title: The effects of neurotoxic hippocampal lesions on two effects of context after fear extinction.
abstract: Three conditioned suppression experiments with rats examined the role of the hippocampus in 2 effects of context after extinction. Reinstatement is the context-specific recovery of fear to an extinguished conditioned stimulus (CS) that occurs following independent presentations of the unconditioned stimulus (US), after extinction. Renewal is the recovery of fear when the CS is presented in the context in which it was conditioned, after extinction in a different context. Results indicated that neurotoxic lesions of the hippocampus, performed before conditioning, abolished reinstatement, which depends on context-US associations, but not renewal, which does not. This dissociation is not the result of differences in the recentness of context learning that ordinarily governs the 2 effects. The results suggest that the hippocampus is necessary for some, but not all, types of contextual learning.
authors.affiliation: Department of Psychology, University of Vermont, Burlington 05405, USA. rfrohard@zoo.uvm.edu
authors.forename: R J
authors.initials: RJ
authors.lastname: Frohardt
authors.forename: F A
authors.initials: FA
authors.lastname: Guarraci
authors.forename: M E
authors.initials: ME
authors.lastname: Bouton
mesh_terms: D000818:Animals; D001245:Association Learning / Q000502:physiology*; D001931:Brain Mapping; D003214:Conditioning, Classical / Q000502:physiology*; D005108:Extinction, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007051:Ibotenic Acid / Q000633:toxicity; D007267:Injections; D011939:Mental Recall / Q000502:physiology*; D016202:N-Methylaspartate / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar
chemical_list: D007051:Ibotenic Acid; D016202:N-Methylaspartate