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.)
File:Gray762.png 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
TA
TH	{{#property:P1694}}
TE	{{#property:P1693}}
FMA	{{#property:P1402}}
Anatomical terms of neuroanatomy [[[d:|edit on Wikidata]]]

The Edinger–Westphal nucleus (accessory oculomotor nucleus) is the parasympathetic pre-ganglionic nucleus that innervates 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, lateral septal nuclei, lateral hypothalamic area and the central nucleus of the amygdala, among other regions

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.

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

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.

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.

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.

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.

Additional images

• 

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

• Gray697.png

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

• Gray698.png

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

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