Pervasive social deficits, but normal parturition, in oxytocin receptor-deficient mice

The oxytocin receptor (OXTR) and its ligand, oxytocin (OXT), regulate reproductive physiology (i.e., parturition and lactation) and sociosexual behaviors. To define the essential functions of OXTR, we generated mice with a null mutation in the Oxtr gene (Oxtr-/-) and compared them with OXT-deficient (Oxt-/-) mice. Oxtr-/- mice were viable and had no obvious deficits in fertility or reproductive behavior. Oxtr-/- dams exhibited normal parturition but demonstrated defects in lactation and maternal nurturing. Infant Oxtr-/- males emitted fewer ultrasonic vocalizations than wild-type littermates in response to social isolation. Adult Oxtr-/- males also showed deficits in social discrimination and elevated aggressive behavior. Ligand Oxt-/- males from Oxt-/- dams, but not from Oxt+/- dams, showed similar high levels of aggression. These data suggest a developmental role for the OXT/OXTR system in shaping adult aggressive behavior. Our studies demonstrate that OXTR plays a critical role in regulating several aspects of social behavior and may have important implications for developmental psychiatric disorders characterized by deficits in social behavior

The V1a Vasopressin Receptor Is Necessary and Sufficient for Normal Social Recognition: A Gene Replacement Study

SummaryVasopressin modulates many social and nonsocial behaviors, including emotionality. We have previously reported that male mice with a null mutation in the V1a receptor (V1aR) exhibit a profound impairment in social recognition and changes in anxiety-like behavior. Using site-specific injections of a V1aR-specific antagonist, we demonstrate that the lateral septum, but not the medial amygdala, is critical for social recognition. Reexpressing V1aR in the lateral septum of V1aR knockout mice (V1aRKO) using a viral vector resulted in a complete rescue of social recognition. Furthermore, overexpression of the V1aR in the lateral septum of wild-type (wt) mice resulted in a potentiation of social recognition behavior and a mild increase in anxiety-related behavior. These results demonstrate that the V1aR in the lateral septum plays a critical role in the neural processing of social stimuli required for complex social behavior