It has long been known that we also lose a lot of our noradrenaline neurons too. Recent research shows that it may be that noradrenaline loss is primary cause of most PD symptoms including the motor ones. It also is looking like it is the locus of dyskinesia, So what does this mean for me? It means you may have another way to treat this without experiencing the dark side of levodopa. It means you may be able to significantly decrease your intake of ldopa and live many more years without invasive brain surgeries. If you are at all considering DBS, please read it and discuss with your doctor. The drug classes involved are used for other conditions but it is worth asking your doctor.
Here is the skinny (the abstract)
In the present review, we analyze the latest evidence for the implication of NA in the pathophysiology of PD obtained from animal models of parkinsonism and from parkinsonian patients. Recent studies have shown that NA depletion alone, or combined with DA depletion, results in motor as well as in non-motor dysfunctions. In addition, by using selective agonists and antagonists of noradrenaline alpha receptors we, and others, have shown that a2 receptors are implicated in the control of motor activity and that a2 receptor antagonists can improve PD motor symptoms as well as l-Dopa-induced dyskinesia. In this review we argue that the loss of NA neurons in PD has an impact on all PD symptoms and that the addition of NAergic agents to dopaminergic medication could be beneficial in the treatment of the disease.