Schell G R, Strick P L
J Neurosci. 1984 Feb;4(2):539-60. doi: 10.1523/JNEUROSCI.04-02-00539.1984.
We have used retrograde transport of wheat germ agglutinin conjugated to horseradish peroxidase to examine the origin of thalamic input to the two premotor areas with the densest projections to the motor cortex: the arcuate premotor area (APA) and the supplementary motor area (SMA). Retrograde transport demonstrated that the two premotor areas and the motor cortex each receive thalamic input from separate, cytoarchitectonically well defined subdivisions of the ventrolateral thalamus. According to the nomenclature of Olszewski (Olszewski, J. (1952) The Thalamus of the Macaca mulatta. An Atlas for Use with the Stereotaxic Instrument, S. Karger, AG, Basel), input to the APA originates largely from area X, input to the SMA originates largely from the pars oralis subdivision of nucleus ventralis lateralis (VLo), and that to the motor cortex originates largely from the pars oralis subdivision of nucleus ventralis posterior lateralis (VPLo). These observations, when combined with prior studies on the termination of various subcortical efferents in the thalamus, lead to the following scheme of connections: (1) rostral portions of the deep cerebellar nuclei project to the motor cortex via VPLo; (2) caudal portions of the deep cerebellar nuclei project to the APA via area X; and (3) the globus pallidus projects to the SMA via VLo. Thus, each thalamocortical pathway is associated with a distinct subcortical input.
我们利用与辣根过氧化物酶结合的小麦胚凝集素的逆行运输，来研究丘脑输入到与运动皮层有最密集投射的两个运动前区的起源：弓形运动前区（APA）和辅助运动区（SMA）。逆行运输表明，这两个运动前区和运动皮层各自从腹外侧丘脑在细胞构筑学上定义明确的不同亚区接收丘脑输入。根据奥尔谢夫斯基的命名法（奥尔谢夫斯基，J.（1952年）《恒河猴的丘脑。与立体定位仪配合使用的图谱》，S.卡尔格出版社，巴塞尔），输入到APA的主要来自X区，输入到SMA的主要来自腹外侧核（VLo）的口部亚区，而输入到运动皮层的主要来自腹后外侧核（VPLo）的口部亚区。这些观察结果与先前关于各种皮质下传出纤维在丘脑终止的研究相结合，得出以下连接模式：（1）小脑深部核的前部通过VPLo投射到运动皮层；（2）小脑深部核的后部通过X区投射到APA；（3）苍白球通过VLo投射到SMA。因此，每条丘脑皮质通路都与一种独特的皮质下输入相关联。
