Cerebellar cortical throughput involved in motor control comprises granule cells (GCs) and Purkinje cells (PCs), both of which receive inhibitory GABAergic input from interneurons. The GABAergic input to PCs is essential for learning and consolidation of the vestibulo-ocular reflex, but the role of GC excitability remains unclear. We now disrupted the Kcc2 K-Cl cotransporter specifically in eit...

Coding head movement involves representing the head’s velocity and axis of rotation. The neural representation can then be used to inform perceptual and motor processes. An important motor response to head movement is the compensatory eye movements evoked, one component of which is the vestibulo-ocular reflex (VOR). Historically a three-neuron arc has been described as the core of the neural me...

The motor system responds to perturbations with reflexes, such as the vestibulo-ocular reflex or stretch reflex, whose gains adapt in response to novel and fixed changes in the environment, such as magnifying spectacles or standing on a tilting platform. Here we demonstrate a reflex response to shifts in the hand's visual location during reaching, which occurs before the onset of voluntary reac...

Background and Aim: The video head-impulse test (vHIT) measures the vestibulo-ocular reflex (VOR) driven by each semicircular canal, following high-acceleration head rotations. The main measurable response is the ratio of eye movement velocity to the angular head velocity, which reflects canal function. Although normative data is available for VOR gain, most studies only report horizontal VOR c...

Geometric considerations indicate that the human translational vestibulo-ocular reflex (tVOR) should have substantially different properties than the angular vestibulo-ocular reflex (aVOR). Specifically, tVOR cannot simultaneously stabilize images of distant and near objects on the retina. Most studies make the tacit assumption that tVOR acts to stabilize foveal images even though, in humans, t...

Telescopic spectacles can theoretically improve function of low vision patients by enlarging retinal images. However, unintended head movement may produce sufficient instability of enlarged retinal images to negate the visual benefit. We investigated this phenomenon as a cause of failure in 38 low vision patients who had previously attempted use of telescopic spectacles. Patients underwent eval...

BACKGROUND Unsteadiness during standing and walking is a frequent complaint of patients with polyneuropathy (PNP). OBJECTIVE To determine whether balance disorders in patients with PNP may be caused by reduced proprioceptive input from the feet alone or whether impaired vestibular input, resulting from involvement of the vestibular nerve, can be an additional factor. METHODS A total of 37 p...

BACKGROUND Although adult vertebrates sense changes in head position by using two classes of accelerometer, at larval stages zebrafish lack functional semicircular canals and rely exclusively on their otolithic organs to transduce vestibular information. RESULTS Despite this limitation, we find that larval zebrafish perform an effective vestibulo-ocular reflex (VOR) that serves to stabilize g...

We present a new hypothesis that the cerebellum plays a key role in actively controlling the acquisition of sensory infonnation by the nervous system. In this paper we explore this idea by examining the function of a simple cerebellar-related behavior, the vestibula-ocular reflex or VOR, in which eye movements are generated to minimize image slip on the retina during rapid head movements. Consi...