Alteration of Ganglioside at the Synapse of Central Nervous System through Nutritional Behavior

Abstract

Gangriosides compromise a family of acidic glycolipids that are characterized by the presence of sialic acid on the terminal carbohydrate portion. The localization of gangliosides is very high in a synapse membrane, amounting to 10% of total lipids in a nerve cell. In the neurotransmission system gangliosides may act together with neuroreceptor and interact with a neurotransmitter. It have been observed that a conformational change of gangliosides through acute or chronic administration of ethanol result in the degeneration of neurotransmission function. In this study, the effects of ascorbic acid deficiency, zinc deficiency and injection of ibotenic acid into olfactory bulb on the behavior of gangriosides at synapse in hippocampus were determined by HPLC and or in vivo micro dialysis technique with radioactive tracer. In the rat fed the ascorbic acid deficient diet for 3 weeks, the sialic acid originated from ganglioside (GSA) was decreased in hippocampus but no significant difference was observed in other parts of brain. In the rat fed the zinc deficient diet for 6 weeks, the sialic acid originated from sialoglycoconjugats (TSA) was decreased in hippocampus and striatum but no changes were observed for GSA. The amount of GSA in rat hippocampus under the effect of ibotenic acid injected (20 nmol) into olfactory bulb was increased on 4-day and recovered on 7-day. The sialic acid released from sialoconjugate on the synapse membrane of hippocampus by neuraminidase (30 mUmit) in vivo was 1.8 times more than that of control on 4-day.

It was clarified that the deficiency of trace nutrients effects on the amounts of gangriosides in central nerve system and on the function of neurotransmission.