摘要：SummaryIndirect pathway medium-sized spiny neurons (iMSNs) in the neostriatum are well known to project to the external segment of the globus pallidus (GPe). Although direct MSNs (dMSNs) also send axon collaterals to the GPe, it remains unclear how dMSNs and iMSNs converge within the GPe. Here, we selectively labeled neighboring dMSNs and iMSNs with green and red fluorescent proteins using an adeno-associated virus vector and examined axonal projections of dMSNs and iMSNs to the GPe in mice. Both dMSNs and iMSNs formed two axonal arborizations displaying topographical projections in the dorsoventral and mediolateral planes. iMSNs displayed a wider and denser axon distribution, which included that of dMSNs. Density peaks of dMSN and iMSN axons almost overlapped, revealing convergence of dMSN axons in the center of iMSN projection fields. These overlapping projections suggest that dMSNs and iMSNs may work cooperatively via interactions within the GPe.Graphical AbstractDisplay OmittedHighlights•Neighboring dMSNs and iMSNs were exclusively labeled with GFP and RFP•dMSNs and iMSNs formed two axonal arborizations in the GPe in a topographic manner•Axonal arborizations of dMSNs were embedded within the arborizations of iMSNs•The centers of projections from neighboring dMSNs and iMSNs were almost overlappedBiological Sciences; Neuroscience; Cellular Neuroscience
