The locus coeruleus directs sensory-motor reflex amplitude across environmental contexts

Abstract

Animals possess a remarkable ability to quickly and accurately respond to challenges to their balance and posture. Postural corrections are the implementation of a motor act by the nervous system that counteracts a perturbation and returns the body to a stable state. These corrections must respect both the current position of the limbs and trunk, as well as the external environment. However, how motor circuits integrate multiple streams of information regarding both these internal and external factors, and adjust motor actions accordingly, are poorly understood. Here we show that the lateral vestibular nucleus in the brainstem generates motor corrections following perturbation, and that this reflex can be altered by manipulating the surrounding environment. The strength of the motor correction is influenced by noradrenergic signalling from the locus coeruleus, suggesting a potential link between forebrain structures which convey sensory information about the environment, and brainstem circuits that generate motor corrections.