Brain: Edinger-Westphal nucleus
Section through superior colliculus (unlabeled) showing path of oculomotor nerve. ("Edinger-Westphal nucleus" is not on diagram, but would be near oculomotor nuclei.)
Figure showing the different groups of cells, which constitute, according to Perlia, the nucleus of origin of the oculomotor nerve. 1. Posterior dorsal nucleus. 1’. Posterior ventral nucleus. 2. Anterior dorsal nucleus. 2’. Anterior ventral nucleus. 3. Central nucleus. 4. Nucleus of Edinger and Westphal. 5. Antero-internal nucleus. 6. Antero-external nucleus. 8. Crossed fibers. 9. Trochlear nerve, with 9’, its nucleus of origin, and 9", its decussation. 10. Third ventricle. M, M. Median line.
Latin	nuclei accessorii nervi oculomotorii
NeuroNames	hier-489

The Edinger-Westphal nucleus (also known as the accessory oculomotor nucleus ) is the accessory parasympathetic cranial nerve nucleus of the oculomotor nerve (cranial nerve III), supplying the constricting muscles of the iris. Alternatively, the Edinger-Westphal nucleus is a term often used to refer to the adjacent population of non-preganglionic neurons that do not project to the ciliary ganglion, but rather project to the spinal cord, dorsal raphe nucleus, and lateral septal nuclei. Unlike the classical, preganglionic Edinger-Westphal neurons that contain choline acetyltransferase, neurons of the non-preganglionic Edinger-Westphal nucleus have been shown to contain various stress- and feeding-related neuropeptides, such as Urocortin and cocaine- and amphetamine-regulated transcript ^[1]. Proper nomenclature for this distinct brain region has not yet been established.

[edit] Location

The paired nuclei are posterior to the main motor nucleus (oculomotor nucleus) and anterolateral to the cerebral aqueduct in the rostral midbrain at the level of the superior colliculus.

It is the most rostral of the parasympathetic nuclei in the brain stem.

[edit] Function

The Edinger-Westphal nucleus supplies preganglionic parasympathetic fibers to the eye, constricting the pupil and accommodating the lens.

It has also been implicated in the mirroring of pupil size in sad facial expressions. When seeing a sad face, participants' pupils dilated or constricted to mirror the face they saw, which predicted both how sad they perceived the face to be, as well as activity within this region.^[2][3]

[edit] Eponym

The nucleus is named for both Ludwig Edinger, from Frankfurt, who demonstrated it in the fetus in 1885, and for Karl Friedrich Otto Westphal, from Berlin, who demonstrated it in the adult in 1887.^[4]

[edit] Additional images

The cranial nerve nuclei schematically represented; dorsal view. Motor nuclei in red; sensory in blue.

Nuclei of origin of cranial motor nerves schematically represented; lateral view.

Primary terminal nuclei of the afferent (sensory) cranial nerves schematically represented; lateral view.

[edit] References

1. ^ Kozicz T. (2003). Neurons colocalizing urocortin and cocaine and amphetamine-regulated transcript immunoreactivities are induced by acute lipopolysaccharide stress in the Edinger-Westphal nucleus in the rat. Neuroscience. 116(2): 315-20. PMID 12559087
2. ^ Harrison NA, Wilson CE, Critchley HD. (2007). Processing of observed pupil size modulates perception of sadness and predicts empathy. Emotion. 7(4):724-9. PMID 18039039
3. ^ Harrison NA, Singer T, Rotshtein P, Dolan RJ, Critchley HD. (2006). Pupillary contagion: central mechanisms engaged in sadness processing. Soc Cogn Affect Neurosci. 1(1):5-17. PMID 17186063
4. ^ synd/893 at Who Named It?

[edit] External links

• -248184792 at GPnotebook
• Diagram at Columbia
• BrainMaps at UCDavis Edinger-Westphal nucleus

• MedEd at Loyola Neuro/frames/nlBSs/nl18fr.htm
• Cranial Nerves at Yale 3-12