Williams G W, McGinnis M Y, Lumia A R
Biopsychology Program, Skidmore College, Saratoga Springs, NY 12866.
Physiol Behav. 1992 Oct;52(4):755-60. doi: 10.1016/0031-9384(92)90410-4.
The effects of olfactory bulb removal (OBX) and chronic psychosocial stress on serum glucocorticoids and sexual behavior were assessed in female rats primed with a subthreshold level of estradiol (E2). Ovariectomized females underwent either OBX or sham surgery. Half of the OBX and half of the sham animals were exposed to chronic psychosocial stress (crowding, strobe light, and intermittent noise) for one-half h per day for 27 days. On day 22, three blood samples were collected from each animal for serum corticosterone analysis; 1) before, 2) during, and 3) after acute stress (one-half h restraint). On day 28, females were exposed to either 4 or 24 h of E2. On day 29, all females received 500 micrograms progesterone (P) 4 h prior to sexual behavior testing. Sexual receptivity was measured using the lordosis quotient (LQ = [number of lordotic responses/10 mounts] x 100). Sexual proceptivity (dart and ear wiggling sequences) and rejection (number of nonlordotic responses to mount attempts) were measured throughout a 10-min test period. Results showed that chronic psychosocial stress dramatically increased sexual receptivity and proceptivity while decreasing sexual rejection in female rats primed with a subthreshold level of E2. Chronic psychosocial stress also elevated serum glucocorticoids and significantly exacerbated the glucocorticoid response to acute stress. OBX, while increasing sexual receptivity and decreasing sexual rejection, had no effect on serum glucocorticoids. These findings support the hypothesis that OBX potentiates female sexual behavior directly through an increase in neural sensitivity to E2. In contrast, the enhancing effect of chronic psychosocial stress on female sexual behavior may result from alterations of the hypothalamo-pituitary-adrenal system.
在接受亚阈值水平雌二醇（E2）预处理的雌性大鼠中，评估了嗅球切除（OBX）和慢性心理社会应激对血清糖皮质激素和性行为的影响。对卵巢切除的雌性大鼠进行了OBX手术或假手术。将一半的OBX大鼠和一半的假手术动物每天暴露于慢性心理社会应激（拥挤、频闪灯和间歇性噪音）中，持续27天，每天暴露半小时。在第22天，从每只动物身上采集三份血样用于血清皮质酮分析；1）急性应激（半小时束缚）前，2）急性应激期间，3）急性应激后。在第28天，雌性大鼠接受4小时或24小时的E2处理。在第29天，所有雌性大鼠在性行为测试前4小时接受500微克孕酮（P）。使用脊柱前凸商数（LQ = [脊柱前凸反应次数/10次爬跨]×100）来测量性接受能力。在整个10分钟的测试期内测量性主动行为（跳跃和耳朵摆动序列）和拒绝行为（对爬跨尝试的非脊柱前凸反应次数）。结果表明，慢性心理社会应激显著增加了接受亚阈值水平E2预处理的雌性大鼠的性接受能力和性主动行为，同时降低了性拒绝行为。慢性心理社会应激还提高了血清糖皮质激素水平，并显著加剧了对急性应激的糖皮质激素反应。OBX虽然增加了性接受能力并降低了性拒绝行为，但对血清糖皮质激素没有影响。这些发现支持了以下假设：OBX通过增加对E2的神经敏感性直接增强雌性性行为。相比之下，慢性心理社会应激对雌性性行为的增强作用可能源于下丘脑 - 垂体 - 肾上腺系统的改变。
