Figure 5.

Hypothesized roles of the vasopressin 1a receptor (Avpr1a) and the vasopressin 1b receptor (Avpr1b) in the regulation of social behavior. Absence of the Avpr1a results in impaired olfaction, suggestive that the Avpr1a may be important to responses to chemosensory input (Wersinger et al., 2007b). On the other hand, absence of the Avpr1b results in reduced aggression and impaired social memory in the absence of olfactory deficits (Wersinger et al., 2004; Wersinger et al., 2007a). As the Avpr1b is found predominantly within the CA2 pyramidal neurons of the hippocampus, it has been proposed to be involved in the evaluation of accessory olfactory chemosensory cues (i.e., associating the cue with the behavioral context) (Young et al., 2006).