NICOTINE INTERACTIONS WITH DOPAMINE AGONISTS - EFFECTS ON WORKING-MEMORY FUNCTION

Nicotine has been found to improve memory performance in a variety of tests including the radial-arm maze. Nicotine may have effects mediated by promoting the release of dopamine. The present study was conducted to determine the interactions of nicotine with D-1 and D-2 agonists. Rats were acutely administered nicotine, the D-1 agonist SKF 38393, and D-2/D-3 agonist quinpirole, and nicotine together with each of these agonists. Nicotine significantly improved choice accuracy in the radial-arm maze. The D-1 agonist SKF 38393 significantly impaired choice accuracy. Nicotine was effective in reversing this effect. The D-2/D-3 agonist quinpirole showed a trend toward potentiating the improvement in choice accuracy caused by 0.2 mg/kg (0.43 mu mol/kg) of nicotine. These data show that, as with the nicotinic antagonist mecamylamine, there are significant interactions of dopamine systems with nicotine effects. (C) 1994 Wiley-Liss, Inc.