Bakker J, Van Ophemert J, Slob A K
Department of Endocrinology & Reproduction, Faculty of Medicine, Erasmus University, Rotterdam, The Netherlands.
Physiol Behav. 1996 Aug;60(2):489-94. doi: 10.1016/s0031-9384(96)80023-0.
Previous studies have shown that adult male rats, in which brain estrogen formation was inhibited neonatally by SC administration of the aromatase inhibitor 1,4, 6-androstatriene-3,17-dione (ATD), show an altered sexual partner preference. When tested in a three-compartment box, such gonadally intact ATD males approach and mate both with the estrous female and the sexually active male, whereas normal males prefer to approach and mate with the estrous female, avoiding the stimulus male. After castration in adulthood and estradiol treatment, ATD males prefer sexually active males. Similarly treated normal males prefer estrous females, and estrous females prefer to mate with males. In the present study, we asked what stimulus characteristics of active males vs. estrous females determined the different sexual preferences of males, ATD males, and of females. Were they chemosensory cues or more distal cues such as actually seeing and hearing the stimulus animals or the reward of sexual activity with the stimulus animals? Sex differences in preference were evident when animals were given a choice between soiled bedding from estrous females and from sexually active males. ATD and control males spent significantly more time on soiled bedding from estrous females than on soiled bedding from sexually active males. Control females spent significantly more time on soiled bedding from sexually active males than on soiled bedding from estrous females. More distal cues, such as seeing and hearing the stimulus animals, revealed differences in preference between control males and females, but not between ATD and control males. Physical interaction with the stimulus animals was a prerequisite for revealing differences in preference between ATD and control males. Then, the behavior of ATD males was clearly intermediate between that of normal male and female rats. In conclusion, neonatal estradiol is important for the psychosexual development of the male rat. However, the present data suggest that the psychosexual development of the male rat also requires either prenatal estradiol or perinatal testosterone.
先前的研究表明，成年雄性大鼠若在新生期经皮下注射芳香化酶抑制剂1,4,6 - 雄甾三烯 - 3,17 - 二酮（ATD）来抑制脑内雌激素的生成，其性伴侣偏好会发生改变。在三室箱中进行测试时，这类性腺完整的ATD雄性大鼠会接近发情期雌性和性活跃雄性并与之交配，而正常雄性则更倾向于接近发情期雌性并与之交配，回避刺激雄性。成年去势并接受雌二醇治疗后，ATD雄性大鼠偏好性活跃雄性。同样接受处理的正常雄性大鼠偏好发情期雌性，发情期雌性则更倾向于与雄性交配。在本研究中，我们探究了性活跃雄性与发情期雌性的哪些刺激特征决定了雄性、ATD雄性大鼠以及雌性大鼠不同的性偏好。这些特征是化学感觉线索，还是更远端的线索，比如实际看到和听到刺激动物，或者与刺激动物进行性活动的奖赏？当动物在来自发情期雌性和性活跃雄性的脏垫料之间进行选择时，偏好的性别差异很明显。ATD雄性大鼠和对照雄性大鼠在来自发情期雌性的脏垫料上花费的时间显著多于来自性活跃雄性的脏垫料。对照雌性大鼠在来自性活跃雄性的脏垫料上花费的时间显著多于来自发情期雌性的脏垫料。更远端的线索，比如看到和听到刺激动物，揭示了对照雄性和雌性之间偏好的差异，但ATD雄性大鼠和对照雄性大鼠之间没有差异。与刺激动物的身体互动是揭示ATD雄性大鼠和对照雄性大鼠偏好差异的前提条件。然后，ATD雄性大鼠的行为明显介于正常雄性和雌性大鼠之间。总之，新生期雌二醇对雄性大鼠的性心理发育很重要。然而，目前的数据表明，雄性大鼠的性心理发育还需要产前雌二醇或围产期睾酮。
