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

The concentration and composition of brain gangliosides have been comp aratively investigated by means of one- and two-dimensional high perfo rmance thin layer chromatography in several European fish species exhi biting a pronounced capacity for thermal adaptation. The values were c ompared with those of tropical and Antarctic fish as well as with home o- and heterothermic mammals. The relative proportion of higher sialyt ated (more polar) ganglioside fractions was elevated in brains of fish (a) whose habitat was naturally cold or (b) that had been experimenta lly or seasonally adapted to a cold versus a warm habitat. Furthermore , in adaptation to the cold, more alkali-labile brain ganglioside frac tions were found with the following sequence: Antarctic fish (53-67%), cold acclimated fish (45-51%), warm acclimated fish (38-44%), tropica l species (<35%), hamsters in torpor (9%), active hamsters (4%) and pi g (3%). These results indicate a possible mechanism at a molecular lev el to keep the neuronal membrane functional, even under changing tempe rature conditions.