Zona incerta gabaergic output controls a signaled locomotor action in the midbrain tegmentum

Abstract

The zona incerta is a subthalamic nucleus proposed to link sensory stimuli with motor responses to guide behavior, but its functional role is not well established. Using mice of either sex, we studied the effect of manipulating zona incerta gabaergic cells on the expression of a signaled locomotor action, known as signaled active avoidance. We found that modulation of gabaergic zona incerta cells, but not of cells in the adjacent thalamic reticular nucleus, fully controls the expression of signaled active avoidance responses. Inhibition of zona incerta gabaergic cells drives active avoidance responses, while excitation of these cells blocks signaled active avoidance mainly by inhibiting cells in the midbrain pedunculopontine tegmentum (PPT). The zona incerta regulates signaled locomotion in the midbrain.

Significance Statement The zona incerta is an enigmatic nucleus in the forebrain whose functional role is not well established. We found that gabaergic cells in the zona incerta, that project to the midbrain, control the ability of mice to avoid a threat signaled by a sensory stimulus. Inhibiting these cells drives avoidance responses, while exciting them blocks avoidance responses by inhibiting targets in the midbrain.