Deep brain stimulation surgery has been performed in various movement disorders and psychiatric diseases. However, electrical stimulation may unexpectedly affect other types of adjacent neurons outside of the target area. Recently, optogenetics has provided the opportunity to modulate specific target neurons. Since this novel technique can individually control specific neurons in freely moving animals, it could be proposed to restore neural circuit function to related diseases, such as affective disorders, Huntington’s disease (HD), and Parkinson’s disease (PD). Herein, we discuss how optogenetics works as a treatment for Parkinson’s disease and other neural circuit dysfunctions.