And now to a new finding about Parkinson's Disease, which is usually treated with a drug called levadopa. This mimics a brain chemical called dopamine, and it's needed because the bit of the brain that produces dopamine, the substantia nigra, deteriorates in people with Parkinson's. But after a few years of taking levadopa, it tends not to work so well.
Complications can develop, like periods when movement is lost completely.
So researchers have wondered if something else is going wrong. Dr Jasmine Henderson, from the Prince of Wales Medical Research Institute in Sydney, has just taken part in a study of the brains of people who'd died with Parkinson's Disease. And they've found that this is in fact the case. OK, let's look at the thalamus, because this area is important for movement, and nobody's actually quantified or measured the cell content in this part of the brain before, to determine whether or not there is loss. What we found was that a very important, but small area, within the thalamus that specifically relates to movement, is lost.