Sensory processing in external globus pallidus neurons

Sensory processing is crucial for execution of appropriate behavior. The external globus pallidus (GPe), a nucleus within the basal ganglia, is highly involved in the control of movement and could potentially integrate sensory-motor information. The GPe comprises prototypic and arkypallidal cells, which receive partially overlapping inputs. It is unclear, however, which inputs convey sensory information to them. Here, we used in vivo whole-cell recordings in the mouse GPe and optogenetic silencing to characterize the pathways that shape the response to whisker stimulation in prototypic and arkypallidal cells. Our results show that sensory integration in prototypic cells is controlled by the subthalamic nucleus and indirect pathway medium spiny neurons (MSNs), whereas in arkypallidal cells, it is primarily shaped by direct pathway MSNs. These results suggest that GPe subpopulations receive sensory information from largely different neural populations, reinforcing that the GPe consists of two parallel pathways, which differ anatomically and functionally. [Display omitted] •Whole-cell recordings show the source of sensory responses in the external globus pallidus•The indirect and hyperdirect pathways relay sensory information to prototypic cells•The direct pathway relays sensory information to arkypallidal neurons•Photoinhibition of prototypic neurons minimally affects arkypallidal neurons Johansson and Ketzef dissect the inputs underlying tactile responses in the mouse external globus pallidus using in vivo whole-cell recordings and optogenetic photoinhibition. They show that prototypic and arkypallidal neurons receive somatosensory information from different sources. Their findings support the idea that the GPe hosts parallel pathways for information processing.