Cordner A P, Herwood M B, Helmreich D L, Parfitt D B
Department of Biology and Neuroscience Program, Middlebury College, Middlebury, VT 05753, USA.
J Neuroendocrinol. 2004 Jul;16(7):628-36. doi: 10.1111/j.1365-2826.2004.01214.x.
Stress decreases sexual activity. However, emerging research suggests that the psychological aspect of control prevents the detrimental effects of stress on male mating behaviour. The present study examined the effects of chronic escapable/inescapable stress on mating behaviour in the male Syrian hamster. Additionally, the ability of the antidepressant clomipramine to prevent the adverse effects of stress on mating behaviour was explored. In this paradigm, two groups received the same electric footshock stress, but differed in the psychological aspect of control. Cohorts were divided into two groups. One group received clomipramine via a sugar water solution while the other received plain sugar water. Mating behaviour was quantified before and after 12 consecutive days of stress. The morning following the final stress and behaviour session, trunk blood and brains were collected to assess: (i) plasma concentrations of testosterone and glucocorticoids and (ii) corticotropin-releasing hormone (CRH) mRNA expression within the paraventricular nucleus of the hypothalamus (PVN). In the drug-free groups, several aspects of mating behaviour were disrupted by inescapable but not escapable stress, including anogenital investigation before the first ejaculation and time of first ejaculation. Additionally, both escapable and inescapable stress caused a decrease in total hit rate compared to the no-stress control group. Unlike the sugar-water treated animals, hamsters in either stress condition receiving clomipramine showed no differences in anogenital investigation, time of first ejaculation, hit rate, or any other aspect of mating behaviour measured, compared to the clomipramine no-stress control males. The stress-induced inhibition of mating behaviour could not be explained by changes in baseline plasma concentrations of testosterone or total glucocorticoids; these values did not vary between any of the six treatment groups. It was found that clomipramine lowers CRH mRNA expression in the PVN by 74%, regardless of stressor conditions. The results of the present study have broad implications for understanding the relationships between stress, depression and reproduction, and for the treatment of people and animals suffering from the adverse effects of stress.
压力会降低性行为。然而，新出现的研究表明，控制的心理层面可防止压力对雄性交配行为产生有害影响。本研究考察了慢性可逃避/不可逃避压力对雄性叙利亚仓鼠交配行为的影响。此外，还探讨了抗抑郁药氯米帕明预防压力对交配行为产生不利影响的能力。在这个范式中，两组接受相同的电足部电击压力，但在控制的心理层面上有所不同。将仓鼠分为两组。一组通过糖水接受氯米帕明，而另一组接受普通糖水。在连续12天的压力前后对交配行为进行量化。在最后一次压力和行为测试后的早晨，采集躯干血液和大脑以评估：（i）睾酮和糖皮质激素的血浆浓度，以及（ii）下丘脑室旁核（PVN）内促肾上腺皮质激素释放激素（CRH）的mRNA表达。在无药物组中，不可逃避而非可逃避的压力扰乱了交配行为的几个方面，包括首次射精前的肛门生殖器检查和首次射精时间。此外，与无压力对照组相比，可逃避和不可逃避的压力均导致总命中率下降。与接受糖水治疗的动物不同，接受氯米帕明的任何一种压力条件下的仓鼠，与氯米帕明无压力对照雄性相比，在肛门生殖器检查、首次射精时间、命中率或所测量的交配行为的任何其他方面均无差异。压力诱导的交配行为抑制无法通过睾酮或总糖皮质激素的基线血浆浓度变化来解释；这些值在六个治疗组中的任何一组之间均无变化。研究发现，无论应激源条件如何，氯米帕明均可使PVN中的CRH mRNA表达降低74%。本研究结果对于理解压力、抑郁和生殖之间的关系以及治疗遭受压力不利影响的人和动物具有广泛意义。
