Intra-hippocampal lidocaine injections impair acquisition of a place task and facilitate acquisition of a response task in rats.
While hippocampal lesions impair learning and memory in many tasks, such lesions also enhance learning and memory in other tasks. The present experiment examines the effects of inactivation of the hippocampus with lidocaine prior to learning, to find food in a place or response version of a four-arm plus-shaped maze. Rats received lidocaine injections 6 min prior to training. Rats were trained in a single session to a criterion of 9/10 correct responses. Compared to artificial cerebrospinal fluid (aCSF)-injected controls, rats with intra-hippocampal injections of lidocaine exhibited significantly retarded acquisition of place learning. In marked contrast, rats with intra-hippocampal injections of lidocaine exhibited significantly enhanced acquisition of response learning compared to their controls. In addition to showing that the hippocampus is important for learning the place task, these findings suggest that processing of information by the hippocampus interferes with learning a task dependent on a different neural system.
Chang
Qing
Q
Department of Psychology, University of Illinois at Urbana-Champaign, 603 East Daniel Street, Champaign, IL 61820, USA.
Gold
Paul E
PE
D000779:Anesthetics, Local / Q000494:pharmacology*; D000818:Animals; D003213:Conditioning, Psychological; D005508:Food Deprivation; D006624:Hippocampus / Q000187:drug effects*; D008012:Lidocaine / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012153:Retention, Psychology; D013028:Space Perception / Q000187:drug effects; D013037:Spatial Behavior / Q000187:drug effects
D000779:Anesthetics, Local; D008012:Lidocaine