Masculinization and feminization of rat sexual behavior has been supposed to occur during a short postnatal period. However, much data have made it evident that these processes may continue until adolescence. In the present study, we evaluated whether androgen treatment of females from postnatal day 20 and onwards could alter sexual motivation and behavior in a male direction. Juveniles were ovariectomized on day 20 and concurrently implanted with Silastic capsules containing either testosterone or dihydrotestosterone. Controls were implanted with an empty capsule. Tests for sexual incentive motivation and male sexual behavior were performed every fifth day when the females were between 50 and 75 days of age. At day 80, a test for female sexual behavior was performed. Females treated with testosterone approached a female sexual incentive far more than a male incentive, showing that sexual motivation had been changed in a male-like direction. Dihydrotestosterone had a similar, albeit smaller, effect. Females implanted with an empty capsule approached both incentives equally. Testosterone produced a high level of mounting behavior, whereas intromission-like behavioral patterns were rare and ejaculation-like behavior was absent. In the test for female sexual behavior, the testosterone-treated animals displayed a relatively high lordosis quotient, far above that displayed in females implanted with dihydrotestosterone or an empty capsule. It is concluded that treatment with an aromatizable androgen during the peripubertal-adolescent period masculinizes sexual motivation and partly sexual behavior. A non-aromatizable androgen weakly masculinize sexual motivation without enhancing male sexual behavior. It appears that simultaneous actions on androgen and estrogen receptors are needed for significant masculinization during the period studied here. Since the testosterone-treated females displayed lordosis, sexual behavior was not defeminized. In sum, these results suggest that sexual differentiation continues well into the peripubertal and adolescent periods.

老鼠性行为的男性化和女性化被认为是在出生后的短时间内发生的。但是，许多数据表明这些过程可能会持续到青春期。在本研究中，我们评估了从出生后第20天开始对女性进行雄激素治疗是否可以改变男性的性动机和行为。在第20天将卵巢切除，并同时植入包含睾丸激素或二氢睾丸激素的Silastic胶囊。对照植入空胶囊。当女性年龄在50至75天之间时，每五天进行一次性刺激动机和男性性行为测试。在第80天，对女性的性行为进行了测试。用睾丸激素治疗的女性对女性的性刺激远大于男性的性刺激，这表明性动机已经在类似于男性的方向上发生了变化。二氢睾丸激素具有相似的作用，尽管作用较小。植入空胶囊的雌性对两种诱因均等接近。睾丸激素产生高水平的坐骑行为，而很少出现内向型行为模式，而没有射精型行为。在女性性行为测试中，用睾丸激素治疗的动物表现出较高的脊柱前凸商数，远高于植入双氢睾丸激素或空胶囊的雌性动物的前凸度商数。可以得出结论，青春期前后青春期用芳香性雄激素治疗会男性化性动机和部分性行为。不可芳香化的雄激素在不增强男性性行为的情况下会弱化男性的性动机。似乎在此研究期间，雄激素和雌激素受体需要同时起作用才能显着男性化。由于用睾丸激素治疗的女性表现出脊柱前凸，因此性行为并未女性化。总而言之，这些结果表明，性别分化一直持续到青春期和青春期。