Heinsbroek R P, van Haaren F, Feenstra M G, Boon P, van de Poll N E
Netherlands Institute for Brain Research, Amsterdam.
Brain Res. 1991 Jun 14;551(1-2):247-55. doi: 10.1016/0006-8993(91)90939-s.
Effects of controllable and uncontrollable footshock on monoaminergic activity in the frontal cortex and plasma corticosterone levels were studied in male and female rats. Subjects were exposed to a shuttle-box procedure for a period of either 30 min (60 shocks) or 90 min (180 shocks). A shuttle response ended shock presentation for escape subjects, whereas their yoked, same-sex, counterparts were unable to escape from shock presentation. A third group was exposed to the experimental environment, but did not receive any shocks. Concentrations of noradrenaline, serotonin and dopamine and their major metabolites were measured in the frontal cortex by high performance liquid chromatography with electrochemical detection. Plasma corticosterone was measured by radioimmunoassay. Results of this experiment show that: (1) exposure to the experimental environment without shock already increased the activity of all 3 transmitter systems. In particular, serotonin was very responsive to mere confinement to the shuttle-box. Changes induced by exposure to the experimental environment were similar for males and females. (2) Presentation of footshocks further increased transmitter activity. The activation of noradrenaline and dopamine was larger after uncontrollable shock than after controllable shock. Moreover, uncontrollable shock resulted in higher serotonin levels than controllable shock. (3) Sex-dependent effects of controllability were found for noradrenaline and dopamine, but not for serotonin. Differences in catecholaminergic activity between controllable and uncontrollable shock were larger in females than in males. (4) In both males and females, corticosterone levels in plasma were increased by exposure to the experimental environment. A further elevation was found in response to footshock presentation, which was independent of the controllability of shock.
研究了可控和不可控足部电击对雄性和雌性大鼠额叶皮质单胺能活性及血浆皮质酮水平的影响。将实验对象置于穿梭箱程序中30分钟（60次电击）或90分钟（180次电击）。对于可逃避电击的实验对象，穿梭反应可终止电击，而与其配对的、同性别的对照实验对象则无法逃避电击。第三组暴露于实验环境中，但未接受任何电击。采用高效液相色谱-电化学检测法测定额叶皮质中去甲肾上腺素、5-羟色胺和多巴胺及其主要代谢产物的浓度。采用放射免疫分析法测定血浆皮质酮。本实验结果表明：（1）暴露于无电击的实验环境中已增加了所有3种递质系统的活性。特别是，5-羟色胺对仅仅被限制在穿梭箱中反应非常敏感。暴露于实验环境所引起的变化在雄性和雌性中相似。（2）足部电击的施加进一步增加了递质活性。不可控电击后去甲肾上腺素和多巴胺的激活程度大于可控电击后。此外，不可控电击导致的5-羟色胺水平高于可控电击。（3）发现去甲肾上腺素和多巴胺存在可控性的性别依赖性效应，但5-羟色胺不存在。可控电击和不可控电击之间儿茶酚胺能活性的差异在雌性中大于雄性。（4）在雄性和雌性中，暴露于实验环境均会使血浆皮质酮水平升高。对足部电击的施加会发现进一步升高，这与电击的可控性无关。
