Comparative analysis of fish aggregation in channel depressions of the Irtysh

We present the results of ichthyological studies in principal channel depressions of the Irtysh developing the notions on polyfunctional biological role of these formations. The study is made by means of a computerized hydroacoustic complex “Askor”. Quantitative estimation of the size composition, abundance, density, and spatial distribution of fish on water area of channel depressions in different seasons confirms the hypothesis of multifaceted biological significance of these formations. Universal traits in the organization of fish aggregations, specificity of distribution, composition, and seasonal dynamics of the fish population on the largest channel depressions of the Irtysh are revealed.     

Memory and depressions

A hypothesis of depression development is put forward. It is suggested that depression develops as a result of the disorders of the normal mechanisms of learning and memory. To assess the hypothesis, a functional system of behavioral control with the key role of memory apparatus and its links with other units of the system is proposed. According to the behavioral control system, memory is organized and works as the integration of activity of sensory, motivational and emotional inputs. It was shown that disorders of each of these inputs make specific contribution into the origin and manifestations of depression and corresponding morphological, electrophysiological, trophic, neurochemical, molecular-genetic and other changes.