Dopamine D3 receptor agonists for protection and repair in Parkinson's disease.

Parkinson's disease is a severe, age-related neurodegenerative disorder in which a loss of substantia nigra-derived dopaminergic pathways to the striatum triggers profound motor perturbation, as well as cognitive, sensory and mood deficits. Although the dopamine precursor, L-dopa, is effective in the short-term in relieving motor dysfunction, it does not stop the progressive disappearance of dopaminergic neurons, encouraging interest in alternative therapeutic strategies. Dopaminergic agonists, such as pramipexole, appear to have neuroprotective and neurorestorative actions based on clinical and, most convincingly, experimental work. The role of specific dopaminergic receptor subtypes is an important issue, especially with respect to new drug development. Of particular interest, dopamine D3 receptors contribute to the beneficial influence of dopaminergic agonists for the protection and restoration of dopaminergic pathways in Parkinson's disease.