Neuronal circuitry related to working memory in the prefrontal cortex

为了研究前额叶神经元如何保留多个空间位置的信息，记录了两只猴子在执行两项任务时前额叶皮层的神经元活动;在延迟顺序到达任务中，猴子被要求保留两个提示位置及其呈现顺序，而在延迟到达任务中，猴子只被要求保留一个位置。在138个任务相关神经元中，72个表现出统计学上显著的延迟期活动。通过比较两种任务的活动，延迟期活动分为四组。19个神经元仅在视觉线索出现在特定位置时才表现出延迟期活动;在6个神经元中，线索位置对引发活动很重要，而13个神经元仅在视觉线索以特定顺序出现在特定位置时才表现出活动。39个神经元仅在视觉线索呈现时才表现出延迟期活动， ...更多信息 测试两个特定位置; 13名被试无论提示呈现的时间顺序如何都表现出这种活动，而26名被试只有在视觉提示以特定的时间顺序呈现时才表现出这种活动。其余14个表现出非差异性活性或其他活性。本实验表明，新的延迟期活动出现，以保持多个位置和提示呈现的时间顺序，对依赖和时间顺序依赖的活动。成对依赖延迟期活动可能是一种机制，可以同时保留多个空间信息位，并通过单个神经元有效地将这些信息互连。具有时序依赖性的活动的存在表明，主周区在计划和执行顺序行为中起着作用，并且保留呈现的位置和时序可能是保留和互连多个信息位的另一种有效策略。少

To investigate how information for multiple spatial positions is retained by prefrontal neurons, neuron activity was recorded from the prefrontal cortex of two monkeys while they performed two tasks ; in the delayd sequential reaching task, monkeys were required to retain two cue locations and the order of their presentation, while in the delayd reaching task, monkeys were required to retain only one location. Among 138 task-related neurons, 72 showed statistically significant delay-period activity. By comparing the activity across both tasks, the delay-period activity were classified into four groups. 19 neurons exhibited delay-period activity only when the visual cue was presented at a particular position ; in 6 neurons, the cue position was important for eliciting the activity, whereas 13 exhibited the activity only when the visual cues were presented at a particular position in a particular order. 39 neurons exhibited delay-period activity only when the visual cues were presented a … More t two particular positions ; 13 exhibited this activity regardless of the temporal order of cue presentation, whereas 26 exhibited the activity only when the visual cues were presented in a particular temporal order. The remaining 14 exhibited either non-differential activity or miscellaneous activity. The present experiment shows that the new class of delay-period activity emerged to retain multiple positions and the temporal order of cue presentation ; pair-dependent and temporal order-dependent activity. Pair-dependent delay-period activity could be a mechanism for simultaneously retaining multiple bits of spatial information and for effectively interconnecting these information by a single neuron. The presence of the activity with temporal order-dependency suggests that the periprincipal area plays a role in planning and executing sequential behaviors and that retaining both the positions and the temporal order of the presentation could be an another effective strategy for retaining and interconnecting multiple bits of information. Less