Vestibular and optokinetic function in the normal guinea pig.
Vestibular and optokinetic function was quantitatively studied in the normal guinea pig through investigation of the vestibulo-ocular reflex (VOR), optokinetic nystagmus (OKN), and the visual vestibulo-ocular reflex (VVOR) by means of sinusoidal stimulation with a computer-controlled rate table (VOR and VVOR) or an optokinetic drum. The VOR exhibited high-pass filter characteristics with steady state gain achieved at 0.125 Hz. The maximum gain was 0.55 at a velocity of 60 degrees/s. The VOR was modeled by a transfer function with best fits obtained with an adaptation time constant of 12.5 seconds. The OKN showed low-pass filter characteristics with a decrease in gain for increase in stimulus amplitude. The maximum gain measured was 0.64. A fractional pole model provided a fit of these data. The VVOR exhibited a mean gain of between 0.6 and 0.7 across the stimulus bandwidth and peak velocities. A model based on a linear combination of the actual OKN and VOR gains provided an estimate of the VVOR gain.
Andrews
J C
JC
Division of Head and Neck Surgery, University of California-Los Angeles School of Medicine 90095-1624, USA.
Li
J
J
Koyama
S
S
Hoffman
L F
LF
D000818:Animals; D004195:Disease Models, Animal; D018159:Endolymphatic Hydrops / Q000503:physiopathology; D006168:Guinea Pigs / Q000502:physiology*; D016014:Linear Models; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D010812:Physical Stimulation; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D015203:Reproducibility of Results; D012399:Rotation; D013997:Time Factors