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C Junquera

Publications and source records attributed to C Junquera.

At least 19 recordsLinked to original sources
PubMed2004

S-100 protein immunoreactivity in the upper eyelid of the sheep Ovis aries.

The aim of this work was to analyse the distribution pattern of S-100-immunoreactive elements in the upper eyelid of the sheep. This pattern may be of importance regarding the diagnosis and prognosis of eyelid tumours that are linked to deregulation of S-100 gene expression. Thirty upper eyelids taken from 15 adult male Ovis aries were studied by means of the peroxidase-antiperoxidase method for light microscopy. S-100-immunopositive cells were found in the eyelid edge. S-100-immunopositive steams and thinner fibres were found throughout the eyelid. These nerve processes typically were denser around glands, hair follicles and blood vessels. S-100-immunopositive elements may play a role as neuromodulator and also in the development of the vegetative innervation of the epithelium and its derivatives.

Animals↗
PubMed2001

Acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive innervation in the upper eyelid of the sheep (Ovis aries).

This is the first study which describes the innervation of some eyelid structures, such as the glands of Moll and the glands of Zeiss. It is also the first to investigate the innervation pattern of the eyelid as a whole. We have studied the acetylcholinesterase-positive and paraformaldehyde-induced-fluorescence-positive (FIF+) innervation pattern of the different structures that constitute the upper eyelid of the sheep. There is widespread acetylcholinesterase-positive innervation in the epithelium, but not such an abundant FIF+ innervation. Both types of innervation are represented in the connective tissue by trunks or fibers that are distributed towards the different structures immersed within them. In the glands of Zeiss, cholinesterase-positive innervation is much more widespread than FIF innervation. On the contrary, the glands of Moll present denser FIF+ innervation than acetylcholinesterase-positive innervation. The Meibomian glands and the lachrymal glands show a rich acetylcholinesterase-positive and FIF+ innervation. Eyelid muscle innervation is mainly acetylcholinesterase-positive. In the conjunctive membrane there is no acetylcholinesterase-positive innervation, and only scarce FIF+ fibers can be demonstrated.

Acetylcholinesterase↗
PubMed2001

Enteric plexus and interstitial cells of Cajal: interrelationship in the stomach of Podarcis hispanica (Reptilia). An ultrastructural study.

The ultrastructure organization of the stomach enteric plexus was examined in the lizard Podarcis hispanica. The ganglions of the myenteric plexus present a low number of nerve cell bodies with a peculiar nucleus, which occasionally establish direct contacts with cells of the circular muscle layer. Glial cells are smaller than the neurones, and their nucleus is very electron-dense. They surround the axons that constitute the fibres of the myenteric plexus. Four main types of axon profile are described in a morphological consideration of the vesicle population. In the interstice of the circular muscle layer we describe two types of interstitial cells that, due to their ultrastructural characteristics, may be equivalent to the interstitial cells of Cajal which have been described in mammalians. These cells shows parallel distribution to the stomach nerve plexuses, establishing close contacts with them through their long cytoplasmic prolongations. By means of small gap-like unions, they contact both each other and the smooth muscle cells near them. We describe a submucous plexus, where neuronal bodies are scattered among bundles of nervous fibres, some of which are myelinated. A mucous plexus with isolated neurones is located in the lamina propria. Axonal varicosities containing vesicles contact with the cells of the mucous. Interconnected interstitial cells may also be found in this plexus.

Animals↗
PubMed2000

Intrinsic innervation in the intestine of the lizard Podarcis hispanica.

The aim of this study was the description of the morphology and distribution of nerve structure elements in the intestine of the lizard Podarcis hispanica using different histochemical methods; namely acetylcholinesterase (AChE), formol-induced fluorescence for catecholamines (FIF), nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), and immunohistochemistry for vasoactive intestinal peptide (VIP), as well as substance P (SP) and electron microscopy. The AChE method showed fibres in the myenteric and submucosal plexus, with a higher fibre density in the large intestine. The highest number of related neurons was located in the myenteric plexus ganglia. Noradrenergic innervation was distributed through the myenteric and submucosal plexus, and also around blood vessels, with the highest fibre density in the large intestine. VIP immunohistochemistry showed a wide distribution of positive fibres throughout the intestine, although the highest density was again detected in the large intestine. Small positive cells for VIP were located at internodal segments in the plexus. SP labeling, although subtle, was present all along the intestine. It showed delicate varicose nets and few fibres innervating blood vessels. Small positive cells for SP were located in the large intestine. The indirect method to detect nitric oxide (NO)-producing system showed neural cells in the myenteric plexus ganglia of the large intestine. Electron microscopy showed ganglion neurons with scattered chromatin condensations, glial cells with higher electron density, and axons with varicosities occupied by different vesicles. We also identified certain cells as interstitial cells of Cajal due to their ultrastructural features. They were mostly located in the region of the myenteric plexus.

Acetylcholinesterase↗
PubMed1998

Distribution of NADPH diaphorase-positive neurons in the enteric nervous system of the rabbit intestine.

Nitric oxide (NO) has been proposed as an inhibitory transmitter in gastrointestinal muscle relaxation. We analyzed the distribution of nitric-oxide producing neurons in the rabbit intestine through nicotinamide-adenine-dinucleotide-phosphate-diaphorase histochemistry. By this reliable and convenient method, we visualized neuronal nitric-oxide-synthase, the enzyme responsible for nitric oxide generation, in the rabbit intestine. In the ileum and rectum, nitric-oxide-synthase-related diaphorase activity was present in the myenteric plexus ganglion cells, and in the nerve fibers in the internodal strand, secondary, and tertiary plexuses. These fibers were particularly abundant in the deep circular rather than in the outer longitudinal muscle layer. In the inner submucosal plexus, we found scarce labeled neurons. Labeled neural somata showed a range of sizes and shapes suggesting different functional roles. The present basic information is required to use the rabbit as an experimental animal in neurochemical NO enteric research.

Animals↗
PubMed1998

Histochemical, immunohistochemical, and electron microscopy study of the caudal portion of the chicken intestinal nerve of Remak.

In order to deepen our knowledge of the different components of the chicken intestinal nerve of Remak (I.N.R.), we have studied it by means of histochemical, immunohistochemical and electron microscopy techniques to distinguish the different neurotransmitters. We have found cholinergic cell bodies, as well as acetylcholinesterase (AChE) positive neuronal fibers, forming part of the web that constitutes the I.N.R. in its caudal portion, with a higher density of neuronal bodies in the ganglia. We also observed catecholaminergic neuronal bodies and fibers, located fundamentally in the periphery of the nerve, and a low density of catecholaminergic cell bodies. With respect to the vasoactive intestinal peptide (VIP) and substance P (SP) positive peptidergic innervation, we found more abundant neuronal bodies positive for the V.I.P. than for S.P. Electron microscopy corroborated the results observed under the optic microscope, showing the various types of vesicles containing different neurotransmitters.

Acetylcholinesterase↗
PubMed1998

Intrinsic innervation of a reptilian esophagus (Podarcis hispanica).

We study the esophagus of Podarcis hispanica through different methods to clarify the structure and affinities of its wall innervation. The acetylcholinesterase method reveals cholinesterase activity in two submucosal nervous plexuses, with an increasing degree of structural complexity in the reptilian esophagus, compared with amphibians. Noradrenergic innervation, detected through fluorescence induced by formol, widely spreads its network in both the myenteric and submucosal plexuses (around the blood vessels in the external submucosal plexus, and to the glandular lamina propria in the inner submucosal plexus). Immunohistochemistry for vasoactive intestinal peptide shows a widespread innervation, with neurons clustered in ganglia and also scattered through the VIPergic network, only at the myenteric plexus. Immunohistochemistry for substance P shows a rich innervation along the entire wall of the esophagus, more concentrated in its caudal region, around the blood vessels. Electron microscopy shows the enteric neuronal ultrastructure and its relationship with the esophagus wall.

Acetylcholinesterase↗
PubMed1997

Intrinsic innervation of the chicken lower digestive tract.

We have studied the different components of the enteric nervous system in the rectum and cloaca of the chicken by means of histochemical and immunohistochemical techniques. We found cholinergic neuronal bodies as well as nervous fibers, which constitute part of the Meissner and Auerbach plexuses. We also observed plentiful catecholaminergic fibers in both plexuses, though there were no catecholaminergic neuronal bodies. With respect to the Vasoactive Intestinal Peptide (VIP) and substance P (SP) positive peptidergic innervation, only positive fibers were found, which were less abundant than in the other zones of the gastrointestinal tract. The optic microscopy results were confirmed by electron microscopy.

Acetylcholinesterase↗
PubMed1992

Submucosal plexus of terminal ileum: a study of the cholinergic and noradrenergic nerves in rats with streptozotocin-induced diabetes.

In order to study the type and degree of the alterations in the innervation of the intestine in experimental diabetes, a histochemical study on the cholinergic and noradrenergic nerves of the submucosal plexus of terminal ileum from rats with streptozotocin-induced diabetes was performed. The results obtained suggest that the diabetic animals keep the cholinergic activity undamaged 20 weeks after the induction of the illness, while the number of the catecholaminergic nerves appears to be markedly reduced.

Adrenergic Fibers↗
PubMed1990

Frog stomach enteric plexuses in culture: isolation, morphological characterization and bioelectrical recordings.

We have succeeded in the isolation, culture and morphological characterization of Rana ridibunda stomach enteric plexuses. We have furthermore obtained intra and extracellular bioelectric recordings from the explants in culture. The culture medium used (Eagle MEM), the collagenase digestion and the general culture conditions followed are similar to those applied to mammal enteric plexus explant cultures. The most striking difference is that the solutions were diluted to 70% in order to maintain the osmolar conditions required by the amphibian cells. Acetylcholinesterase, osmium tetroxide-zinc iodide- and para-formaldehyde-induced fluorescence methods reveal similar morphological images from the perivascular fibre plexuses. The different cell types observed by phase contrast light microscopy from the myenteric explants in culture have been identified by comparison with those revealed by the acetylcholinesterase method. The prevailing neurons show piramidal somas; other neurons are bipolar with oval somas and a third type shows oval somas tightly aligned, following sinusoidal courses. The intra and extracellular bioelectric recordings from the explants in culture show that the culture conditions we have applied preserve the electrophysiological properties of the neuronal membranes. These preliminary recordings will allow us to undertake the synaptic characterization of the gastrointestinal neurotransmitters in frogs.

Animals↗
PubMed1990

Effects of experimental diabetes in the noradrenergic and cholinergic nerves of the rat small intestine.

An histochemical research on cholinergic and noradrenergic fibres of the adventitia layer and of the myenteric plexus of the terminal ileum from rats with streptozotocin-induced diabetes, after 20 weeks of evolution of the illness, was carried out to study changes in the innervation of the gut. The cholinergic nerves, revealed through their acetylcholinesterase activity, did not present alterations, but an evident reduction in number of the noradrenergic nerves and swollen intensely fluorescent varicosities, were observed, both in the perivascular and myenteric plexus of terminal ileum from diabetic animals.

Acetylcholinesterase↗
PubMed1990

The autonomic innervation of the liver and gallbladder of Podarcis hispanica.

The innervation of the liver and gallbladder of the lizard Podarcis hispanica has been studied by the following methods: a) demonstration of cholinesterase activity; b) FIF method for catecholamines; and c) immunohistochemistry for VIP. The hepatic parenchyma of the reptile's liver show hepatocytes arranged in regular rows of hepatic cords, the portal triad being typical of higher vertebrates (birds and mammals). Nerve fibers are found in the scarce connective tissue distributed among the hepatocytes. The innervation is restricted to the big branches of blood vessels and biliary ducts. It is represented by cholinergic, noradrenergic and VIPergic fibers. The gallbladder shows a well developed cholinergic plexus with pyramidal cells in the interconnection points of the fiber network. The noradrenergic and VIPergic plexuses are also more widely distributed in the gallbladder than in the liver.

Animals↗
PubMed1989

The autonomic innervation of the liver and gallbladder of Rana ridibunda.

1--The innervation of the liver and gallbladder of Rana ridibunda has been studied by the following methods: (a) demonstration of cholinesterase activity; (b) FIF method for catecholamines; (c) immunohistochemistry for VIP and (d) electron microscopy. 2--The hepatocytes are arranged in regular rows of hepatic cords, very little connective tissue is distributed in the parenchyma, the innervation being restricted to the big branches of blood vessels. 3--Well defined cholinergic and adrenergic plexuses surround the hepatic arteries, portal veins and biliary ducts. The VIPergic innervation is scarce in the liver but a richly branched plexus spreads in the wall of the gallbladder. 4--Cholinesterase-positive cells are widely distributed accompanying the nerve trunks of the gallbladder. The innervation distribution is prominent in the portion of the gallbladder next to the hepatic hilus. 5--A population of melanin-storing cells besides free melanin granules are present in the liver parenchyma and are prominent in the gallbladder where the melanocytes are disposed in close contact with blood vessels and nerve structures. We have observed that the number of these visceral melanocytes considerably increases in winter, particularly in the liver.

Acetylcholinesterase↗
PubMed1988

Intrinsic and extrinsic innervation of the amphibians esophagic myenteric plexuses.

The innervation of Rana ridibunda esophagus myenteric plexuses has been studied by the following methods: demonstration of cholinesterase activity; FIF method for catecholamines; immunohistochemistry for VIP, SP and SOM, and conventional electron microscopy. The cholinergic innervation is important in the esophagus wall where, in addition to the well known extrinsic component, there is a rich intrinsic plexus with cells and fibres widely distributed. The esophagus, together with the intestine, are the Rana gut portions where the adrenergic component is more broadly expressed. The adrenergic innervation seems to be almost entirely of extrinsic origin. We have shown that, for the tested peptides, there is an intrinsic innervation represented by VIP, SP and SOM like plexuses. We do not discard nonetheless an extrinsic component. The ultrastructure reveals the morphological characteristics of the enteric neurons as well as the fine inter-relationships between the nervous elements and the functional components of the esophagic wall.

Animals↗
PubMed1987

Melanin storing cells in anuran gut.

1. The location, distribution and morphological characteristics of the pigment cells found in the frog gut are described. 2. The pigment cells show long and large protoplasmic projections. At the ultrastructural level, the nucleus is elongated with prominent nucleolus and dense marginal chromatin. The cytoplasm is full with pigment granules (2500-7500 A) and typical premelanosome structures have been observed. 3. The pigment cells number is higher in the esophagus and large intestine than in the stomach or small intestine and the pigment cells are always located in close contact with blood vessels and nervous structures (ganglia and fibres). 4. We have observed that the pigment content depends upon seasonal variations, increasing during the cold months. 5. We have demonstrated by histological methods that the cells pigment content is melanin. 6. According to their morphological and tinctorial characteristics the anuran gut melanin storing cells are similar to the skin epidermal melanocytes.

Animals↗
PubMed1987

The autonomic innervation of Rana ridibunda intestine.

1. The innervation of Rana ridibunda intestine has been studied by the following methods: (a) demonstration of cholinesterase activity; (b) FIF method for catecholamines; (c) immunohistochemistry for VIP, SP and SOM, and (d) conventional electron microscopy. 2. The intrinsic intestinal innervation is represented by cholinergic-, VIPergic-, SP- and SOM-like plexuses. The intestinal adrenergic component is of extrinsic origin. 3. The intestinal peptidergic innervation is the most developed, the large intestine being the portion where the studied peptidergic plexuses are more widely distributed. 4. Against a poorly developed cholinergic/adrenergic innervation, it seems that there is a predominant peptidergic innervation in the amphibians intestine wall. 5. Taking into account that amphibians sacral parasympathetic as well as sympathetic innervation development are limited, it could be considered that in vertebrates the intestinal peptidergic innervation is phylogenetically earlier and hence better developed.

Adrenergic Fibers↗
PubMed1986

The enteric nervous system of Rana ridibunda stomach.

The innervation of Rana ridibunda stomach has been studied by the following methods: demonstration of cholinesterase activity; FIF method for catecholamines; immunohistochemistry for VIP; SP and SOM and conventional electron microscopy. The cholinergic innervation is important in the stomach wall where in addition to the intrinsic plexuses there is an extrinsic contribution coming with the vagus nerve. The density of the fibres decreases towards the pyloric sphincter. The adrenergic innervation seems to be almost entirely of extrinsic origin. Fine networks have been localized at the myenteric and submucosal plexuses. The fibres density increases at the pylorus. At the myenteric plexus, apart from the cholinergic neurons, we have found VIP and SOM like cells. The VIP like plexus is very well developed. A SOM like plexus is also present but with scarce fibres in comparison with the VIPergic one. The submucosal plexus is exclusively made by nervous fibres of the types described for the myenteric one. We have got positive immunoreactivity for SP only on the fibres. They are scarce in the stomach wall, only at the pyloric region their density increases. We describe the ultrastructural morphological characteristics of the enteric neurons as well as the fine inter-relationships between the nervous elements and the functional components of the stomach wall.

Animals↗