Premium
Modification of the Cervico‐ocular Reflex by Canal Plugging
Author(s) -
Yakushin Sergei B.,
Tarasenko Yelena,
Raphan Theodore,
Suzuki JunIchi,
Della Santina Charles C.,
Minor Lloyd B.,
Cohen Bernard
Publication year - 2009
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2009.03775.x
Subject(s) - reflex , amplitude , vestibulo–ocular reflex , physics , semicircular canal , stimulus (psychology) , ear canal , optics , materials science , acoustics , audiology , medicine , vestibular system , anesthesia , psychology , psychotherapist
The cervico‐ocular reflex (COR) has a low gain in normal animals. In this study, we determined whether COR gain increases were specific to the low/midband frequency range, which is the range over which the angular vestibulo‐ocular reflex (aVOR) is compromised by plugging. The gain and phase of the yaw and pitch COR and aVOR were compared in normal monkeys and those with all six semicircular canals or only the lateral canal plugged. During experiments animals sat with the body fixed to a chair and the head fixed in space. The body was oscillated about body‐yaw and body‐pitch axes over a frequency range of 0.05–6 Hz, with amplitude <10°. For normal animals, both yaw and pitch eye velocities were compensatory to the relative velocity of the head with respect to the body. The gains were 0.1–0.2 at frequencies below 1 Hz and decreased to zero as stimulus frequency increased above 1 Hz. Canal‐plugged animals had COR gains close to 1.0 at low frequencies, decreasing to ≈0.6 at 0.5 Hz and to 0.2 for stimulus frequencies above 3 Hz. The phase of eye velocity was 180° relative to head‐re‐body velocity at frequencies below 0.5 Hz and shifted toward 270° as frequencies were increased to 4 Hz. This study demonstrates that adaptation of COR gain is tuned to a frequency range at which the aVOR is compromised by the canal plugging.