Anderson S M, Saviolakis G A, Bauman R A, Chu K Y, Ghosh S, Kant G J
Division of Neurosciences, Walter Reed Army Institute of Research, Washington DC 20307-5100, USA.
Physiol Behav. 1996 Jul;60(1):325-9. doi: 10.1016/0031-9384(96)00023-6.
Our laboratory has previously conducted a number of studies to determine the effects of chronic stress on the physiology and behavior of male rats. The present study was performed to extend these investigations to female rats. Female rats were chronically stressed using a behavioral paradigm of around-the-clock signalled intermittent foot shock in which some rats can pull a chain to avoid/escape shock (stress) while another group of rats is yoked to the first group (yoked-stress) and does not have control over shock termination. Control rats were never shocked but all groups lever pressed for food pellets on an FR1 schedule (one pellet per lever press). Daily vaginal samples were obtained for several weeks prior to stress onset and throughout the chronic stress period. After 14 days of stress, the experiment was terminated and morning blood samples were collected for hormonal assays. Stress transiently decreased lever pressing for food pellets and body weights, but both measures returned to prestress levels by day 14 of stress. Plasma adrenocorticotropic hormone (ACTH) concentrations were significantly elevated in the yoked-stress group compared to the other two groups, but there were no significant effects of 14 days of stress treatment on plasma corticosterone, prolactin, estradiol, or progesterone concentrations. There were no significant differences in estrous cycle length among experimental groups.
我们实验室之前进行了多项研究，以确定慢性应激对雄性大鼠生理和行为的影响。本研究旨在将这些调查扩展到雌性大鼠。使用全天候信号间歇性足部电击的行为范式对雌性大鼠进行慢性应激，其中一些大鼠可以拉链条以避免/逃脱电击（应激），而另一组大鼠与第一组相连（束缚应激），无法控制电击终止。对照大鼠从未受到电击，但所有组均按照FR1程序（每次按压杠杆获得一粒食丸）按压杠杆获取食丸。在应激开始前几周以及整个慢性应激期间，每天采集阴道样本。应激14天后，实验终止，采集早晨血样进行激素测定。应激使按压杠杆获取食丸的次数和体重暂时下降，但在应激第14天时，这两项指标均恢复到应激前水平。与其他两组相比，束缚应激组的血浆促肾上腺皮质激素（ACTH）浓度显著升高，但应激处理14天对血浆皮质酮、催乳素、雌二醇或孕酮浓度没有显著影响。各实验组的发情周期长度没有显著差异。
