Hassani O K, François C, Yelnik J, Féger J
Laboratoire de Pharmacologie, Faculté des Sciences Pharmaceutiques et Biologiques, Universite R. Descartes, Paris, France.
Brain Res. 1997 Feb 21;749(1):88-94. doi: 10.1016/s0006-8993(96)01167-5.
The dopaminergic connection from the substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) to the subthalamic nucleus in the rat was investigated using anterograde and retrograde tracers. Iontophoretic injection of the retrograde tracer fluoro-gold (FG) into the subthalamic nucleus resulted in a substantial number of labeled neurons in the SNc. Immunohistochemistry of tyrosine hydroxylase (TH) confirmed the dopaminergic nature of these labeled neurons. Retrogradely labeled neurons were also found in the VTA. Injection of the anterograde tracer biocytin into the SNc produced biocytin-labeled terminals in the subthalamic nucleus hence providing clear evidence for a dopaminergic innervation of this nucleus. Quantitative analysis of labeled axons revealed that there were 15-38 terminal branches per axon, each branch being 50-150 microm long. The overall dimensions of one terminal arborization were 400 x 250 x 150 microm. There was no clear-cut topographical organization of the projection, but a slight mediolateral difference in the density of terminals. This direct dopaminergic projection is thought to interact with cortical and pallidal inputs in the subthalamic nucleus, which implies that the functions of the subthalamic nucleus are more complex than previously assumed.
利用顺行和逆行示踪剂，研究了大鼠中脑黑质致密部（SNc）和腹侧被盖区（VTA）至丘脑底核的多巴胺能连接。将逆行示踪剂荧光金（FG）离子电渗注入丘脑底核，结果在SNc中发现大量标记神经元。酪氨酸羟化酶（TH）免疫组织化学证实了这些标记神经元的多巴胺能性质。在VTA中也发现了逆行标记的神经元。将顺行示踪剂生物素注入SNc，在丘脑底核产生了生物素标记的终末，从而为该核的多巴胺能神经支配提供了明确证据。对标记轴突的定量分析显示，每条轴突有15 - 38个终末分支，每个分支长50 - 150微米。一个终末分支的总体尺寸为400×250×150微米。投射没有明显的拓扑组织，但终末密度在中外侧有轻微差异。这种直接的多巴胺能投射被认为与丘脑底核中的皮质和苍白球输入相互作用，这意味着丘脑底核的功能比以前认为的更为复杂。
