J Korean Ophthalmol Soc.  1975 Mar;16(1):1-9.

Retractor Oculi Muscle Response to Vestibular Canal Nerve Excitation in the Rabbits

• Park BI
• Han HJ

Abstract

v16n1(Mar) This experiment was designed to observe the vestibular response of the retractor oculi muscles. The vestibular canal excitation was simulated by the electric stimulation of the ampullary nerve, and the responses of the retractor bulbi muscles were recorded in terms of the tension changes and EMG activities. Experimental results are summarized as foIlows: 1) In response to vestibular canal nerve excitation, an antagonism was demonstrated between the superior and inferior slips as weIl as between the medial and lateral slips. 2) Vestibular response of the each retractor muscle slip was similar to that of nearby rectus muscle; for instance, the superior slip was synergic to the superior rectus muscle and the lateral slip to the lateral rectus muscle. 3) The superior and medial slips were contracted by the ipsilateral canal excitation and were relaxed by the contralateral canal excitation; by contraries, the inferior and lateral slips were contracted by the contralateral canal excitation and were relaxed by the ipsilateral excitation. The above experimental observations on the vestibular responses of the retractor oculi muscles weIl demonstrate that the muscles have ocular rotatory function in addition to the ocular retractive role. If the retractor oculi muscles were developed for only ocular retraction, vestibular canal excitation would never elicit such reflex; responses of the muscles.

MeSH Terms

Electric Stimulation
Muscles
Rabbits*
Reflex