Beckstead R M
Neuroscience. 1987 Feb;20(2):557-76. doi: 10.1016/0306-4522(87)90110-2.
A portion of the nigrostriatal projection that originates from presumably dopaminergic neurons in the caudal pars compacta of the substantia nigra and the suprajacent pars dorsalis (retrorubral area), was shown by [3H]amino acid autoradiographic tracing to distribute nonhomogeneously in the head of the caudate nucleus, such that zones of high density termination are in register with the archipelago of substance P cell clusters revealed immunohistochemically in the same and adjacent tissue sections of the cat's brain. Axons from this same portion of the substantia nigra distribute densely at caudal levels of the putamen where again substance P-immunoreactive striatal cells are numerous. In nearby tissue sections from the same cases, tyrosine hydroxylase-like immunoreactivity suggested only subtle variations in the density of the catecholamine axon network within the striatum. Thus, whereas dopamine axons are distributed densely throughout the striatum, those originating from cells in the caudal pars compacta et dorsalis of the substantia nigra and ending in the head of the caudate nucleus appear to terminate preferentially within the substance P cell clusters. These data suggest that the striatal substance P cells, which send their axons selectively to the entopeduncular nucleus and substantia nigra, but much less so the globus pallidus, are a major target of nigrostriatal dopamine transmission. This result is discussed with respect to the anatomical, neurochemical and functional organization of the striatifugal projection system.
用[3H]氨基酸放射自显影追踪法显示，黑质致密部尾侧及相邻的背侧部（红核后区）中推测为多巴胺能神经元发出的黑质纹状体投射的一部分，在尾状核头部呈非均匀分布，使得高密度终末区与在猫脑的相同及相邻组织切片中免疫组化显示的P物质细胞簇群岛相对应。来自黑质同一部分的轴突在壳核尾侧水平密集分布，此处同样有大量P物质免疫反应性纹状体细胞。在同一病例的附近组织切片中，酪氨酸羟化酶样免疫反应性表明纹状体内儿茶酚胺轴突网络密度仅有细微变化。因此，虽然多巴胺轴突密集分布于整个纹状体，但那些起源于黑质致密部尾侧及背侧细胞并终止于尾状核头部的轴突似乎优先终止于P物质细胞簇内。这些数据表明，纹状体P物质细胞将其轴突选择性地发送到内苍白球核和黑质，但发送到苍白球的则少得多，它们是黑质纹状体多巴胺传递的主要靶点。本文就纹状体外投射系统的解剖、神经化学和功能组织对这一结果进行了讨论。
