title: Oxytocin modulates social interaction but is not essential for sexual behavior in male mice.
abstract: Recently, several studies have shown different conclusions regarding the effect of oxytocin (OT) on the social behaviors of male mice. Most of these studies used exogenous OT, but currently, investigations of the neural bases of social behavior are increasingly employing gene inactivation. This study aimed to analyze the role of OT in the modulation of social behaviors (i.e., sexual and social interaction behaviors) in male mice with selective deletions of the OT gene (OTKO) and the influence of this deletion in basal vasopressin (AVP) plasma concentrations. Our results showed that in the social interaction test, OTKO mice exhibited lower levels of social behaviors and higher levels of non-social behaviors compared to the wild type (WT) group. Additionally, the OTKO group showed a decrease in the number of agonistic behaviors delivered, and consequently, their dominance score was lower than that of the WT group. In the ethological analysis, the OTKO group had a lower aggressive performance and increased social investigation than the WT group. No significant differences were observed in the sexual behavior between groups. Finally, we found lower AVP plasma concentrations in the OTKO compared with the WT group. In conclusion, our data suggest that OT modulates social investigation behavior and the aggressiveness of male mice. The decrease in AVP concentrations in the OTKO group allows us to infer that AVP is physiologically relevant to these behavioral modulations. However, sexual behaviors do not seem to be affected by the lack of OT or by a decrease in the AVP concentration.
authors: Programa de Pós-Graduação em Ciências da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil.
authors: Virgínia Meneghini
authors: VM
authors: Lazzari
authors: Roberta Ouriques
authors: RO
authors: Becker
authors: Marcia Scherem
authors: MS
authors: de Azevedo
authors: Mariana
authors: M
authors: Morris
authors: Katya
authors: K
authors: Rigatto
authors: Silvana
authors: S
authors: Almeida
authors: Aldo Bolten
authors: AB
authors: Lucion
authors: Márcia
authors: M
authors: Giovenardi
mesh_terms: D000374:Aggression / Q000502:physiology; D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood; D005260:Female; D008297:Male; D051379:Mice; D018345:Mice, Knockout / Q000097:blood; D010121:Oxytocin / Q000235:genetics / Q000502:physiology*; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012919:Social Behavior
chemical_list: D001127:Arginine Vasopressin; D010121:Oxytocin