Impaired passive avoidance learning in mice lacking central neuronal nicotinic acetylcholine receptors

The nicotinic cholinergic system influences cognition, anxiety, locomotion, and addiction by acting upon nicotinic acetylcholine receptors (nAChRs). To date, there are 12 known neuronal mammalian nAChR subunits leading to a rich pharmacological diversity that is difficult to attribute to specific subunits. We generated alpha7-beta2 nAChR double mutant mice by breeding to investigate the effect of a minimal number of nAChRs in the CNS. These mice have been used to determine the role these receptor subunits play in a variety of behaviors. A battery of behavioral tests was used to determine the effect of the mutation in anxiety, locomotor activity, startle response, pre-pulse inhibition, motor coordination and learning and memory. Mice lacking both the alpha7 and the beta2 nAChR subunits displayed impaired learning and memory performance in a passive avoidance test and showed enhanced motor performance on the rotarod.