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This Article Full Text Full Text (PDF) All Versions of this Article: 100/2/945    most recent 90319.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Beraneck, M. Articles by Cullen, K. E. PubMed PubMed Citation Articles by Beraneck, M. Articles by Cullen, K. E.

Asymmetric Recovery in Cerebellar-Deficient Mice Following Unilateral Labyrinthectomy

¹Department of Physiology, McGill University, Montreal, Quebec, Canada; and ²Laboratoire de Neurobiologie des Réseaux Sensorimoteurs, Unité Mixte de Recherche Centre National de la Recherche Scientifque 7060, UFR Biomédicale, Université Paris Descartes, Paris, France

Submitted 29 February 2008; accepted in final form 27 May 2008

The term "vestibular compensation" refers to the resolution of motor deficits resulting from a peripheral vestibular lesion. We investigated the role of the cerebellum in the compensation process by characterizing the vestibuloocular reflex (VOR) evoked by head rotations at frequencies and velocities similar to those in natural behaviors in wild-type (WT) versus cerebellar-deficient Lurcher (Lc/+) mice. We found that during exploratory activity, normal mice produce head rotations largely consisting of frequencies 4 Hz and velocities and accelerations as large as 400°/s and 5,000°/s², respectively. Accordingly, the VOR was characterized using sinusoidal rotations (0.2–4 Hz) as well as transient impulses (400°/s; 2,000°/s²). Before lesions, WT and Lc/+ mice produced similar VOR responses to sinusoidal rotation. Lc/+ mice, however, had significantly reduced gains for transient stimuli. After unilateral labyrinthectomy, VOR recovery followed a similar course for WT and Lc/+ groups during the first week: gain was reduced by 80% for ipsilesionally directed head rotations on day 1 and improved for both strains to values of 0.4 by day 5. Moreover, responses evoked by contralesionally directed rotations returned to prelesion in both strains within this period. However, unlike WT, which showed improving responses to ipsilesionally directed rotations, recovery plateaued after first week for Lc/+ mice. Our results show that despite nearly normal recovery in the acute phase, long-term compensation is compromised in Lc/+. We conclude that cerebellar pathways are critical for long-term restoration of VOR during head rotation toward the lesioned side, while noncerebellar pathways are sufficient to restore proper gaze stabilization during contralesionally directed movements.