Anatomically segregated basal ganglia pathways allow parallel behavioral modulation

Abstract

In the basal ganglia (BG), anatomically segregated and topographically-organized feedforward circuits are thought to modulate multiple behaviors in parallel. Although topographically-arranged BG circuits have been described, the extent to which these relationships are maintained across the BG output nuclei and in downstream targets is unclear. Here, using focal transsynaptic anterograde tracing, we show that the motor-action related topographical organization of the striatum is preserved in all BG output nuclei. The topography is also maintained downstream of the BG and in multiple parallel closed loops that provide striatal input. Furthermore, focal activation of two distinct striatal regions induce either licking or turning, consistent with the structure of projections to targets outside the BG. Our results confirm the parallel model of BG function, and suggest that the integration and competition of information relating to different behavior occurs largely outside of the BG.