Osborne B, Silverhart T, Markgraf C, Seggie J
Department of Psychology, Middlebury College, New Hampshire 05753.
Behav Neurosci. 1987 Aug;101(4):504-12. doi: 10.1037//0735-7044.101.4.504.
We examined whether the absence of a dynamic pituitary-adrenal response contributes to the behavioral deficit seen in hippocampally damaged rats following the transition to extinction of a learned behavior. In the first experiment, total lever presses and detailed behaviors of rats with fornix transection and replacement ACTH4-10 or ACTH were compared with the behavior of fornix-transected and sham-transection groups during acquisition and extinction of lever pressing. Fornix-transected rats showed increased resistance to extinction and an altered pattern or mode of extinction responding. ACTH4-10 or ACTH acted similarly in reducing extinction lever presses in fornix-transected rats without altering the mode of extinction responding. In the second experiment the extinction behaviors of rats with fornix transection were compared with those of normal, sham-transection adrenalectomized, or dexamethasone-treated rats. Fornix-transected rats again showed increased resistance to extinction and a different mode of responding during extinction. Adrenalectomized rats showed an extinction deficit but differed from fornix-transected rats. The behavior of dexamethasone-treated rats was similar to that of controls. The results are interpreted to mean that ACTH and corticosterone both affect extinction behavior (in opposite ways) but do not account for the extinction deficit seen in hippocampally damaged rats.
我们研究了缺乏动态垂体 - 肾上腺反应是否会导致海马损伤大鼠在习得行为向消退转变后出现行为缺陷。在第一个实验中，比较了穹窿横断并给予替代ACTH4 - 10或ACTH的大鼠在杠杆按压习得和消退过程中的总杠杆按压次数及详细行为，以及穹窿横断组和假手术组的行为。穹窿横断的大鼠表现出对消退的抵抗力增加以及消退反应模式或方式的改变。ACTH4 - 10或ACTH在减少穹窿横断大鼠的消退杠杆按压方面作用相似，但未改变消退反应模式。在第二个实验中，比较了穹窿横断大鼠与正常、假手术肾上腺切除或地塞米松处理大鼠的消退行为。穹窿横断大鼠再次表现出对消退的抵抗力增加以及在消退过程中不同的反应模式。肾上腺切除的大鼠表现出消退缺陷，但与穹窿横断大鼠不同。地塞米松处理大鼠的行为与对照组相似。结果被解释为意味着ACTH和皮质酮都影响消退行为（以相反的方式），但不能解释海马损伤大鼠中出现的消退缺陷。
