Multisensory coding of angular head velocity in the retrosplenial cortex

Summary

To successfully navigate the environment, animals depend on their ability to continuously track their heading direction and speed. Neurons that encode angular head velocity (AHV) are fundamental to this process, yet the contribution of various motion signals to AHV coding in the cortex remains elusive. By performing chronic single-unit recordings in the retrosplenial cortex (RSP) of the mouse and tracking the activity of individual AHV cells between freely moving and head-restrained conditions, we find that vestibular inputs dominate AHV signaling. Moreover, the addition of visual inputs onto these neurons increases the gain and signal-to-noise ratio of their tuning during active exploration. Psychophysical experiments and neural decoding further reveal that vestibular-visual integration increases the perceptual accuracy of angular self-motion and the fidelity of its representation by RSP ensembles. We conclude that while cortical AHV coding requires vestibular input, where possible, it also uses vision to optimize heading estimation during navigation.

Highlights

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  Angular head velocity (AHV) coding is widespread in the retrosplenial cortex (RSP)

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  AHV cells maintain their tuning during passive motion and require vestibular input

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  The perception of angular self-motion is improved when visual cues are present

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  AHV coding is similarly improved when both vestibular and visual stimuli are used

Abstract

Keshavarzi et al. report that mouse retrosplenial cortical neurons can reliably track the direction and speed of head turns in complete darkness by relying on vestibular information. Addition of visual input improves perception of angular self-motion and increases the accuracy of this cortical head motion signal.