In this issue of Neuron, McElvain et al. demonstrate for the first time plasticity at the synapse between vestibular nerve afferents and their postsynaptic targets in the medial vestibular nuclei. This new type of plasticity, which is gated by inhibition, is well suited to drive motor learning during adaptation of the vestibulo-ocular reflex.

The authors highlights the importance of the vestibulo-ocular reflex examination through the head impulse test as a diagnostic method for vestibular dysfunction as well as, and primarily, a bedside semiotic resource capable of differentiating between acute peripheral vestibulopathy and a cerebellar or brainstem infarction in emergency rooms.

The primary purpose of the vestibulo-ocular reflex (VOR) is to allow clear vision during walking and other faster movements. These occur at frequencies greater than 1 Hz. Other oculo-motor systems, such as smooth pursuit and optokinetic, respond poorly at these higher frequencies. The VOR functions as the major oculo-motor system responsible for maintaining visual fixation during faster head mo...