Reinforced alternation performance is impaired by muscarinic but not by nicotinic receptor blockade in rats.

In pre-trained rats, food-rewarded reinforced alternation in a T-maze was markedly impaired by scopolamine, but unaffected by the centrally-active nicotinic antagonist mecamylamine (0.2-6.3 mg/kg s.c.). The nicotinic antagonist chlorisondamine (10 micrograms i.v.t.) was also ineffective, despite demonstrated blockade of nicotine-induced locomotor depression. These results question the extent to which central nicotinic receptors are involved in memory function.