Quantitative Evaluation of a New Posturo-Locomotor Phenotype in a Rodent Model of Acute Unilateral Vestibulopathy

Abstract

Vestibular pathologies are difficult to diagnose. Existing devices make it possible to quantify and follow the evolution of posturo-locomotor symptoms following vestibular loss in static conditions. However, today, there are no diagnostic tools allowing the quantitative and spontaneous analysis of these symptoms in dynamic situations. With this in mind, we used an open-field video tracking test aiming at identifying specific posturo-locomotor markers in a rodent model of vestibular pathology. Using Ethovision XT 14 software (Noldus), we identified and quantified several behavioral parameters typical of unilateral vestibular lesions in a rat model of vestibular pathology. The unilateral vestibular neurectomy (UVN) rat model reproduces the symptoms of acute unilateral peripheral vestibulopathy in humans. Our data show deficits in locomotion velocity, distance traveled and animal mobility in the first day after the injury. We also highlighted alterations in several parameters, such as head and body acceleration, locomotor pattern, and position of the body, as well as "circling" behavior after vestibular loss. Here, we provide an enriched posturo-locomotor phenotype specific to full and irreversible unilateral vestibular loss. This test helps to strengthen the quantitative evaluation of vestibular disorders in unilateral vestibular lesion rat model. It may also be useful for testing pharmacological compounds promoting the restoration of balance. Transfer of these novel evaluation parameters to human pathology may improve the diagnosis of acute unilateral vestibulopathies and could better follow the evolution of the symptoms upon pharmacological and physical rehabilitation.

Selective Optogenetic Stimulation of Glutamatergic, but not GABAergic, Vestibular Nuclei Neurons Induces Immediate and Reversible Postural Imbalance in Mice

“…To assess the functional consequences of unilateral optogenetic stimulation of VN on locomotor functions, we next studied several parameters previously identified as biomarkers of locomotor dysfunctions in rodents (Rastoldo et al 2020). These parameters were monitored on animals placed in an open field before, 5 minutes after, and 1 hour after optogenetic stimulation.…”

Breaking a Dogma: Acute Anti-Inflammatory Treatment Alters Both Post-Lesional Functional Recovery and Endogenous Adaptive Plasticity Mechanisms in a Rodent Model of Acute Peripheral Vestibulopathy.

“…Since vestibular receptors detect accelerations, this parameter is particularly relevant to assess vestibular dysfunction following UVN (Rastoldo et al, 2020). We observed a significant increase of this parameter after UVN for both UVN+placebo and UVN+met groups in the compensated phase ( Figure 8D).…”

“…We assessed the posturo-locomotor activity of the animals under ecological conditions by measuring different parameters known to be affected by UVN in rats (see (Rastoldo et al, 2020) for details). At the beginning of the session, rats were placed individually in the center of an open field (80x80x40cm) for 10 minutes and tracked with Ethovision TM XT 14 software (Noldus).…”

Vestibular physical therapy improves turning not straight walking during the inertial sensor-instrumented Timed Up and Go test

“…Ours is the first study to distinguish patients with vestibular pathology from healthy controls and non-vestibular dizzy patient controls based on the ratio between walking and turning while completing the instrumented TUG. This is a critical result as it has been reported that typical measures of gait, such as the 10-meter walking test, may not provide consistent results in screening patients with vestibular impairments [10,[35][36][37][38].…”