Varenicline ameliorates ethanol-induced deficits in learning in C57BL/6 mice

Ethanol is a frequently abused drug that impairs cognitive processes such as learning. Varenicline, an α4β2 nicotinic receptor partial agonist and α7 nicotinic receptor full agonist prescribed for smoking cessation, has been shown to decrease ethanol consumption. The current study investigated whether varenicline could ameliorate ethanol-induced deficits in learning and whether varenicline alters blood alcohol concentration in C57BL/6 mice. Conditioning consisted of two auditory conditioned stimulus (CS; 30 s, 85 dB white noise)-foot shock unconditioned stimulus (US; 2 s, 0.57 mA) pairings. For all studies, saline or ethanol (1.0, 1.5, 2.0 g/kg i.p.) was administered 15 min before training, and saline or varenicline (0.05, 0.1, 0.2 mg/kg i.p.) was administered 60 min before either training or testing. For blood alcohol analysis, saline or varenicline (0.1 mg/kg) was administered 60 min before collection, and saline or ethanol (1.0, 1.5, 2.0 g/kg) was administered 15 min before collection. Varenicline dose-dependently ameliorated ethanol-induced conditioning deficits for all three doses of ethanol when administered before training but not when administered 24 h later, before testing. In addition, varenicline did not alter blood alcohol concentration. The smoking cessation aid varenicline may have therapeutic uses for treating ethanol-associated disruptions in cognitive processes.