Cue-guided performance is disrupted during pedunculotegmental-induced motor arrest

Abstract

Optogenetic stimulation of the rostral pedunculotegmental nucleus (PTg) induces global motor arrest, but it remains unclear whether this is merely a suppression of motor activity or a broader disruption of brain processes required to guide action. We developed a visuospatial cue task for rats, to test if sensory information presented during PTg-induced arrest can guide later responses. Here, we show that optogenetic stimulation during cue presentation reduces accuracy to chance level. By moving stimulation to only before or only after the cue, we found that performance was only affected when stimulation and cue presentation overlapped, that rats recover cue-guided behavior almost immediately at the end of stimulation, and that stimulation does not appear to abolish responses based on cue information acquired before arrest. These findings indicate that stimulation of the rostral PTg does not only pause motor output but transiently disrupts the ability to process and use cue information effectively.