Sound-evoked myogenic potentials on the sternocleidomastoid muscle in monkeys.
CONCLUSIONS
We recorded sound-evoked myogenic potentials of the sternocleidomastoid (SCM) muscle using awake monkeys. The characteristics of these potentials are similar to those of vestibular evoked myogenic potentials (VEMPs) in humans, suggesting that the sound-evoked myogenic potentials of the SCM muscle in monkeys may be utilized as an animal model of VEMPs.


OBJECTIVE
The pathway of the VEMPs remains uncertain as no animal model has yet been used to record sound-evoked myogenic potentials in the SCM muscle. Therefore, the present study aimed to establish an animal model of VEMPs using macaque monkeys.


METHODS
Four macaque monkeys were used. A pair of electrodes was attached on the SCM muscle ipsilateral side to the intense sound stimulation.


RESULTS
The sound-evoked myogenic potentials of the SCM muscle exhibited a biphasic waveform. When a click at 125 dBSPL was applied, the peak latency of the first positive wave was 12.5 ms and was not delayed when the stimulating sound intensity was reduced. The thresholds of the myogenic potentials were 103 dBSPL, which were 43 dB higher than those of the auditory brainstem response (ABR). When a short tone burst was applied, the reactive optimal frequency of the myogenic potentials was relatively low (500-1000 Hz).
Tsubota
Masahito
M
Department of Otolaryngology, University of Toyama, Japan.
Shojaku
Hideo
H
Hori
Etsuro
E
Fujisaka
Michiro
M
Nishijo
Hisao
H
Ono
Taketoshi
T
Yamamoto
Hiroshi
H
Watanabe
Yukio
Y
D000161:Acoustic Stimulation; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology; D004576:Electromyography; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D007537:Isometric Contraction / Q000502:physiology; D008144:Loudness Perception / Q000502:physiology; D008251:Macaca; D008253:Macaca mulatta; D008416:Mastoid / Q000294:innervation; D018482:Muscle, Skeletal / Q000294:innervation*; D009434:Neural Pathways / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013018:Sound Spectrography; D013116:Spinal Cord / Q000502:physiology*; D014725:Vestibular Nerve / Q000502:physiology*