Hontanilla B, de las Heras S, Giménez-Amaya J M
Departmento de Morfologia, Facultad de Medicina, Universidad Autónoma de Madrid, Spain.
Neuroscience. 1996 May;72(2):485-503. doi: 10.1016/0306-4522(95)00547-1.
The anatomical organization of the cat nigrostriatal projections to the caudate nucleus was studied by retrograde tracer techniques. Horseradish peroxidase conjugated with wheat germ agglutinin and fluorescent retrograde tracers such as Fast Blue and Diamidino Yellow were injected concomitantly in different regions of the caudate nucleus. The distribution of single and double retrogradely labeled neurons was analysed in the substantia nigra pars compacta, substantia nigra pars lateralis, retrorubral area and adjacent ventral tegmental area. Adjacent sections processed for acetylcholinesterase were used as histochemical markers for the densocellular zone of the substantia nigra. The main findings of this study are: (1) The rostral caudate nucleus receives projections mainly from the caudal substantia nigra while the caudal caudate nucleus receives projections from all rostrocaudal levels of the substantia nigra. (2) The substantia nigra pars lateralis projects very specifically to the caudal caudate nucleus. (3) The ventral retrorubral area close to the medial lemniscus projects to all rostrocaudal levels of the caudate nucleus. (4) The rostral caudate nucleus receives projections mainly from the medial substantia nigra while more caudal sectors of the caudate nucleus receive projections from the medial and lateral substantia nigra. (5) A dorsoventral inversion of nigrostriatal projections from the medial substantia nigra pars compacta and the adjacent ventral tegmental area to the caudate nucleus was established. In contrast, we found zones within the retrorubral area projecting both to the dorsal and ventral caudate nucleus. (6) Distant injections of two different fluorescent tracers regarding both the dorsoventral and the rostrocaudal coordinates, yielded double-labeled neurons that were mainly located in the medial and caudal portions of the substantia nigra and in the ventral retrorubral area. However, the number of double-labeled neurons was higher after separated injections in the dorsoventral axis, suggesting that the collateralization to the caudate nucleus occurs mainly in the dorsoventral plane. (7) A clustering organization of nigrostriatal cells projecting to the caudate nucleus was detected mainly in the intermediate rostrocaudal part of the substantia nigra pars compacta and in the retrorubral area. The results of this comprehensive study on the cat nigrostriatal pathway to the caudate nucleus show novel findings on the anatomical organization of the nigrostriatal projections which might help the understanding of the complex architecture of nigral neurons projecting to the caudate nucleus in carnivores.
采用逆行示踪技术研究了猫黑质纹状体向尾状核的投射的解剖学组织。将与麦胚凝集素结合的辣根过氧化物酶以及诸如快蓝和双脒基黄等荧光逆行示踪剂同时注射到尾状核的不同区域。分析了黑质致密部、黑质外侧部、红核后区及相邻腹侧被盖区中单标记和双标记神经元的分布。用处理过的乙酰胆碱酯酶相邻切片作为黑质致密细胞区的组织化学标记物。本研究的主要发现如下：(1) 尾状核头部主要接受来自黑质尾部的投射，而尾状核尾部接受来自黑质所有头-尾水平的投射。(2) 黑质外侧部非常特异性地投射到尾状核尾部。(3) 靠近内侧丘系的腹侧红核后区投射到尾状核的所有头-尾水平。(4) 尾状核头部主要接受来自黑质内侧部的投射，而尾状核更靠后的部分接受来自黑质内侧部和外侧部的投射。(5) 确定了黑质致密部内侧和相邻腹侧被盖区向尾状核的黑质纹状体投射存在背-腹倒置。相比之下，我们发现红核后区内有一些区域既投射到尾状核背侧也投射到腹侧。(6) 在背-腹和头-尾坐标方面进行两种不同荧光示踪剂的远距离注射，产生的双标记神经元主要位于黑质的内侧和尾部以及腹侧红核后区。然而，在背-腹轴上进行分开注射后双标记神经元的数量更多，这表明向尾状核的侧支化主要发生在背-腹平面。(7) 在黑质致密部中间的头-尾部分和红核后区主要检测到了投射到尾状核的黑质纹状体细胞的聚类组织。这项关于猫黑质纹状体通向尾状核通路的综合研究结果显示了黑质纹状体投射解剖学组织方面的新发现，这可能有助于理解食肉动物中投射到尾状核的黑质神经元的复杂结构。
