Lidocaine inactivation of ventral subiculum attenuates cocaine-seeking behavior in rats.
The role of the ventral subiculum in cocaine- or cue-induced cocaine-seeking behavior was investigated in rats tested on a between-session reinstatement model. Rats were trained to self-administer cocaine (0.25 mg/infusion, i.v.) in a lever-pressing operant task in a daily 2 hr session. Responding was reinforced contingent on a modified fixed-ratio 5 schedule. Reinstatement tests began after the lever-pressing behavior was extinguished in the absence of cocaine and conditioned cues (light and tone). Bilateral microinjections of lidocaine (100 microg) into the ventral subiculum decreased cocaine- or cue-induced reinstatement of cocaine-seeking behavior compared with saline microinjections into the same area in another group of rats. Lidocaine microinjections, however, had no effect on cocaine self-administration behavior or food-maintained or food-reinstated responding. Collectively, these results suggest that the ventral subiculum plays an important role in cocaine-seeking behavior. Considering the role of this structure in context learning, our data suggest that the full expression of cocaine- or cue-induced reinstatement may depend on the context in which the cocaine experience occurred.
Sun
WenLin
W
Program in Neural Science, Department of Psychology, Indiana University, Bloomington, Indiana 47405, USA.
Rebec
George V
GV
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D003042:Cocaine / Q000494:pharmacology*; D019970:Cocaine-Related Disorders / Q000188:drug therapy* / Q000503:physiopathology; D003216:Conditioning, Operant / Q000187:drug effects; D003463:Cues; D004336:Drug Antagonism; D005108:Extinction, Psychological / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects* / Q000503:physiopathology; D008012:Lidocaine / Q000494:pharmacology*; D008297:Male; D008845:Microinjections; D051381:Rats; D017207:Rats, Sprague-Dawley; D012054:Reinforcement, Psychology; D012646:Self Administration
D000779:Anesthetics, Local; D008012:Lidocaine; D003042:Cocaine