Edinger–Westphal nucleus

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.
Details
Latin	nuclei accessorii nervi oculomotorii
Components	Provides input to Parasympathetic root of ciliary ganglion
Identifiers
NeuroNames	hier-489
NeuroLex ID	Parvocellular oculomotor nucleus
Dorlands /Elsevier	n_11/12580082
Anatomical terms of neuroanatomy

The Edinger–Westphal nucleus (accessory oculomotor nucleus) are the parasympathetic pre-ganglionic neurons that originate the oculomotor nerve. It supplies the iris sphincter muscle and the ciliary muscle.

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.^[1]

Unlike the classical preganglionic Edinger–Westphal neurons that contain choline acetyltransferase, neurons of the non-preganglionic Edinger–Westphal nucleus contain various neuropeptides, such as Urocortin and cocaine- and amphetamine-regulated transcript.^[2]

Previously, it had been proposed to rename this group of non-preganglionic, neuropeptide-containing neurons to perioculomotor subgriseal neuronal stream, abbreviated pIII_SG.^[3]

However, more recently, a final nomenclature has been determined. Preganglionic oculomotor neurons within the Edinger–Westphal nucleus shall be referred to as the EWpg, and the neuropeptide-containing neurons shall be known as the centrally-projecting Edinger Westphal nucleus, or EWcp.^[1]

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.

Function

The Edinger–Westphal nucleus supplies preganglionic parasympathetic fibers to the eye, constricting the pupil, accommodating the lens, and convergence of the eyes.^[4]

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.^[5][6]

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.^[7]

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.

References

1. ^ ^{a b} Kozicz T, Bittencourt JC, May PJ, Reiner A, Gamlin PD, Palkovits M, Horn AK, Toledo CA, Ryabinin AE (2011). "The Edinger–Westphal nucleus: A historical, structural and functional perspective on a dichotomous terminology". J. Comp. Neurol. In press. 519 (8): 1413–34.  
2. ^ 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.  
3. ^ May PJ, Reiner AJ, Ryabinin AE (March 2008). "Comparison of the Distributions of Urocortin Containing and Cholinergic Neurons in the Perioculomotor Midbrain of the Cat and Macaque". J. Comp. Neurol. 507 (3): 1300–16.  
4. ^ Kaufman, Paul L.; Levin, Leonard A.; Alm, Albert (2011). Adler's Physiology of the Eye. Elsevier Health Sciences. p. 508.  
5. ^ Harrison, NA; Wilson, CE; Critchley, HD (2007). "Processing of observed pupil size modulates perception of sadness and predicts empathy". Emotion (Washington, D.C.) 7 (4): 724–9.  
6. ^ Harrison, NA; Singer, T; Rotshtein, P; Dolan, RJ; Critchley, HD (2006). "Pupillary contagion: central mechanisms engaged in sadness processing". Social cognitive and affective neuroscience 1 (1): 5–17.  
7. ^ synd/893 at Who Named It?

External links

• -248184792 at GPnotebook
• Diagram at Columbia
• Stained brain slice images which include the "Edinger–Westphal nucleus" at the BrainMaps project
• MedEd at Loyola Neuro/frames/nlBSs/nl18fr.htm
• Cranial Nerves at Yale 3-12