GYPE and Parkinson disease: In one of the main output regions of the STN, the motor-related GPe, this need for cell-type specific targeting is further highlighted: while optogenetic stimulation of the whole GPe did not rescue PD motor symptoms, optogenetic activation of GPe PV-positive neurons (Mastro et al., 2017; Pamukcu et al., 2020) and inhibition of GPe Lhx6 neurons (Mastro et al., 2017) revealed a locomotion-promoting effect with a potential long-lasting recovery effect.