Substance P and Parkinson's:
: Brain Res. 1990 Feb 26;510(1):104-7.
Loss of brainstem serotonin- and substance P-containing neurons in Parkinson's disease.
Centre for Neuroscience, Flinders Medical Centre, Bedford Park, Australia.
Using postmortem immunohistochemical analysis, we have identified degeneration of several different neuronal cell groups in the brainstem of patients dying with idiopathic Parkinson's disease.
We report the first chemically identified loss of presumed serotonin neurons in the median raphe nucleus of the pons and of substance P-containing preganglionic neurons in the dorsal motor vagal nucleus.
This evidence is concordant with other evidence that the primary neuropathological process is not confined either to a single pathway or to neurons containing a particular transmitter. Rather it appears that Parkinson's disease affects several classes of neurons in localized areas of the brainstem.
PMID: 1691042 [PubMed - indexed for MEDLINE]
***************************
"In PD striatum, the concentrations of GABA are generally above-normal (Fig. 7), especially in the posterior putamen, being inversely correlated with the severity of DA loss ( Kish et al., 1986). A trend towards above-normal GABA levels is also present in the external and internal globus pallidus. Similarly, glutamate concentrations are elevated in the PD striatum ( Fig. 7), with a statistically significant increase in the putamen, and a trend towards increased concentrations in the subthalamic nucleus.
In contrast to the elevated striatal GABA levels, the corresponding neuropeptides met-enkephalin and substance P are subnormal in PD basal ganglia. (However, the level of preproenkephalin has been reported to be above-normal in PD putamen.) ( Agid; Nisbet and Fernandez) Since in PD, the intrinsic neuronal cellularity of the basal ganglia is preserved, the observed changes in GABA, glutamate and neuropeptide levels are very likely the result of the changed functional state, in PD, of the respective neuronal components of the basal ganglia.
Full article:
Chemical neuroanatomy of the basal ganglia — normal and in Parkinson's disease
Oleh HornykiewiczCorresponding Author Contact Information
Institute for Brain Research, University of Vienna, Spitalgasse 4, A-1090 Vienna, Austria
Received 7 September 2000; accepted 13 November 2000 Available online 18 July 2001.
http://www.sciencedirect.com/science...839d4bc3#toc15