Sulfhydryl proteins and the engram

A scheme, which is selectional not instructional, is described for the molecular basis of the engram. It uses as reactants intermediates formed during the catabolism of neuronal membrane sulfhydryl proteins. It is proposed that these compounds undergoing intermolecular association generate a large number of diverse structures, some of which are selected for further complex formation. The basis of selection is the binding of a particular compound to membrane lipid, which enhances its reaction with another bound compound. Because the composition and configuration of membrane lipids are influenced by environmental factors, the scheme implies that incoming sensory signals are matched with endogenously generated chemical structures.