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…

Describes recent research findings in the area of neurobiology and its relationship to learning and memory. The article provides definitions of associative and nonassociative learning, identifies essential memory trace circuits of the mammalian brain, and discusses some neural mechanisms of learning. (TW)