Dependence of the torsional vestibulo-ocular reflex on the direction of gravity.
The torsional vestibulo-ocular reflex (tVOR), which is mainly driven by input from the semicircular canals, has been shown to be augmented by otolith input: its gain is increased in the upright as compared to the supine head orientation. We tested whether otolith input in right/left ear down and upside-down orientation also contributes to the tVOR. In contrast to current models of canal-otolith interaction, which predict equal responses in upright and upside-down orientations, we found that the tVOR in the upside-down position is significantly decreased, possibly due to an additive interaction of canal and otolith signals.
Bartl
Klaus
K
Center for Sensorimotor Research, Department of Neurology, Ludwig-Maximilian-University, Marchioninistr. 23, D-81377 Munich, Germany. kbartl@nefo.med.uni-muenchen.de
Schneider
Erich
E
Glasauer
Stefan
S
D006112:Gravitation; D006801:Humans; D009068:Movement; D011187:Posture; D012016:Reference Values; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D012399:Rotation; D016683:Supine Position; D014102:Torsion Abnormality