"Parkinson's Disease: Working Towards a Cure" Part 3 -- Towards a Cure
This is the third post from a three part series written by Andrew Greene, a graduate student at McGill University studying Parkinson's Disease.

http://bawbrainblog.blogspot.com/201...ards-cure.html

... I'll try to delve more deeply into one particular line of research that I believe holds great promise.
Let's begin by taking a step back and recalling that the movement-related difficulties that afflict those suffering from Parkinson's are largely due to the death of a subset of brain cells (neurons) known as the dopaminergic neurons of the substantia nigra pars compacta. The ultimate goal therefore becomes finding a way to stop these neurons from dying, but to do that we first need to understand why they die. This has proven to be an incredibly difficult
Particularly puzzling is why these neurons... succumb when other groups of neurons remain healthy. The obvious answer is that they have intrinsic properties that make them different from other neurons... James Surmeier's lab in Chicago has identified some particularly interesting attributes, which may very well contribute to the SNc DA neurons' selective vulnerability. Foremost among these is the heavy reliance of SNc DA neurons on an unusual type of calcium conductor called an L-type calcium channel. SNc DA neurons take in large amounts of calcium through these channels at regular intervals as part of their normal signaling processes. The problem is that [calcium is] actually quite toxic when too much of it accumulates within a cell like an SNc DA neuron ... Because this calcium 'ingestion' is an ordinary part of an SNc DA neuron's... activity these neurons are equipped with miniature pumps that pump calcium out before it reaches toxic levels... these pumps require a massive amount of energy to power, and thus represent a heavy burden for the SNc DA neuron's metabolism. On top of this, SNc DA neurons each make approximately 370,000 output connections with other neurons, hundreds of times more than what most other neurons of the brain make. These output connections also require a massive amount of energy to maintain and operate, adding to the energetic burden imposed by the calcium pumps....

Posted by BrainBlogger at 5:08 PM