Helmreich Dana L, Crouch Megan, Dorr Nathan P, Parfitt David B
Department of Biology and Program of Neuroscience, Middlebury College, Middlebury, VT 05753, USA.
Physiol Behav. 2006 Jan 30;87(1):114-9. doi: 10.1016/j.physbeh.2005.09.010. Epub 2005 Oct 26.
Changes in peripheral thyroid hormone levels are associated with changes in human affective disorders, particularly depression. In the current study we used an animal stress paradigm, proposed to be an animal model of depression, to examine peripheral T(3) levels during and after escapable or inescapable stress in adult male rats. In this model, one animal can control the termination of foot-shock stress by performing a lever press, and therefore experiences escapable stress. His lever press also terminates the shock for his yoked partner, who has no control over the stressor, and therefore experiences inescapable stress. In three separate experiments, blood samples were collected during and after one or two sessions of escapable/inescapable stress. We found that exposure to inescapable stress, but not escapable stress, caused a decrease in T(3) levels 120 min post-stress initiation. Peripheral T(3) levels were not significantly altered in animals exposed to escapable stress. In sum, these results add to a large body of previous data indicating that psychological coping can prevent the effects of physical stress on many diverse systems.
外周甲状腺激素水平的变化与人类情感障碍尤其是抑郁症的变化有关。在本研究中，我们使用一种被认为是抑郁症动物模型的动物应激范式，来检测成年雄性大鼠在可逃避或不可逃避应激期间及之后的外周T(3)水平。在这个模型中，一只动物可以通过按压杠杆来控制足部电击应激的终止，因此经历可逃避应激。它按压杠杆也会终止其被束缚同伴的电击，该同伴无法控制应激源，因此经历不可逃避应激。在三个独立实验中，在一或两个可逃避/不可逃避应激阶段期间及之后采集血样。我们发现，暴露于不可逃避应激而非可逃避应激会导致应激开始后120分钟T(3)水平降低。暴露于可逃避应激的动物外周T(3)水平没有显著改变。总之，这些结果补充了大量先前的数据，表明心理应对可以预防身体应激对许多不同系统的影响。
