FUNCTIONAL REPRESENTATION IN THE OCULOMOTOR AND TROCHLEAR NUCLEI

Abstract

The localization of function in the cell masses of the oculomotor nucleus has not been established. While allocation of pupillary constriction to the small-celled Edinger-Westphal nucleus has been generally recognized, there is still controversy regarding the representation of functions of the extrinsic ocular muscles subserved by the third cranial nerve. Tsuchida¹ stated that there was no exact localization and that the ocular muscles received their innervation diffusely from all the cell groups. The most widely accepted view is that of Brouwer,² who from a review of the literature and from a single clinicopathologic observation postulated the following cephalocaudal arrangement of functional representation of the ocular muscles within the oculomotor nucleus; (a) sphincter pupillae; (b) levator palpebrarum; (c) superior rectus; (d) medial rectus; (e) inferior oblique, and (f) inferior rectus. This scheme of segmentation had been suggested previously by Bernheimer³ on the basis of the retrograde cell degeneration