Miyachi Shigehiro, Lu Xiaofeng, Imanishi Michiko, Sawada Kaori, Nambu Atsushi, Takada Masahiko
Department of System Neuroscience, Tokyo Metropolitan Institute for Neuroscience, Tokyo Metropolitan Organization for Medical Research, Fuchu, Tokyo 183-8526, Japan.
Neurosci Res. 2006 Nov;56(3):300-8. doi: 10.1016/j.neures.2006.07.012. Epub 2006 Sep 12.
Employing retrograde transsynaptic transport of rabies virus, we investigated the organization of basal ganglia inputs to hindlimb, proximal and distal forelimb, and orofacial representations of the macaque primary motor cortex (MI). Four days after rabies injections into these MI regions, neuronal labeling occurred in the striatum and the subthalamic nucleus (STN) through the cortico-basal ganglia loop circuits. In the striatum, two distinct sets of the labeling were observed: one in the dorsal putamen, and the other in the ventral striatum (ventromedial putamen and nucleus accumbens). The dorsal striatal labeling was somatotopically arranged and its distribution pattern was in good accordance with that of the corticostriatal inputs, such that the hindlimb, orofacial, or forelimb area was located in the dorsal, ventral, or intermediate zone of the putamen, respectively. The distribution pattern of the ventral striatal labeling was essentially the same in all cases. In the STN, the somatotopic arrangement of labeled neurons was in register with that of corticosubthalamic inputs. The present results suggest that the cortico-basal ganglia motor circuits involving the dorsal putamen and the STN may constitute separate closed loops based on the somatotopy, while the ventral striatum provides common multisynaptic projections to all body-part representations in the MI.
我们利用狂犬病毒的逆行跨突触运输，研究了猕猴初级运动皮层（MI）中基底神经节向 hindlimb、近端和远端前肢以及口面部表征区域的输入组织。在向这些 MI 区域注射狂犬病毒四天后，通过皮质 - 基底神经节环路，在纹状体和丘脑底核（STN）中出现了神经元标记。在纹状体中，观察到两组不同的标记：一组在背侧壳核，另一组在腹侧纹状体（腹内侧壳核和伏隔核）。背侧纹状体的标记呈躯体定位排列，其分布模式与皮质 - 纹状体输入的分布模式高度一致，即 hindlimb、口面部或前肢区域分别位于壳核的背侧、腹侧或中间区域。腹侧纹状体标记的分布模式在所有情况下基本相同。在 STN 中，标记神经元的躯体定位排列与皮质 - 丘脑底核输入的排列一致。目前的结果表明，涉及背侧壳核和 STN 的皮质 - 基底神经节运动环路可能基于躯体定位构成独立的闭环，而腹侧纹状体为 MI 中所有身体部位的表征提供共同的多突触投射。
