A M A Archives of Ophthalmology · 1953 · 23 citations · 9 references
Life SciencesNeurobiologyNeuroscienceNeuroanatomyNeurophysiologyOcular AnatomyOcular InnervationReflex PhysiologyRetinal AnatomyRetinal NeuroscienceVisual PhysiologyVisual SystemElectrical StimulationFibersOptic TractPretectal LesionsReflex Arc FunctionReflex Arc PhysiologyRetinal PhysiologySuperior Colliculus Function
THE PATHWAYS of the pupillary reflex to light have been the subject of many investigations. A survey of the older literature was given by Behr<sup>1</sup>and one of the more recent work, by Magoun and Ranson.<sup>2</sup>Research included experiments by electrical stimulation and degeneration studies after lesions, in many species, especially the rat, rabbit, dog, cat, and monkey. A functional evaluation of the effect of lesions at various sites within the reflex arc was attempted.<sup>3</sup> The general course of the reflex arc is now agreed upon. In cats, a majority of the retinal fibers cross in the optic chiasm, and a minority remain uncrossed (Fig. 1). The fibers run in the optic tract and pass to the pretectal area through the brachium of the superior colliculus. The existence of a synapse in this region is established, although its exact site is debated. Magoun and Ranson believed that
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