Activity properties and location of neurons in the motor thalamus that project to the cortical motor areas in monkeys
Activity properties and location of neurons in the motor thalamus that project to the cortical motor areas in monkeys
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DOI：
10.1152/jn.01034.2004
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发表时间：
2005-07-01
影响因子：
2.5
通讯作者：
Kurata, K
中科院分区：
文献类型：
--
作者：
Kurata, K
研究人员在猴子身上研究了投射到皮质运动区（初级运动皮质、腹侧和背侧前运动皮质和辅助运动区）的丘脑运动核中神经元的活动，这些猴子正在执行一项任务，在该任务中，在运动开始之前，视觉空间线索指示手腕伸展和屈曲运动。运动是由视觉、听觉或体感刺激触发的。通过尖峰碰撞识别丘脑皮质神经元，并表现出两种不同类型的任务相关活动：1）在指示准备期间响应指令提示的活动持续变化（与设定相关的活动）； 2) 反应和运动时间段内活动的阶段性变化（运动相关活动）。许多与集合和力矩相关的神经元表现出方向选择性。大多数与运动相关的神经元都同样活跃，无论运动提示的感觉方式不同。无论其目标皮质运动区域如何，神经元活动的这些特性都是相似的。投射到初级和非初级运动区的神经元的逆向潜伏期没有显着差异。这些结果表明，丘脑皮质神经元在运动的准备、启动和执行中发挥着重要作用，但在模态选择性感觉运动转化中不如非初级皮质运动区的神经元重要。这种转变很可能发生在非初级皮质运动区，但不是通过丘脑皮质信息通道。
The activity of neurons in the motor nuclei of the thalamus that project to the cortical motor areas (the primary motor cortex, the ventral and dorsal premotor cortex, and the supplementary motor area) was investigated in monkeys that were performing a task in which wrist extension and flexion movements were instructed by visuospatial cues before the onset of movement. Movement was triggered by a visual, auditory, or somatosensory stimulus. Thalamocortical neurons were identified by a spike collision, and exhibited 2 distinct types of task-related activity: 1) a sustained change in activity during the instructed preparation period in response to the instruction cues (set-related activity); and 2) phasic changes in activity during the reaction and movement time periods (movement-related activity). A number of set- and moment-related neurons exhibited direction selectivity. Most movement-related neurons were similarly active, irrespective of the different sensory modalities of the cue for movement. These properties of neuronal activity were similar, regardless of their target cortical motor areas. There were no significant differences in the antidromic latencies of neurons that projected to the primary and nonprimary motor areas. These results suggest that the thalamocortical neurons play an important role in the preparation for, and initiation and execution of, the movements, but are less important than neurons of the nonprimary cortical motor areas in modality-selective sensorimotor transformation. It is likely that such transformations take place within the nonprimary cortical motor areas, but not through thalamocortical information channels.