Mormède P, Lemaire V, Castanon N, Dulluc J, Laval M, Le Moal M
Laboratoire de Psychobiologie de Comportements Adaptatifs, INRA-INSERM U259, Université de Bordeaux II, France.
Physiol Behav. 1990 Jun;47(6):1099-105. doi: 10.1016/0031-9384(90)90358-b.
After four weeks of individual housing, male Wistar rats (selected for high or low spontaneous aggressiveness by multiple round-robin encounters) were housed three per cage and submitted to four weeks of chronic social stress consisting of changing membership in the social groups by daily rotation of the animals among cages every day according to a random permutation procedure. In addition, half the males in each condition were housed with three females. Each environmental condition triggered different neuroendocrine changes. Cohabitation with females increased the hypothalamo-pituitary-adrenocortical axis activity, including enlargement of adrenals and increased circulating corticosterone levels. On the other hand, daily rotation of the rats between different social groups activated part of the sympathetic nervous system, such as increased phenylethanolamine N-methyl transferase (PNMT) activity in the adrenals. The level of aggressiveness, however, had no direct influence but interacted with environmental factors on such neuroendocrine measures as circulating testosterone or plasma renin activity. These results indicate that during chronic stress, there is no single, unique response by the animal, but a highly complex set of neuroendocrine changes, dependent on the interaction between individual characteristics (the level of aggressiveness is an example) and situational factors.
经过四周的单独饲养后，雄性Wistar大鼠（通过多轮循环相遇挑选出高或低自发攻击性的大鼠）三只一组饲养在笼中，并经历四周的慢性社会应激，即每天根据随机排列程序将动物在笼子间每日轮换，从而改变社会群体的成员构成。此外，每种条件下的雄性大鼠中有一半与三只雌性大鼠一起饲养。每种环境条件都会引发不同的神经内分泌变化。与雌性大鼠同居会增加下丘脑 - 垂体 - 肾上腺皮质轴的活性，包括肾上腺增大和循环皮质酮水平升高。另一方面，大鼠在不同社会群体间的每日轮换会激活部分交感神经系统，比如肾上腺中苯乙醇胺N - 甲基转移酶（PNMT）活性增加。然而，攻击性水平没有直接影响，而是与环境因素相互作用，影响诸如循环睾酮或血浆肾素活性等神经内分泌指标。这些结果表明，在慢性应激期间，动物并非只有单一、独特的反应，而是存在高度复杂的一系列神经内分泌变化，这取决于个体特征（攻击性水平就是一个例子）和情境因素之间的相互作用。
