Intracellularly labeled pyramidal neurons in the cortical areas projecting to the spinal cord - II. Intra- and juxta-columnar projection of pyramidal neurons to corticospinal neurons
Intracellularly labeled pyramidal neurons in the cortical areas projecting to the spinal cord - II. Intra- and juxta-columnar projection of pyramidal neurons to corticospinal neurons
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DOI：
10.1016/j.neures.2004.08.007
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发表时间：
2004-12-01
影响因子：
2.9
通讯作者：
Kaneko, T
中科院分区：
文献类型：
--
作者：
Cho, RH;Segawa, S;Kaneko, T
采用细胞内染色结合Golgi样逆行标记技术，观察了大鼠运动感觉皮质锥体神经元与皮质脊髓神经元的柱状内或柱状旁联系。在108个细胞内标记的锥体神经元中，选择27个神经元通过其轴突分支的成功染色和皮质脊髓神经元的充分逆行标记进行形态学分析。每个锥体神经元的局部轴突侧支的许多血管与皮质脊髓神经元的树突紧密并列，表明II-VI层锥体神经元向皮质脊髓神经元的会聚投射。特别是，静脉曲张的第四层星锥体神经元作出两至三倍以上的appositions皮质脊髓神经元的树突比那些锥体神经元在其他层。15个并置进行了电子显微镜检查，其中60%的不对称轴棘突触。目前的结果以及之前报告的结果表明，丘脑输入优先通过具有阶段性反应特性的IV层星锥体神经元传递到皮质脊髓神经元，从而可能有助于运动的启动或切换。与此相反，从其他层的紧张性反应特性的输入似乎是整合在皮质脊髓神经元，并可能是有用的，在维持皮质脊髓神经元的活动。(C)2004年Elsevier爱尔兰有限公司和日本神经科学学会。All rights reserved.
Intra- or juxta-columnar connections of pyramidal neurons to corticospinal neurons in rat motorsensory cortices were examined with brain slices by combining intracellular staining with Golgi-like retrograde labeling of corticospinal neurons. Of 108 intracellularly labeled pyramidal neurons, 27 neurons were selected for morphological analysis by successful staining of their axonal arborizations and sufficient retrograde labeling of corticospinal neurons. Many varicosities of local axon collaterals of each pyramidal neuron were closely apposed to the dendrites of corticospinal neurons, suggesting the convergent projections of layer II-VI pyramidal neurons to corticospinal neurons. Particularly, the varicosities of a layer IV star-pyramidal neuron made two- to three-fold more appositions to the dendrites of corticospinal neurons than those of a pyramidal neuron in the other layers. Fifteen appositions were examined electron-microscopically and 60% of them made asymmetric axospinous synapses. The present results together with those of the preceding report suggest that thalamic inputs are conveyed to corticospinal neurons preferentially via layer IV star-pyramidal neurons with phasic response properties, and thereby might contribute to the initiation or switching of movement. In contrast, inputs with tonic response properties from the other layers seem to be integrated in corticospinal neurons, and might be useful in maintaining the activity of corticospinal neurons. (C) 2004 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.