Social motivation is reduced in vasopressin 1b receptor null mice despite normal performance in an olfactory discrimination task

• Published in: Hormones and behavior 2004-12, Vol.46 (5), p.638-645
• Main Authors: Wersinger, Scott R., R. Kelliher, Kevin, Zufall, Frank, Lolait, Stephen J., O'Carroll, Anne-Marie, Young, W. Scott
• Format: Article
• Language: English
• Subjects: Aggression; Aggression - physiology; Animals; Behavior; Behavioral psychophysiology; Biological and medical sciences; Chemosensory; Conditioning, Operant - physiology; Discrimination Learning - physiology; Fundamental and applied biological sciences. Psychology; Hormones and behavior; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Motivation; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Random Allocation; Receptors, Vasopressin - deficiency; Receptors, Vasopressin - physiology; Sex Factors; Sexual Behavior, Animal - physiology; Smell - physiology; Social Behavior; Vasopressin V3 receptor
• ISSN: 0018-506X; 1095-6867
• DOI: 10.1016/j.yhbeh.2004.07.004

In this study, we characterized more thoroughly the social behavior of vasopressin 1b receptor null (V1bR−/−) mice. We confirmed that V1bR−/− males exhibit less social aggression than their wild-type (V1bR+/+) littermates. We tested social preference by giving male subjects a choice between pairs of soiled or clean bedding. In general, V1bR+/+ mice spent significantly more time engaged in chemoinvestigation of these social stimuli than V1bR−/− mice. Male V1bR+/+ mice preferred female-soiled bedding over male-soiled bedding, male-soiled bedding over clean bedding, and female-soiled bedding over clean bedding. In contrast, V1bR−/− males failed to exhibit a preference for any bedding. This difference in behavior is not explained by an anosmic condition as there were no differences between V1bR−/− and V1bR+/+ mice in their abilities to detect a cookie buried in clean bedding, or in their ability to perform in an operant conditioning task using a fully automated liquid dilution olfactometer. In the latter task, male V1bR−/− mice were fully capable of discriminating between male and female mouse urine. The latencies to learn this task did not differ between the two genotypes. Thus, a V1bR−/− male's ability to differentiate between male and female chemosensory cues appears no different than that of a V1bR+/+ male's. We propose that the V1bR plays an important role in social motivation, perhaps by coupling the processing, integration, and/or interpretation of chemosensory cues with the appropriate behavioral response.