Not sure if this will turn out to be a significant find that alters the course of research or if it is another one of those finds ending up on the road to nowhere. Nonetheless, it stresses how PD involves much more than loss of dopamine. This may explain a lot about why levodopa efficacy varies so much....as if things could not get more complex.

I have always found it interesting how loss of dopamine alone does not cause neuronal cell death in most animal models of PD, and I know many of us here feel that dopamine is the proverbial tip of the iceberg. It looks we are finally getting some evidence of that and hopefully this leads to better understanding of degeneration. In fact, I have read that our initial loss of dopamine is unrelated to the degeneration that occurs over the course of the disease. Maybe this protein plays a role or might yield some answers on this weird disconnect.



Gladstone Scientists Identify Protein that Contributes to Symptoms of Parkinson’s Disease

The newly identified protein is RGS4 is thought to facilitate striatal neuron transition under normaal conditions. The most fascinating part is that this protein is linked to learning and it requires dopamine. Well, in the PD brain the lack of dopamine causes the exact opposite effect...the protein actually disrupts our circuits causing the typical PD motor symptoms. This could explain why no one can ever get a correlative in brain imaging between decreased striatal cell loss and clinical severity of disease.

The presence of RGS4 may prove to be more important than loss of dopamine in our symptom expression, motor fluctuations, etc. It is just interesting to learn that (mice models keep in mind) that dopamine loss alone does not result in motor dysfunction. Also makes you wonder about autopsy cases where people have a brain that looks Parkinsonian but the person never developed signs of PD.

I'll be following this study. We had a good discussion on how it felt we "unlearned" basic movements. Could also explain why we freeze in trying to walk yet can ride a bike? Why at times when we first wake up we amble around looking pretty normal.?

L aura