Leuner Benedetta, Mendolia-Loffredo Sabrina, Shors Tracey J
Department of Psychology and Center for Collaborative Neuroscience, Rutgers University, 153 Frelinghuysen Road, Piscataway, NJ 08854, USA.
Biol Psychiatry. 2004 Dec 15;56(12):964-70. doi: 10.1016/j.biopsych.2004.09.018.
Women are much more likely to suffer from stress-related mental illness than men; yet few, if any, animal models for such sex differences exist. Previously, we reported that exposure to an acute stressor enhances learning in male rats yet severely impairs learning in female rats. Here, we tested whether these opposite effects in males versus females could be prevented by establishing control over the stressor or by antidepressant treatment.
Learning was assessed using the hippocampal-dependent task of trace eyeblink conditioning. In the first experiment, groups of male and female rats were exposed to controllable or uncontrollable stress and trained. In a second experiment, they were exposed to an uncontrollable stressor after chronic treatment with the antidepressant fluoxetine (Prozac). In a final experiment, females were exposed to uncontrollable stress after acute treatment with fluoxetine.
Establishing control over the stressful experience eliminated the detrimental effect of stress on learning in females as well as the enhancing effect of stress in males. Moreover, chronic but not acute treatment with fluoxetine prevented the learning deficit in females after exposure to stress. Treatment with fluoxetine did not alter the male response to stress.
These data indicate that males and females not only respond in opposite directions to the same stressful event but also respond differently to controllability and antidepressant treatments.
女性比男性更容易患与压力相关的精神疾病；然而，几乎没有针对这种性别差异的动物模型。此前，我们报道过，暴露于急性应激源会增强雄性大鼠的学习能力，但会严重损害雌性大鼠的学习能力。在此，我们测试了对压力源建立控制或进行抗抑郁治疗是否可以预防雄性和雌性大鼠的这些相反效应。
使用海马体依赖的痕迹眨眼条件反射任务评估学习能力。在第一个实验中，将雄性和雌性大鼠分组，使其暴露于可控或不可控的压力下并进行训练。在第二个实验中，在对其进行抗抑郁药氟西汀（百忧解）的慢性治疗后，让它们暴露于不可控的应激源。在最后一个实验中，在对雌性大鼠进行氟西汀急性治疗后，使其暴露于不可控的压力下。
对压力体验建立控制消除了压力对雌性大鼠学习能力的有害影响以及压力对雄性大鼠学习能力的增强作用。此外，氟西汀的慢性而非急性治疗可预防雌性大鼠在暴露于压力后出现的学习缺陷。氟西汀治疗并未改变雄性大鼠对压力的反应。
这些数据表明，雄性和雌性大鼠不仅对相同的应激事件有相反的反应，而且对可控性和抗抑郁治疗的反应也不同。
