Jacques Léonard

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In physiological conditions, neurogenesis occurs in restricted regions of the adult mammalian brain, giving rise to integrated neurons into functional networks. In pathological or postlesional conditions neurogenesis and astrogenesis can also occur, as demonstrated in the deafferented vestibular nuclei after immediate unilateral vestibular neurectomy (UVN)(More)
Visual vertical perception, posture and equilibrium are impaired in patients with a unilateral vestibular loss. The present study was designed to investigate whether body position (standing upright, sitting on a chair and lying supine) influences the visual vertical perception in Menière's patients tested before and after a unilateral vestibular neurotomy.(More)
Vision has long been recognized as a sensorimotor system which plays a major role in substitution for functional deficits induced by unilateral or bilateral exclusion of primary vestibular afferents. Little is known, however, about the post-lesion influence of visual inputs on the recovery of posturo-kinetic balance in a situation where fine,(More)
Unilateral lesion of the vestibular system induces posturo-locomotor deficits that are compensated for with time. Drug therapy is currently used to improve the recovery process and to facilitate vestibular compensation. Betahistine dihydrochloride is an histamine-like substance that has been employed in vestibular pathology; it was found effective in many(More)
Posture control is based on central integration of multisensory inputs, and on internal representation of body orientation in space. This multisensory feedback regulates posture control and continuously updates the internal model of body's position which in turn forwards motor commands adapted to the environmental context and constraints. The peripheral(More)
Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the(More)
Neurogenesis occurs in some regions of the adult mammalian brain and gives rise to neurons integrated into functional networks. In pathological or postlesional conditions, neurogenesis and astrogenesis can also occur, as demonstrated in the deafferented vestibular nuclei after unilateral vestibular neurectomy in the adult cat. Here we report that in cats(More)
The purpose of this study was to investigate changes in neck muscle and eye movement responses during the early stages of vestibular compensation (first 3 weeks after unilateral vestibular neurectomy, UVN). Electromyographic (EMG) activity from antagonist neck extensor (splenius capitis) and flexor (longus capitis) muscles and eye movements were recorded(More)
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