Williams M N, Faull R L
Neuroscience. 1985 Apr;14(4):991-1010. doi: 10.1016/0306-4522(85)90271-4.
In a light and electron microscopic study of the substantia nigra of the rat, the distribution and morphology of nigrotectal neurons and the pattern of termination of striatonigral fibres have been examined following the placement of horseradish peroxidase injections in the superior colliculus and kainic acid lesions in the dorsal striatum. In confirmation of previous findings, nigrotectal neurons which had been identified by the retrograde transport of horseradish peroxidase from the superior colliculus had mainly medium sized somata, varied from fusiform to stellate in shape and were found in mainly ventral regions of the rostral two-thirds of the substantia nigra pars reticulata. On electron microscopic examination, single and multiple (from two to six) degenerating striatonigral boutons were found in synaptic contact with the soma, proximal mainstem dendrites and small dendrites (but mainly on small dendrites) of labelled nigrotectal and unlabelled nigral neurons in the ventral region of the pars reticulata. In addition, a small number of degenerating striatonigral boutons formed axoaxonic synapses with degenerating or normal boutons which were presynaptic to nigral dendrites. Almost all of the identified striatonigral synapses were of the symmetrical type, although a few degenerating boutons established asymmetrical synaptic contacts on unlabelled dendrites. These findings provide evidence of a monosynaptic input from the dorsal striatum to nigrotectal projection neurons in the substantia nigra and thus demonstrate the existence of a bineuronal pathway from the striatum through the substantia nigra to the superior colliculus. The possible significance of the pattern of termination of striatonigral fibres in the substantia nigra is discussed with reference to the known dendritic arborization of nigral neurons.
在对大鼠黑质进行的光镜和电镜研究中，通过将辣根过氧化物酶注射到上丘以及在背侧纹状体中制造 kainic 酸损伤，研究了黑质 - 顶盖神经元的分布和形态以及纹状体 - 黑质纤维的终末模式。证实了先前的研究结果，通过辣根过氧化物酶从上丘逆行运输鉴定出的黑质 - 顶盖神经元主要具有中等大小的胞体，形状从梭形到星形不等，主要位于黑质网状部前三分之二的腹侧区域。电镜检查发现，在网状部腹侧区域，单个和多个（2至6个）变性的纹状体 - 黑质终扣与标记的黑质 - 顶盖神经元和未标记的黑质神经元的胞体、近端主树突和小树突（但主要是小树突）形成突触联系。此外，少数变性的纹状体 - 黑质终扣与位于黑质树突前的变性或正常终扣形成轴 - 轴突触。几乎所有已鉴定的纹状体 - 黑质突触都是对称型的，尽管少数变性终扣在未标记的树突上建立了不对称突触联系。这些发现提供了从背侧纹状体到黑质中黑质 - 顶盖投射神经元单突触输入的证据，从而证明了从纹状体经黑质到上丘的双神经元通路的存在。并参考黑质神经元已知的树突分支情况，讨论了纹状体 - 黑质纤维在黑质中的终末模式的可能意义。
