Electrophysiology of dopamine in normal and denervated striatal neurons

Parkinson's disease (PD) symptoms originate from the loss of the dopaminerg ic control of neuronal activity in the striatum. Permanent loss of dopamine rgic terminals in the striatum results in an abnormal activity of striatal neurons. The therapeutic treatment with exogenous dopamine, therefore, temp orarily restores a balanced synaptic excitation of striatal neurons, counte racting pre- and postsynaptically the excessive glutamate release caused by the degeneration of nigrostriatal dopaminergic fibers. However, chronic tr eatment is associated with adverse effects that might reflect nonphysiologi cal dopamine replacement. Basic studies on experimental animal models of PD are of crucial importance for the development of therapeutic agents able t o provide relief to individuals with PD, without the adverse effects associ ated with currently available drugs.