Intrinsic choroidal neurons in the duck eye express galanin

Schrödl, Falk; Brehmer, Axel; Neuhuber, Winfried

doi:10.1002/1096-9861(20000911)425:1<24::aid-cne3>3.0.co;2-k

Cited by 23 publications

(37 citation statements)

References 55 publications

(88 reference statements)

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“…2). Their morphology was identical to earlier descriptions (Bergua et al 1996;Schrödl et al 2000). Double staining for TH or DBH and one of the markers for ICN, in most cases nNOS, demonstrated TH-or DBH-immunoreactive fibres in close apposition to the somata and dendrites of ICN (Fig.…”

Section: Close Appositions Of Th/dbh-immunoreactive Nerve Fibres On Icnsupporting

confidence: 85%

“…choroidal arteries (Bergua et al 1996) and NVSMC of the stroma (Schrödl et al 2000), are also directly innervated by sympathetic adrenergic fibres (Ehinger 1967;Guglielmone and Cantino 1982;Klooster et al 1996;this study). Again, this is reminiscent of the arrangement in the digestive tract where postganglionic sympathetic neurons, in addition to their prominent termination in enteric ganglia, also innervate blood vessels and smooth muscle, particulary in sphincters (Furness and Costa 1987).…”

Section: Functional Considerationsmentioning

confidence: 90%

“…However, our study indicates that ICN serve as an intermediate to integrate sympathetic signals into their own actions, thus sharing hodological and also probably functional aspects with enteric and cardiac ganglia. Another similarity with these ganglia is indicated by suggestive evidence for intrinsic connections between ICN (Schrödl et al 2000). Further studies should clarify whether ICN also receive preganglionic parasympathetic input from brainstem nuclei or postganglionic parasympathetic fibres from the ciliary ganglion.…”

Section: Functional Considerationsmentioning

confidence: 92%

“…The source of sympathetic innervation to the eye is located in the superior cervical ganglion, in birds and in mammals (Kirby et al 1978;Guglielmone and Cantino 1982;ten Tuscher et al 1994). We have previously demonstrated that, from extrinsic sources supplying the eye in Cairina moschata (pterygopalatine, ciliary, and superior cervical ganglia), TH-immunoreactive neurons are only detectable by immunohistochemistry in the superior cervical ganglion (Schrödl et al 2000). Therefore, this ganglion probably also represents the main source for sympathetic innervation of the choroid in this species.…”

Section: General Considerationsmentioning

confidence: 96%

“…As in primates, duck ICN co-stain for nNOS/VIP and innervate choroidal arteries (Bergua et al 1996). Virtually all ICN co-express galanin (GAL), which can be used as a reasonably specific marker for these neurons in the duck (Schrödl et al 2000). GAL immunocytochemistry has shown that non-vascular smooth muscle, which is abundant in the avian choroid (Kajikawa 1923;Guglielmone and Cantino 1982;De Stefano and Mugnaini 1997b), is a main target for ICN (Schrödl et al 2000).…”

Section: Introductionmentioning

confidence: 99%

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Intrinsic choroidal neurons in the duck eye receive sympathetic input: anatomical evidence for adrenergic modulation of nitrergic functions in the choroid

Schrödl

Tines²,

Brehmer³

et al. 2001

Cell and Tissue Research

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Intrinsic choroidal neurons (ICN) in the duck eye form an intramural ganglionic plexus that may subserve complex integrative functions. A key feature of such ganglia is an innervation by sympathetic postganglionic neurons. The present study was thus aimed at determining the sympathetic postganglionic innervation of ICN. Choroids were processed for double immunofluorescence labelling with the following markers: tyrosine-hydroxylase (TH)/nitric oxide synthase (nNOS), TH/galanin (GAL), dopamine-beta-hydroxylase (DBH)/vasoactive intestinal polypeptide (VIP), TH/DBH and DBH/alpha-smooth-muscle actin (alphaSMA), and for triple immunofluorescence labelling with VIP/DBH/TH. Epifluorescence and confocal laser scanning microscopy were used for evaluation. Immunoperoxidase staining for TH or DBH in combination with NADPH-diaphorase histochemistry was applied for electron microscopy. ICN spread over the entire choroid but were concentrated in an equatorial zone passing obliquely from naso-cranial to temporocaudal. More than 80% of nNOS-positive ICN showed close appositions of TH/DBH-immunoreactive varicose nerve fibres at the light-microscopic level, as could be confirmed by confocal laser scanning microscopy. Ultrastructurally, these appositions could be defined as both synapses or close contacts without synaptic specialisation. Vascular and non-vascular smooth muscle fibres also received TH/DBH-immunopositive innervation. Our findings suggest that most ICN receive a sympathetic input that might modulate their nitrergic effects upon vascular and non-vascular smooth muscle fibres in the choroid and that they may have more complex functions than merely being a simple parasympathetic relay.

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Section: Close Appositions Of Th/dbh-immunoreactive Nerve Fibres On Icnsupporting

confidence: 85%

Section: Functional Considerationsmentioning

confidence: 90%

Section: Functional Considerationsmentioning

confidence: 92%

Section: General Considerationsmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Intrinsic choroidal neurons in the duck eye receive sympathetic input: anatomical evidence for adrenergic modulation of nitrergic functions in the choroid

Schrödl

Tines²,

Brehmer³

et al. 2001

Cell and Tissue Research

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Autonomic Control of the Eye

McDougal

Gamlin

2014

Comprehensive Physiology

336

369

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The autonomic nervous system influences numerous ocular functions. It does this by way of parasympathetic innervation from postganglionic fibers that originate from neurons in the ciliary and pterygopalatine ganglia, and by way of sympathetic innervation from postganglionic fibers that originate from neurons in the superior cervical ganglion. Ciliary ganglion neurons project to the ciliary body and the sphincter pupillae muscle of the iris to control ocular accommodation and pupil constriction, respectively. Superior cervical ganglion neurons project to the dilator pupillae muscle of the iris to control pupil dilation. Ocular blood flow is controlled both via direct autonomic influences on the vasculature of the optic nerve, choroid, ciliary body, and iris, as well as via indirect influences on retinal blood flow. In mammals, this vasculature is innervated by vasodilatory fibers from the pterygopalatine ganglion, and by vasoconstrictive fibers from the superior cervical ganglion. Intraocular pressure is regulated primarily through the balance of aqueous humor formation and outflow. Autonomic regulation of ciliary body blood vessels and the ciliary epithelium is an important determinant of aqueous humor formation; autonomic regulation of the trabecular meshwork and episcleral blood vessels is an important determinant of aqueous humor outflow. These tissues are all innervated by fibers from the pterygopalatine and superior cervical ganglia. In addition to these classical autonomic pathways, trigeminal sensory fibers exert local, intrinsic influences on many of these regions of the eye, as well as on some neurons within the ciliary and pterygopalatine ganglia.

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