Specificity of molecular changes in neurons involved in memory storage.

Evidence implicating molecular steps in memory storage is discussed, particularly with reference to molecular specificity and uniqueness and the possible relevance of these steps to other types of long-lasting transformations such as those of development, regeneration, and tumorigenesis. The role of protein kinase C-mediated phosphorylation of identified protein subtrates, such as a 20,000-dalton GTP-binding protein, is described for associative memory of the snail Hermissenda, associative conditioning of the rabbit, and long-term potentiation. Cyclic AMP-mediated phosphorylation during sensitization of the snail Aplysia is also examined.