The study combines whole-brain anterograde axon mapping, rabies tracing, single-neuron reconstruction, and single-nucleus RNA sequencing to dissect the organization of GPe projection neurons. Distinct subpopulations, defined by transcriptomic identity and projection target, connect with cortex, thalamus, and brainstem circuits in ways that support action-specific behavioral control.
Functionally, GPe neurons projecting to the pedunculopontine nucleus were linked to locomotor control, while GPe neurons projecting to the parafascicular thalamus were associated with skilled forelimb actions. Together, the findings support a model in which the GPe is organized into parallel, projection-defined channels rather than acting as a single uniform output structure.
Luke Hammond contributed BrainJ-based whole-brain mapping and quantitative analysis, providing a framework for measuring axonal projection patterns across brain-wide datasets. The work highlights the Quantitative Imaging Group's broader role in developing reproducible imaging methods that connect circuit architecture with molecular and behavioral function.
The external globus pallidus is a basal ganglia output hub with action-specific circuits. Gu Z, Lewis ZR, Tang J, Mendelsohn A, Vicente AM, … Hammond LA, Peterka DS, Zeng H, Tasic B, Costa RM. bioRxiv. 2026.