Distribution and origin of peptide-containing nerve fibers in the celiac superior mesenteric ganglion of the guinea-pig

The origin of the peptidergic nerve fibers and terminals in the celiac superior mesenteric ganglion of the guinea-pig was studied. The distribution of immunoreactivity to enkephalin, substance P, calcitonin gene-related peptide, cholecystokinin, vasoactive intestinal polypeptide/peptide histidine isoleucine, bombesin and dynorphin was analysed in intact animals and in animals subjected to various denervation and ligation procedures. The present results show that each of the connected nerve trunks carries peptidergic pathways and contributes to the peptidergic networks in the celiac superior mesenteric ganglion. Thus, the thoracic splanchnic nerves contain enkephalin-, substance P- and calcitonin gene-related peptide-immunoreactivity of which substance P and calcitonin gene-related peptide coexist in the same nerve fibers. In addition, cholecystokinin-, vasoactive intestinal polypeptide/peptide histidine isoleucine- and dynorphin-immunoreactivity is present in some fibers. All of these immunoreactivities are present in sensory neurons except enkephalin which probably originates in the spinal cord. The mesenteric nerves carry enkephalin-, calcitonin gene-related peptide-, cholecystokinin-, vasoactive intestinal polypeptide/peptide histidine isoleucine-, bombesin- and dynorphin-immunoreactive fibers from the intestine and are the main source for cholecystokinin, vasoactive intestinal polypeptide/peptide histidine isoleucine, bombesin and dynorphin fibers. Double-staining experiments indicate that many of these peptides are synthesized in the same enteric neurons. Also the intermesenteric nerve contains peptide-immunoreactive fibers to the celiac superior mesenteric ganglion from different sources, probably including the distal colon as well as dorsal root ganglia and spinal cord at lower thoracic and lumbar levels. The results are discussed in relation to earlier morphological and physiological studies supporting the view of a role of the celiac superior mesenteric ganglion in local reflex mechanisms involved in regulation of gastrointestinal functions.     

Origin of peptide-containing fibers in the inferior mesenteric ganglion of the guinea-pig: Immunohistochemical studies with antisera to substance P,enkephalin, vasoactive intestinal polypeptide,cholecystokinin and bombesin

After different denervation procedures the guinea-pig inferior mesenteric ganglion was analysed by immunohistochemistry using antisera to substance P, enkephalin, vasoactive intestinal polypeptide, cholecystokinin and bombesin. The results demonstrate that each of the nerve trunks connected to the ganglion carries specific peptidergic pathways. Thus, the lumbar splachnic nerves contain substance P-immunoreactive primary afferent neurons, which to a large extent traverse the ganglion, and enkephalin-immunoreactive preganglionic neurons; the colonie nerves carry vasoactive intestinal polypeptide-, cholecystokinin- and bombesin-immunoreactive fibers from the distal colon to the ganglion; the hypogastric nerves contain vasoactive intestinal polypeptide-positive fibers from the pelvic plexus; and the intermesenteric nerve contains vasoactive intestinal polypeptide, cholecystokinin, substance P and enkephalin from divergent sources. By studying accumulations of peptides in ligated lumbar splanchnic, intermesenteric, hypogastric and colonic nerves the existence of these major peptidergic pathways was confirmed and evidence was obtained for additional, not so prominent, peptidergic projections. The results are discussed in view of earlier morphological and physiological studies.     

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.     

Enkephalin immunoreactive nerve fibres and cell bodies in sympathetic ganglia of the guinea-pig and rat.

The occurrence and distribution of enkephalin-like immunoreactivity was studied by light microscopy, using an indirect fluorescent-labelled antibody technique, in the superior cervical ganglion, the inferior mesenteric ganglion and the coeliac-superior mesenteric ganglion complex of the guinea-pig and rat. In theguinea-pig a very dense network of enkephalin-positive fibres was observed in the inferior mesenteric ganglion and a less dense one in the coeliac-superior mesenteric ganglion complex. In both ganglia some ‘small intensely fluorescent’ cells were immunoreactive. In the superior cervical ganglion only few fluorescent fibres were seen but several ‘small intensely fluorescent’ cells were enkephalin-positive. In therat the inferior and coeliac-superior mesenteric ganglia contained medium-dense networks of enkephalin-positive fibres. An irregularly distributed network of fluorescent fibres was observed in the superior cervical ganglion, where also several principal ganglion cells were enkephalinimmunoreactive, particularly after colchicine treatment. These findings indicate the presence of several peripheral neuron systems containing enkephalin or a similar peptide.Several antisera raised to methionine- and leucine-enkephalin as well as to α- and β-endorphin were used. Some of these antisera were compared by incubating sections of the inferior mesenteric ganglion with increasing dilutions of antiserum as well as with antisera treated with increasing concentrations of methionine- and leucine-enkephalin, respectively. On the basis of these findings the problem of differentiating between methionine- and leucine-enkephalin is discussed.     

Immunohistochemical study of neuropeptides in vagal and glossopharyngeal afferent neurons in the rat

The presence and distribution of multiple neuropeptides in vagal and glossopharyngeal afferent ganglia of the rat were studied using immunohistochemistry. Substance P-, calcitonin-gene related peptide-, cholecystokinin-, neurokinin A-, vasoactive intestinal polypeptide-, and somatostatin-immunoreactive neurons were detected in each visceral afferent ganglion. Neurotensin-immunoreactive cells were not observed. In the nodose ganglion (inferior ganglion of the vagus nerve) occasional immunoreactive cells were scattered throughout the main (caudal) portion of the ganglion with small clusters of cells seen in the rostral portion. The pattern of distribution of the various peptides in the nodose ganglion was similar, with the exception of vasoactive intestinal polypeptide-immunoreactive neurons which exhibited a more caudal distribution. The relative numbers of immunoreactive cells varied, with the greatest numbers being immunoreactive for substance P or vasoactive intestinal polypeptide, and the lowest numbers being immunoreactive for neurokinin A and somatostatin. A build-up of immunoreactivity for each of the peptides, except somatostatin and neurotensin, was detected in vagal nerve fibers of colchicine-injected ganglia. Numerous peptide-immunoreactive cells were also found in the petrosal (inferior ganglion of the glossopharyngeal nerve) and jugular (superior ganglion of the vagus nerve) ganglia. No specific intraganglionic distribution was noted although the relative numbers of cells which were immunoreactive for the different peptides varied considerably. Substance P and calcitonin-gene related peptide were found in large numbers of cells, cholecystokinin was seen in moderate numbers of cells, and neurokinin A, vasoactive intestinal polypeptide and somatostatin were seen in fewer cells. These data provide evidence for the presence and non-uniform distribution of multiple peptide neurotransmitters in vagal and glossopharyngeal afferent neurons. In general, relatively greater numbers of immunoreactive cells were located in the rostral compared with caudal nodose ganglion, and in the petrosal and jugular ganglia compared with the nodose ganglion. Thus, multiple neuropeptides may be involved as afferent neurotransmitters in the reflexes mediated by vagal and glossopharyngeal sensory nerves.     

Neuropeptide Y co-exists with vasoactive intestinal polypeptide and acetylcholine in parasympathetic cerebrovascular nerves originating in the sphenopalatine, otic, and internal carotid ganglia of the rat

Neuropeptide Y co-exists with noradrenaline in the majority of the sympathetic nerves supplying cerebral blood vessels. However, after sympathectomy in the rat the number of cerebrovascular neuropeptide Y nerve fibers are only reduced in number despite a complete disappearance of the adrenergic markers. The origin of these non-sympathetic neuropeptide Y fibers was studied by nerve transections and retrograde axonal tracing utilizing True Blue. Three days after bilateral superior cervical sympathectomy, the number of neuropeptide Y-containing nerve fibers decreased to about 40% of that in non-treated animals. One week after True Blue application on the proximal portion of the middle cerebral artery, the tracer accumulated in neurons of the sphenopalatine, otic, and internal carotid ganglia. Of these cells 80%, 95% and 5%, respectively, were neuropeptide Y-positive. Some of the True Blue/neuropeptide Y-positive cells displayed immunoreactivity for vasoactive intestinal polypeptide and some were positive for choline acetyltransferase. Two weeks after bilateral removal of the sphenopalatine ganglion or transection of postganglionic fibers from the ganglion reaching the pial vessels through the ethmoidal foramen, together with subsequent sympathectomy, no neuropeptide Y-containing nerve fibers could be observed on the anterior cerebral and internal ethmoidal artery or the distal portion of the middle cerebral artery, whereas a few nerve fibers remained on the proximal portion of the middle cerebral artery, internal carotid artery, and the rostral portion of the basilar artery. In conclusion, neuropeptide Y in cerebrovascular nerves is co-stored not only with noradrenaline in sympathetic nerves from the superior cervical ganglion, but also with acetylcholine (reflected in the presence of choline acetyltransferase) and vasoactive intestinal polypeptide in parasympathetic nerves originating in the sphenopalatine, otic, and internal carotid 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)     

Distributions of neuropeptide Y, vasoactive intestinal peptide and somatostatin in populations of postganglionic neurons innervating the rat kidney, spleen and intestine.

Some peripheral peptidergic nerves selectively innervate different types of tissue in abdominal organs. Neuropeptide Y- and vasoactive intestinal peptide-immunoreactive nerve terminals have been identified in the kidney, spleen and intestine and these peptides may have important physiological actions. Somatostatin has been found in sympathetic ganglia, and nerve terminals containing this peptide have been identified in the intestine. We have used fluorescent retrograde tracers to identify renal, splenic and mesenteric postganglionic neurons in rat sympathetic ganglia and then used immunocytochemistry to determine the proportions of these three identified groups of neurons displaying immunoreactivity for neuropeptide Y, vasoactive intestinal peptide and somatostatin. Most renal, splenic and mesenteric neurons were immunoreactive for neuropeptide Y and less than 1% of cells innervating these organs were immunoreactive for vasoactive intestinal peptide. Somatostatin immunoreactivity was present only in a small percentage of mesenteric neurons and not in renal or splenic neurons. The present study demonstrates that (i) the rat kidney, spleen and intestine do not differ in the proportion of innervation by neuropeptide Y-immunoreactive neurons, (ii) the solar plexus, splanchnic ganglion and chain ganglia (T12 and T13) provide very little vasoactive intestinal peptide-immunoreactive inputs to these organs, and (iii) somatostatin-immunoreactive neurons innervate the intestine but not the kidney or spleen.     

Receptor binding sites for cholecystokinin, galanin, somatostatin, substance P and vasoactive intestinal polypeptide in sympathetic ganglia.

Sympathetic ganglia are innervated by neuropeptide-containing fibers originating from pre- and postganglionic sympathetic neurons, dorsal root ganglion neurons, and in some cases, myenteric neurons. In the present report receptor autoradiography was used to determine whether sympathetic ganglia express receptor binding sites for several of these neuropeptides including bombesin, calcitonin gene-related peptide-alpha, cholecystokinin, galanin, neurokinin A, somatostatin, substance P, and vasoactive intestinal polypeptide. The sympathetic ganglia examined included the rat and rabbit superior cervical ganglia and the rabbit superior mesenteric ganglion. High levels of receptor binding sites for cholecystokinin, galanin, somatostatin, substance P, and vasoactive intestinal polypeptide were observed in all sympathetic ganglia examined, although only discrete neuronal populations within each ganglion appeared to express receptor binding sites for any particular neuropeptide. These data suggest that discrete populations of postganglionic sympathetic neurons may be regulated by neuropeptides released from pre- and postganglionic sympathetic neurons, dorsal root ganglion neurons, and myenteric neurons.     

Parasympathetic innervation of cutaneous blood vessels by vasoactive intestinal polypeptide-immunoreactive and acetylcholinesterase-positive nerves: histochemical and experimental study on rat lower lip

The distribution and origin of perivascular acetylcholinesterase-active and vasoactive intestinal polypeptide-immunoreactive nerve fibers were studied in the rat lower lip by means of acetylcholinesterase histochemistry and vasoactive intestinal polypeptide immunohistochemistry. The perivascular nerve fibers stained intensely with both histochemical techniques and were widely distributed on small arteries and arterioles of the lower lip, especially in the transitional zone between the hairy skin and the mucous membrane. The distributions of the two types of fibers were very similar and most of them showed overlapping coloration, on consecutive staining for vasoactive intestinal polypeptide and acetylcholinesterase. Both acetylcholinesterase-positive and vasoactive intestinal polypeptide-immunoreactive fibers were completely lost on removal of the otic ganglion, while they were not affected by sympathetic ganglion removal or sensory nerve sectioning. In the otic ganglion, most cells exhibited acetylcholinesterase activity, and about 60% of the cells showed light to heavy vasoactive intestinal polypeptide immunoreactivity. These findings indicate that vessels in the rat lip are innervated by parasympathetic fibers originating from the otic ganglion and support the view that vasoactive intestinal polypeptide is present in cholinergic neurons. This may suggest the possible control by the parasympathetic nervous system of cutaneous blood vessels through vasoactive intestinal polypeptide-containing cholinergic neurons, in general or at least in the facial area.     

Expression of neurotrophins in hippocampal interneurons immunoreactive for the neuropeptides somatostatin, neuropeptide-Y, vasoactive intestinal polypeptide and cholecystokinin.

Using a double detection method, which combines in situ hybridization for the detection of neurotrophin messenger RNA with immunocytochemistry against the neuropeptides somatostatin, neuropeptide Y, vasoactive intestinal polypeptide and cholecystokinin, we have analysed the expression of the neurotrophins, nerve growth factor, brain-derived neurotrophic factor and neurotrophin-3, in distinct populations of neuropeptide-immunoreactive hippocampal interneurons. Nerve growth factor messenger RNA expression was found in subsets of the four subpopulations of neuropeptide-immunoreactive interneurons. The highest degree of co-localization was observed in the neuropeptide-Y-positive cells (up to 70%) and in somatostatin-immunoreactive cells (48%). Only small subsets of cholecystokinin- and vasoactive intestinal polypeptide-positive neurons (21% and 10%, respectively) displayed nerve growth factor hybridization signals. In contrast, expression of neurotrophin-3 messenger RNA was exclusively observed in 26% of neuropeptide-Y-immunoreactive cells. Brain-derived neurotrophic factor hybridization signals were never detected in the neuropeptide-positive hippocampal interneurons. Morphological analysis of neuropeptide-immunoreactive interneurons that express or lack nerve growth factor messenger RNA revealed that most perisomatic inhibitory neurons, such as large vasoactive intestinal polypeptide/ cholecystokinin-immunoreactive cells, showed positive nerve growth factor hybridization signals. In addition, some somatostatin/neuropeptide-Y-immunoreactive interneurons, which are responsible for dendritic inhibition of principal hippocampal neurons, expressed nerve growth factor messenger RNA. In contrast, interneurons specialized to innervate other GABAergic cells, such as small vasoactive intestinal polypeptide-positive cells, lacked nerve growth factor expression. All these data indicate that expression of neurotrophins is differentially regulated in functionally distinct classes of hippocampal interneurons immunoreactive for neuropeptides. We also analysed whether neuropeptide-immunoreactive interneurons expressing neurotrophins were targets of the GABAergic septohippocampal pathway. We used a triple detection method, combining anterograde tracing of this connection, with in situ hybridization for the detection of neurotrophin mRNA, and immunocytochemistry against neuropeptides. Our data showed that the four populations of hippocampal interneurons studied (somatostatin, neuropeptide-Y, vasoactive intestinal polypeptide and cholescystokinin) received GABAergic afferents from the septum. However, no preference for neuropeptide-immunoreactive cells expressing neurotrophins was observed, compared to neuropeptide-positive neurons lacking neurotrophin expression.     

Light and electron microscopic immunocytochemical localization of vasoactive intestinal polypeptide VIP-like activity in the rat small intestine

Vasoactive intestinal polypeptide nerve processes and cell bodies were identified by electron microscopic immunocytochemistry in the rat small intestine. Labeled nerve processes were numerous in the inner circular smooth muscle coat and mainly in the mucosa, but were absent in the longitudinal muscle layer. Submucosal blood vessels were often surrounded by immunoreactive vasoactive intestinal polypeptide positive nerves, in close associations (distance less than 40 mn) to blood vessel basement membranes and to smooth muscle cells. In the ganglia of the myenteric and submucous plexuses, labeled fibers surrounded unstained neural cell bodies. The synaptic vesicles of vasoactive intestinal polypeptide positive terminals were 35-40 nm in diameter and some dense core vesicles (80-120 nm in diameter) were also observed in the same profiles. These observations suggest that vasoactive intestinal polypeptide nerves may participate in regulating smooth muscle activity and local blood flow in the small intestine.     

Localization of L-glutamate decarboxylase and GABA transaminase immunoreactivity in the sympathetic ganglia of the rat

The location of L-glutamate decarboxylase and gamma-aminobutyrate (GABA)-transaminase immunoreactivity in the superior cervical ganglion and in the coeliac-superior mesenteric ganglion complex of the rat was studied by an indirect immunofluorescence method and by immunoelectron microscopy, with specific antisera raised in rabbits against the corresponding enzymes. In light microscopy, several glutamate decarboxylase- or GABA-transaminase-immunoreactive principal nerve cells were detected in the superior cervical ganglion and coeliac-superior mesenteric ganglion complex. In addition, numerous small cells in both the superior cervical ganglion and coeliac-superior mesenteric ganglion complex showed intense immunoreactivity to glutamate decarboxylase or GABA-transaminase. The small cells were 10-20 micron in diameter and resembled in size and morphology the small intensely fluorescent cells. In consecutive sections, the small glutamate decarboxylase-immunoreactive cell clusters also showed immunoreactivity to tyrosine hydroxylase, suggesting that these cells contain the enzymes for both GABA and catecholamine synthesis. In the superior cervical ganglion and in the coeliac-superior mesenteric ganglion complex, GABA-transaminase immunoreactivity was also localized in fibre-like processes around and between the principal nerve cells, in nerve trunks traversing the ganglia, and around or in close contact with ganglionic blood vessels. Furthermore, GABA-transaminase immunoreactivity was observed in fibre-like structures close to the capsule of the ganglia. Division of the preganglionic nerve trunk of the superior cervical ganglion caused no detectable change in GABA-transaminase immunoreactivity in the ganglion. In immunoelectron microscopy of the superior cervical ganglion, GABA-transaminase immunoreactivity was localized in nerve fibres in association with neurotubules. A large number of GABA-transaminase labelled principal nerve cells were detected, containing immunoreactivity evenly distributed in their cytoplasm. GABA-transaminase immunoreactivity was also observed in satellite cells and their processes in the superior cervical ganglion. The present immunocytochemical results provide evidence that the rat sympathetic ganglia contain an intrinsic neuronal system showing histochemical markers for GABA synthesis and inactivation, but its functional role in the modulation of ganglionic neurotransmission remains to be established.     

Origin and peptide content of nerve fibers in the nasal mucosa of rats

Injection of the retrograde neuronal tracer True blue into the anterior-lateral part of the nasal mucosa of rats labeled nerve cell bodies in the superior cervical ganglion, the sphenopalatine ganglion, the otic ganglion and the trigeminal ganglion on the ipsilateral side. In the superior cervical ganglion, the sphenopalatine ganglion and the trigeminal ganglion on the contralateral side, very few nerve cell bodies were labeled, indicating that these ganglia provide minor contributions only. The number of labeled cell bodies indicates that the superior cervical ganglion, the sphenopalatine ganglion and the trigeminal ganglion contribute most to the innervation of the nose, while the contribution from the otic ganglion is minor. Cell bodies in the superior cervical ganglion harbored noradrenaline (NA) or NA/neuropeptide Y (NPY); in the sphenopalatine ganglion vasoactive intestinal peptide (VIP) or VIP/NPY; in the otic ganglion VIP, VIP/NPY or VIP/substance P (SP) and in the trigeminal ganglion calcitonin gene-related peptide (CGRP) or CGRP/SP. The results from denervations and tracer experiments suggest that all NA-containing and the majority of NPY-containing fibers in the nasal mucosa are derived from the superior cervical ganglion (sympathetic nerve supply). VIP- and VIP/NPY-containing fibers originate from the sphenopalatine and otic ganglia (parasympathetic nerve supply). Nerve fibers containing CGRP and CGRP/SP emanate from the trigeminal ganglion (sensory nerve supply).     

Calbindin immunoreactivity in sensory and autonomic ganglia in the guinea pig

Immunoreactivity (IR) for the calcium binding protein, calbindin, was localized in sensory ganglia (nodose, trigeminal and dorsal root), in parasympathetic ganglia (otic and sphenopalatine) in sympathetic chain ganglia and in sympathetic pre-vertebral ganglia of guinea pig. In sensory ganglia, fine nerve fibres with calbindin-IR surrounded the majority of cell bodies, a low proportion of which were themselves reactive. In cranial parasympathetic and in sympathetic chain ganglia, a small proportion of nerve cells was surrounded with baskets of calbindin-IR nerve fibres, but very few cell bodies were reactive. In prevertebral sympathetic ganglia, dense networks of terminals surrounded many cell bodies, but few somata were themselves reactive. In the coeliac and inferior mesenteric ganglia, the calbindin-IR nerve fibres surrounded somatostatin-IR cell bodies, but not those with neuropeptide Y-IR. It is concluded that specific subgroups of peripheral autonomic and sensory neurones have calbindin-IR.     

扬子鳄大肠和输尿管的神经肽分布

目的:观察扬子鳄大肠的神经肽Y（neuropeptide Y,NPY）、血管活性肠肽（vasoactive intestinal peptide,VIP）和输尿管的P物质（substance P,SP）、血管活性肠肽分布。方法:免疫荧光方法。结果:扬子鳄大肠的NPY和VIP免疫反应（NPY-and VIP-immunoreactive,NPY和VIP-IR）阳性神经纤维皆呈弯曲的细线状,主要位于粘膜下层,其次为浅部肌层,且在粘膜下层NPY-IR神经纤维交织成密集的神经丛;VIP-IR神经纡维在粘膜下层构成稀疏的网络状。输尿管的SP免疫反应（SP-immunoreactive,SP-IR）和VIP-IR神经纤维均呈点线状;其中,SP-IR神经纤维位于外膜层,较稀疏,VIP-IR神经纤维位于肌层,较密集,纤维间可见两个近似圆形的VIP-IR阳性神经细胞体。结论:扬子鳄大肠和输尿管分别存在有NPY、VIP和SP、VIP神经分布。     

Macro- and microstructural organization of the rabbit''s celiac-mesenteric ganglion complex (Oryctolagus cuniculus)

The macro- and microstructures of the rabbit celiac-mesenteric ganglion complex are described in 20 young animals. We found ten celiac ganglia, twenty-seven cranial mesenteric ganglia and eleven celiac-mesenteric ganglia. The celiac ganglia had a rectangular shape in nine cases (90%) and a circular one in one case (10%). The cranial mesenteric ganglia presented triangular (66.7%), rectangular (11.1%), L-shape (18.5%) and semi-lunar (3.7%) arrangements. The celiac-mesenteric ganglia were organized in three patterns: a single left celiac-mesenteric ganglion having a caudal portion (72.7%); celiac-mesenteric ganglia without a caudal portion (18.2%) and a single celiac-mesenteric ganglion with two portions: left and right (9.1%). The microstructure was investigated in nine celiac-mesenteric ganglia. The results showed that the celiac-mesenteric ganglion is actually a ganglion complex constituted of an agglomerate of ganglionic units separated by nerve fibers, capillaries and septa of connective tissue. Using the semi-thin section method we described the cellular organization of the celiac-mesenteric ganglion complex. Inside of each ganglionic unit, there were various cell types: principal ganglion neurons (PGN), glial cells (satellite cells) and SIF cells (small intensely fluorescent cells or small granular cells), which are the cytologic basis for each ganglionic unit of the rabbit's celiac-mesenteric ganglion complex.     

Substance P immunoreactivity in the vagal nerve of mice

After horseradish peroxidase was applied to the main trunk of the mouse vagal nerve, anterogradely labeled cells in the vagal ganglia and fibers in the solitary complex, and retrogradely labeled cells in the dorsal motor nucleus and the ambiguous nucleus were observed. Most of the cells in the nodose ganglion were labeled, but only a few cells in the jugular ganglion were labeled. Heavily labeled nerve terminals and fibers were found in 3 areas in the solitary nucleus: i.e., the lateral half of the medial nucleus, the ventrolateral nucleus, and the commissural nucleus. There was only weak labeling in the dorsolateral nucleus, ventral nucleus, and intermediate nucleus. Substance P immunoreactive neurons in the vagal ganglia were found in the jugular ganglion and the dorsal part of the nodose ganglion, but not in the ventral part of the nodose ganglion. Substance P immunoreactivity in the solitary nucleus was moderate in the commissural nucleus and the intermediate nucleus, but was lacking or very weak in the lateral half of the medial nucleus, ventral nucleus, dorsolateral nucleus, and ventrolateral nucleus. We conclude that most substance P containing fibers in the main trunk of the vagal nerve project centrally to the commissural nucleus and peripherally to some of the thoracic viscera.     

Calcitonin gene-related peptide-immunoreactive nerve fibers in mandibular periosteum of rat: evidence for primary afferent origin

Peptidergic neurons may play a role in the local regulation of bone mineralization. The neuropeptide vasoactive intestinal peptide (VIP) increases bone resorption in vitro, while calcitonin gene-related peptide (CGRP) has been shown to inhibit bone resorption in vitro. We have previously reported that sympathetic nerves with VIP-immunoreactivity innervate bone and periosteum. In the present study we sought to determine if CGRP fibers, like VIP fibers, exist in periosteum and what their origin might be. In whole-mount preparations of mandibular periosteum from rat, CGRP- and VIP-immunoreactive (IR) nerve fibers were present as networks within the periosteum. In preparations using two-color immunofluorescence, most CGRP-IR fibers were also immunoreactive for substance P (SP). In rats in which the subperiosteal space subjacent to the mandibular molars was injected with Fast blue or Fluoro-gold, retrogradely labeled cells were seen in ipsilateral trigeminal ganglia, superior cervical ganglia, and nodose ganglia. Individual cells labeled with both CGRP immunoreactivity and retrograde tracer were seen only in the mandibular portion of the trigeminal ganglion. These data suggest that CGRP-IR nerve fibers in periosteum may be of primary afferent origin. Given the reported effects of CGRP on bone mineralization, the present results suggest that primary afferent nerves containing CGRP and SP, as well as sympathetic nerves containing VIP, may play a role in focal bone remodeling.     

Immunohistochemical localization of [Met5]enkephalin and [Met5]enkephalin-Arg6-Gly7-Leu8 in sympathetic and parasympathetic neurons and nerve fibers projecting to the rat submandibular gland.

The localization of [Met5]enkephalin, [Met5]enkephalin-Arg6-Gly7-Leu8, vasoactive intestinal polypeptide and tyrosine hydroxylase immunoreactivities was studied in the submandibular gland of adult Sprague-Dawley and Wistar rats using the indirect immunofluorescence technique. Immunoreactivities for [Met5]enkephalin and [Met5]enkephalin-Arg6-Gly7-Leu8, a proenkephalin A-derived octapeptide, showed identical distributions. A large number of enkephalin-immunoreactive nerve fibers were detected around secretory acini, along intercalated ducts, convoluted granular tubules, intra- and interlobular ducts, as well as in close contact with blood vessels. The submandibular ganglia contained several enkephalin-immunoreactive neurons and nerve fibers. In the superior cervical ganglion numerous enkephalin-immunoreactive neurons and nerve fibers were also detected. Immunohistochemical co-localization studies indicated that [Met5]enkephalin and [Met5]enkephalin-Arg6-Gly7-Leu8 immunoreactivities co-exist with vasoactive intestinal polypeptide in a subpopulation of neurons of the rat submandibular ganglia, in nerve trunks along the salivary ducts of the gland, and in nerve fibers around the acini. Uni- or bilateral superior cervical ganglionectomies for 1-4 weeks resulted in a complete disappearance of tyrosine hydroxylase immunoreactivity in the glandular parenchyma, while moderate tyrosine hydroxylase immunoreactivity was seen in some neurons of the submandibular ganglia. Abundant [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive nerve fibers were still seen around the acini and blood vessels, as well as close to salivary ducts. These operations did not affect the [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive neurons in the submandibular ganglia. Many principal neurons in the superior cervical ganglion contained both [Met5]enkephalin-Arg6-Gly7-Leu8 and tyrosine hydroxylase immunoreactivity. Nerve ligation experiments indicated that [Met5]enkephalin-Arg6-Gly7-Leu8-immunoreactive sympathetic fibers project along the external carotid nerve. Accordingly, nerve fibers were found around the acini and blood vessels as well as in nerve trunks along the salivary ducts of the submandibular gland, showing co-localization of [Met5]enkephalin-Arg6-Gly7-Leu8 and tyrosine hydroxylase. Taken together, these observations suggest that the nerve fibers of the rat submandibular gland containing proenkephalin A-derived peptides are of both sympathetic and parasympathetic origin.