Widespread vestibular activation of the rodent cortex

Much of our understanding of the neuronal mechanisms of spatial navigation is derived from chronic recordings in rodents in which head-direction, place, and grid cells have all been described. However, despite the proposed importance of self-reference information to these internal representations of space, their congruence with vestibular signaling remains unclear. Here we have undertaken brain-wide functional mapping using both fMRI and electrophysiological methods to directly determine the spatial extent, strength, and time course of vestibular signaling across the rat forebrain. We find distributed activity throughout thalamic, limbic, and particularly primary sensory cortical areas in addition to known head-direction pathways. We also observe activation of frontal regions, including infralimbic and cingulate cortices, indicating integration of vestibular information throughout functionally diverse cortical regions. These whole-brain activity maps therefore suggest a widespread contribution of vestibular signaling to a self-centered framework for multimodal sensorimotor integration in support of movement planning, execution, spatial navigation, and autonomic responses to gravito-inertial changes.E.A.R. held a Sir Henry Wellcome Fellowship from the Wellcome Trust (Grant 085509/Z/08/Z). F.D. and T.W.M. were funded by the Medical Research Council (Grant MC_U1175975156). J.M. and S.C. were funded by the Spanish Ministry of Education and Science (Grant BFU 2012-39958). The Institute of Neuroscience of Alicante is a Severo Ochoa Center of Excellence.Peer reviewe