Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, United States.
Elife. 2020 Dec 24;9:e63035. doi: 10.7554/eLife.63035.
The prefrontal cortex (PFC)'s functions are thought to include working memory, as its activity can reflect information that must be temporarily maintained to realize the current goal. We designed a flexible spatial working memory task that required rats to navigate - after distractions and a delay - to multiple possible goal locations from different starting points and via multiple routes. This made the current goal location the key variable to remember, instead of a particular direction or route to the goal. However, across a broad population of PFC neurons, we found no evidence of current-goal-specific memory in any previously reported form - that is differences in the rate, sequence, phase, or covariance of firing. This suggests that such patterns do not hold working memory in the PFC when information must be employed flexibly. Instead, the PFC grouped locations representing behaviorally equivalent task features together, consistent with a role in encoding long-term knowledge of task structure.
前额叶皮层（PFC）的功能被认为包括工作记忆，因为其活动可以反映出必须暂时保留的信息，以实现当前的目标。我们设计了一个灵活的空间工作记忆任务，要求老鼠在分心和延迟后，从不同的起点和通过多条路线导航到多个可能的目标位置。这使得当前的目标位置成为需要记住的关键变量，而不是到达目标的特定方向或路线。然而，在广泛的 PFC 神经元群体中，我们没有发现任何以前报告形式的当前目标特定记忆的证据——即放电率、序列、相位或协方差的差异。这表明，当信息必须灵活使用时，这种模式并不能在 PFC 中保持工作记忆。相反，PFC 将代表行为等效任务特征的位置组合在一起，这与在编码任务结构的长期知识方面的作用一致。
