Ultrastructural Localization of Four Different Neuropeptides Within Separate Populations of p-Type Nerves in the Guinea Pig Colon (original) (raw)
Related papers
Neuroscience, 1980
The distribution of peptide-containing neurons in the oesophagus, stomach and small and large intestine of the rat and the guinea-pig has been studied with the indirect immunofluorescence technique of COONS & Co-workers (1958) using antisera to substance P. vasoactive intestinal polypeptide (VIP), enkephalin, somatostatin. gastrin and neurotensin. (The gastrin antiserum is to the C-terminal portion and consequently reacts also with cholecystokinin (CCK)-like peptides.) For comparison, the noradrenergic innervation was visualized with antiserum to dopamine b-hydroxylase. For improved visualization of peptide-containing cell bodies, a mitotic inhibitor (colchicine or vinbIastine) was applied locally on the different parts of the gastro-intestinal tract of several animals.
Projections of peptide-containing neurons in rat small intestine
Neuroscience, 1987
Ahstraet-The distribution, origin and projections of nerve fibers containing vasoactive intestinal peptide, neuropeptide Y, somatostatin, substance P, enkephalin and calcitonin gene-related peptide were studied in the rat jejunum by immunocytochemistry and immunochemistry. Their origin was determined by the use of various procedures for extrinsic denervation (chemical sympathectomy, bilateral vagotomy or clamping of mesenterial nerves). The terminations of the different types of intramural nerve fibers were identified by examination of the loss of nerve fibers that followed local disruption of enteric nervous pathways (intestinal myectomy, transection or clamping). The majority of the peptide-containing nerve fibers in the gut wall were intramural in origin, each nerve fiber population having its own characteristic distribution and projection pattern. Nerve fibers emanating from the myenteric ganglia terminated within the myenteric ganglia and in the smooth muscle layers: those storing vasoactive intestinal ~ptide/neuro~ptide Y, somatostatin and substance P were descending, those storing enkephalin were ascending and those containing calcitonin gene-related peptide projected in both directions. Nerve fibers emaMting from the submu~ous ganglia terminated mainly within the submucous ganglia and in the mucosa: those storing calcitonin gene-related peptide or vasoactive intestinal ~ptide/neuro~ptide Y were ascending and those storing substance P or somatostatin were both ascending and descending. Enkephalin nerve fibers could not be detected in the mucosa. The gastrointestinal tract harbors a wide variety of peptide-containing nerve fibers, the majority of which derive from intramural ganglia (for reviews see Refs 16 and 33). Much work has been done to identify their distribution and origin (see e.g. Refs lo-12, 17, 22, 25-27, 29, 31, 34 and 3% but comparatively fewer studies have dealt with their projection patterns.6,8.'2,'5.U The analysis of the polarities and terminations of the different enteric ~pt~de-containing nerve fiber populations have involved the localized severing of intrinsic nervous pathways.8*15*23 The present study examines the origin and terminations of nerve fibers storing vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), somatostatin, substance P (SP), enkephalin and calcitonin generelated peptide (CGRP) in the rat jejunum.
Neuroscience, 1980
Immunoreactivity for vasoactive intestinal polypeptide has been localized in neurons in the guinea-pig ileum, colon and stomach. In the ileum, 2.5% of the nerve cell bodies of the myenteric plexus and 45% of those of the submucous plexus showed vasoactive intestinal polypeptide-like immunoreactivity. Varicose axons containing vasoactive intestinal polypeptide ramified amongst the nerve cell bodies of both plexuses and in some cases formed rings of varicosities around non-reactive nerve cells. Axons were traced from the myenteric plexus to the circular muscle and deep muscular plexus. There were numerous positive axons running in fine strands within the circular muscle, parallel to the muscle bundles. Axons containing vasoactive intestinal polypeptide were associated with mucosal blood vessels, but few supplied the vascular network of the submucosa; some immunoreactive axons also contributed to the periglandular plexus of the mucosa. There were no changes in the distribution of axons in the ileum after extrinsic denervation.
Neuroscience Letters, 1979
were performed to determine if the distribution of vasoactive intestinal peptide(V~)-Rke immunoreactivity in nerve cell bodies sad 8xons of the my~ plexus and circular muscle of the small inte~ tine is consiste~ witl VIP being the transmitter of enteric inhibitory neu-ron~ Immunonmctivlty for VIP was found in nerve cell bodies of the myenteric plexus and m axon~ #ith-~ the my~ plexus and circular muscle. When the axow in th~ myenterlc plexus were interrupJml, there was accumulation of material showing reactivity for VIP on the oral side, indicating that the n~ project in im anal direction. The ViF-like immunoreactivity in ~omm w'~tich ~p~ly the circular m~ ~pe~md after a myectomy in ~ the ovedyir4g myenteric plexus was removed, but remained intact when ~t=in~ ner#eb were served.
Distribution of enteric neurons showing immunoreactivity for substance P in the guinea-pig ileum
Neuroscience, 1980
Immunoreactivity for vasoactive intestinal polypeptide has been localized in neurons in the guinea-pig ileum, colon and stomach. In the ileum, 2.5% of the nerve cell bodies of the myenteric plexus and 45% of those of the submucous plexus showed vasoactive intestinal polypeptide-like immunoreactivity. Varicose axons containing vasoactive intestinal polypeptide ramified amongst the nerve cell bodies of both plexuses and in some cases formed rings of varicosities around non-reactive nerve cells. Axons were traced from the myenteric plexus to the circular muscle and deep muscular plexus. There were numerous positive axons running in fine strands within the circular muscle, parallel to the muscle bundles. Axons containing vasoactive intestinal polypeptide were associated with mucosal blood vessels, but few supplied the vascular network of the submucosa; some immunoreactive axons also contributed to the periglandular plexus of the mucosa. There were no changes in the distribution of axons in the ileum after extrinsic denervation.
Neuroscience, 1983
We have analyzed changes in the distributions of terminals with vasoactive intestinal polypeptide (VIP)-like immunoreactivity, and accumulations in severed processes, that occur after lesions of intrinsic and extrinsic nerve pathways of the guinea-pig small intestine. The observations indicate that enteric vasoactive intestinal polypeptide immunoreactive neurons have the following projections. Nerve cell bodies in the myenteric plexus provide varicose processes to the underlying circular muscle; the majority of these pathways, if they extend at all in the anal or oral directions, do so for distances of less than 1 mm. Nerve cell bodies of the myenteric plexus also project anally to provide terminals to other myenteric ganglia. The lengths of the majority of these projections are between 2 and 10 mm, with an average length of about 6 mm. Processes of myenteric neurons also run anally in the myenteric plexus and then penetrate the circular muscle to provide varicose processes in the submucous ganglia at distances of up to 15 mm, the average length being 9-12 mm. In addition, there is an intestinofugal projection of myenteric neurons whose processes end around nerve cell bodies of the coeliac ganglia. A similar projection from the colon supplies the inferior mesenteric ganglia. The nerve cell bodies in submucous ganglia give rise to a subepithelial network of fibres in the mucosa and also supply terminals to submucous arterioles.
Localization of Substance P-Immunoreactive Nerve Structures in the Rat Colon
Proceedings of the Bulgarian Academy of Sciences
The tachykinins, including their major representative substance P (SP), are an essential component of its non-adrenergic, non-cholinergic transmission of the myenteric plexus of the enteric nervous system. Hence, the understanding of the role that SP plays in the conduction of a wide variety of motility and secretory reflexes lies in the evidence-based understanding of the sites of its expression. In the present study, the presence, distribution and staining intensity of the SP-positive nerve structures in the myenteric plexus of the proximal and distal colon of the adult rat have been investigated by means of immunohistochemistry at the light microscopic level. We observed an abundance of intensely stained beaded SP-immunopositive fibres, surrounding the SP-immunonegative myenteric neuronal cell bodies in a basket-like manner. Fine bundles of SP-immunostained varicose fibres were also registered in the adjacent smooth muscle layers. The statistical analysis revealed discernible pre...
Comparative biochemistry and physiology. Part A, Physiology, 1997
Gastrointestinal events such as peristalsis and secretion/absorption processes are influenced by the enteric nervous system, which is capable of acting largely independently from other parts of the nervous system. Several approaches have been used to further our understanding of the underlying mechanisms of specific enteric microcircuits. Apart from pharmacological and physiological studies, the deciphering of the chemical coding of distinct morphological and functional enteric neuron classes, together with a detailed analysis of their projections by the application of immunocytochemistry, of tracing, and of denervation techniques, have substantially contributed to our knowledge. In view of existing interspecies and regional differences, it is of major importance to expand our knowledge of the enteric nervous system in mammals other than the guinea-pig, the most commonly used experimental animal in this research area. This will increase our chances of finding a valid model, from whi...
Neuroscience, 1998
Nerve circuits within the proximal duodenum were investigated using a combination of immunohistochemistry for individual neuron markers and lesion of intrinsic nerve pathways to determine axon projections. Cell shapes and axonal projections were also studied in cells that had been injected with a marker substance. Several major neuron populations were identified. Calbindin immunoreactivity occurred in a population of myenteric nerve cells with Dogiel type II morphology. These had axons that projected to other myenteric ganglia, to the circular muscle and to the mucosa. All were immunoreactive for the synthesizing enzyme for acetylcholine, choline acetyltransferase, and some were also immunoreactive for calretinin. Myenteric neurons with nitric oxide synthase immunoreactivity projected anally to the circular muscle. These were also immunoreactive for vasoactive intestinal peptide, and proportions of them had enkephalin and/or neuropeptide Y immunoreactivity. It is suggested that they are inhibitory motor neurons to the circular muscle. A very few (about 2%) of nitric oxide synthase-immunoreactive neurons had choline acetyltransferase immunoreactivity. Tachykinin (substance P)-immunoreactive nerve cells were numerous in the myenteric plexus. Some of these projected orally to the circular muscle and are concluded to be excitatory motor neurons. Others projected to the tertiary plexus which innervates the longitudinal muscle and others provided terminals in the myenteric plexus. Two groups of descending interneurons were identified, one with somatostatin immunoreactivity and one with vasoactive intestinal peptide immunoreactivity. The two most common nerve cells in submucous ganglia were neuropeptide Yand vasoactive intestinal peptide-immunoreactive nerve cells. Both provided innervation of the mucosa. There was also a population of calretinin-immunoreactive submucous neurons that innervated the mucosal glands, but not the villi.