Computational Neuroscience Graduate Program, University of California, San Diego, San Diego, CA 92093, USA.
Neuron. 2011 Oct 20;72(2):344-56. doi: 10.1016/j.neuron.2011.09.020.
Exploratory whisking in rat is an example of self-generated movement on multiple timescales, from slow variations in the envelope of whisking to the rapid sequence of muscle contractions during a single whisk cycle. We find that, as a population, spike trains of single units in primary vibrissa motor cortex report the absolute angle of vibrissa position. This representation persists after sensory nerve transection, indicating an efferent source. About two-thirds of the units are modulated by slow variations in the envelope of whisking, while relatively few units report rapid changes in position within the whisk cycle. The combined results from this study and past measurements, which show that primary sensory cortex codes the whisking envelope as a motor copy signal, imply that signals present in both sensory and motor cortices are necessary to compute angular coordinates based on vibrissa touch.
大鼠的探索性触须运动是一种自我产生的多时间尺度运动的例子，从触须运动包络的缓慢变化到单个触须周期中肌肉收缩的快速序列。我们发现，作为一个群体，初级触须运动皮层中的单个单位的尖峰火车报告触须位置的绝对角度。这种表示在感觉神经切断后仍然存在，表明存在传出源。大约三分之二的单位被触须运动包络的缓慢变化调制，而相对较少的单位报告在触须周期内位置的快速变化。这项研究的综合结果以及过去的测量结果表明，初级感觉皮层将触须运动包络编码为运动副本信号，这意味着存在于感觉和运动皮层中的信号都是基于触须触觉计算角坐标所必需的。
