INFLUENCE OF AMBIENT-TEMPERATURE ON CONTENT AND COMPOSITION OF BRAIN GANGLIOSIDES IN VERTEBRATES

The concentration and composition of brain gangliosides have been comparatively investigated by means of one- and two-dimensional high performance thin layer chromatography in several European fish species exhibiting a pronounced capacity for thermal adaptation. The values were compared with those of tropical and Antarctic fish as well as with homeo- and heterothermic mammals. The relative proportion of higher sialytated (more polar) ganglioside fractions was elevated in brains of fish (a) whose habitat was naturally cold or (b) that had been experimentally or seasonally adapted to a cold versus a warm habitat. Furthermore, in adaptation to the cold, more alkali-labile brain ganglioside fractions were found with the following sequence: Antarctic fish (53-67%), cold acclimated fish (45-51%), warm acclimated fish (38-44%), tropical species (<35%), hamsters in torpor (9%), active hamsters (4%) and pig (3%). These results indicate a possible mechanism at a molecular level to keep the neuronal membrane functional, even under changing temperature conditions.