Blustein Joshua E, McLaughlin Michael, Hoffman John R
Department of Psychology, Arcadia University, 450 S. Easton Road, Glenside, PA 19038, USA.
Physiol Behav. 2006 Nov 30;89(4):582-6. doi: 10.1016/j.physbeh.2006.07.017. Epub 2006 Sep 1.
Previous studies indicated that intensity level may be a determining factor in the beneficial or detrimental effects of exercise on spatial memory, as chronic low-intensity level exercise appears to enhance learning and memory which stressful situations may impair. This study examines the effects of different intensity levels of acute exercise (treadmill running) on spatial memory in rats. Using the Morris water maze, spatial learning was measured in animals exposed to treadmill running at low- (20-22 m/min for 25 min daily) and high-intensity (25 m/min for 25 min daily) levels of exercise. A stress control using an electric foot shock was used to examine if the high-intensity exercise was sufficient to serve as a stressor. Stress level was estimated by examining tail flick latencies as a measure of stress-induced analgesia. The results indicate that high-intensity exercise at a level that may not induce an analgesic state is sufficient to impair early acquisition of spatial learning. However, with additional trials, all animals are capable of learning the task. Acute exposure to the electric foot shock impaired learning in the Morris water maze. Surprisingly, across all studies, there was a significantly higher analgesic state post-swim as compared to pre-swim. The results indicate that irrespective of stress level prior to water maze testing, swimming in the Morris water maze repeatedly for short durations of time is enough to induce an analgesic state.
先前的研究表明，运动强度水平可能是运动对空间记忆产生有益或有害影响的一个决定性因素，因为长期低强度运动似乎能增强学习和记忆，而应激情况可能会损害这些能力。本研究考察了不同强度的急性运动（跑步机跑步）对大鼠空间记忆的影响。使用莫里斯水迷宫，对暴露于低强度（每天25分钟，速度为20 - 22米/分钟）和高强度（每天25分钟，速度为25米/分钟）跑步机跑步的动物的空间学习能力进行了测量。使用电足部电击进行应激控制，以检验高强度运动是否足以作为一种应激源。通过检查甩尾潜伏期来估计应激水平，以此作为应激诱导镇痛的一种测量方法。结果表明，处于可能不会诱导镇痛状态水平的高强度运动足以损害空间学习的早期获取。然而，经过额外的试验，所有动物都能够学会这项任务。急性暴露于电足部电击会损害在莫里斯水迷宫中的学习。令人惊讶的是，在所有研究中，与游泳前相比，游泳后的镇痛状态显著更高。结果表明，无论在水迷宫测试前的应激水平如何，在莫里斯水迷宫中短时间反复游泳足以诱导出镇痛状态。
