Basal ganglia are a group of subcortical nuclei including striatum, globus pallidus, and substantia nigra. The major function of this system is to integrate both sensory and motor information, eventually leading to motor coordination, action selection, and reward-related learning, most of which are severely impaired in Parkinson’s disease. Our long-term goal is to identify the essential modification of basal ganglia circuitry contributing to the development of neurodegenerative diseases. Taking advantage of multi-disciplinary approaches including whole-cell patch clamp, single-unit recording, two-photon laser microscopy, super-resolution imaging, optogenetics, and behavioral assays, we also aim to identify pre-symptomatic physiological markers for Parkinson’s disease.