Role of Muscarinic Cholinergic Transmission in Edinger-Westphal Nucleus-induced Choroidal Vasodilation in Pigeon

Co-localization of nitric oxide synthase and choline acetyltransferase in the brain of the goldfish (Carassius auratus)

“…Like in land vertebrates, the Edinger-Westphal nucleus projects to the cilliary ganglion in goldfish (Wathey and Wullimann, 1988). In pigeon has been reported that NO participates in eye related parasympathetic reflexes (Zagvazdin et al, 1996), but the source(s) of this NO and the point at which it is critical remain to be determined (Cuthbertson et al, 1999;Zagvazdin et al, 2000). Present work has demonstrated that neurons of the Edinger-Westphal in goldfish produces NO, which could participate in ocular accommodation and regulation of choroidal blood flow (as previously proposed in pigeon, Cuthbertson et al, 1999).…”

Role of M1, M3, and M5 muscarinic acetylcholine receptors in cholinergic dilation of small arteries studied with gene-targeted mice

“…Pharmacological studies making use of subtypepreferring agents as well as functional studies in vascular preparations from muscarinic receptor knockout mice have demonstrated that the M 3 receptor is the predominant mediator of cholinergic vasodilation in coronary and ocular blood vessels (7,20,25,30,35,48). Thus, from a clinical point of view, the M 3 receptor may represent an attractive pharmacological target to modulate cardiac and ocular perfusion.…”

Role of the M3Muscarinic Acetylcholine Receptor Subtype in Murine Ophthalmic Arteries After Endothelial Removal

“…Thus, it is important to define the functional role of individual muscarinic receptor subtypes in conditions of endothelial damage or dysfunction. Although it has been shown that the M 3 acetylcholine receptor subtype mediates vasodilation in endothelium-intact ocular blood vessels, [4][5][6] to our knowledge there are at present no studies reporting on its functional role in ocular blood vessels with damaged or dysfunctional endothelium. Hence, the goal of the present study was to test the hypothesis that the M 3 muscarinic acetylcholine receptor subtype mediates responses in ophthalmic arteries after Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc. www.iovs.org j ISSN: 1552-5783 endothelial removal.…”

“…2,3 Previous studies reported that the M 3 receptor subtype mediates cholinergic vasodilation in the choroid of pigeons and in ocular blood vessels of mice. [4][5][6] Based on these findings, the M 3 receptor may represent a potential pharmacologic target to modulate blood flow in diseases associated with disturbances of ocular perfusion, such as diabetic retinopathy, age-dependent macular degeneration, nonarteritic anterior ischemic optic neuropathy (NAION), and glaucoma. [7][8][9][10] However, in various nonocular vascular beds, cholinergic agonists were shown to exert only limited vasodilation effects or even to induce vasoconstriction when applied in pathologic conditions associated with endothelial dysfunction.…”