Cortical projection to the pedunculopontine nucleus subpopulation for the Go/STOP signal modulation of muscle tone and locomotion

Abstract

The pedunculopontine nucleus is a central actor of motor control with functions at the level of the Basal Ganglia and the Spinal cord and can modulate ongoing behavior as well as movement execution. Physiologically, the PPN is a heterogeneous nucleus, and these disparities can explain the functional outcome of deep brain stimulation in Parkinson's patients. Here, we revealed two individually distributed populations of glutamatergic neurons acting as the only known subcortical bidirectional interface between the Basal Ganglia and the Spinal cord. These subpopulations are under the control of direct cortical inputs from the primary motor cortex, that participate in the PPN microcircuitry to modulate muscle tones, locomotion, and balance. Thus, our data, for the first time revealed a subdivision within the PPN anatomy that is anatomically, physiologically, and functionally separated and could provide the first evidence for a symptoms-based approach in deep brain stimulations.