title: A central mesencephalic reticular formation projection to the Edinger-Westphal nuclei.
abstract: The central mesencephalic reticular formation, a region associated with horizontal gaze control, has recently been shown to project to the supraoculomotor area in primates. The Edinger-Westphal nucleus is found within the supraoculomotor area. It has two functionally and anatomically distinct divisions: (1) the preganglionic division, which contains motoneurons that control both the actions of the ciliary muscle, which focuses the lens, and the sphincter pupillae muscle, which constricts the iris, and (2) the centrally projecting division, which contains peptidergic neurons that play a role in food and fluid intake, and in stress responses. In this study, we used neuroanatomical tracers in conjunction with immunohistochemistry in Macaca fascicularis monkeys to examine whether either of these Edinger-Westphal divisions receives synaptic input from the central mesencephalic reticular formation. Anterogradely labeled reticular axons were observed making numerous boutonal associations with the cholinergic, preganglionic motoneurons of the Edinger-Westphal nucleus. These associations were confirmed to be synaptic contacts through the use of confocal and electron microscopic analysis. The latter indicated that these terminals generally contained pleomorphic vesicles and displayed symmetric, synaptic densities. Examination of urocortin-1-positive cells in the same cases revealed fewer examples of unambiguous synaptic relationships, suggesting the centrally projecting Edinger-Westphal nucleus is not the primary target of the projection from the central mesencephalic reticular formation. We conclude from these data that the central mesencephalic reticular formation must play a here-to-for unexpected role in control of the near triad (vergence, lens accommodation and pupillary constriction), which is used to examine objects in near space.
authors.affiliation: Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39216, USA.|Department of Ophthalmology, University of Mississippi Medical Center, Jackson, MS, 39216, USA.|Department of Neurology, University of Mississippi Medical Center, Jackson, MS, 39216, USA.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: May
authors.affiliation: Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, MS, 39216, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Warren
authors.affiliation: Department of Program in Neuroscience, University of Mississippi Medical Center, Jackson, MS, 39216, USA.
authors.forename: Martin O
authors.initials: MO
authors.lastname: Bohlen
authors.affiliation: Institute of Anatomy and Cell Biology I, Ludwig-Maximilians University, Pettenkoferstrasse 11, 80336, Munich, Germany.
authors.forename: Miriam
authors.initials: M
authors.lastname: Barnerssoi
authors.affiliation: Institute of Anatomy and Cell Biology I, Ludwig-Maximilians University, Pettenkoferstrasse 11, 80336, Munich, Germany. Anja.Bochtler@med.uni-muenchen.de.
authors.forename: Anja K E
authors.initials: AK
authors.lastname: Horn
mesh_terms: D000818:Animals; D059329:Cholinergic Neurons / Q000166:cytology / Q000378:metabolism; D065839:Edinger-Westphal Nucleus / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D008252:Macaca fascicularis; D008297:Male; D066265:Midbrain Reticular Formation / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D009046:Motor Neurons / Q000166:cytology / Q000378:metabolism; D009434:Neural Pathways / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D056347:Neuroanatomical Tract-Tracing Techniques; D009474:Neurons / Q000166:cytology* / Q000378:metabolism / Q000648:ultrastructure; D013569:Synapses / Q000648:ultrastructure; D054832:Urocortins / Q000378:metabolism
chemical_list: D054832:Urocortins
keywords: Eating disorders; Lens; Oculomotor; Parasympathetic; Pupil; Stress; Urocortin