The hypogastric nerve innervates a population of penile neurons in the pelvic plexus

Retrograde dye staining, enkephalin immunocytochemistry and nerve lesion paradigms were used to determine if penile neurons in the pelvic plexus are innervated by fibers in the hypogastric nerve. In the intact major pelvic ganglion of the rat, some 80% of penile neurons are enclosed by an enkephalin-positive fiber plexus. Following surgical interruption of the pelvic nerve, 20% of penile neurons were still surrounded by an enkephalin plexus. After interruption of the pelvic nerve and the hypogastric nerve, the enkephalin plexus in the ganglion was virtually absent, including the plexus around penile neurons. Therefore, possible intrinsic sources of the enkephalin fibers such as enkephalin-positive principal neurons and small intensely fluorescent cells, do not account for the delicate enkephalin fiber system in the pelvic ganglion. It is concluded that the pelvic nerve is the major source of preganglionic innervation to penile neurons in the major pelvic ganglion. However, it is significant that the hypogastric nerve is preganglionic to about 20% of penile neurons. The pathway through the hypogastric nerve may represent an alternate vasodilator system to penile erectile tissue.     

Synaptology and sources of vasoactive intestinal polypeptide and substance p containing axons of the cat celiac ganglion. An experimental electron microscopic immunohistochemical study

We have examined the possible origin of vasoactive intestinal polypeptide (VIP) and substance P-containing axons and the synapses formed by these axons in the celiac ganglion of the cat, by means of ultrastructural immunohistochemistry combined with various surgical lesions.Axons containing VIP as well as those immunopositive for substance P, formed axo-dendritic and axosomatic synapses with principal ganglion cells. After transaction of the superior mesenteric nerve numerous degenerated axonal profiles could be found in the celiac ganglion. Some of these contained VIP immunoreactivity. By contrast in alternate sections stained with substance P antibody only intact axons were labelled.Bilateral vagotomy resulted in the appearance of degenerating axonal profiles in the celiac ganglion, some of which could be stained with substance P antiserum but not with VIP antiserum. Following removal of dorsal root ganglia (Th₆-Th₁₂) from both sides, a large number of degenerated axons were found, many of which were immunopositive for substance P but not for VIP.We conclude that the peripheral input to the celiac ganglion contains VIP fibers which form synapses with principal ganglion cells. Substance P-containing fibers reach the celiac ganglion via the vagal nerve as well as from the dorsal root ganglia, and they form synapses with the principal ganglion cells. It is proposed that the VIP and the substance P-containing axons are involved in two different peripheral reflex loops.     

Immunohistochemical evidence from co-localization and denervation studies for four types of substance P-containing nervous structures in the rat superior cervical ganglion

Four types of substance P-immunoreactive structures have been distinguished in the rat superior cervical ganglion by double-immunofluorescence microscopy: (1) A major population of mainly varicose fibres enmeshed singly-scattered neuronal perikarya, some of which contained vasoactive intestinal polypeptide-immunoreactivity. These substance P-immunoreactive fibres did not contain colocalized calcitonin gene-related peptide (CGRP) and were absent after transection of the cervical sympathetic trunk. (2) A rather small substance P-immunoreactive fibre population with colocalized calcitonin gene-related peptide-immunoreactivity was distributed in a patchy manner and disappeared after cutting the postganglionic branches. (3) Most of the intraganglionic small intensely fluorescent (SIF) cell clusters were intensely substance P-immunoreactive. SIF cells were not visibly changed in number and fluorescence intensity by either surgical procedure. (4) Immunoreactivity was not visible in principal ganglionic neurons of control ganglia, but occurred in cell bodies after pre- as well as after postganglionic nerve transection. Some of the substance P-immunolabelled perikarya in addition revealed immunostaining to antisera against the catecholamine-synthesizin enyzme tyrosine hydroxylase or against the neuropeptides leu-enkephalin and vasoactive intestinal polypeptide, respectively. The results strongly suggest that, in addition to a substance P-containing preganglionic input (1), and a supply by substance P-containing sensory axon collaterals (2), the superior cervical ganglion of the rat gives origin to a paraganglionic (3) and a postganglionic (4) substance P-immunoreactive intrinsic system, the latter becoming visible only after disconnection of the sympathetic pathway.     

Effects of chronic deafferentation on adrenergic ganglion cells and small intensely fluorescent cells

Summary To determine the reaction of adrenergic ganglion cells and small intensely fluorescent (SIF) cells to chronic deafferentation, catecholamine fluorescence of the major pelvic ganglion (MPG) of the rat has been studied following section of the hypogastric nerve, pelvic nerve and sympathetic trunk. Only minor changes occurred following section of the hypogastric nerve; the fluorescence surrounding a few adrenergic ganglion cells became brighter. In contrast, pelvic neurectomy resulted in the appearance of numerous varicose fibres and an increase in the fluorescent intensity of fibres enclosing many ganglion cells. Varicose fibres seem to originate from adrenergic ganglion cells and SIF cells. In many instances, nests of SIF cells gave rise to radially oriented fibres. Removal of the sympathetic trunk appeared to have no effect on the MPG. It is suggested that the appearance of varicose fibres from SIF cells following deafferentation may be due to collateral sprouting of these cells or to the increased fluorescence of pre-existing processes.     

Immunohistochemical localization of putative neurotransmitters within the feline nucleus tractus solitarii

With the aid of immunohistochemical techniques the distribution of substance P, met-enkephalin, serotonin, somatostatin, alpha-melanocyte stimulating hormone, neurotensin and neurophysin immunoreactivities were mapped throughout the rostro-caudal extent of the cat's nucleus tractus solitarii. Three of the putative neurotransmitters (substance P, enkephalin and serotonin) were found to be widely distributed as varicose fibers and punctate structures. The densities of their immunoreactivities were plotted in a range from very dense, dense, moderate, occasional, to none, at different levels of the nucleus of the solitary tract. Substance P immunoreactivity was the most varied and dense of all the neurotransmitters studied. Its accumulations ranged from very dense in the lateral, dense in portions of the parvocellular and lateral, moderate in medial and commissural and occasional in ventrolateral and portions of the parvocellular subdivisions. Both the enkephalin and serotonin immunoreactivities had patterns similar to that of substance P immunoreactivity, although their amounts were not as great. Following colchicine treatment neurons containing substance P and enkephalin immunoreactivity were found in many subdivisions of the nucleus of the solitary tract. Somatostatin, alpha-melanocyte stimulating hormone, neurotensin and neurophysin immunoreactivities were present in the nucleus of the solitary tract as isolated varicose fibers scattered throughout the nucleus. Immunoreactive neurons were not found for these putative neurotransmitters after colchicine treatment. The presence of substance P immunoreactivity within subdivisions which receive visceral afferent input is discussed in relation to the role of substance P as a possible transmitter of the afferent limb of the vagus nerve. The distribution of enkephalin and serotonin immunoreactivities in the nucleus of the solitary tract reflect their involvement in the regulation or modulation of cardiovascular and respiratory functions. While the significance of somatostatin, alpha-melanocyte stimulating hormone, neurotensin and neurophysin immunoreactivities within the nucleus of the solitary tract is not understood at present, these substances might possibly play a role in visceral functions.     

Some intrinsic neurons of the guinea-pig heart contain substance P

Whole-mount preparations of the posterior wall of the atria of the guinea pig heart containing intrinsic ganglion cells and nerve plexuses were stained for substance P-like immunoreactivity by the peroxidase-antiperoxidase method. Substance P-like nerve fibres are present as pericellular baskets around most, but not all, of the neuronal cell bodies, and are also found in the connecting nerve bundles, as perivascular nerve plexuses and in the myocardium and pericardium. The majority of ganglion cell bodies are negative for substance P, as reported previously, but we describe for the first time, a small subpopulation of intrinsic neuronal cell bodies which show immunoreactivity for substance P. Therefore, not all cardiac substance P nerves are extrinsic afferent fibres. At present, the physiological role of intrinsic substance P neurones is not clear.     

Paracervical ganglia of the female rat: Histochemistry and immunohistochemistry of neurons,SIF cells,and nerve terminals

The paracervical ganglia of the female rat were studied to elucidate the variety of neural elements in the ganglia. Light and electron microscopy, histochemistry, and immunohistochemistry were employed to reveal subtypes of neurons; small, intensely fluorescent (SIF) cells; and nerve terminals and to examine the relationships between these elements. On the basis of their histochemical markers, four subtypes of principal neurons were identified: acetylcholinesterase (ACHE)-positive, noradrenergic, neuropeptide tyrosine-immunoreactive (NPY-I), and vasoactive intestinal polypeptide-immunoreactive (VIP-I). The NPY-I neurons appeared to be the most numerous and the noradrenergic the least common type of neuron. Four subtypes of chemically coded SIF cells were revealed: catecholamine-containing, NPY-I, and those immunoreactive for calcitonin-gene-related peptide (CGRP-I) and cholecystokinin-octapeptide (CCK-8-I). The SIF cells were present (1) as single cells among and adjacent to principal neurons and (2) as large clusters near the edges of the ganglia or in nearby nerve trunks. Synaptic contacts on SIF cells, or between SIF-cell processes and neurons, were not observed. Seven subtypes of nerve terminals were stained: ACHE-positive, CGRP-I, CCK-8-I, VIP-I, substance P-I, enkephalin-I, and atrial na-triuretic factor-I. Nerve terminals enwrapped the neurons as perineuronal plexuses in synaptic-like relationships. These results demonstrate that the paracervical ganglia of the female rat are a complex system of neural elements. For example, several classes of chemically coded neurons, SIF cells, and terminals exist in the ganglia. Each of these components contains a number of substances, some of which are putative neurotrans-mitters, which could influence activity in the ganglia or in the effector organs innervated by the ganglia.     

5-Hydroxytryptamine-immunoreactive neurons and nerve fibers in the superior cervical ganglion of the rat

Indirect immunofluorescence method was used to localize 5-hydroxytryptamine-immunoreactive structures in the superior cervical ganglion of adult rats. In the ganglia of normal rats, 5-hydroxytryptamine immunoreactivity was localized in the small intensely fluorescent cells, but not in principal nerve cells. In the superior cervical ganglion of rats, pretreated with nialamide, a monoamine oxidase inhibitor, 150 mg/kg i.p., and the 5-hydroxytryptamine precursor, L-tryptophan, 45 mg/kg i.p., a large number of 5-hydroxytryptamine-immunoreactive principal nerve cells and small intensely fluorescent cells were detected. The immunoreactive principal nerve cells had long processes, and 5-hydroxytryptamine-immunoreactive nerve fibers were observed traversing the ganglion. In ganglia of rats pretreated with colchicine, occasional 5-hydroxytryptamine-immunoreactive principal nerve cells and several small intensely fluorescent cells were detected. Ligation of the main postganglionic nerve trunks of the superior cervical ganglion of normal rats resulted in the appearance of several 5-hydroxytryptamine-immunoreactive principal nerve cells and nerve fibers in the ganglion. To study whether the 5-hydroxytryptamine immunoreactivity in the superior cervical ganglion represented uptake or synthesis of 5-hydroxytryptamine, rats were injected with a specific 5-hydroxytryptamine uptake inhibitor, fluoxetine, 10 mg/kg i.p. twice a day for 5 days, and then they were treated with nialamide and L-tryptophan, as described above. In the superior cervical ganglion of fluoxetine-treated rats, a few 5-hydroxytryptamine-immunoreactive principal nerve and small intensely fluorescent cells, as well as some nerve fibers, were detected.(ABSTRACT TRUNCATED AT 250 WORDS)     

The olfactory tubercle of the cat II. Immunohistochemical compartmentation

Summary In this study immunohistochemistry is used to investigate the distribution of opioid peptides, substance P (SP), neuropeptide Y (NPY) and acetylcholine (ChAT) in the olfactory tubercle (OT) of the cat. On the basis of our histochemical findings we divide the OT into two parts: the cortical part and the cap regions, the latter containing the granule cell islands. The cortical part shows an intensely ir-punctate staining pattern (opioid and SP), similar to that observed in the striatum, to which it is connected via plexus bridges. The pyramidal neurons representing the main cell type of the cortical part are ir-negative. NPY-ir neurons invade the OT via the plexus bridges from the striatum and are restricted to the cortical part. A different staining pattern exists in the cap regions: dwarf and small pyramidal-like cells display opioid- and SP-like immunoreactivity and therefore are clearly separated from the cortical part. The intensely stained axonal plexus of the cap-region neurons occupies the hilus regions dorsal to the granule islands. In addition, dendrites of large pallidal neurons densely enmeshed in opioid- and SP-ir fibers (woolly fibers) enter the OT from the dorsally located ventral pallidum, pass through the hilus, traverse the granule islands and reach the dwarf cell layer, where the ir-axons apparently terminate. The granule islands do not receive ir-terminals and the granule cells are ir-negative, except some SP-positive granules in the medial islands. Within the hilus regions some large neurons are ChAT-positive, but the majority is ir-negative. The hilus neurons are regarded as the main target of the cap region efferent system. The findings of this study parallel and confirm our morphological observations (Meyer and Wahle 1986).     

Target specific organization and neuron types of the dog pelvic ganglia: a retrograde-tracing and immunohistochemical study

The major pelvic ganglion in both the rat and guinea pig has been extensively studied because of its anatomical simplicity. To clarify the target specific neural pathway in the diffusely distributed pelvic ganglia of larger animals, the pelvic plexus of the female dog was investigated by retrograde tracing and immunohistochemistry. The whole mount staining of the pelvic plexus with acetylcholinesterase histochemistry revealed 70-100 ganglia of varying sizes. Neurons retrogradely labeled from the rectum were mainly found in ganglia located in the dorso-caudal part of the plexus. The majority of these were non-catecholaminergic, immunoreactive for either calbindin (Calb) or neuropeptide Y (NPY), and characteristically associated with baskets of enkephalin (ENK)-immunoreactive varicose fibers. Neurons projecting to the utero-vaginal walls were distributed in ganglia located in the ventro-caudal part of the plexus. These mainly consisted of two major neuron groups: catecholaminergic Calb-immunoreactive neurons, and non-catecholaminergic neurons containing nitric oxide synthase (NOS) and/or vasoactive intestinal peptide (VIP), which were preferentially associated with a network of ENK-immunoreactive varicose fibers. Neurons retrogradely labeled from the urinary bladder mainly occurred in ganglia located around the junction between the ureter and the bladder. These consisted of catecholaminergic Calb neurons and noncatecholaminergic neurons containing Calb or NOS. Only a few ENK-immunoreactive fibers were found within the clusters of catecholaminergic neurons. These results indicate that organ specific neurons are located in separate ganglia and have both a distinctive composition of neuron types as well as different innervation by preganglionic fibers.     

Neuropeptide distributions in the colon,cecum, and jejunum of the horse

The pelvic flexure portion of the equine large colon is the proposed location of a pacemaker mechanism. This study was conducted to ascertain whether the distribution of certain putative neurotransmitters differs at the pelvic flexure compared to other sampling sites. Tissue samples were collected from the intestinal tracts of six horses. Serial sections from these samples were reacted with primary antisera specific for substance P, vasoactive intestinal polypeptide (VIP), methionine-Enkephalin, and calcitonin gene-related peptide (CGRP). The regional distribution of immunoreactive neuronal elements was uniform for each of the neuropeptides except VIP. Although neurons exhibiting VIP-like immunoreactivity were abundant throughout the colon, they were somewhat more plentiful near the apex of the pelvic flexure and the left dorsal colon. These neurons may participate in the initiation and propagation of the propulsive/retropulsive contraction waves, which emanate from this location and are believed to lend a sphincter-like capacity to the pelvic flexure. The submucosal plexus was replete with neurons with intense substance P and VIP-like reactivity. Reactive fibers left submucosal ganglia to project to the intestinal mucosa, reflecting a possible secretogogic role for these neurons. This role may be especially important for the horse as a hindgut fermenter. There were abundant methionine-Enkephalin and substance P-like reactive varicosities throughout the myenteric plexus, many of which established a pericellular plexus of varicose fibers. The abundance of these varicosities, which may correlate with a high degree of neuronal integration, did not vary regionally. These data may enhance our understanding of both normal colonic peristalsis and motility disorders caused by a depletion of these neuropeptides. © 1993 Wiley-Liss, Inc.     

Distribution of enteric neurons showing immunoreactivity for substance P in the guinea-pig ileum

Substance P-like immunoreactivity has been localized in whole mount preparations of the isolated layers of the guinea-pig ileum. Axons containing substance P formed dense networks around the nerve cells and ran in the primary, secondary and tertiary nerve bundles of the myenteric plexus. 3.6% of the nerve cell bodies of the myenteric plexus and 11.3% of the cell bodies in the submucous plexus showed immunoreactivity for substance P. Axons ran in fine nerve bundles parallel to the longitudinal muscle, between this muscle and the myenteric plexus. Axons containing substance P also ran in small nerve trunks parallel to the circular muscle throughout its thickness and in the deep muscular plexus at the base of this muscle coat. In the submucosa, these axons ramified amongst ganglion cells of the plexus and ran in the internodal strands. In addition they formed a perivascular network around submucous arteries and contributed to the paravascular nerves following these arteries. Axons containing substance P formed a delicate plexus in the mucosa. After extrinsic denervation the nerves containing substance P that were associated with submucous arteries, and some in the submucous plexus, disappeared. The nerves in the other areas were not detectably different from normal.Comparison with the distribution of somatostatin, enkephalin and vasoactive intestinal polypeptide indicated the neurons containing substance P constitute a separate population within the enteric nervous system.     

Histochemical study of the heart of the axolotl (Ambystoma mexicanum).

We have investigated the presence of cells containing monoamines, substance P, and neuron-specific enolase (NSE) in the heart and in the pericardial wall of a urodele amphibian, the axolotl. Fibers containing substance P-like immunoreactivity were present in the heart but not in the pericardial wall. Also present in the heart were small branched cells, which stained metachromatically with toluidine blue. Similar cells were found in the peritoneum and were tentatively identified as mast cells. NSE-immunoreactive fibers were found both in the heart and in the pericardial wall. Small intensely fluorescent (SIF) cells of the pericardial wall contained a high concentration of norepinephrine but no other monoamines, substance P, or NSE. Comparison with data available for the mudpuppy, Necturus maculosus, a closely related amphibian species, suggests that the innervation of the heart in the axolotl is substantially different.     

Origin of the primary efferent neurons projecting to the prostate of the dog.

The retrograde tracing technique of neuronal tracer Fast Blue was used to determine sources of origin of efferent nerve fibers supplying the prostate of the dog. After injection of Fast Blue into the canine prostate retrogradely labelled neurons were found in bilateral L3-S3 sympathetic chain ganglia, bilateral caudal mesenteric ganglion and in bilateral pelvic plexus ganglia. No Fast Blue-positive neurons were present in bilateral L1-L2 sympathetic chain ganglia and in coeliac-mesenteric ganglion complex. The vast majority of Fast Blue-positive efferent prostate-projecting neurons (56.2% +/- 1.7) were located in bilateral caudal mesenteric ganglion, whereas 28.7% +/- 1.5 of them were located in bilateral pelvic plexus ganglia and 14.9% +/- 0.5 in bilateral L3-S3 sympathetic chain ganglia. Immunohistochemical staining for tyrosine hydroxylase and dopamine beta-hydroxylase was applied to determine the neurochemical character of Fast Blue-positive efferent neurons. Immunohistochemistry revealed that in all tyrosine hydroxylase immunoreactive Fast Blue-positive neurons immunoreactivity for dopamine beta-hydroxylase was also found (noradrenergic neurons) while all tyrosine hydroxylase-negative Fast Blue-positive neurons did not express dopamine beta-hydroxylase (non-noradrenergic neurons). In bilateral sympathetic chain ganglia, 96.4% +/- 2.1 of the prostate-projecting neurons were adrenergic and in bilateral caudal mesenteric ganglion this frequency amounted to 95.6% +/- 1.6. In bilateral pelvic plexus ganglia, 26.7% +/- 1.5 of the prostate-supplying efferent neurons did not express either tyrosine hydroxylase or dopamine beta-hydroxylase immunoreactivity which makes discussion of their cholinergic character possible.     

Differential effects of axotomy on substance P-containing and nicotinic acetylcholine receptor-containing retinal ganglion cells: time course of degeneration and effects of nerve growth factor.

The time course of degeneration of chick retinal ganglion cells was examined with Nissl stains and immunohistochemical methods for detection of substance P-like immunoreactive and nicotinic acetylcholine receptor immunoreactive neurons. Small lesions were made in the retinae, adjacent to the optic nerve head, and were subsequently sectioned parallel to the vitreal surface, permitting direct comparison of normal and axotomized retinal ganglion cells distal to the site of axon damage. At four and six days after surgery, a large number of degenerating cells with clear cytoplasm and pyknotic nuclei were seen. After eight, 10 and 14 days, many retinal ganglion cells displayed a chromatolytic response with dispersed Nissl granules, eccentric nuclei and the cells appeared crenulated. The number of apparently normal neurons in the ganglion cell layer in the axotomized region was reduced by about 50% six days following surgery, by about 70% on the 10th day and by about 75% on the 17th day. The remaining neurons in the ganglion cell layer were identified as displaced amacrine cells. From day 2 onwards, increased numbers of glial cells were present in the optic fibre, ganglion cell and inner plexiform layers. Many glial cells were enlarged and displayed extensive cytoplasmic processes, while others showed mitotic activity. Somata and proximal dendrites of retinal ganglion cells were intensely stained for substance P-like immunoreactivity at two and four days following surgery. At six, eight and 10 days, staining intensity was markedly reduced though still evident and at 14 and 17 days, substance P-like immunoreactivity had virtually disappeared. The persistence of limited substance P-like immunoreactive ganglion cells 10 days after surgery indicates that these cells have a relatively protracted response to axotomy. Nicotinic acetylcholine receptor-like immunoreactivity in the ganglion cells at two and four days following axotomy was substantially reduced. The majority of faintly stained nicotinic acetylcholine receptor-like immunoreactive ganglion cells, as visualized in counterstained sections, did not exhibit pyknosis in the immediate period following axotomy. Double label studies demonstrated that substance P-like immunoreactive ganglion cells were distinct from the nicotinic acetylcholine receptor-like immunoreactive ganglion cells. In a second set of experiments, nerve growth factor was then placed into the vitreous humor following intra-retinal axotomy. The somata, dendrites and proximal axons of lesioned substance P-like immunoreactive ganglion cells in these retinae were more intensely stained for a longer period of time and appeared more robust than cells from untreated retinae.(ABSTRACT TRUNCATED AT 400 WORDS)     

Immunohistochemical evidence of vasoactive intestinal polypeptide-containing neurons and nerve fibers in sympathetic ganglia

Neurons and nerve fiber networks showing immunoreactivity for vasoactive intestinal polypeptide have been observed in some sympathetic ganglia with the help of the indirect immunofluorescence technique. Antisera to tyrosine hydroxylase and dopamine β-hydroxylase were used to identify catecholamine cells on consecutive sections. In the coeliac-superior mesenteric ganglion complex and the inferior mesenteric ganglion of the guinea-pig very dense networks of vasoactive intestinal polypeptide-positive varicose nerve fibers were observed around the principal ganglion cells. Only very few immunofluorescent fibers were seen in relation to the small intensely fluorescent cells. Occasionally some immunoreactive principal ganglion cells were found. In the same ganglia of the rat a considerably less dense network of vasoactive intestinal polypeptide-positive nerve fibers was present. The superior cervical ganglia of both species contained only a few vasoactive intestinal polypeptide-immunofluorescent fibers and no positively reacting cells were found.     

Nitrergic and VIPergic neurons in the choroid and ciliary ganglion of the duck Anis carina

Immunohistochemistry for neuronal nitric oxide synthase (nNOS) and vasoactive intestinal peptide (VIP), and NADPH diaphorase histochemistry, were applied to investigate neurons in the choroid and the ciliary ganglion of the muscovy duck Anis carina. Up to 1000 neurons in the choroid stained for NADPH diaphorase and showed virtually complete colocalization for nNOS immunoreactivity. Almost all of them co-stained for VIP, while about 90% of VIP immunoreactive cell bodies showed colocalization for nNOS. Two-thirds of the neurons were located, mostly singly, at nodes of a widemeshed nerve plexus in the suprachoroid and were only rarely grouped in ganglia of up to 3 neurons. Numerous varicose nNOS/NADPH-diaphorase-positive nerve fibers were seen around large arterial blood vessels. These fibers derived mainly from paravascular cell bodies that represented about one-third of all choroidal neurons and also displayed costaining for nitrergic markers and VIP. Colocalization of nNOS/NADPH-d and VIP could be demonstrated in most of the perivascular fibers, while slightly more VIP-positive axons in the suprachoroid plexus did not costain for nNOS/NADPH-d. Small-caliber blood vessels and those localized in the choriocapillaris were not endowed with VIP/nNOS/NADPH-diaphorase-positive fibers. A few reactive neuronal cell bodies were also found in ciliary nerves, while most ciliary axons were unstained. In the ciliary ganglion a small subpopulation of neurons showed VIP/nNOS/NADPH-diaphorase colocalization. There were also nNOS/ NADPH-d-positive cap-like terminals on ciliary ganglion cells. The presence of VIP/nNOS/NADPH-diaphorase positive neurons and nerve fibers in both the choroid and ciliary ganglion, and in the choroidal perivascular plexus, indicates peripheral nitrergic and VIPergic control of blood flow in the choroid of the duck.     

Nitrergic and VIPergic neurons in the choroid and ciliary ganglion of the duck Anis carina

Immunohistochemistry for neuronal nitric oxide synthase (nNOS) and vasoactive intestinal peptide (VIP), and NADPH diaphorase histochemistry, were applied to investigate neurons in the choroid and the ciliary ganglion of the muscovy duck Anis carina. Up to 1000 neurons in the choroid stained for NADPH diaphorase and showed virtually complete colocalization for nNOS immunoreactivity. Almost all of them co-stained for VIP, while about 90% of VIP immunoreactive cell bodies showed colocalization for nNOS. Two-thirds of the neurons were located, mostly singly, at nodes of a widemeshed nerve plexus in the suprachoroid and were only rarely grouped in ganglia of up to 3 neurons. Numerous varicose nNOS/NADPH-diaphorase-positive nerve fibers were seen around large arterial blood vessels. These fibers derived mainly from paravascular cell bodies that represented about one-third of all choroidal neurons and also displayed costaining for nitrergic markers and VIP. Colocalization of nNOS/NADPH-d and VIP could be demonstrated in most of the perivascular fibers, while slightly more VIP-positive axons in the suprachoroid plexus did not costain for nNOS/NADPH-d. Small-caliber blood vessels and those localized in the choriocapillaris were not endowed with VIP/nNOS/NADPH-diaphorase-positive fibers. A few reactive neuronal cell bodies were also found in ciliary nerves, while most ciliary axons were unstained. In the ciliary ganglion a small subpopulation of neurons showed VIP/nNOS/NADPH-diaphorase colocalization. There were also nNOS/ NADPH-d-positive cap-like terminals on ciliary ganglion cells. The presence of VIP/nNOS/NADPH-diaphorase positive neurons and nerve fibers in both the choroid and ciliary ganglion, and in the choroidal perivascular plexus, indicates peripheral nitrergic and VIPergic control of blood flow in the choroid of the duck.     

The co-localization of neuropeptides in the submucosa of the small intestine of normal Wistar and non-diabetic BB rats.

Immunocytochemical double and triple staining techniques were employed on whole mounts of the submucosal plexus from normal Wistar and non-diabetic BB rat jejunum and ileum, to determine the patterns of co-localization of vasoactive intestinal polypeptide-, peptide histidine-isoleucine-, somatostatin-, neuropeptide Y-, calcitonin gene-related peptide-, substance P-, and galanin-immunoreactive nerves. Neuropeptide Y immunoreactivity was found in 38% of submucosal plexus neurons, within the same neuronal elements as vasoactive intestinal polypeptide immunoreactivity (39% of submucosal plexus neurons) and peptide histidine-isoleucine immunoreactivity. A small population (1% of submucosal plexus neurons) containing vasoactive intestinal polypeptide- and peptide histide isoleucine-like immunoreactivity without NPY-like immunoreactivity was also observed. A significant population of fibers containing vasoactive intestinal polypeptide and galanin immunoreactivity were observed in the mucosa and submucosa, although no cell bodies were detected which contained both neuropeptides. Galanin-like immunoreactivity was seen in a small (2% of submucosal plexus neurons) population, not co-localized with any of the other neuropeptides examined. All somatostatin-immunoreactive neuronal elements (18% of submucosal plexus neurons) contained calcitonin gene-related peptide immunoreactivity, just over half of which also contained substance P immunoreactivity. An additional 25% of submucosal plexus neurons contained calcitonin gene-related peptide- without somatostatin-like immunoreactivity and 28% of submucosal plexus neurons contained substance P without somatostatin-like immunoreactivity. Some degree of co-localization was seen between calcitonin gene-related peptide- and substance P-like immunoreactivity, however, this could not be directly quantified.(ABSTRACT TRUNCATED AT 250 WORDS)     

Some nerve endings in the rat pelvic paracervical autonomic ganglia and varicosities in the uterus contain calcitonin gene-related peptide and originate from dorsal root ganglia

The pelvic paracervical autonomic ganglia of female rats were studied for a subpopulation of nerve endings that could be derived from sensory nerve fibers. Immunohistochemical staining using an antiserum against the synaptic-terminal protein synapsin I was used to identify terminal boutons, while an antiserum against the neuropeptide calcitonin gene-related peptide was used to reveal a subpopulation of sensory nerve fibers. The uterine cervix was also examined for the existence of calcitonin gene-related peptide and synapsin I immunoreactivity in nerve fiber varicosities. In addition, the location of nerve endings in the paracervical ganglion was compared to that in the superior cervical ganglion. Synapsin I immunoreactivity was present in the paracervical ganglion in abundant boutons around neuron somata and in the cervix in varicose nerve fibers of the myometrium, vasculature and epithelium. Double labeling immunocytochemistry revealed calcitonin gene-related peptide-like immunoreactivity in subpopulations of synapsin I-immunoreactive endings in ganglia and nerve varicosities in the cervix. Injection of a retrograde axonal tracer, fluorogold, into the paracervical ganglion produced labeled neurons in dorsal root ganglia and spinal cord; however, fluorogold-labeled neurons containing calcitonin gene-related peptide immunoreactivity were visualized only in dorsal root ganglia. Injections of fluorogold into the uterine cervix produced labeled neurons in the paracervical ganglion and dorsal root ganglia; however, only those in dorsal root ganglia contained immunoreactivity for calcitonin gene-related peptide. These results suggest that immunoreactivity for calcitonin gene-related peptide is present in a subpopulation of nerve endings in the paracervical ganglion and not merely in fibers of passage. The nerve endings in the ganglion and varicosities in the uterine cervix originate from sensory neurons in dorsal root ganglia. The arrangement of endings in the ganglia could play a role in sensory/autonomic interactions for modulation of visceral activity.