Localization in the vagal ganglia of calcitonin gene-related peptide- and calretinin-immunoreactive neurons that innervate the cervical and the subdiaphragmatic esophagus of the rat

We have determined the localization of calcitonin gene-related peptide-immunoreactive (CGRP-ir) and calretinin-ir neurons in the vagal ganglia that innervate the cervical or subdiaphragmatic esophagus. Many CGRP-ir neurons were found exclusively in the jugular ganglion located in the cranial cavity. Calretinin-ir neurons were distributed throughout the vagal ganglia. Injection of Fluorogold into the cervical esophagus resulted in many Fluorogold-labeled neurons in the jugular and nodose ganglia. Injection of Fluorogold into the subdiaphragmatic esophagus resulted in many Fluorogold-labeled neurons, with most in the nodose ganglion. In the case of Fluorogold injection into the cervical esophagus, double-labeling combining immunohistochemistry and retrograde tracing showed that about 40% of the Fluorogold-labeled neurons in the jugular ganglion express CGRP-like immunoreactivity, and about 20% of the Fluorogold-labeled neurons in both the jugular and nodose ganglia express calretinin-like immunoreactivity. In the case of injection into the subdiaphragmatic esophagus, only a few Fluorogold-labeled neurons express CGRP-like immunoreactivity or calretinin-like immunoreactivity in the vagal ganglia. These results indicate that the cervical esophagus receives projections from many CGRP-ir neurons in the jugular ganglion and from calretinin-ir neurons in the jugular and nodose ganglia, while the subdiaphragmatic esophagus receives projections from only a few CGRP-ir and calretinin-ir neurons in the vagal ganglia.     

Brain-derived neurotrophic factor immunoreactive vagal sensory neurons innervating the gastrointestinal tract of the rat

We have determined whether brain-derived neurotrophic factor immunoreactive (BDNF-ir) neurons in the vagal ganglia innervate the gastrointestinal tract. Many BDNF-ir neurons were medium in size and located throughout the jugular and nodose ganglia. When Fluorogold was injected into the wall of the cervical esophagus, many retrogradely Fluorogold-labeled neurons were found in both the jugular ganglion and the nodose ganglion. When Fluorogold was injected into the body of the stomach or applied to the cut end of the subdiaphragmatic vagus nerve, numerous Fluorogold-labeled neurons were found mostly in the nodose ganglion. Double-labeling combining immunohistochemistry for BDNF and retrograde tracing with Fluorogold showed that more than 90% of the neurons in the jugular ganglion and the nodose ganglion projecting to the cervical esophagus contained BDNF-like immunoreactivity. In the cases of both Fluorogold injection into the stomach and Fluorogold application to the subdiaphragmatic vagus nerve, almost all Fluorogold-labeled neurons in the nodose ganglion contained BDNF-like immunoreactivity. These results indicated that almost all vagal sensory neurons located in either the jugular ganglion or the nodose ganglion that innervate the gastrointestinal tract are BDNF-ir neurons.     

Calcitonin gene-related peptide immunoreactive sensory neurons in the vagal and glossopharyngeal ganglia innervating the larynx of the rat

We have examined whether calcitonin gene-related peptide-immunoreactive (CGRP-ir) neurons in the vagal and glossopharyngeal ganglia innervate the larynx. Many CGRP-ir neurons were located mostly in the superior glossopharyngeal–jugular ganglion complex that was fused the superior glossopharyngeal ganglion and the jugular ganglion in the cranial cavity. When Fluorogold was applied to the cut end of the superior laryngeal nerve (SLN) or the recurrent laryngeal nerve (RLN), many Fluorogold-labeled neurons were found in the superior glossopharyngeal–jugular ganglion complex and the nodose ganglion. Double-labeling for CGRP and Fluorogold showed that about 80% of Fluorogold-labeled neurons in the superior glossopharyngeal–jugular ganglion complex expressed CGRP-like immunoreactivity in the case of application to the SLN, and about 50% of Fluorogold-labeled neurons expressed CGRP-like immunoreactivity in the case of the RLN. Only a few double-labeled neurons were found in the nodose ganglion. The number of the Fluorogold-labeled neurons and double-labeled neurons in the superior glossopharyngeal–jugular ganglion complex in the case of the SLN was larger than that in the case of the RLN. These results indicate that sensory information from the larynx might be conveyed by many CGRP-ir neurons located in the superior glossopharyngeal–jugular ganglion complex by way of the SLN and the RLN.     

Calcitonin gene-related peptide immunoreactive neurons innervating the soft palate,the root of tongue,and the pharynx in the superior glossopharyngeal ganglion of the rat

We have examined whether calcitonin gene-related peptide immunoreactive (CGRP-ir) neurons in the glossopharyngeal ganglia innervate the soft palate, the root of tongue, and the pharynx of the rat. Immunohistochemical observations revealed that numerous CGRP-ir neurons are located in the superior glossopharyngeal ganglion located ventrolateral to the medulla oblongata in the cranial cavity, and that CGRP-ir neurons are also located in the inferior glossopharyngeal ganglion at the jugular foramen. When Fluorogold was injected into the soft palate, the root of tongue, or the pharyngeal constrictor muscles, many retrogradely Fluorogold-labeled neurons were found in the superior glossopharyngeal ganglion and the nodose ganglion, and several Fluorogold-labeled neurons were found in the inferior glossopharyngeal ganglion. Double labeling with immunohistochemistry for CGRP and Fluorogold showed that in every case of injections of Fluorogold into the soft palate, the root of tongue, or the pharynx, about 30% of the Fluorogold-labeled neurons in the superior glossopharyngeal ganglion expressed CGRP-like immunoreactivity, while no double-labeled neurons were found in the inferior glossopharyngeal ganglion or the nodose ganglion. These results indicate that nociceptive sensory information from the soft palate, the root of tongue, and the pharynx might be conveyed by the neurons in the superior glossopharyngeal ganglion to the nucleus tractus solitarii.     

山羊迷走神经感觉纤维的来源——HRP法研究

为了探讨山羊迷走神经感觉纤维的来源,本文将HRP注入颈迷走神经干后,在结状节出现大量密集的标记细胞,颈静脉节中也有较多的细胞被标记,但其密度和数量远不如结状节。在颈1—8和胸1—3的背根节中出现一定数量的标记细胞。此外,少量的标记细胞见于迷走神经干的纤维束中,这些标记细胞的形态与结状节的基本相同。     

Evidence for nodose ganglion as the source of innervation to the anterior lobe of the pituitary gland.

Recent studies have provided convincing evidence for the presence of peptidergic nerve fibers in the pituitary anterior lobe in several animal species. This study was aimed at elucidating the origin of this innervation by neuroanatomical tracing, denervation experiments, and immunohistochemistry. Immunohistochemistry against substance P and growth-associated protein 43 revealed a dense fiber plexus within the anterior lobe, and these markers were mostly colocalized. Retrograde tracing with Fluorogold from the pituitary gland stained neurons in the hypothalamus, superior cervical ganglia and the nodose ganglia. None of the Fluorogold-labelled neurons in the hypothalamus or superior cervical ganglion were substance P-immunoreactive, while many of the neuronal cell bodies in the nodose ganglion exhibited substance P immunoreactivity. There were no Fluorogold-labelled neurons in the trigeminal, otic or cervical dorsal root ganglia. Surgical transection of the pituitary stalk or bilateral removal of the superior cervical ganglion did not abolish the anterior lobe nerve fibers, and anterograde tracing with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindo-carbocyanine perchlorate from the pituitary stalk failed to stain any nerve fibers within the anterior lobe. Our findings suggest that the nodose ganglion neurons likely innervate the pituitary anterior lobe, while neither hypothalamus nor sympathetic superior cervical ganglion may be a source of this innervation.By showing a distinct neuronal system in the pituitary anterior lobe our findings (i) support the previous functional studies demonstrating a distinct regulation of the morphology of the anterior lobe innervation by hormonal changes, and (ii) suggest that the innervation of the pituitary anterior lobe is a part of the visceral innervation by the vagus nerve rather than a part of the other intracranial innervation. These findings provide a neuroanatomic basis for the reported observations about the neural regulation of the pituitary anterior lobe.     

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.     

Excitotoxin-induced degeneration of rat vagal afferent neurons

The inferior vagal or nodose ganglion contains the perikarya of vagal afferent neurons that function as cardiopulmonary and abdominal visceral receptors as well as aortic arch baroreceptors. In this study we have sought to utilize the axon-sparing properties of the excitotoxins kainic acid, N-methyl-D-aspartic acid and alpha-amino-3-hydroxy-4-isoxazolepropionic acid to destroy the perikarya of these sensory neurons and thus selectively de-afferent the vagus in the rat. Kainic acid (0.5 nmol/microliters, 2 X 2 microliters) was applied topically to both nodose ganglia and the rats were allowed to recover for 7-8 days. Baroreceptor heart rate reflex activity was assessed in these conscious rats. Baroreceptor heart rate reflex gain was reduced (-51%) in kainic acid-treated rats, as was the maximal reflex bradycardia induced by the pressor agent, phenylephrine. Kainic acid treatment did not alter resting mean arterial pressure or heart rate. Vagal efferent neurons were spared by kainic acid treatment since bradycardic responses to electrical stimulation of the peripheral end of a cut vagus were not impaired. Histological studies showed marked destruction of perikarya within the nodose ganglia of kainic acid-treated rats: inflammatory and degenerative changes were evident at 2 days, and at 10 days there was considerable loss of neuronal cell bodies, but sparing of axons. Topical application to the nodose ganglion of alpha-methyl-DL-aspartic acid (6.8 nmol/microliters, 2 X 2 microliters), a non-excitotoxic dicarboxylic acid, failed to alter baroreflex sensitivity or produce perikaryal degeneration in nodose ganglia.(ABSTRACT TRUNCATED AT 250 WORDS)     

The origin of sensory innervation of the peritoneum in the rat

The distribution of sensory neurons innervating the peritoneum was studied using axonal transport of fluoro-gold. The tracer was injected into parietal peritoneum, diaphragm, mesentery, mesocolon, visceral peritoneum covering the stomach, small intestine, colon, liver, spleen, kidney, urinary bladder or uterus. After ten days of survival bilateral dorsal root ganglia from C2 to S6, and the nodose ganglia were dissected. The cryostat sections of these ganglia were mounted on glass slides and observed with a fluorescence microscope. In cases where the tracer was placed on the peritoneum covering the abdominal wall, labeled neurons were observed only in the ipsilateral dorsal root ganglia. A small number of neurons in nodose and cervical dorsal root ganglia of both sides were labeled after placing the tracer on the central part of the diaphragm. When fluoro-gold was applied to the peripheral part of the diaphragm, nodose ganglion was negative, and dorsal root ganglia from T6 to T12 were positive. Many neurons in the nodose ganglia in addition to somata in the dorsal root ganglia from T4 to T13 were labeled when the tracer was placed on the peritoneum lining the stomach, small intestine or caecum. After applying the tracer onto the colon, labeled neurons were observed in the dorsal root ganglia from T13 to L2 and L5 to S1. Ganglion cells in the nodose and dorsal root ganglia from T5 to T13 were positive when fluoro-gold was placed on the mesentery. No labeled neurons were observed in any ganglia when the tracer was applied to the peritoneum covering the spleen, kidney, uterus, urinary bladder and liver. These results suggest that most of the parietal peritoneum receives sensory nerves from dorsal root ganglia and the visceral peritoneum from both spinal nerves and the vagus nerve.     

Afferent and efferent innervation of the rat esophagus

Summary The technique of retrograde labeling of nerve cells with HRP and nuclear yellow as well as transganglionic anterograde HRP-tracing of sensory projections into the CNS were used to establish the motor and sensory innervation pattern of two parts of the rat esophagus: the cervical and the abdominal segment. For comparison, also the innervation of the anterior wall of the stomach was studied.Application of HRP to the cervical part of the esophagus resulted in bilateral labeling of neurons in the nucleus ambiguns exclusively, while application of the tracer to the abdominal part was followed by labeling of cells in both the nucleus ambiguus and the dorsal motor nucleus of the vagus. Application of tracer to the wall of the stomach caused labeling of cells in the dorsal motor nucleus of the vagus exclusively. Labeling appeared always bilaterally.In all experiments there was a profuse labeling of primary afferent neurons with cell bodies in both nodose ganglia and endings in certain subnuclei of the solitary nucleus. Endings related to the cervical esophagus projected into the ventral subnuclei, projections from the abdominal esophagus were located in the ventral and medial subnuclei, those from the stomach in the medial subnucleus solely. The area postrema and the commissural nucleus received afferents from both organs, the esophagus and the stomach.Double labeling experiments with HRP and nuclear yellow provided no signs of overlap of sensory innervation areas of the sites investigated in this study. Within the wall of the esophagus no labeled intramural cells nor nerve fibers were found in sections beyond the injection sites.     

Subtypes of vagal afferent C-fibres in guinea-pig lungs

An ex vivo , vagally innervated, lung preparation was used to address the hypothesis that vagal C-fibres comprise at least two distinct phenotypes. Histological and extracellular electrophysiological experiments revealed that vagal C-fibres innervating the pulmonary system are derived from cell bodies situated in two distinct vagal sensory ganglia. The jugular (superior) ganglion neurones project C-fibres to both the extrapulmonary airways (larynx, trachea and bronchus) and the lung parenchymal tissue. By contrast, C-fibres from nodose (inferior) neurones innervate primarily structures within the lungs. Histologically, nodose neurones projecting lung C-fibres were different from the jugular neurones in that they were significantly less likely to express neurokinins. The nerve terminals within the lungs of both nodose and jugular C-fibres responded with action potential discharge to capsaicin and bradykinin application, but only the nodose C-fibre population responded with action potential discharge to the P2X selective receptor agonist α,β-methylene-ATP. Whole cell patch clamp recording of capsaicin-sensitive nodose and jugular ganglion neurones retrogradely labelled from the lung tissue revealed that, like the nerve terminals, lung specific nodose C-fibre neurones express functional P2X receptors, whereas lung specific jugular C-fibres do not. The data support the hypothesis that both neural crest-derived neurones (jugular ganglia) and placode-derived neurones (nodose ganglia) project C-fibres in the vagus, and that these two C-fibre populations represent distinct phenotypes.     

狗肾脏感觉神经来源

目的探讨狗肾脏感觉神经来源。方法应用辣根过氧化物酶(HRP)逆行追踪技术,将CB-HRP注入一侧狗肾脏内,动物存活2~3 d,TMB法成色反应,光镜下观察。结果狗肾脏感觉神经来源于双侧背根节T5~L3节段,主要集中在T10~L2节段,占背根节内标记细胞总数90.56%,符合既集中(T10~L2)又分散(T5~L3)的分布特点,无左右侧差异;背根节内标记细胞以卵圆形、圆形的细胞为主,少见细胞突起,细胞分布弥散,多分布于节的边缘部位。在4例注射侧迷走神经结状节内也见有少量标记细胞,体积大,突起不明显。结论狗肾脏感觉神经来源于双侧背根节T5~L3段和同侧迷走神经结状节细胞。     

Distribution of vagal CGRP-immunoreactive fibers in the lower esophagus and the cardia of the stomach of the rat

We have examined whether the smooth muscle fibers in the lower esophagus and the cardia of the stomach of the rat are innervated by calcitonin gene-related peptide-immunoreactive (CGRP-ir) fibers coming from the nucleus ambiguus. Immunohistochemical observations revealed that there were many CGRP-ir fibers and free endings in all external muscular layers of the lower esophagus and the cardia. Occasionally, bundles of CGRP-ir fibers were found in the inner oblique muscle layer of the cardia. There were also many CGRP-ir fibers in the mucous membrane in the lower esophagus and the cardia. When Fluorogold was injected into the junction of the lower esophagus and the cardia, many retrogradely labeled neurons were found in the compact formation of the nucleus ambiguus and the dorsal motor nucleus of the vagus nerve. Double labeling with immunohistochemistry for CGRP and the retrograde tracer Fluorogold showed that almost all of neurons (more than 90%) in the nucleus ambiguus that project to the lower esophagus or the cardia contained CGRP, while no CGRP-ir neurons were found in the dorsal motor nucleus of the vagus nerve. These results indicate that the vagal motor neurons of the nucleus ambiguus that contain CGRP project not only to the striated muscle fibers of the esophagus but also to the smooth muscle fibers of the external muscle layers of the lower esophagus and the cardia.     

Degranulation of mast cells in the trachea and bronchi of the rat following stimulation of the vagus nerve

In the trachea and bronchi of the atropinized rat, the proportion of degranulating mast cells (defined as having one or more granules outside the body of the cell in a 10-microns thick section) was increased from 35-40% to 48-55% following electrical stimulation of one or both vagus nerves for 3 min. The increase occurred bilaterally, though it was greater on the stimulated side. The degranulation of mast cells was prevented by transection of the nerve rostral to the nodose ganglion 8-10 days before stimulation. Pre-treatment of rats with capsaicin also prevented the degranulation of mast cells that otherwise would have followed stimulation of the vagus nerve. These observations indicate that tracheo-bronchial mast cells discharge their granules in response to the activity of capsaicin-sensitive axons of neurons whose cell bodies are rostral to the nodose ganglion. These are probably substance P-containing polymodal nociceptive neurons of the jugular ganglion. If similar neurons exist in man, axon reflexes in their intrabronchial branches would be expected to stimulate the release of mast cell-derived agents that cause bronchoconstriction in asthma.     

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.     

A new monoclonal antibody against the GABA-protein conjugate shows immunoreactivity in sensory neurons of the rat.

A monoclonal antibody, 115AD5, was raised against GABA coupled to bovine serum albumin. The monoclonal antibody 115AD5 also reacted with other GABA-protein conjugates. The specificity of the monoclonal antibody was corroborated by enzyme-linked immunoassay, dot-immunobinding experiments and immunostaining of rat cerebellum sections. The monoclonal antibody 115AD5 could successfully be applied on Vibratome and cryostat sections using either indirect immunofluorescence or peroxidase techniques. In rat cerebellar cortex the monoclonal antibody 115AD5 gave an intense immunoreaction in stellate cells, in Golgi neurons, and in basket cells and their processes around Purkinje cell bodies. Purkinje cell dendrites showed GABA immunoreactivity while the cell bodies were non-reactive or only weakly reactive. There was labelling in some nuclei of Purkinje cells. GABA immunoreactivity was also found in dot-like structures in the granular layer. A large population of sensory neurons in rat thoracic and lumbar spinal dorsal root ganglia presented an intense immunoreactivity for the monoclonal antibody 115AD5. Nerve bundles immunoreactive for GABA were also seen in these ganglia. In the trigeminal ganglion, a major population of sensory neurons and some of their processes presented immunoreactivity for GABA. In the sensory nodose ganglion of the vagus nerve, many neuronal cell bodies and some fibres were immunoreactive for GABA. Ligation of the vagus nerve caudal to the ganglion resulted in an increased GABA immunoreactivity in neuronal somata of the ganglion, as well as in nerve fibres on the ganglionic side of the ligature. The present results suggest that in the rat, a population of sensory neurons in thoracic and lumbar spinal dorsal root ganglia, as well as in the trigeminal and nodose ganglia contain GABA. The presence of GABA immunoreactivity in these neurons raises the possibility of a neurotransmitter or modulator role.     

Chemical communication between vagal afferent somata in nodose Ganglia of the rat and the Guinea pig in vitro

The cell bodies of spinal afferents, dorsal root ganglion neurons, are depolarized several millivolts, and their probability of spiking increased when axons of neighboring somata in the same ganglion are electrically stimulated repetitively. This form of neural communication has been designated cross-depolarization (CD) and cross-excitation (CE). The existence of CD and CE between somata of vagal afferents (nodose ganglion neurons, NGNs) of rats and guinea pigs was investigated by electrically stimulating the vagus nerve while recording the electrical activity of NGNs in intact nodose ganglia with sharp intracellular microelectrodes. CD and CE in NGNs were manifested by a membrane depolarization (approximately 4 mV), the presence of spontaneous action potentials, and a decreased spike threshold. CD was dependent on the frequency and intensity of vagal nerve stimulation. Two distinct types of CD were observed: 1) in NGNs with large input resistances (R(in)), CD was dependent on [Ca2+]o, associated with increased membrane conductance, and had an extrapolated reversal potential (E(rev)) value of about -25 mV; and 2) in NGNs with low R(in), CD was independent of [Ca2+]o, not accompanied by a membrane conductance change, or a measurable E(rev) value. These data reveal the existence of a chemical communication pathway between vagal afferent somata and suggest the possibility that communication between different visceral organs may occur at the level of the primary vagal afferent neuron.     

Selectivity of neuronal degeneration produced by chronic guanethidine treatment

Summary Chronic guanethidine treatment of rats produced extensive damage to sympathetic neurons of the superior cervical ganglion and pelvic plexus. No ultrastructural changes were observed in parasympathetic cholinergic neurons in the ciliary ganglion and pelvic plexus, nor in sensory neurons in nodose and dorsal root ganglia. A total of only six nerve cell bodies free of degenerative changes were observed in sections of superior cervical ganglia from 20 rats. This suggests either that the earlier estimates of 5% cholinergic neurons in the superior cervical ganglion based on acetylcholinesterase staining are too high, or implies that sympathetic cholinergic neurons, unlike parasympathetic neurons, are damaged by chronic guanethidine treatment.