Dopamine-β-hydroxylase activity in the locus coeruleus and hypothalamus in cold-stressed rats
Abstract Dopamine-β-hydroxylase (DBH) activity was determined in the locus coeruleus, anterior hypothalamus and posterior hypothalamus of cold-stressed rats. In the acute cold stress, rats were exposed to an ambient temperature of 5°C in a cold room for 5–20 min. In the chronic cold stress, rats were exposed to the same cold temperature for 4 hr once every day in the morning for periods ranging from 1 to 3 weeks. There was decreased DBH activity in the locus coeruleus following acute cold stress and increased activity in both the locus coeruleus and the anterior hypothalamus following the chronically repeated cold stress.
Harmful Algal Blooms (HABs) events were analyzed in this study at four monitoring stations in the Gulf of Nicoya between January 2008 and December 2010. Water samples were collected at 1 and 5 m deep during each HAB event. Furthermore, the following physicochemical parameters were measured in situ: Secchi disk depth, temperature, salinity, dissolved oxygen, and saturation percentage of oxygen in water. Radiation and precipitation data was provided by the National Meteorological Institute of Costa Rica. The concentration of dominant microalgae and associated species was determined. A total of 11 events were recorded, 72.7% during rainy season and 27.3% during dry season, most of them during the La Nina atmospheric phenomenon. Dominant species included the following dinoflagellates; Alexandrium monilatum, Levanderina 1