Spatial segregation of different modes of movement control in the whisker representation of rat primary motor cortex
Spatial segregation of different modes of movement control in the whisker representation of rat primary motor cortex
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DOI：
10.1523/jneurosci.3760-04.2005
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发表时间：
2005-02-09
影响因子：
5.3
通讯作者：
Schwarz, C
中科院分区：
文献类型：
--
作者：
Haiss, F;Schwarz, C
初级运动皮层（M1）的表面映射了什么？经典的躯体位置图在肢体表示的水平上是正确的。然而，在小尺度上（在肢体内表示），无论是躯体解剖学还是运动动力学/运动学似乎都不是组织原则。我们调查的假设，整合到M1的身体表示可能有不同的电机控制模式的单独表示，使用不同的皮层下计算，但共享相同的电机周边。使用清醒的大鼠和长皮层内刺激列车在M1晶须表示（wM 1）显示，自然的，有节奏的搅拌（通常用于触觉探索）可以诱发从wM 1的后内侧亚区。另一方面，非节律性的胡须收缩，诱发在相邻的，但更前外侧位于区域内wM 1。诱发的胡须收缩总是伴随着复杂的面部运动，这表明相应的子区域能够在特定的行为背景下与其他表征相互作用。这种联想在诱发的有节奏的拂动中是不存在的。相应的子区域，而似乎激活下游的中央模式发生器，振荡频率是依赖于平均诱发皮层活动。然而，联合刺激的两个相邻的子区域表明其潜力，以功能上有用的方式相互作用。因此，我们认为皮层分离的原因是产生不同类型运动所需的皮层下结构的特定驱动，而不是执行运动的不同行为背景。
What is mapped on the surface of the primary motor cortex (M1)? The classic somatotopic map holds true on the level of limb representations. However, on the small scale ( at within-limb representations), neither somatotopy nor movement dynamics/kinematics seem to be organizational principles. We investigated the hypothesis that integrated into the body representation of M1 there may be separate representation of different modes of motor control, using different subcortical computations but sharing the same motor periphery. Using awake rats and long intracortical stimulation trains in M1 whisker representation (wM1) revealed that natural-like, rhythmic whisking ( normally used for tactile exploration) can be evoked from a posteromedial subregion of wM1. Nonrhythmic whisker retraction, on the other hand, was evoked in an adjacent but more anterolaterally located region within wM1. Evoked whisker retraction was always accompanied by complex movements of the face, suggesting that the respective subregion is able to interact with other representations in specific behavioral contexts. Such associations were absent for evoked rhythmic whisking. The respective subregion rather seemed to activate a downstream central pattern generator, the oscillation frequency of which was dependent on the average evoked cortical activity. Nevertheless, joint stimulation of the two neighboring subregions demonstrated their potency to interact in a functionally useful way. Therefore, we suggest that the cause of cortical separation is the specific drive of subcortical structures needed to generate different types of movements rather than different behavioral contexts in which the movements are performed.