In this graphic, the effects of Parkinson's disease are shown. Parkinson's causes the death of numerous dopamine neurons in the substantia nigra. The subsequent decrease in dopamine output to the striatum affects the entire dopamine network.
The input to the thalamus is increasingly inhibitory, resulting in less stimulating signals towards the frontal cortex and thus muscles.
I. Parkinson’s disease can be treated with DA agonists.
II. Parkinson’s disease can be treated with cholinergic agonists.
Extra info: Parkinson’s disease is caused by a decreased dopaminergic neurotransmission and responds well to treatment with DA agonists such as pergolide. Cholinergic antagonists are used in the treatment of Parkinson’s.
In Parkinson’s disease
Extra info: In the dopamine network, the decreased release of dopamine from the substantia nigra results in the thalamus receiving stronger inhibitory input.