Regulation of Female Rat Sexual Motivation in Olfactory Nervous System

在这个项目中，我们研究了雌性大鼠性动机的神经内分泌机制，通过两个行为测试范式，节奏交配（交配测试与逃避的地方，为女性）和伴侣偏好（女性喜欢的气味性活跃的男性，而不是那些不活跃的一个）。内侧杏仁核放射性损伤消除了伴侣偏好，缩短了起搏交配试验中接近性雄性的潜伏期。相比之下，内侧视前病变消除了伴侣偏好而不影响起搏行为，而外侧间隔病变使他们的起搏更快，但不影响伴侣偏好。这些结果表明，前脑结构，已被称为控制脊柱前凸可能发挥不同的作用，在调节雌性大鼠的性动机。其次，我们研究了影响性腺类固醇激素的偏好同种气味的雄性和雌性大鼠。性活跃的男性喜欢的气味，而不是那些接受女性的男性和卵巢切除的女性（阳性模式），而发情期的女性喜欢的气味的性活跃的男性比女性和卵巢切除的男性（女性模式）。雄性和雌性的性腺切除消除了所有的偏好。虽然睾丸激素治疗去势女性恢复了女性的偏好模式，雌激素和孕激素治疗去势男性激活了女性的模式，但不是男性的模式，偏好。这些表明，男性的偏好模式是由雄激素调节，而女性的模式是由雌激素和/或孕激素调节。雄激素治疗后女性没有出现变性模式，表明正常女性没有阳性模式的神经回路，因为在围产期缺乏雄激素暴露。需要进一步的研究来阐明这一机制。

In this project, we investigated the neuroendocrine mechanisms of sexual motivation in female rats by means of two behavioral test paradigms, paced mating (mating test with an escapable place for females) and partner preference (females prefer odors of sexually active males rather than those of inactive one). Radiofrequency lesions in the medial amygdala eliminated partner preference and shortened latency to access sexual males in paced mating test. In contrast, medial preoptic lesions eliminated partner preference without effect on pacing behavior, whereas lateral septal lesions made their pace faster but did not affect partner preference. These results suggest that the forebrain structures that have been known to control lordosis may play different roles in the regulation of sexual motivation in female rats.Secondly, we examined effects of gonadal steroids on preference of conspecific odors in male and female rats. Sexual active males preferred odors of receptive females rather than those of males and ovariectomized females (masculine pattern), while estrous females preferred odors of sexually active males than those of females and orchidectomized males (feminine pattern). Gonadectomy in both males and females eliminated all the preference. Although treatment with testosterone to castrated females restored the feminine pattern of preference, treatment of estrogen and progesterone to castrated males activated the feminine pattern, but not the masculine pattern, of preference. These suggest that the masculine pattern of preference is regulated by androgen, whereas the feminine pattern is regulated by estrogen and/or progesterone. No transsexual pattern appeared after androgen treatment in females suggests that normal females have no neural circuits for the masculine pattern because of a lack of androgen exposures in their perinatal periods. Further studies are required to elucidate this mechanism.