Glycolipids are localized on the outer surface of cell membranes, providing recognition sites for various ligands. Glycolipid contents vary according to cell types, and different sugar chain spectra are developed among different cell types. The specific sugar chains are one of phenotypes of differentiated cells, and at the same time they should play some physiological roles. In the first section of this article, possible roles of glycolipids are discussed in relation to membrane functions, such as membrane surface functions, roles in ontogeny and organogenesis, receptor functions, cell growth regulation, and regulation of membrane-bound enzymes. Description about gangliosides is placed in the second section in special relation to neural functions.
Since gangliosides are specifically distributed among each membrane and are supposed to play different roles, myelin and synaptic plasma membrane which are two representative membrane systems in the central nervous system are dealt for discussion. Finally, a new trend in the ganglioside researches is briefly mentioned, suggesting possible participation of gangliosides in neuronal membrane plasticity.
