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Bilateral Vestibular Loss In Cats Leads To Active Destabilization Of Balance During Pitch And Roll Rotations Of The Support Surface, Jane Macpherson, Dirk Everaert, Paul Stapley, Lena Ting
Bilateral Vestibular Loss In Cats Leads To Active Destabilization Of Balance During Pitch And Roll Rotations Of The Support Surface, Jane Macpherson, Dirk Everaert, Paul Stapley, Lena Ting
Dr Paul J Stapley
Although the balance difficulties accompanying vestibular loss are well known, the underlying cause remains unclear. We examined the role of vestibular inputs in the automatic postural response (APR) to pitch and roll rotations of the support surface in freely standing cats before and in the first week after bilateral labyrinthectomy. Support surface rotations accelerate the body center of mass toward the downhill side. The normal APR consists of inhibition in the extensors of the uphill limbs and excitation in the downhill limbs to decelerate the body and maintain the alignment of the limbs with respect to earth-vertical. After vestibular lesion, …
Bilateral Vestibular Loss Leads To Active Destabilization Of Balance During Voluntary Head Turns In The Standing Cat, Paul Stapley, Lena Ting, Chen Kuifu, Dirk Everaert, Jane Macpherson
Bilateral Vestibular Loss Leads To Active Destabilization Of Balance During Voluntary Head Turns In The Standing Cat, Paul Stapley, Lena Ting, Chen Kuifu, Dirk Everaert, Jane Macpherson
Dr Paul J Stapley
The purpose of this study was to determine the source of postural instability in labyrinthectomized cats during lateral head turns. Cats were trained to maintain the head in a forward orientation and then perform a rapid, large-amplitude head turn to left or right in yaw, while standing freely on a force platform. Head turns were biomechanically complex with the primary movement in the yaw plane accompanied by an ipsilateral ear-down roll and nose-down pitch. Cats used a strategy of pushing off by activating extensors of the contralateral forelimb while using all four limbs to produce a rotational moment of force …