Humm J L, Lambert K G, Kinsley C H
Department of Psychology, University of Richmond, VA 23173, USA.
Brain Res Bull. 1995;37(4):363-8. doi: 10.1016/0361-9230(95)00011-9.
Normal male rats display high levels of sexual activity when paired with sexually receptive females, a behavior regulated, in large part, by the medial preoptic area (MPOA). It has been documented that onset of c-fos proteins in the MPOA accompanies sexual behavior. Because prenatal stress (PS) demasculinizes sexual behavior in male rats, the present study examined whether such effects might be accompanied by a decrease in the neuronal activation in MPOA associated with sexual behavior. Adult prenatally stressed (P-S) and unstressed control males were paired with sexually receptive females, and sexual behavior allowed to commence. After a single mount, the pair was separated by a partition for the remainder of an hour, at the end of which the male was killed and the brain processed for c-fos immunocytochemistry; quantification was performed by means of computerized image analysis. P-S males expressed significantly less c-fos activity in the region of the MPOA, compared to nonstressed control males. Thus, the sexual deficits associated with P-S males may be due to a relative dearth of activity in the MPOA at the neuronal level. Coupled to earlier work showing decreased luteinizing hormone secretion in P-S males under similar conditions, the present data suggest a constellation of factors that contribute to PS-induced deficits in sexual behavior.
正常雄性大鼠与处于性接受期的雌性大鼠配对时会表现出高水平的性行为，这种行为在很大程度上受内侧视前区（MPOA）调节。据记载，MPOA中c-fos蛋白的出现伴随着性行为。由于产前应激（PS）会使雄性大鼠的性行为去雄性化，本研究考察了这种影响是否可能伴随着与性行为相关的MPOA中神经元激活的减少。将成年期受到产前应激（P-S）的雄性大鼠和未受应激的对照雄性大鼠与处于性接受期的雌性大鼠配对，让性行为开始。在单次爬跨后，用隔板将这对大鼠隔开一小时，一小时结束时将雄性大鼠处死，对大脑进行c-fos免疫细胞化学处理；通过计算机图像分析进行定量。与未受应激的对照雄性大鼠相比，P-S雄性大鼠在MPOA区域的c-fos活性明显较低。因此，与P-S雄性大鼠相关的性行为缺陷可能是由于MPOA在神经元水平上相对缺乏活性。结合早期研究表明在类似条件下P-S雄性大鼠促黄体生成素分泌减少，目前的数据表明一系列因素导致了PS诱导的性行为缺陷。
