McVea David A, Taylor Andrew J, Pearson Keir G
Graduate Program in Neuroscience, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
J Neurosci. 2009 Jul 22;29(29):9396-404. doi: 10.1523/JNEUROSCI.0746-09.2009.
Walking animals rely on working memory to avoid obstacles. One example is the stepping of the hindlegs of quadrupeds over an obstacle. In this case, the obstacle is not visible at the time of hindleg stepping, because of its position between the fore and hindlegs, and working memory must be used to avoid it. We have previously shown that this memory is very precise and surprisingly long-lasting and that it depends on the stepping of the forelegs over the obstacle for its initiation. In this study, we test the hypothesis that area 5 in the posterior parietal cortex of cats is necessary for the maintenance of this long-lasting working memory. We report that small bilateral lesions to area 5 do not affect the amplitude of normal stepping of the hindlegs over obstacles, but they profoundly reduce the long-lasting working memory of obstacles. We propose that inputs to area 5 associated with foreleg stepping initiate long-lasting activity that maintains the memory of obstacle height in another brain region to guide the hindlegs over obstacles.
行走的动物依靠工作记忆来避开障碍物。一个例子是四足动物的后腿跨过障碍物的动作。在这种情况下，由于障碍物位于前腿和后腿之间，后腿迈步时它是看不见的，必须利用工作记忆来避开它。我们之前已经表明，这种记忆非常精确且惊人地持久，并且它的启动依赖于前腿跨过障碍物的动作。在本研究中，我们测试了这样一个假设：猫后顶叶皮质的5区对于维持这种持久的工作记忆是必要的。我们报告称，对5区进行双侧小损伤并不影响后腿正常跨过障碍物的幅度，但会显著降低对障碍物的持久工作记忆。我们提出，与前腿迈步相关的输入到5区的信息会引发持久的活动，这种活动在另一个脑区维持对障碍物高度的记忆，以引导后腿跨过障碍物。
