
The substantia nigra pars reticulata (SNr) and globus pallidus externa (GPe) differentially innervate pedunculopontine nucleus (PPN) subpopulations, challenging the canonical basal ganglia model by demonstrating non-canonical roles in locomotion and valence processing.


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The canonical basal ganglia model predicts that the substantia nigra pars reticulata (SNr) and the globus pallidus externa (GPe) will have specific effects on locomotion: the SNr inhibiting locomotion and the GPe enhancing it. In this manuscript, we use in vivo optogenetics to show that a projection-defined neural subpopulation within each structure exerts non-canonical effects on locomotion. These non-canonical subpopulations are defined by their projection to the pedunculopontine nucleus (PPN) and mediate opposing effects on reward. To understand how these structures differentially modulate the PPN, we use ex vivo whole-cell recording with optogenetics to comprehensively dissect the SNr and GPe connections to regionally– and molecularly-defined populations of PPN neurons. The SNr inhibits all PPN subtypes, but most strongly inhibits caudal glutamatergic neurons. The GPe selectively inhibits caudal glutamatergic and GABAergic neurons, avoiding both cholinergic and rostral cells. This circuit characterization reveals non-canonical basal ganglia pathways for locomotion and valence.

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Graphical Abstract



### Competing Interest Statement

The authors have declared no competing interest.

 [1]: pending:yes

Inhibitory basal ganglia nuclei differentially innervate pedunculopontine nucleus subpopulations and evoke opposite motor and valence behaviors

differential-innervation-of-pedunculopontine-nucleus-subpopulations-by-inhibitory-basal-ganglia-nuclei-reveals-non-canonical-pathways-for-motor-and-valence-behaviors


Differential Innervation of Pedunculopontine Nucleus Subpopulations by Inhibitory Basal Ganglia Nuclei Reveals Non-Canonical Pathways for Motor and Valence Behaviors
