The outer surface of intact synaptosomes was covalently labelled with trinitrobenzenesulfonic acid prior to isolation of the synaptic plasma membrane. Analysis of the membrane lipid demonstrated an asymmetric distribution of phospholipids across the synaptosomal plasma membrane. In addition, the fatty acyl composition of phosphatidylethanolamine from this neuronal membrane fraction was also distributed asymmetrically. The data are consistent with a de novo generation of phospholipid asymmetry independent of serum lipid exchange processes. This structural asymmetry may have important consequences for neurotransmission. 1979.
