Distinct Contributions and Sensorimotor Encoding of PV and FoxP2 Neurons in the External Globus Pallidus during Perceptual Decision-making.

Abstract

The external globus pallidus (GPe), the central nucleus of the basal ganglia, comprises diverse cell types, including parvalbumin (PV) and forkhead box protein P2 (FoxP2) neurons. Their roles in movement regulation and sensory processing are well established; however, their contribution to perceptual decision-making remains unclear. Using a Go/No-Go visual task in mice, we found that optogenetic activation of either population impaired performance, whereas PV inhibition, but not FoxP2 inhibition, disrupted behavioral accuracy. Electrophysiological recordings showed that PV and FoxP2 neurons differentially encoded visual stimuli, licking movements, and trial outcomes. FoxP2 inhibition produced minimal changes in the spontaneous firing of substantia nigra pars reticulata (SNr) neurons. PV inhibition altered spontaneous SNr firing and, together with PV activation, altered task-evoked SNr activity, reducing the preference for reward-predicting stimuli in one subpopulation and unrewarded outcomes in another. These findings reveal the distinct roles of GPe PV and FoxP2 neurons in shaping perceptual decisions and modulating basal ganglia output.