Edinger-Westphal nucleus

Impact of Retinal Stimulation on Neuromodulation

Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017

The Edinger–Westphal nucleus is an accessory nucleus of the oculomotor nerve and receives input for pupillary constriction from external light. This nucleus also receives internal information from the olivary pretectal nuclei, which also receive signals from a subtype of the intrinsically photosensitive retinal ganglion (ipRGC) cells. The olivary pretectal nuclei are involved in linking internal metabolism with external luminance—through the suprachiasmatic nuclei (SCN) of the hypothalamus and intergeniculate leaflet (IGL) of the thalamus (Ishikawa 2013).

A computational model of pupil dilation

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Journal Information

Published in Connection Science, 2018

Birger Johansson, Christian Balkenius

The control of the constriction of the pupil is part of the parasympathetic systems. The pupillary sphincter receives signals from the Edinger–Westphal nucleus (EW) through the Ciliary ganglion (CG). EW, in turn, receives its primary input from the pretectal area (PTA) that receives input from the retinal ganglion cells. This results in a loop where increased light stimulation of the retina will produce constriction of the pupil. Both the PTA and EW are paired structures. The left and right PTA receive signals from the corresponding visual fields of both eyes, thus adding up light responses from both eyes. Each PTA subsequently projects to both sides of EW producing a second step of summation where both sides react to light from both eyes. Consequently, light from either eye will let the pupils of both eyes constrict, and as expected, stimulation of the PTA results in constriction of the pupil (Reiner, Karten, Gamlin, & Erichsen, 1983).

Edinger-Westphal nucleus

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Impact of Retinal Stimulation on Neuromodulation

A computational model of pupil dilation