Kemel M L, Desban M, Gauchy C, Glowinski J, Besson M J
Chaire de Neuropharmacologie, I.N.S.E.R.M. U.114, Collège de France, Paris.
Brain Res. 1988 Jul 12;455(2):307-23. doi: 10.1016/0006-8993(88)90090-x.
The topographical organization of the efferent projections from the cat substantia nigra (SN) to the thalamus and the superior colliculus was examined using the anterograde transport of horseradish peroxidase-wheat germ agglutinin (HRP-WGA) and of labelled proteins. HRP-WGA or a mixture of [14C]amino acids was injected into various areas of the SN and the transported material visualized on coronal brain sections by histochemistry or autoradiography, respectively. The retrograde transport of [14C]gamma-aminobutyric acid ([14C]GABA) injected into thalamic nuclei was used also to determine the identity of the nigrothalamic projections. Identical results were found using either the anterograde transport of HRP-WGA or of labelled proteins. In the thalamus, dense nigral projections were observed in the nucleus ventralis medialis (VM) and in the rostromedioventral part of the nucleus ventralis lateralis (VL) whilst more limited projections were seen in the nuclei centralis lateralis (CL) and paracentralis (PC) as well as in the paralamellar zone of the nucleus medialis dorsalis (MD-Il). In addition, a patchy distribution of HRP-WGA or of radioactivity was found in the intermediate layer of the superior colliculus. More precisely, labelling of the VM was dense following injection of [14C]amino acids into the intermediate part of the SN pars reticulata (SNR) regardless of the depth of the injection site, whilst the intralaminar nuclei were labelled preferentially following injections made into the dorsal part of the intermediate SNR. Nigral projections to the intermediate layer of the superior colliculus were visualized over the whole mediocaudal and laterorostral extent when [14C]amino acids were injected into the rostral part of the SNR. Labelling of the superior colliculus was also seen following injection of [14C]amino acids into the intermediate part of the SNR but, in this case, ventral injections led to a more intense labelling than dorsal ones. Both the SNR and the SN pars compacta (SNC) were labelled when [14C]GABA was injected into the VM nucleus of the thalamus, confirming that the nigro VM projection is GABAergic and showing that recurrent collaterals of these GABAergic cells innervating the SNC also contained the transported radioactive material. In this condition ([14C]GABA injection into the VM), the thalamic reticularis nucleus also exhibited a dense labelling.(ABSTRACT TRUNCATED AT 400 WORDS)
利用辣根过氧化物酶-小麦胚凝集素（HRP-WGA）和顺行性标记蛋白的转运，研究了猫黑质（SN）至丘脑和上丘的传出投射的拓扑组织。将HRP-WGA或[14C]氨基酸混合物注入SN的不同区域，通过组织化学或放射自显影分别在冠状脑切片上观察转运物质。向丘脑核团注射[14C]γ-氨基丁酸（[14C]GABA）的逆行转运也用于确定黑质-丘脑投射的特征。使用HRP-WGA或标记蛋白的顺行性转运得到了相同的结果。在丘脑中，黑质的密集投射见于腹内侧核（VM）和腹外侧核（VL）的嘴侧中间腹侧部分，而在外侧中央核（CL）、中央旁核（PC）以及背内侧核（MD-Il）的板旁区可见较有限的投射。此外，在上丘中间层发现了HRP-WGA或放射性的斑片状分布。更确切地说，无论注射部位的深度如何，将[14C]氨基酸注入SN网状部（SNR）的中间部分后，VM的标记都很密集，而向中间SNR的背侧部分注射后，层内核优先被标记。当将[14C]氨基酸注入SNR的嘴侧部分时，黑质至上丘中间层的投射在整个中尾侧和外侧嘴侧范围内都可见。将[14C]氨基酸注入SNR的中间部分后也可见上丘的标记，但在这种情况下，腹侧注射比背侧注射导致更强的标记。当将[14C]GABA注入丘脑的VM核时，SNR和黑质致密部（SNC）都被标记，证实黑质-VM投射是γ-氨基丁酸能的，并表明这些支配SNC的γ-氨基丁酸能细胞的回返侧支也含有转运的放射性物质。在这种情况下（将[14C]GABA注入VM），丘脑网状核也显示出密集的标记。（摘要截于400字）
