Dataset Information

GABAergic innervation of the ciliary ganglion in macaque monkeys - A light and electron microscopic study.

ABSTRACT: The vertebrate ciliary ganglion (CG) is a relay station in the parasympathetic pathway activating the iris sphincter and ciliary muscle to mediate pupillary constriction and lens accommodation, respectively. While the postganglionic motoneurons in the CG are cholinergic, as are their inputs, there is evidence from avian studies that GABA may also be involved. Here, we used light and electron microscopic methods to examine the GABAergic innervation of the CG in Macaca fascicularis monkeys. Immunohistochemistry for the gamma aminobutyric acid synthesizing enzyme glutamic acid decarboxylase (GAD) and choline acetyltransferase (ChAT) revealed that all CG neurons are contacted by ChAT-positive terminals. A subpopulation of 17.5% of CG neurons was associated with terminal boutons expressing GAD-immunoreactivity in addition. Double-labeling for GAD and synaptophysin confirmed that these were synaptic terminals. Electron microscopic analysis in conjunction with GABA-immunogold staining showed that (1) GAD-positive terminals mainly target dendrites and spines in the perisomatic neuropil of CG neurons; (2) GABA is restricted to a specific terminal type, which displays intermediate features lying between classically excitatory and inhibitory endings; and (3) if a CG neuron is contacted by GABA-positive terminals, virtually all perisomatic terminals supplying it show GABA immunoreactivity. The source of this GABAergic input and whether GABA contributes to a specific CG function remains to be investigated. Nevertheless, our data indicate that the innervation of the ciliary ganglion is more complex than previously thought, and that GABA may play a neuromodulatory role in the control of lens or pupil function. J. Comp. Neurol. 525:1517-1531, 2017. © 2016 Wiley Periodicals, Inc.

SUBMITTER: Barnerssoi M

PROVIDER: S-EPMC5808918 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

GABAergic innervation of the ciliary ganglion in macaque monkeys - A light and electron microscopic study.

Barnerssoi Miriam M May Paul J PJ Horn Anja K E AK

The Journal of comparative neurology 20170227 7

The vertebrate ciliary ganglion (CG) is a relay station in the parasympathetic pathway activating the iris sphincter and ciliary muscle to mediate pupillary constriction and lens accommodation, respectively. While the postganglionic motoneurons in the CG are cholinergic, as are their inputs, there is evidence from avian studies that GABA may also be involved. Here, we used light and electron microscopic methods to examine the GABAergic innervation of the CG in Macaca fascicularis monkeys. Immuno ...[more]

PMID: 27864939

Similar Datasets

Project description:BackgroundKawasaki disease is recognized as the most common cause of acquired heart disease in children in the developed world. Clinical, epidemiologic, and pathologic evidence supports an infectious agent, likely entering through the lung. Pathologic studies proposing an acute coronary arteritis followed by healing fail to account for the complex vasculopathy and clinical course.Methodology/principal findingsSpecimens from 32 autopsies, 8 cardiac transplants, and an excised coronary aneurysm were studied by light (n=41) and transmission electron microscopy (n=7). Three characteristic vasculopathic processes were identified in coronary (CA) and non-coronary arteries: acute self-limited necrotizing arteritis (NA), subacute/chronic (SA/C) vasculitis, and luminal myofibroblastic proliferation (LMP). NA is a synchronous neutrophilic process of the endothelium, beginning and ending within the first two weeks of fever onset, and progressively destroying the wall into the adventitia causing saccular aneurysms, which can thrombose or rupture. SA/C vasculitis is an asynchronous process that can commence within the first two weeks onward, starting in the adventitia/perivascular tissue and variably inflaming/damaging the wall during progression to the lumen. Besides fusiform and saccular aneurysms that can thrombose, SA/C vasculitis likely causes the transition of medial and adventitial smooth muscle cells (SMC) into classic myofibroblasts, which combined with their matrix products and inflammation create progressive stenosing luminal lesions (SA/C-LMP). Remote LMP apparently results from circulating factors. Veins, pulmonary arteries, and aorta can develop subclinical SA/C vasculitis and SA/C-LMP, but not NA. The earliest death (day 10) had both CA SA/C vasculitis and SA/C-LMP, and an "eosinophilic-type" myocarditis.Conclusions/significanceNA is the only self-limiting process of the three, is responsible for the earliest morbidity/mortality, and is consistent with acute viral infection. SA/C vasculitis can begin as early as NA, but can occur/persist for months to years; LMP causes progressive arterial stenosis and thrombosis and is composed of unique SMC-derived pathologic myofibroblasts.

Project description:The exact knowledge of hydrogel microstructure, mainly its pore topology, is a key issue in hydrogel engineering. For visualization of the swollen hydrogels, the cryogenic or high vacuum scanning electron microscopies (cryo-SEM or HVSEM) are frequently used while the possibility of artifact-biased images is frequently underestimated. The major cause of artifacts is the formation of ice crystals upon freezing of the hydrated gel. Some porous hydrogels can be visualized with SEM without the danger of artifacts because the growing crystals are accommodated within already existing primary pores of the gel. In some non-porous hydrogels the secondary pores will also not be formed due to rigid network structure of gels that counteracts the crystal nucleation and growth. We have tested the limits of true reproduction of the hydrogel morphology imposed by the swelling degree and mechanical strength of gels by investigating a series of methacrylate hydrogels made by crosslinking polymerization of glycerol monomethacrylate and 2-hydroxyethyl methacrylate including their interpenetrating networks. The hydrogel morphology was studied using cryo-SEM, HVSEM, environmental scanning electron microscopy (ESEM), laser scanning confocal microscopy (LSCM) and classical wide-field light microscopy (LM). The cryo-SEM and HVSEM yielded artifact-free micrographs for limited range of non-porous hydrogels and for macroporous gels. A true non-porous structure was observed free of artifacts only for hydrogels exhibiting relatively low swelling and high elastic modulus above 0.5 MPa, whereas for highly swollen and/or mechanically weak hydrogels the cryo-SEM/HVSEM experiments resulted in secondary porosity. In this contribution we present several cases of severe artifact formation in PHEMA and PGMA hydrogels during their visualization by cryo-SEM and HVSEM. We also put forward empirical correlation between hydrogel morphological and mechanical parameters and the occurrence and intensity of artifacts.

Dataset Information

GABAergic innervation of the ciliary ganglion in macaque monkeys - A light and electron microscopic study.

Publications

GABAergic innervation of the ciliary ganglion in macaque monkeys - A light and electron microscopic study.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure