INTRINSIC ORGANIZATION OF THE RAT CUTANEUS TRUNCI MOTOR NUCLEUS
INTRINSIC ORGANIZATION OF THE RAT CUTANEUS TRUNCI MOTOR NUCLEUS
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DOI：
10.1152/jn.1988.60.2.463
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发表时间：
1988-08-01
影响因子：
2.5
通讯作者：
DIAMOND, J
中科院分区：
文献类型：
--
作者：
THERIAULT, E;DIAMOND, J
1.我们用HRP逆行标记供应不同解剖和生理肌区的运动神经元，研究了躯干皮质肌(CTM)运动核的组织如何与其生理激活模式相对应(见所附报告，61)。CTM运动神经元池由一列紧密排列的位于腹侧的细胞组成，从尾侧C6延伸到吻侧T1，每侧含有1,183个细胞；这一异常大量的运动神经元与肌肉表现出的精确定位的反射行为相一致。2.将CTM分为背侧、外侧、腹侧三个主要纵行肌区的三种主要运动神经中的每一种都被发现来自不同的运动神经元亚柱，该亚柱延伸至母体CTM运动核的整个吻尾长度，即背侧运动神经来自位于内侧的亚柱，外侧运动神经来自位于中央的亚柱，腹侧运动神经来自位于CTM运动核最外侧的运动神经元亚柱。3.肌吻尾侧不同区域局部注射HRP后，CTM运动核进一步细分：位于运动神经元池吻侧的运动神经元供应吻侧肌肉，而位于运动神经元池更靠近尾侧的运动神经元逐渐提供更多的尾侧部位。4.这些结果揭示了运动核既有内侧分支又有吻尾分支的存在，因此运动神经元的这种固有的空间组织在地形图上与其靶肌肉的身体坐标有关。讨论了这些发现与CTM反射中局部信号表达的可能关系，以及潜在回路如何适当地发展。
1. We have investigated how the organization of the cutaneus trunci muscle (CTM) motor nucleus might correspond to the pattern of its physiological activation (see accompanying report, 61) by using HRP to label retrogradely the motoneurons supplying different anatomically and physiologically defined muscle compartments. The CTM motoneuron pool was found to be comprised of a tightly packed column of ventrolaterally located cells extending from caudal C6 to rostral T1 and to contain 1,183 cells per side; this unusually large number of motoneurons is consistent with the precisely localized reflex behavior exhibited by the muscle. 2. Each of three major motor nerves that functionally divide the CTM into three major longitudinal muscle fields (dorsal, lateral, ventral) was found to derive from a distinct subcolumn of motoneurons, which extends for the full rostrocaudal length of the parent CTM motor nucleus, such that the dorsal motor nerves derive from a medially located subcolumn, the lateral motor nerves from a centrally located subcolumn, and the ventral motor nerves from a subcolumn of motoneurons that sits most laterally in the CTM motor nucleus. 3. Localized injections of HRP into different rostrocaudal regions of the muscle revealed a further subdivision of the CTM motor nucleus: motoneurons located rostrally in the motoneuron pool supplied the rostral regions of the muscle, whereas more caudally located motoneurons in the pool supplied progressively more caudal sites in the muscle. 4. These results reveal the existence of both a mediolateral and a rostrocaudal subdivision of the motor nucleus; thus this intrinsic spatial organization of motoneurons relates the CTM motor nucleus topographically to the body coordinates of its target, the muscle. The possible relation of these findings to the expression of local sign in the CTM reflex, and how the underlying circuitry could develop appropriately, is discussed.