Luine V, Martinez C, Villegas M, Magariños A M, McEwen B S
Department of Psychology, Hunter College, New York, NY 10021, USA.
Physiol Behav. 1996 Jan;59(1):27-32. doi: 10.1016/0031-9384(95)02016-0.
The effects of restraint stress on performance of a spatial memory task, the eight arm radial maze, was examined in rats. When stress was given for 6 h/day for 7 days and performance evaluated days 10-13 post stress, no effect on performance was noted; however, daily restraint stress for 13 days caused a small, but significant, enhancement of performance days 10-13 post stress. Stressed rats performed better than controls: their number of correct choices in the first 8 visits was higher than the controls, and stressed rats took fewer total choices to finish the maze than controls. Stress-dependent, enhanced performance does not appear permanent since further maze testing on days 14 and 15 post stress showed no differences between the groups. Performance of the stressed rats significantly correlated with their stress-induced, serum corticosterone levels measured after 6 h of restraint on the last day of restraint, day 13 (r = -0.63, P < 0.05); rats with higher levels of CORT took fewer choices to finish the task. Examination of hippocampal CA3c pyramidal neurons with Golgi techniques showed no effect of stress on the basal or apical dendritic arbors. Since our previous study showed that 21 days of restraint stress is associated with impaired spatial memory performance (10), these results suggest that the duration of stress may differentially affect learning/memory with shorter periods of stress serving an adaptive function while longer durations causing maladaptive changes.
研究了束缚应激对大鼠空间记忆任务——八臂放射状迷宫表现的影响。当每天施加应激6小时，持续7天，并在应激后第10 - 13天评估表现时，未观察到对应激表现的影响；然而，每天束缚应激13天导致在应激后第10 - 13天表现有轻微但显著的提高。应激大鼠的表现优于对照组：它们在前8次访问中的正确选择次数高于对照组，并且应激大鼠完成迷宫所需的总选择次数比对照组少。应激依赖性增强的表现似乎不是永久性的，因为在应激后第14天和第15天进行的进一步迷宫测试显示两组之间没有差异。应激大鼠的表现与在束缚最后一天（第13天）束缚6小时后测量的应激诱导血清皮质酮水平显著相关（r = -0.63，P < 0.05）；皮质酮水平较高 的大鼠完成任务所需的选择次数较少。用高尔基技术检查海马CA3c锥体细胞显示应激对基底或顶端树突分支没有影响。由于我们之前的研究表明21天的束缚应激与空间记忆表现受损有关（10），这些结果表明应激持续时间可能对学习/记忆有不同影响，较短时间的应激起适应性作用，而较长时间的应激会导致适应不良变化。
