Roles of narrow- and broad-spiking dorsal premotor area neurons in reach target selection and movement production.
Roles of narrow- and broad-spiking dorsal premotor area neurons in reach target selection and movement production.
复制标题
窄峰和宽峰背侧前运动区神经元在到达目标选择和运动产生中的作用。
DOI：
10.1152/jn.00238.2009
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发表时间：
2010
影响因子：
2.5
通讯作者：
McPeek,RobertM
中科院分区：
文献类型：
--
作者：
Song,Joo-Hyun;McPeek,RobertM
大多数视觉场景都是复杂而拥挤的，有几个不同的物体在争夺注意力和动作。因此，对目标导向行动的产生的完整理解必须包含目标选择的更高层次的过程。为了研究视觉引导到达的目标选择的神经基质，我们记录了执行反应时间视觉搜索任务的猴子的背侧运动前区（PMD）的孤立神经元的活动。在这项任务中，猴子在三个干扰物面前到达一个颜色奇怪的目标。我们发现，PMd神经元通常在运动开始前识别目标，在搜索阵列出现后大约150-200 ms。在一个子集的神经元，歧视发生在一个一致的时间搜索阵列发病后，无论何时达到运动发生，这表明这些神经元参与目标选择。在第二组神经元中，辨别时间取决于到达反应时间，这与参与运动产生但不参与目标选择一致。为了寻找这两个功能定义的组的生理学确证，我们分析了记录的神经元的细胞外锋电位波形。该分析显示了一群具有窄动作电位的神经元，其携带与目标选择相关的信号。具有更广泛动作电位的第二个群体更加异质，一些神经元显示出与目标选择相关的活动，而另一些神经元仅显示出运动产生活动。这些结果表明，PMD包含的信号与目标选择和运动执行，不同的信号进行不同的神经亚群。
Most visual scenes are complex and crowded, with several different objects competing for attention and action. Thus a complete understanding of the production of goal-directed actions must incorporate the higher-level process of target selection. To examine the neural substrates of target selection for visually guided reaching, we recorded the activity of isolated neurons in the dorsal premotor area (PMd) of monkeys performing a reaction-time visual search task. In this task, monkeys reached to an odd-colored target presented with three distractors. We found that PMd neurons typically discriminate the target before movement onset, ∼150–200 ms after the appearance of the search array. In one subset of neurons, discrimination occurred at a consistent time after search array onset regardless of when the reaching movement occurred, suggesting that these neurons are involved in target selection. In a second group of neurons, discrimination time depended on reach reaction time, consistent with involvement in movement production but not in target selection. To look for physiological corroboration of these two functionally defined groups, we analyzed the extracellular spike waveforms of recorded neurons. This analysis showed a population of neurons with narrow action potentials that carried signals related to target selection. A second population with broader action potentials was more heterogeneous, with some neurons showing activity related to target selection and others showing only movement production activity. These results suggest that PMd contains signals related to target selection and movement execution and that different signals are carried by distinct neural subpopulations.