Abstract
Neurochemical studies suggest that baclofen, an agonist at GABA(B) receptors, may be useful for treatment of nicotine dependence. However, its ability to selectively reduce nicotine's abuse-related behavioral effects remains in question. We assessed effects of baclofen doses ranging from 0.1 to 3mg/kg on nicotine-induced conditioned place preferences (CPPs), nicotine discrimination, locomotor activity and food-reinforced behavior in male Sprague-Dawley rats. The high dose of baclofen (3mg/kg) totally eliminated food-reinforced responding and significantly decreased locomotor activity. Lower doses of baclofen did not have nicotine-like discriminative effects in rats trained to discriminate 0.4mg/kg nicotine from saline under a fixed-ratio 10 schedule of food delivery. Lower doses of baclofen also did not reduce discriminative stimulus effects of the training dose of nicotine and did not significantly shift the dose-response curve for nicotine discrimination. Rats treated with the high 3mg/kg dose of baclofen did not express nicotine-induced CPP. These experiments, along with previous reports that baclofen can reduce intravenous nicotine self-administration behavior, confirm the potential utility of baclofen as a tool for smoking cessation.