THE CENTRAL PATH OF THE PUPILLOCONSTRICTOR REFLEX IN RESPONSE TO LIGHT

Abstract

A part of the work being done on the optic system in the laboratory of Northwestern University Medical School has been concerned with determining the central path of the pupilloconstrictor reflex in response to light. Information concerning this path should be of general interest as well as of clinical value in providing the anatomic basis for an understanding of the Argyll Robertson pupil and other disturbances of pupillary innervation. Certain features of the course taken by the light reflex are already known. The work of Karplus and Kreidl¹ on the cat and the monkey established that the constrictor pathway runs centrad from the optic tract in the brachium of the superior colliculus. In spite of a large amount of contrary evidence, the view has long been held that the impulses pass from the brachium into the tectum of the superior colliculus, and thence by way of the tectobulbar tract