Synaptic correlates of odor habituation in the rat anterior piriform cortex.
Responses of anterior piriform cortex layer II/III neurons to both odors and electrical stimulation of the lateral olfactory tract (LOT) were measured with intracellular recordings in urethan-anesthetized, freely breathing rats. Odor-evoked, respiration-entrained postsynaptic potentials (PSPs) rapidly habituated during a 50-s odor stimulus, then spontaneously recovered within 2 min of odor termination. Associated with the decrease in odor-evoked PSP amplitude was a decrease in the monosynaptic excitatory postsynaptic potentials (EPSPs) evoked by electrical stimulation of the LOT. The decrement in LOT-evoked EPSPs recovered with a time course similar to the odor response recovery. These results demonstrate that odor habituation is associated with a decrease in afferent synaptic efficacy in the anterior piriform cortex.
Wilson
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DA
Department of Zoology, University of Oklahoma, Norman, Oklahoma 73019, USA.
D000200:Action Potentials / Q000502:physiology; D000818:Animals; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology*; D008297:Male; D009475:Neurons, Afferent / Q000502:physiology; D009812:Odorants; D009833:Olfactory Pathways / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000502:physiology; D012903:Smell / Q000502:physiology*; D013569:Synapses / Q000502:physiology*