The functional properties of biological membranes are primarily governed by the physico-chemical characteristics of the individual constituents. Basic parameters like pressure, gravity and particularly temperature strongly influence the reactivity of the various compounds. - Concerning temperature, cold-blooded vertebrates (fishes, amphibians, reptiles) had to develop specific strategies during evolution to survive dramatic changes in their environment. But also warm-blooded species (birds, mammals) developed compensatory mechanisms throughout individual development or during adaptation phases (like hibernation) versus seasonal temperature fluctuations.
The synaptic terminals within the nervous system were found to be the most thermo-sensitive structures of the whole organism. They show significant functional changes in adaptation to alterations in the environmental temperature. On this background, charged sialo-glycosphingolipids (= gangliosides) being highly concentrated particularly in the synaptic terminals, according to quite unusual physico-chemical properties became favourite candidates to play the essential role in the process of thermal adaptation of neuronal activities (transmission and storage of information; (1)).
The biochemical data presented reveal that the brain ganglioside composition of cold-blooded vertebrates living in different climates and of mammals during their early development or seasonal changes adapts according to the rule: "The lower the environmental temperature the more polar is the composition (polarity) of brain gangliosides" (2).
These in vivo-results can be corralated with additional physico-chemical data obtained with artificial mono- and bilayer model systems demonstrating a peculiar thermosensitivity of the surface behaviour of neuronal gangliosides with the consequence to maintain homeoviscosity in areas surrounding functional membraneous proteins (ion channels, receptors etc.) independent from the environmental temperature.