Volpe B T, Davis H P, Colombo P J
Department of Neurology and Neuroscience, Cornell University Medical School, Burke Rehabilitation Center, White Plains, NY 10605.
Stroke. 1989 Dec;20(12):1700-6. doi: 10.1161/01.str.20.12.1700.
Rats exposed to 30 minutes of four-vessel occlusion reliably develop severe bilateral CA1 hippocampal injury; under certain conditions of radial maze training, such rats perform the reference memory component as well as controls yet perform the working memory component worse than controls. Reference memory is thought to depend on invariable and working memory on variable spatial information. We assessed the effect of training before ischemia. In Experiment 1, rats trained for 36 trials on 12-arm radial mazes before ischemia demonstrated a persistent impairment on the working memory task but eventually performed the reference memory task comparable to controls. Ischemic rats made more working memory errors as the number of choices increased. This pattern of working memory errors was similar to that in controls except, as expected, ischemic rats made many more errors. In Experiment 2, training for 80 trials before ischemia in rats decreased the severity of both the working and the reference memory impairment. Ischemia did not affect motor behavior in either experiment. These results characterize the working memory deficit in ischemic rats and demonstrate the importance of experimental factors, particularly in the design of treatment strategies to reduce functional impairments caused by ischemia.
暴露于30分钟四动脉闭塞的大鼠会可靠地发生严重的双侧海马CA1区损伤；在某些放射状迷宫训练条件下，此类大鼠的参考记忆成分表现与对照组相当，但工作记忆成分的表现比对照组差。参考记忆被认为依赖于不变的信息，而工作记忆依赖于可变的空间信息。我们评估了缺血前训练的效果。在实验1中，在缺血前于12臂放射状迷宫上训练36次的大鼠在工作记忆任务上表现出持续的损伤，但最终在参考记忆任务上的表现与对照组相当。随着选择次数的增加，缺血大鼠出现更多的工作记忆错误。这种工作记忆错误模式与对照组相似，只是正如预期的那样，缺血大鼠的错误要多得多。在实验2中，大鼠在缺血前训练80次可减轻工作记忆和参考记忆损伤的严重程度。在这两个实验中，缺血均未影响运动行为。这些结果描述了缺血大鼠的工作记忆缺陷，并证明了实验因素的重要性，尤其是在设计治疗策略以减少缺血引起的功能损伤方面。
