Morphocytochemical characteristics of cerebellar neuronal populations in fishes with various ambulatory activities

Abstract

The cytoplasmic distribution of basophilic substance and the number of chromatin granules in nuclei of cerebellar neurons were studied. Neuronal proteins were assayed in the molecular, ganglionic, and granular cerebellar layers in fishes of various ecological and morphological groups. A quantitative analysis of Nissl bodies and chromatin granules revealed a polymorphism of neuronal populations. Protein concentrations per body volume of stellate and Purkinje cells in pelagic fishes were higher than in benthophages by 7.9% and 12.3%, respectively. However, the content of protein substances in granular cells of pelagic fishes was 8.9% lower than in those cells of benthophages. Tinctorial heterogeneity of cell populations and peculiarities of the distribution of protein substances in various neurons reflect specific feattres of structural and functional organization of the cerebellum in fishes with different ambulatory activities.Key Words: fish cerebellum; neuronal populations; chromophilia; proteins Ecological morphology of the brain, a new branch of evolutional neuromorphology, evaluates the role of exogenous factors, environment, and lifestyle in the formation of specific features of sense organs and related brain structures [ 1,11,13].The degree and diversity of ambulatory activity result in enlargement and more complex organization of the central nervous system [7,14]. The cerebellum playing an essential role in the development of the coordination system is responsible for adequate adaptation to environmental conditions. However, histo-and neurochemical peculiarities of cerebellum of aquatic vertebrates (especially lower animals) received little attention. Only the brain stem, cortex, and subcortical ganglia of mammalian brain were studied in this aspect [5,9].A comparison of morphocytochemical peculiarities of cerebellar neuronal populations in fishes of