The scientists here recently demonstrated that human induced pluripotent stem cells derived mDA progenitors grafted into the substantia nigra pars compacta in a mouse model of Parkinson disease, differentiated into mature mDA neurons, restored the degenerated nigrostriatal pathway, and induced motor recovery. The objective of the present study was to evaluate the long-term functionality of these intranigral-grafted mDA neurons by assessing their electrophysiological properties.