CORTICOMOTONEURONAL SYNAPSES IN THE MONKEY - LIGHT MICROSCOPIC LOCALIZATION UPON MOTONEURONS OF INTRINSIC MUSCLES OF THE HAND
CORTICOMOTONEURONAL SYNAPSES IN THE MONKEY - LIGHT MICROSCOPIC LOCALIZATION UPON MOTONEURONS OF INTRINSIC MUSCLES OF THE HAND
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DOI：
10.1002/cne.902320407
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发表时间：
1985-01-01
影响因子：
2.5
通讯作者：
REDMAN, SJ
中科院分区：
文献类型：
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作者：
LAWRENCE, DG;PORTER, R;REDMAN, SJ
一些皮质脊髓神经元产生轴突，轴突直接终止于运动神经元，从而建立皮质神经元连接。利用轴突内和细胞内的辣根过氧化物酶（HRP）证实了皮质神经元突触在支配猴子手部固有肌肉的运动神经元上的位置。在[颈]C7-C8的侧索静脉注射HRP后，一些来自中央前回手部区域的皮质脊髓轴突被注射，一些附近已确定的手部肌肉运动神经元被注射。用钴增强二氨基联苯胺法重建皮质神经元纤维和运动神经元之间的连接。侧索的皮质脊髓轴突产生主侧枝，这在第九层提供了广泛的树枝化，在那里主要是纵向的，在邻近的中间区。在这些乔木的前顶枝上产生大量的、单个的或簇生的顶枝。在光镜下发现了7个皮质神经突触。它们位于受体运动神经元的树突上40-750 .mu。从体细胞中提取M，大小从0.6倍不等。3.0 .mu。M到2.4倍。3.6 .mu.m。皮质神经元轴突的每个主侧枝与受体运动神经元的树突建立很少的突触接触，可能只有1个。每个运动神经元的少量接触与前肢和手部运动神经元记录的最小和单一皮质运动神经元EPSP（兴奋性snap后电位）的小振幅一致。
Some corticospinal neurons give rise to axons which terminate directly upon motoneurons, thereby establishing corticomotoneuronal connections. The location of corticomotoneuronal synapses upon motoneurons innervating intrinsic muscles of the hand in the monkey was demonstrated by the use of intra-axonal and intracellular horseradish peroxidase (HRP). After a number of corticospinal axons originating from the hand area of the precentral gyrus were injected with HRP in the lateral funiculus at [cervical] C7-C8, a number of nearby identified intrinsic hand muscle motorneurons were injected. Connections between corticomotoneuronal fibers and motoneurons were reconstructed from longitudinal parasagittal sections treated by the cobalt-enhanced diaminobenzidine method. Corticospinal axons in the lateral funiculus gave rise to main collaterals which provided an extensive arborization in lamina IX, where it was predominantly longitudinal and in the adjacent intermediate zone. En passant and single or clustered groups of terminal boutons arose from preterminal branches of these arbors. Seven light-microscopically identified corticomotoneural synapses were found. They were located upon the dendrities of recipient motoneurons at 40-750 .mu.m from the soma and ranged in size from 0.6 .times. 3.0 .mu.m to 2.4 .times. 3.6 .mu.m. Each main collateral of a corticomotoneuronal axon establishes very few synaptic contacts, and possibly only 1, with the dendrities of recipient motoneurons. This small number of contacts per motoneuron is consistent with the small amplitudes of minimal and unitary corticomotoneuronal EPSP [excitatory postsnaptic potentials] recorded from forelimb and hand motoneurons.