Chonnam Med J.  1995 Jun;31(1):79-90.

Reflex responses of the superior rectus and splenius capitis muscles to stimulation of superior semicircular canal nerve in cats

• Byon HS
• Park JS
• Kim JH

Abstract

In urethane anesthetized cats, the superior semicircular canal nerve was selectively stimulated, and the electromyographic response of the extraocular superior rectus and splenius capitis muscles were recorded to make a comparison between the neural organizations for vestibulo-ocular and vestibulo-collic reflexes. 1) The superior rectus muscle was excited by stimulating the ipsilateral superior canal nerve and inhibited by stimulation of the contralateral nerve. 2) The inferior rectus muscle was excited by stimulating the contralateral superior canal nerve and inhibited by stimulation of the ipsilateral nerve. 3) The splenius rectus muscle was inhibited by stimulating of the ipsilateral superior canal nerve and excited by the contralateral nerve. 4) To stimulation of a unilateral superior canal nerve, the bilateral superior rectus muscles of the both eyes and the bilateral splenius capitis muscles of the neck responded with opposite patterns to each other. Thus, the superior rectus and splenius capitis muscles, the elevatory muscles of the eyeball and the head produced opposite responses to the superior canal nerve stimulation. Nevertheless, responses of the motoneurons of these axial muscles to the canal nerve stimulation were found out to be consistent.

MeSH Terms

Animals
Cats*
Head
Muscles*
Neck
Paraspinal Muscles*
Reflex*
Semicircular Canals*
Urethane
Urethane