Influence of bupropion and calcium channel antagonists on the nicotine-induced memory-related response of mice in the elevated plus maze in mice

Abstract

In this study, we investigated the effects of acute administration of nicotine on memory-related behavior in mice using the elevated plus maze test. In this test, the time necessary for mice to move from the open arm to the enclosed arm (i.e., transfer latency) was used as an index of memory. Our results revealed that nicotine (0.035 and 0.175mg/kg, base, sc) shortened the transfer latency relative to the saline-treated group. Moreover, we investigated the effects of bupropion (10, 20 and 40mg/kg, ip) and L-type voltage-dependent calcium channel antagonists (nimodipine, flunarizine, verapamil, diltiazem – 5, 10 and 20mg/kg, ip) on memory-related behavior. At all tested doses, bupropion, did not significantly affect transfer latency. However, flunarizine and verapamil (both at 10mg/kg) resulted in a slight decrease in transfer latency, whereas nimodipine (10mg/kg) increased transfer latency. Interestingly, both bupropion (20mg/kg) and calcium channel blockers (5mg/kg) attenuated the improvement of memory induced by nicotine.Our findings indicate that the cholinergic nicotinic system may play an important role in memory consolidation, and that neural calcium-dependent mechanisms can be involved in the modulation of memory-related responses induced by nicotine. The results of these studies have revealed neuronal mechanisms that are important for nicotinic modulation of cognition and will be useful for the treatments of human disorders in which cholinergic pathways have been implicated, such as psychiatric disorders and addiction.