Sher Yoel, Cohen Oren, Zinger Nofya, Harel Ran, Rubinsky Boris, Prut Yifat
Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, Hadassah Medical School, The Hebrew University Jerusalem, Israel.
Front Neurosci. 2010 Nov 25;4:195. doi: 10.3389/fnins.2010.00195. eCollection 2010.
Spinal neurons operate as a processing link that integrates descending and peripheral information and in turn, generates a specific yet complex muscle command. The functional organization of spinal circuitry during normal motor behavior dictates the way in which this translation process is achieved. Nonetheless, little is known about this organization during normal motor behavior. We examined the spatial organization of neural activity in the cervical spinal cord of behaving primates performing an isometric wrist task by estimating the averaged intraspinal activity of neuronal populations. We measured population response profiles and frequency content around torque onset and tested the tendency of these profiles to exhibit a specific organization within the spinal volume. We found that the spatial distribution of characteristic response profiles was non-uniform; namely, sites with a specific response profile tended to have a preferred spatial localization. Physiologically, this finding suggests that specific spinal circuitry that controls a unique feature of motor actions (with a particular task-related response pattern) may have a segregated spinal organization. Second, attempts to restore motor function via intraspinal stimulation may be more successful when the spatial distribution of these task-related profiles is taken into account.
脊髓神经元作为一个处理环节，整合下行和外周信息，进而产生特定而复杂的肌肉指令。正常运动行为期间脊髓回路的功能组织决定了这种转换过程的实现方式。然而，对于正常运动行为期间的这种组织情况，我们知之甚少。我们通过估计神经元群体的平均脊髓内活动，研究了执行等长腕部任务的灵长类动物颈椎脊髓中神经活动的空间组织。我们测量了扭矩开始时周围的群体反应曲线和频率成分，并测试了这些曲线在脊髓体积内呈现特定组织的趋势。我们发现特征反应曲线的空间分布并不均匀；也就是说，具有特定反应曲线的部位往往有一个偏好的空间定位。从生理学角度来看，这一发现表明，控制运动动作独特特征（具有特定任务相关反应模式）的特定脊髓回路可能具有分离的脊髓组织。其次，当考虑到这些任务相关曲线的空间分布时，通过脊髓内刺激恢复运动功能的尝试可能会更成功。
