Subdivisions of primary motor cortex based on cortico-motoneuronal cells
Subdivisions of primary motor cortex based on cortico-motoneuronal cells
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DOI：
10.1073/pnas.0808362106
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发表时间：
2009-01-20
影响因子：
11.1
通讯作者：
Strick, Peter L.
中科院分区：
文献类型：
--
作者：
Rathelot, Jean-Alban;Strick, Peter L.
我们从恒河猴的单个肌肉中逆行跨神经元运输狂犬病病毒，以确定初级运动皮质(M1)中的皮质运动神经元(CM)细胞，这些细胞与支配肩部、肘部和手指肌肉的运动神经元进行单突触连接。我们发现M1有两个细分。吻区缺乏CM细胞，代表了许多哺乳动物的标准M1。从旧的M1传出的皮质脊髓传出的下行指令必须使用脊髓的整合机制来产生运动神经元活动和运动输出。相反，M1的尾侧区域包含肩部、肘部和手指的CM细胞。这一区域代表了一种只存在于一些高等灵长类动物和人类中的“新”M1。由CM细胞提供的对运动神经元的直接访问使新发现的M1能够绕过脊髓机制，并塑造对高技能运动至关重要的新的运动输出模式。
We used retrograde transneuronal transport of rabies virus from single muscles of rhesus monkeys to identify cortico-motoneuronal (CM) cells in the primary motor cortex (M1) that make monosynaptic connections with motoneurons innervating shoulder, elbow, and finger muscles. We found that M1 has 2 subdivisions. A rostral region lacks CM cells and represents an "old" M1 that is the standard for many mammals. The descending commands mediated by corticospinal efferents from old M1 must use the integrative mechanisms of the spinal cord to generate motoneuron activity and motor output. In contrast, a caudal region of M1 contains shoulder, elbow, and finger CM cells. This region represents a "new" M1 that is present only in some higher primates and humans. The direct access to motoneurons afforded by CM cells enables the newly recognized M1 to bypass spinal cord mechanisms and sculpt novel patterns of motor output that are essential for highly skilled movements.