In this important paper, Murphy and Glanzman provided the first firm demonstration of LTP in a synapse known to control an important behavior, the siphon withdrawal reflex of the sea slug Aplysia.
Mediation of classical conditioning in Aplysia californica by long-term potentiation of sensorimotor synapses.
Murphy GG, Glanzman DL.
Interdepartmental Graduate Program in Neuroscience, School of Medicine, University of California, Los Angeles, CA 90095, USA.
Long-term potentiation (LTP) is considered an important neuronal mechanism of learning and memory. Currently, however, there is no direct experimental link between LTP of an identified synapse and learning. A cellular analog of classical conditioning in Aplysia was used to determine whether this form of invertebrate learning involves N-methyl-D-aspartate (NMDA)-type LTP. The NMDA receptor-antagonist dl-2-amino-5-phosphonovalerate significantly disrupted synaptic enhancement after associative training but did not disrupt synaptic enhancement after nonassociative training. Thus, classical conditioning in Aplysia appears to be mediated, in part, by LTP due to activation of NMDA-related receptors.