Differential effects of ibotenic acid lesions of the hippocampus and blockade of N-methyl-D-aspartate receptor-dependent long-term potentiation on contextual processing in rats.
Behav Neurosci 1997 Dec;111(6):1171-83 Unique Identifier : AIDSLINE 98099625 Good M; Bannerman D; Centre for Neuroscience, University of Edinburgh, Scotland.
Abstract:
The contextual specificity of appetitive conditioned responding was examined in rats undergoing chronic intracerebroventricular infusion of 15 or 30 mM D-2-amino-5-phosphonopentanoic acid (D-AP5) or with excitotoxic hippocampal lesions. The magnitude of conditioned responding by control rats and rats infused with D-AP5 to a conditioned stimulus (CS) trained in Context A was attenuated when the same stimulus was presented in Context B. By contrast, hippocampal-lesioned rats displayed comparable levels of responding to the CS when presented in either Context A or B. Subsequent in vivo electrophysiological investigations showed that the D-AP5 concentrations were effective in blocking long-term potentiation (LTP) in the dentate gyrus. Results indicate that rats are capable of processing contextual information in the absence of N-methyl-D-aspartate (NMDA) receptor-dependent LTP and demonstrate an important dissociation between the effects of hippocampal lesions and the blockade of NMDA receptors in the hippocampus.
Keywords: JOURNAL ARTICLE Animal Appetitive Behavior/drug effects/physiology Conditioning (Psychology)/*drug effects/physiology Cues Discrimination Learning/*drug effects/physiology Excitatory Amino Acid Agonists Excitatory Amino Acid Antagonists/*pharmacology Excitatory Postsynaptic Potentials Hippocampus/*drug effects/pathology/physiopathology Ibotenic Acid Infusion Pumps, Implantable Long-Term Potentiation/*drug effects/physiology Male Memory/drug effects/physiology Rats Rats, Inbred Strains Receptors, N-Methyl-D-Aspartate/*drug effects/physiology Stereotaxic Techniques Support, Non-U.S. Gov't 2-Amino-5-phosphonovalerate/*pharmacology
SOURCE: National Library of Medicine. NOTICE: This material may be protected by Copyright Law (Title 17, U.S.Code).
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