Heinsbroek R P, Van Haaren F, Feenstra M G, Endert E, Van de Poll N E
Netherlands Institute for Brain Research, Amsterdam.
Physiol Behav. 1991 Jun;49(6):1251-6. doi: 10.1016/0031-9384(91)90359-v.
Previous experiments have revealed sex-dependent effects of inescapable shock in rats. Behavior of male rats was more severely disrupted by inescapable shock than behavior of female rats. These sex differences were found after 1- and 24-hour intervals but not after a 72-hour interval. The present experiment was designed to study various physiological parameters at 1-, 4- and 24-hour intervals after inescapable footshock. The predictability of shock was manipulated by adding a compound light and tone stimulus that preceded shock presentation for one group but was not correlated with shock presentation for another group of subjects. Noradrenaline, dopamine, serotonin, and metabolites of these 3 transmitters were measured in the frontal cortex. Transient shock-induced increments in dopamine and metabolites of dopamine and serotonin were found, but the sex of the animal did not differentially affect this neurotransmitter response. In addition to neurotransmitter concentrations in the frontal cortex, levels of corticosterone were measured in plasma. The pituitary-adrenal axis was activated for a longer period in females than males after shock. The present data do not provide evidence that behavioral sex differences induced by inescapable shock are paralleled by sex differences in neurotransmitter activity. In addition, sex-dependent effects of predictability of shock on neurotransmitter activity were not detected. The relevance of the observed sex-dependent responses in the pituitary-adrenal system is discussed.
先前的实验揭示了不可逃避电击对大鼠的性别依赖性影响。不可逃避电击对雄性大鼠行为的干扰比对雌性大鼠行为的干扰更严重。这些性别差异在间隔1小时和24小时后被发现，但在间隔72小时后未被发现。本实验旨在研究不可逃避足部电击后1小时、4小时和24小时的各种生理参数。通过为一组实验对象在电击呈现之前添加复合光和声刺激来操纵电击的可预测性，而另一组实验对象的该刺激与电击呈现无关。在额叶皮质中测量了去甲肾上腺素、多巴胺、血清素以及这三种神经递质的代谢产物。发现电击引起多巴胺及其代谢产物以及血清素的短暂增加，但动物的性别并未对这种神经递质反应产生差异影响。除了额叶皮质中的神经递质浓度外，还测量了血浆中的皮质酮水平。电击后，雌性大鼠的垂体 - 肾上腺轴被激活的时间比雄性大鼠更长。目前的数据并未提供证据表明不可逃避电击引起的行为性别差异与神经递质活性的性别差异平行。此外，未检测到电击可预测性对神经递质活性的性别依赖性影响。讨论了在垂体 - 肾上腺系统中观察到的性别依赖性反应的相关性。
