Temporal Information Processing in Prefrontal-Basal Ganglia Circuit

前额叶-基底神经节环路的时间信息处理

基本信息

批准号：
18500314
负责人：
INASE Masahiko
金额：
$ 2.38万
依托单位：
Kinki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

项目摘要

We have been conducting neurophysiological experiments to reveal neuronal mechanisms for temporal information processing in the prefrontal-basal ganglia circuit. Monkeys were trained to perform a duration discrimination task. In the task, two visual cues were presented successively in different duration (0.2〜1.6 sec). Each cue presentation was followed by a 1-sec delay period. The subjects were instructed to choose a longer presented cue after the second delay period. Single-unit activity was recorded from the prefrontal cortex and the striatum while the monkeys were performing the task.Prefrontal neurons showed phasic activity during the first cue period. The activity had peak time around 800ms that was close to the midpoint between long and short cue duration. This activity might have functioned for filtering cue duration to discriminate between long and short cues. In the first delay period prefrontal neurons exhibited differential activity following long and short cues. In the neurons with preference for long cues the delay activity after longer cues was uniformly high regardless of cue duration, but that after shorter cues was uniformly low. This binary change in the delay activity indicates that the prefrontal cortex could represent cue duration categorically as long or short. Striatal neurons phasically responded during the first and second delay periods. Responses during the first delay period changed depending on the first cue duration. Activity of populations of these neurons correlated with the first cue duration positively or negatively. Responses during the second delay period differed between long-short and short-long trials. These findings suggest that striatal neurons could encode cue duration with monotonically changing responses and discrimination results between the two cue durations.

我们一直在进行神经生理实验，以揭示前额叶神经节回路中临时信息处理的神经元机制。对猴子进行了训练以执行持续时间歧视任务。在任务中，在不同的持续时间（0.2-1.6秒）成功地呈现了两个视觉提示。每个提示表现之后是1-SEC延迟期。指示受试者在第二个延迟期之后选择更长的提示。在执行任务时，从前额叶皮层和纹状体记录了单单元活性。前额外神经元在第一个提示期间显示出阶段性活性。该活动的高峰时间约为800ms，接近长达和短提示持续时间之间的中点。该活动可能起到过滤提示持续时间的作用，以区分长线和短提示。在第一个延迟期间，前额叶神经元在长长和短提示后暴露了差异活动。在偏爱长线索的神经元中，长线索后的延迟活性均匀地高，无论提示如何，较短的提示均匀较低。延迟活动中的这种二进制变化表明前额叶皮层可以明确或短期表示提示持续时间。纹状体神经元在第一个和第二延迟期间对物理反应。第一个延迟期间的响应根据第一提示持续时间而发生了变化。这些神经元种群的活性与第一个提示持续时间相关。在长短试验和短期试验之间，第二延迟期间的响应有所不同。这些发现表明，纹状体神经元可以用单调变化的响应和两个提示持续时间之间的歧视结果编码提示持续时间。