Distinct contributions and sensorimotor encoding of PV and FoxP2 neurons in the external globus pallidus during perceptual decision-making

The external globus pallidus (GPe), a central nucleus of the basal ganglia (BG), comprises diverse cell types, including PV and FoxP2 neurons. While their roles in movement regulation and sensory processing have been studied, their contributions to perceptual decision-making remain unclear. Using a Go/No-Go visual task in mice, we found that optogenetic activation of either population impaired behavioral performance, whereas only inhibition of PV neurons, but not FoxP2 neurons, disrupted behavior. Electrophysiological recordings revealed that PV and FoxP2 neurons exhibited distinct encoding of visual stimuli, licking movement, and trial outcomes, with a larger fraction of PV neurons positively encoding the reward-predicting (Go) stimulus and the population overall preferring the rewarded over unrewarded outcome. FoxP2 neuron inhibition had minimal effects on spontaneous firing of neurons in the substantia nigra pars reticulata (SNr), a major BG output. By contrast, PV neuron inhibition altered both spontaneous and task-related activity of SNr neurons, reducing their preference for reward-predicting stimulus or unrewarded outcome in a subpopulation-specific manner. These findings indicate that PV and FoxP2 neurons in the GPe differentially influence sensorimotor processing and SNr activity, with PV neurons playing a key role in supporting accurate performance during perceptual decision-making.