| Abstract: | The effect of the benzodiazepine-receptor antagonist flumazenil on the facilitatory effect of (?)-nicotine on memory in septal-lesioned rats in a spatial task and in the inhibitory avoidance test in mice was investigated. In the two-platform spatial discrimination test, septallesioned rats exhibited a significant number of errors in comparison to sham animals, an effect that can be reversed by the administration of (?)-nicotine during the training phase. Flumazenil did not affect the performance of septal-lesioned rats but it blocked the facilitatory effect of (–)-nicotine on lesioned rats. In the inhibitory avoidance test in mice,(?)-nicotine as well as flumazenil facilitated retention of the test at 0.62 and 10 μmol/kg, respectively. However, a low-noneffective dose of flumazenil blocked the memory enhancing effect of (?)-nicotine. The blockade of the facilitatory effect of (?)-nicotine by flumazenil in normal and septal-lesioned animals suggests that the cognitive effect of (?)-nicotine requires the activation of benzodiazepine receptors. © 1994 Wiley-Liss, Inc. |
