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Evidence for a decrease in substance P content of substantia nigra in Huntington's chorea
| Content Provider | Semantic Scholar |
|---|---|
| Author | Kanazawa, Ichiro Bird, Edward Dennis O’connell, R. Powell, David O. |
| Copyright Year | 1977 |
| Abstract | The substantia nigra is sub-divided into the dorsally situated cell-rich area, the pars compacta, and the ventrally located cell-poor area, pars reticulata 25. Most of the neurones in the pars compacta are believed to be dopaminergic in function x2 and send fibres to the striatum 2. This nigrostriatal fibre system is specifically affected in Parkinson's disease. Recent morphological studies have demonstrated that the pars reticulata contains numerous nerve terminals 25, most of which belong to striatonigral fibres 1° which synapse on long dendrites coming down vertically from the nigral neurones in the pars compacta 25. Electrophysiologically, it has been shown that the striatonigral fibres exert a monosynaptic inhibitory effect on nigral neurones 3° and y-aminobutyric acid (GABA) has been proposed as the neurotransmitter of this fibre system ~4. Indeed, destruction of the striatum has been shown to lead to a marked decrease in the concentration of GABA16, Is and its synthesizing enzyme, glutamate decarboxylase (GAD) s in the substantia nigra. In addition, in Huntington's chorea, in which there is severe atrophy of the striatum, the concentration of GABA ~1 and the activity of GAD a,t9 in the substantia nigra are significantly decreased. Recently, evidence for a transmitter role of the undecapeptide, substance p6 has accumulated from studies in the spinal cord 20. Since the concentration of substance P in the substantia nigra is the highest in the nervous system 15,22, and the peptide is localized in synaptosomal fractions in the substantia nigra 7, it seems reasonable to suppose that substance P may also act as a transmitter in the substantia nigra. Iontophoretically applied substance P has been found to excite nigral neurones 29. Furthermore, we have previously reported that substance P is highly localized in the pars reticulata rather than in the pars compacta in the normal human substantia nigra 13, suggesting that distribution of substance P is quite similar to that of GABA 17 in the nigra. It was, therefore, of interest to determine the levels of substance P in the sub- |
| Starting Page | 387 |
| Ending Page | 392 |
| Page Count | 6 |
| File Format | PDF HTM / HTML |
| DOI | 10.1016/0006-8993(77)90919-2 |
| PubMed reference number | 12860 |
| Journal | Medline |
| Volume Number | 120 |
| Alternate Webpage(s) | https://api.elsevier.com/content/article/pii/0006899377909192 |
| Alternate Webpage(s) | https://www.sciencedirect.com/science/article/pii/0006899377909192?dgcid=api_sd_search-api-endpoint |
| Alternate Webpage(s) | https://doi.org/10.1016/0006-8993%2877%2990919-2 |
| Journal | Brain Research |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
