PubMed HealthSearch

PubMed · 57221

[The oculoauricular phenomenon: a new reflex, a new muscle -- m. retroauricularis (polygraphic EMG study) (author's transl)].

Abstract

On forced lateral gaze the outer and upper part of both ears is turned backward (oculoauricular phenomenon). A new, as far as we know, skin muscle of the external ear is described and called "m. retroauricularis". The oculoauricular phenomenon is a reflex mechanism between the abducens (m. rectus externus) and facial (m. retroauricularis) nerves. The verification of the automatic and tonic coinnervation is made polygraphically (EMG, stimulodetection) and clinically (unilateral abolition in case of homolateral facial paralysis). The oculoauricular reflex is a physiological and bilateral phenomenon, often rudimentary in man. It serves in looking, hearing and miming. The bilateral mechanism of innervation in the brainstem via the medial longitudinal fasciculus corresponds to Bell's phenomenon as to the "anti Bell".

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Heuser. 1976-03-23. [The oculoauricular phenomenon: a new reflex, a new muscle -- m. retroauricularis (polygraphic EMG study) (author's transl)].. https://doi.org/10.1007/bf00312492

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

[Ophthalmomimics. Polygraphic EMG study on oculo-facial simultaneous movements and functions of the autochthonous ear muscles].

Ophthalmomimic is the interaction between the extraocular eye muscles and the mimic muscles. Beside their original phylogenetic assisting function in looking and hearing, the ophthalmomimic muscles now serve in psychological communication: The play with the white of the eye ball can be interpreted as devotion ("to turn a blind eye to"); attention ("to be all eyes"); caution ("to have small eyes and to prick up one's ears"). Further on are examined function and innervation of the involuntary M. retro-auricularis (M. transversus auriculae) of the external ear, so far neglected. Practical diagnostic use could be shown, among others, in early ocular forms of myasthenic syndromes and by the help of the oculoauricular phenomenon for the differentiation between nuclear and peripheral-distal pareses of the abducens nerve.

Abducens Nerve

Accessory abducens nucleus and its relationship to the accessory facial and posterior trigeminal nuclei in cat.

Retrograde transport of HRP by the abducens nerve results in the labelling of its principal nucleus and, in addition, a second nucleus about 2.5 mm ventrolateral to the principal nucleus. The presence of this second or accessory nucleus of the abducens in a mammal confirms the observations of several Nineteenth Century anatomists and rebuts the conclusions of more recent investigators who argued that the nucleus was allied instead to the facial or trigeminal nerves. The same HRP technique applied to the facial or trigeminal nerves shows that the accessory nucleus of the abducens is in the same parasagittal plane as the accessory nucleus of the facial nerve and the most caudal cells of the motor trigeminal nucleus. The accessory abducens and accessory facial nuclei fall in a ventrocaudal to dorsorostral line between the principal nucleus of the facial and the motor nucleus of the trigeminal with the accessory abducens just caudal and ventral to the accessory facial.

Abducens Nerve

Stimulation of abducens nucleus supports classical conditioning of the nictitating membrane response.

The acquisition and terminal performance of a classical conditioning group compared with a control group indicated that extension of the nictitating membrane elicited by direct electrical stimulation of the abducens nucleus was successfully conditioned to a previously neutral stimulus. The conditioning so obtained was associative and not due to such nonassociative factors as sensitization, pseudo-conditioning, or alteration in base-rate responding.

Abducens Nerve