellidae gen. sp. 1, Fisserulidae gen. sp. 2, Cornisepta antarctica, Zeidora antarctica, Pleurotomella cf simillima, Cylichna sp. Iothia sp. Microdiscula sp. Pareuthria cf innocens, Turritellopsis gratissima, Cerithiella cf lineata, Cerithiella cf erecta, Eumetula cf strebeli, Marginella ealesae, Clio antarcticaPageBreakClass:BivalviaFamily:Nuculanidae, Nuculidae, Yoldiidae, Limopsidae, Philobryidae, Mytilidae, Limidae, Pectinidae, Propeamussiidae, Thyasiridae, Motacutidae, Lasaeidae, Cyamiidae, Carditidae, Thraciidae, Cuspidariidae, Lyonsiidae, Poromyidae, Neoleptonidae, Siliculidae, Arcidae, Vesicomyidae, Tindariidae, BathyspinulidaeGenus:Propeleda, Ennucula, Yoldiella, Limopsis, Philobrya, Adacnarca, Dacrydium, Limatula, Adamussium, Hyalopecten, Cyclochlamys, Thyasira, Mysella, Waldo, Cyamiocardium, Cyclocardia, Thracia, Cuspidaria, Myonera, Lyonsia, Poromya, Neolepton, Silicula, Bathyarca, Vesicomya, Tindaria, BathyspinulaSpecies:Propeleda longicaudata, Ennucula sp. Yoldiella ecaudata, Yoldiella sabrina, Yoldiella valettei, Yoldiella cf profundorum, Yoldiella oblonga, Yoldiella sp. Limopsis longipilosa, Limopsis knudseni, Philobrya sublaevis, Philobrya quadrata, Adacnarca nitens, Dacrydium albidum, Limatula Limatula sp. Limatula Antarctolima sp. Adamussium colbecki, Hyalopecten pudicus, Cyclochlamys pteriola, Cyclochlamys gaussiana, Thyasira sp. Mysella antarctica, Waldo sp. Cyamiocardium denticulatum, Cyclocardia astartoides, Thracia meridionalis, Cuspidaria infelix, Cuspidaria minima, Myonera fragilissima, Lyonsia arcaeformis, Poromya antarctica, Neolepton sp. Silicula rouchi, Bathyarca sinuata, Vesicomya sirenkoi, Tindaria sp. Bathyspinula sp.Class:ScaphopodaFamily:Dentaliidae, Pulsellidae, GadilidaeGenus:Dentalium, Striopulsellum, CadulusSpecies:Dentalium majorinum, Striopulsellum minimum, Cadulus thieleiGeneral spatial coverage: Amundsen Sea, AntarcticaCoordinates: 74°29'24"S and 70°1'12"S; 110°5'24"W and 104°20'24"WTemporal coverage: February 18, 2008–April 11, 2008Natural collections descriptionParent collection identifier: British Antarctic SurveyCollection name: BIOPEARL II EBS MolluscsCollection identifier: Moreau/LinseSpecimen preservation method: Ethanol/Formaldehyde- Epibenthic sledge sampling in the Amundsen SeaPageBreak- Once on the deck, the content of the samplers from the first deployment was immediately fixed in 96% undenaturated and pre-cooled (at -20°C) ethanol ( ethanol  and kept- The taxonomic identification was performed in the British Antarctic Survey laboratory using a stereomicroscope.Object name: Darwin Core Archive amundsen_sea_molluscsCharacter encoding: UTF-8Format name: Darwin Core Archive formatFormat version: 1.0Distribution: http://ipt.biodiversity.aq/archive.do?r=amundsenseamolluscs_biopearl_iiPublication date of data: 2013-01-09Language: EnglishMetadata language: EnglishDate of metadata creation: 2013-01-09Hierarchy level: Dataset