Testosterone regulations on male sexual behavior and emission of ultrasounds in mice. (#284)
Brain and behavioral masculinization depend on the androgens secreted from the testes in the neonatal period in mammals. In mice, both androgenic and estrogenic effects on the organization of male behavior were demonstrated but detail mechanisms of the sensitive period of each component of male sexual behavior, that is, sniffing to female, ultrasonic vocalization (USVs) and mounting behavior were not determined yet. In this study, we conducted two experiments, one was testosterone (T) treatments to females and the other was fetal Leydig cell-specific Ad4BP/SF-1 gene disruption (FLKO) in male mice, to reveal the sensitive period of testosterone on the male behavior. When female mice were treated with T in both neonatal, peripubertal period and adulthood, they showed comparable amount of sniffing, USVs and mounting behavior. Females treated with T from in the adulthood displayed sniffing and mounting behavior but not USVs. FLKO male showed a decrease of sniffing, USVs and mounting behavior as compared to HT or WT mice, accompanied by decrease of testosterone levels both in neonatal and peripubertal periods. Collectively, there are two components of male sexual behavior, one is sniffing and mounting and the other is emission of USVs; former is dependent on testosterone in the peripubertal period and adulthood, and the latter is dependent on testosterone in neonatal period. This is the first reports demonstrating dissection of the components of male sexual behavior by the time window of testosterone regulations.