Rhythmic Whisking Area (RW) in Rat Primary Motor Cortex: An Internal Monitor of Movement-Related Signals?
Rhythmic Whisking Area (RW) in Rat Primary Motor Cortex: An Internal Monitor of Movement-Related Signals?
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DOI：
10.1523/jneurosci.0337-13.2013
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发表时间：
2013-08-28
影响因子：
5.3
通讯作者：
Schwarz, Cornelius
中科院分区：
文献类型：
--
作者：
Gerdjikov, Todor V.;Haiss, Florent;Schwarz, Cornelius
触须相关的感觉运动皮层通过调制低水平的感觉运动回路和脑干中央模式发生器（CPG）间接控制拂动运动。初级运动皮层（vM1）中两种不同的胡须表征以不同的方式影响胡须运动。长时间的微刺激RF，一个更大的前部亚区的VM1，引起复杂的面部运动和胡须收缩，而同样的刺激引起大幅度的节奏性胡须运动在一个小的尾内侧区（RW）。为了表征探索性拂动运动的运动皮层表征，在这里，我们记录了头固定大鼠的RW单位，训练大鼠用一根胡须接触移动物体。RW单个单位被发现编码两个方面的触须运动独立，虽然在缓慢的时间尺度（数百毫秒）。第一个是胡须的位置。第二个由速度（绝对速度），强度（瞬时功率）和频率（光谱质心）组成。后三个参数的编码是紧密相关的，并实现了一个连续的RW响应范围从运动的偏好，以休息的偏好。信息论分析表明，RW锋电位携带了大部分的位置和频率信息，而强度和速度信息较少。此外，调查多个和单个RW单位，我们发现缺乏相位锁定，运动预期，和接触相关的触觉反应。这些研究结果表明，RW既没有详细的程序晶须轨迹，也没有启动它们。它在处理物体触摸时也不起作用。因此，它与搅拌的关系是间接的，可能与运动监测有关，可能使用来自CPG的反馈。
Vibrissae-related sensorimotor cortex controls whisking movements indirectly via modulation of lower-level sensorimotor loops and a brainstem central pattern generator (CPG). Two different whisker representations in primary motor cortex (vM1) affect whisker movements in different ways. Prolonged microstimulation in RF, a larger anterior subregion of vM1, gives rise to complex face movements and whisker retraction while the same stimulation evokes large-amplitude rhythmic whisker movement in a small caudo-medial area (RW). To characterize the motor cortex representation of explorative whisking movements, here we recorded RW units in head-fixed rats trained to contact a moving object with one whisker. RW single units were found to encode two aspects of whisker movement independently, albeit on slow time scales (hundreds of milliseconds). The first is whisker position. The second consists of speed (absolute velocity), intensity (instantaneous power), and frequency (spectral centroid). The coding for the latter three parameters was tightly correlated and realized by a continuum of RW responses-ranging from a preference of movement to a preference of rest. Information theory analysis indicated that RW spikes carry most information about position and frequency, while intensity and speed are less well represented. Further, investigating multiple and single RW units, we found a lack of phase locking, movement anticipation, and contact-related tactile responses. These findings suggest that RW neither programs detailed whisker trajectories nor initiates them. Nor does it play a role in processing object touch. Its relationship to whisking is thus indirect and may be related to movement monitoring, perhaps using feedback from the CPG.