Increases in Circulating Testosterone Levels of Maturing Male Guinea Pigs Appear Neither Necessary nor Sufficient for Heightened Maternally Directed Sexual and Social/Courtship Behavior

Periadolescent male guinea pigs housed continuously with their mother since birth exhibit little maternally directed sexual behavior. However, if rehoused apart from the mother for 24 h, they show elevations in circulating testosterone concentrations and display frequent sexual responses and increased social/courtship behavior upon reunion with her. We investigated the role of testosterone in the disinhibition of maternally directed sexual and social/courtship behavior. Subcutaneous implants of testosterone (Experiment 1) did not trigger maternally directed sexual behavior or an increase in social/courtship behavior among males housed continuously with their mothers. Further, neither blocking androgen receptors (Experiment 2) nor preventing the surge in testosterone (Experiment 3) prevented males housed without the mother from exhibiting increased maternally directed sexual and social/courtship behavior upon reunion. These findings indicate that the increase in testosterone that males exhibit when rehoused apart from the mother is neither sufficient nor necessary for the disinhibition of maternally directed sexual and social/courtship behavior observed when mother and son are reunited.