CHOLINERGIC DEAFFERENTATION ENHANCES RAT HIPPOCAMPAL PYRAMIDAL NEURONRESPONSIVENESS TO LOCALLY APPLIED NICOTINE

We tested whether cholinegic denervation of the hippocampus of young r ats would result in an enhancement of CA1 pyramidal cell responsivenes s to nicotine. Electrolytic lesions of the medial septal area were per formed in young male Fisher 344 rats. One month later the rats were an esthetized with pentobarbital and nicotine was locally applied to CA1 pyramidal neurons using pressure microejection. The dose of nicotine r equired to excite the pyramidal neurons was significantly lower for ce lls recorded from rats with septal lesions. However, no changes in hip pocampal cytisine or alpha-bungarotoxin binding were found.