What happens to the substantia nigra in persons who have Parkinson's?

What happens to the substantia nigra in persons who have Parkinson's?

Neal Hermanowicz (Director of the Movement Disorders Program) gives expert video advice on: What causes Parkinson's?; What role does race play in Parkinson's?; What is a 'parkinsonian personality'? and more...

In somebody with Parkinson's disease, the brain cells, the neurons, and the substantia nigra are actually being depleted, they are being lost. If you look at the normal brain, you can see the substantia nigra without any kind of special preparation or staining because it is dark it is pigmented. And if you look at the brain of somebody who has Parkinson's disease that dark area, that pigmented area, is less conspicuous, it is not so dark. It is not so easily visible. Again, if you look at that section with a microscope, you can see that the brain cells are actually reduced in number and in their place is the brain's equivalent of scar formation. There is what is called “gliosis” after this brain cells have been injured and die.