Presents a hypothesis about the biochemical processes involved in memory storage. The postulated mechanism is initiated by a signal that is unusual but not unlikely to occur and produces an irreversible change in a key component of synaptic chemistry. Other features of the mechanism and experiments supporting the hypothesis are considered. (JN)

Describes how a behavioral system in Aplysia (marine snail) can be used to examine mechanisms of several forms of learning at different levels of analysis: behavioral, cell-physiological, ultrastructural, and molecular. Focusing on short-term sensitization, suggests how molecular mechanisms can be extended to explain long-term memory and classical…