Long-term synaptic changes produced by a cellular analog of classical conditioning in Aplysia.
A change in synaptic strength arising from the activation of two neuronal pathways at approximately the same time is a form of associative plasticity and may underlie classical or Pavlovian conditioning. A cellular analog of a classical conditioning protocol produces short-term associative plasticity at the connections between sensory and motor neurons in Aplysia. A similar training protocol produced long-term (24-hour) enhancement of excitatory postsynaptic potentials (EPSPs). EPSPs produced by sensory neurons in which activity was paired with a reinforcing stimulus were significantly larger than unpaired controls 24 hours after training. Thus, associative plasticity at the sensory to motor neuron connection can occur in a long-term form in addition to the short-term form. In this system, it should be possible to analyze the molecular mechanisms underlying long-term associative plasticity and classical conditioning.
Buonomano
D V
DV
Department of Neurobiology and Anatomy, University of Texas Medical School, Houston 77225.
Byrne
J H
JH
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001048:Aplysia / Q000502:physiology*; D002118:Calcium / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology; D004558:Electric Stimulation; D005786:Gene Expression Regulation; D009046:Motor Neurons / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology; D013569:Synapses / Q000502:physiology*
D000242:Cyclic AMP; D002118:Calcium