Abstract
The pathogenesis of the second major neurodegenerative disorder, Parkinson's disease (PD), is closely associated with the dysfunction of potassium (K(+)) channels. Therefore, PD is also considered to be an ion channel disease or neuronal channelopathy. Mounting evidence has shown that K(+) channels play crucial roles in the regulations of neurotransmitter release, neuronal excitability, and cell volume. Inhibition of K(+) channels enhances the spontaneous firing frequency of nigral dopamine (DA) neurons, induces a transition from tonic firing to burst discharge, and promotes the release of DA in the striatum. Recently, three K(+) channels have been identified to protect DA neurons and to improve the motor and non-motor symptoms in PD animal models: small conductance (SK) channels, A-type K(+) channels, and K(V)7/KCNQ channels. In this review, we summarize the physiological and pharmacological effects of the three K(+) channels. We also describe in detail the laboratory investigations regarding K(+) channels as a potential therapeutic target for PD.