Non-synaptic neuronal mechanisms of learning and memory in gastropod molluscs.

Gastropod molluscs provide important model systems for investigating the behavioral and neural basis of associative and non-associative learning. Habituation, sensitization, classical and operant conditioning are studied in motor reflex and central pattern generator circuits. Although synaptic plasticity has long been recognized as playing a key role in molluscan learning circuits, non-synaptic changes resulting in alterations in the excitability of neurons are increasingly recognized as an essential component of the memory trace.