Introduction: Tobacco addiction has a strong social component. Therefore, nicotinic acetylcholine receptors (nAChR) may influence social behavior. Because the β4 nicotinic receptor subunit is important for possibly related behaviors, such as anxiety-like behavior and the effects of nicotine, we studied the social behavior of mice null for the β4 nAChR subunit.
Methods: To measure social behavior, we used the intruder test for social memory in wild-type and littermate β4 null mice. In addition, we used a nonsocial olfactory memory test as a control.
Results: In the intruder test, β4 null mice showed social amnesia: Wild-type mice spent less time actively interacting with a younger intruder on Day 2 than on Day 1, but β4 null mice interacted for a similar time on both days. In the nonsocial olfactory memory test, control littermates and β4 null mice learnt the associations to a similar extent, showing that the amnesic phenotype in the intruder test is specific for social settings.
Conclusions: We conclude that nAChRs that contain the β4 subunit are important for social behaviors. As those receptors are necessary to observe several effects of nicotine including withdrawal, it is tempting to speculate that the social component of tobacco use is related to the same neuronal circuits responsible for continuing tobacco use in smokers.