Díaz-Véliz G, Urresta F, Dussaubat N, Mora S
Departamento Medicina Experimental, Facultad de Medicina, Universidad de Chile, Santiago.
Psychoneuroendocrinology. 1994;19(4):387-94. doi: 10.1016/0306-4530(94)90018-3.
This study demonstrates a significant impairment in the acquisition of conditioned avoidance responses in female rats during their estrus phase. Progesterone (PROG 5 mg) injected 6 h prior to the test, significantly enhanced the performance exhibited by rats at estrus, but not at diestrus. In ovariectomized rats, the acquisition of conditioned avoidance responses was similar to the exhibited during diestrus and this behavior was depressed by a single dose of estradiol benzoate (EB 2 micrograms) injected 48 h prior to the test. PROG antagonized the avoidance depression induced by EB, but it was not able to induce changes in the acquisition of conditioned avoidance response in ovariectomized rats without EB pretreatment. Estradiol appears to be the principal ovarian steroid modulating the acquisition of an avoidance task, whereas PROG seems to have a secondary role in this behavior, regulating the actions of estradiol on the brain. PROG failed to induce consistent changes in some spontaneous motor behaviors in intact and ovariectomized rats.
本研究表明，雌性大鼠在发情期获取条件性回避反应的能力显著受损。在测试前6小时注射孕酮（PROG 5毫克），可显著提高发情期大鼠的表现，但对处于间情期的大鼠无效。在去卵巢大鼠中，条件性回避反应的获取与间情期时相似，且在测试前48小时注射单剂量苯甲酸雌二醇（EB 2微克）会抑制这种行为。PROG可拮抗EB诱导的回避行为抑制，但在未进行EB预处理的去卵巢大鼠中，它无法诱导条件性回避反应获取的变化。雌二醇似乎是调节回避任务获取的主要卵巢甾体，而PROG在这种行为中似乎起次要作用，调节雌二醇对大脑的作用。PROG未能在完整和去卵巢大鼠的一些自发运动行为中诱导出一致的变化。
