Parkinson's Disease and Iron Imbalance

According to a study reported in 2004, iron in deficient or excessive doses causes cell death in dopaminergic neurons. Excessive doses are far worse, causing the dopamine-producing neurons to "commit suicide" at faster rates. Cathy Levenson, associate professor of nutrition, food and exercise sciences in Florida State University's College of Human Sciences and a faculty member in the Program in Neuroscience and Graduate Program in molecular biophysics, has been researching the effects of trace metal imbalances affecting gene expression contributing to neuropsychiatric and neurodegenerative diseases, such as Parkinson's. The studies were performed on mice. When mice were given high doses of iron, healthy mice, without risk factors for PD, developed PD-like symptoms, and mice diagnosed with PD either died or the progression of the disease was accelerated. Conversely, low doses of iron slowed the onset of the disease in mice with risk factors of PD, and slowed the progression of PD in those mice with PD. However, low doses of iron also caused decreasing levels of dopamine in mice without risk factors for PD. Conclusion? Both toxicity and deficiencies in iron are somehow related to the genes responsible for dopamine production and neuronal cell death. This brings up a few conjectures in my mind: are there other chemicals produced, or is there a chemical response, to the production of dopamine that affects the dopaminergic neurons, or does dopamine itself have an effect on the dopaminergic neurons. I guess what I'm asking is, do dopaminergic cells need to be bathed in a very specific concentration range of dopamine to maintain a normal life cycle, or do sudden swings in dopamine levels (caused by outside factors) suddenly cause an over-compensating or under-compensating, non-stabilizing effect that destroys these (assumingly) fragile dopaminergic cells? If anyone has any answers, I'd like to hear them.

You can read more about it in the article FSU Scientist Links Iron Imbalance To Parkinson's Disease, or in the original FSU press release. Contact:
Cathy Levenson
Florida State University
Tel: (850) 644-4122
levenson@neuro.fsu.edu