The present invention relates to a method for treating Parkinson's disease. According to this method, a halorhodopsin protein, a polynucleotide encoding the halorhodopsin protein or a vector containing the polynucleotide above is introduced into ventrolateral thalamus (VL) or medial globus pallidus (GPm) neurons of a subject having Parkinson's disease. The VL neurons are then illuminated with green light or exposed to a T type Ca2+ channel blocker to inhibit rebound firing of VL neurons. By inhibiting rebound firing of VL neurons, Parkinson's disease can be treated or prevented.