How does a lack of dopamine affect movement (PD)?

[hitmankratos]

Hi,

 

I am doing a science fair project on a Parkinson's disease and I am wondering how can a lack of dopamine affect movement, as such to cause Parkinson's Disease? Doesn't dopamine affect desire and motivation? So why does someone start shaking when there's a lack of dopamine?

 

Thanks,

[Anura]

Mabye the second pargraph of this might help. Mabye. http://en.wikipedia.org/wiki/Parkinsons

[Ahsan Iqbal]

Dopamine is a neurotransmitter and its deficiency or the damage to its receptors can interfere with normal nervous conduction. I think that is why the symptoms appear.