title: Loss of substance P and enkephalin immunoreactivity in the human substantia nigra after striato-pallidal infarction.
abstract: Post-mortem neuropathological material from 3 patients with striato-pallidal infarction provided the first immunohistochemical evidence for substance P- and enkephalin-containing nerve fibre projections from the striato-pallidum to the substantia nigra in the human. The nigra corresponding to the normal side showed abundant substance P and enkephalin immunoreactivity whose patterns of immunostaining were notably similar. In contrast, the substantia nigra ipsilateral to the striato-pallidal infarction showed a decrease in substance P and enkephalin immunoreactivity which was proportional to the extent of the infarction. This suggests that much of the substance P and enkephalin immunoreactivity in the nigra is present in nerve fibres projecting from the striato-pallidum. Furthermore, the similar distribution of remaining substance P and enkephalin immunoreactivity in corresponding areas of the nigra of the infarcted side indicates that the origins and/or projections of nerve fibres containing these two neuropeptides may be closely approximated anatomically. Depletion of substance P immunoreactivity in the pars reticulata of the substantia nigra in a fourth patient with anterior striatal infarction suggests a topographic projection for substance P immunoreactive fibres from the striatum. There is some evidence in one patient with cognitive and behavioural abnormalities to support the suggestion that the basal ganglia may be involved in non-motor functions.
mesh_terms: D000328:Adult; D000368:Aged; D002544:Cerebral Infarction / Q000378:metabolism*; D003342:Corpus Striatum / Q000098:blood supply / Q000378:metabolism*; D004745:Enkephalins / Q000378:metabolism*; D005917:Globus Pallidus / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D009434:Neural Pathways / Q000378:metabolism; D013373:Substance P / Q000378:metabolism*; D013378:Substantia Nigra / Q000098:blood supply / Q000378:metabolism*
chemical_list: D004745:Enkephalins; D013373:Substance P