A new study, published by a group from the University of Florida in Nature Neuroscience on Monday (16 May 2011), demonstrates how chronic inflammation (caused, for example, by an immune reaction to influenza or other infections – also, one imagines, by hayfever, which is essentially an overreaction of the immune system to pollen) can lead to the deterioration of a particular area of the brain: the nigrostriatal tract, part of the basal ganglia motor loop. This is the area where neuronal loss is known to cause Parkinson’s.
In short, a direct link has been found between chronic inflammation of the brain and Parkinson’s Disease. Past research has suggested a link, but the nature of the link has not previously been established.
Dr. Todd Golde of the University of Florida says:
“Our data show that when a certain master protein that stimulates the immune system and antiviral response is expressed at high levels, it causes neuronal loss primarily in the nigrostriatal tract, thereby creating vulnerability to Parkinson’s and similar movement disorders.”
This “master protein”, known as interferon gamma, is an important regulatory part of the human immune system. In the Florida study, high levels of interferon gamma caused widespread brain inflammation, but only the nigrostriatal tract degenerated as a result.
From what I read in the University of Florida’s news article, it seems that this was an accidental finding; the researchers “had initially set out to understand interferon gamma’s role in Alzheimer’s disease and dementia”.
The mode of study is unclear in the article, and I have, as yet, been unable to determine what type of study was made; reference is made to a “model” of the brain, which initially made me think of computer modelling, but there is nothing to indicate that this is a theoretical finding. Other options include experiments involving tissues (which I think would be too limited for such a conclusion) or animal models. The latter is, I think, most likely. As the source of this news is the University that published the paper, it is possible that the writer was being delicate and deliberately omitting mention of animal experiments.