In brain gangliosides and phospholipids of stenothermal cold-water teleost fishes, higher content of polyenoic and monoenoic fatty acids was revealed than in brain gangliosides and phospholipids of warm-water stenothermal teleosts. The changes in fatty acid composition of lipids during adaptation of fishes to living in cold water (or at great water depth) are directed to the maintenance of liquid-crystalline state of cell membranes and their optimal fluidity, physical state, and microheterogeneity. The results of cluster analysis of the data on composition of carbohydrate component of brain gangliosides of various ectothermic vertebrates were used to create the dendrogram. This dendrogram was found to correspond appreciably to the tree of classical taxonomy of vertebrates. The changes in molecular organization of brain gangliosides in the course of evolution of vertebrates are suggested to contribute to differentiation of brain and complication of its functions in phylogenesis. The main brain gangliosides (GM1, GD1a, GD1b, GT1b) may be considered to be typical adaptogens. They protect neurons against the action of excitatory amino acids, hydrogen peroxide, amyloid β-peptide, and other toxins. Protective effect of gangliosides against these toxins depends on activation of Trk receptor tyrosine kinase and downstream protein kinases.
Part of the book: Evolutionary Physiology and Biochemistry