STUDIES ON BRAIN GANGLIOSIDES: III. EVIDENCE FOR THE LOCATION OF GANGLIOSIDES SPECIFICALLY IN NEURONES

Abstract

The ganglioside content of different regions of the nervous system has been determined by measuring the amount of glycolipid N-acetylneuraminic acid extracted with chloroform-methanol (2:1 v/v). The results indicate that gangliosides are restricted to regions of brain containing neurones. The values are high in cerebral cortex, cerebellum, caudate nucleus, and thalamus, while they are low in centrum semiovale, corpus callosum, and optic tracts. Optic and sciatic nerves, pineal and adrenal glands, and sympathetic ganglia contain no glycolipid NANA. The ganglioside content of brain tissue is decreased in pathological conditions associated with a loss of neurones. The presence of gangliosides in all layers of the cerebral cortex and the demonstration of greater amounts in the superficial layers suggests that gangliosides may be concentrated in dendritic processes. An hypothesis is outlined proposing a role for gangliosides in the transport of potassium ions at inhibitory synapses.