Vagal Reflexes

Widdicombe, J. G.; Wells, U M

doi:10.1007/978-3-0348-7558-5_11

Cited by 10 publications

(8 citation statements)

References 100 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the jugular Ad and C fibres adapted at a relatively slower rate than the nodose Ad fibres, this should not be taken as evidence that the somata of guinea-pig RARs and SARs are in the nodose and jugular ganglia, respectively. The terms RAR and SAR denote a specific type of myelinated A fibre, defined on the basis of a response to an increase in transmural pressure in vivo, which can initiate distinct reflexes (Sant'Ambrogio, 1987;Coleridge & Coleridge, 1994;Widdicombe & Wells, 1994). To our knowledge, the relative distribution of the somata of pulmonary RARs and SARs in the jugular and nodose ganglia has not been investigated.…”

Section: Discussionmentioning

confidence: 99%

Interganglionic segregation of distinct vagal afferent fibre phenotypes in guinea‐pig airways.

Ricco¹,

Kummer²,

Biglari³

et al. 1996

The Journal of Physiology

213

279

View full text Add to dashboard Cite

1. The present study addressed the hypothesis that jugular and nodose vagal ganglia contain the somata of functionally and anatomically distinct airway afferent fibres. 2. Anatomical investigations were performed by injecting guinea-pig airways with the neuronal tracer Fast Blue. The animals were killed 7 days later, and the ganglia were removed and immunostained with antisera against substance P (SP) and neurofilament protein (NF). In the nodose ganglion, NF-immunoreactive neurones accounted for about 98% of the Fast Blue-labelled cells while in the jugular ganglion they accounted for approximately 49%. SP and NF immunoreactivity was never (n = 100) observed in the same cell suggesting that the antisera labelled distinct populations. 3. Electrophysiological investigations were performed using an in vitro guinea-pig tracheal and bronchial preparation with intact afferent vagal pathways, including nodose and jugular ganglia. Action potentials arriving from single airway afferent nerve endings were monitored extracellularly using a glass microelectrode positioned near neuronal cell bodies in either ganglion. 4. The nodose ganglion contained the somata of mainly fast-conducting tracheal Ad fibres whereas the jugular ganglion contained equal numbers of C fibre and Ad fibre tracheal afferent somata. The nodose Ad neurones adapted rapidly to mechanical stimulation, had relatively low mechanical thresholds, were not activated by capsaicin and adapted rapidly to a hyperosmotic stimulus. By contrast, jugular Ad and C fibres adapted slowly to mechanical stimulation, were often activated by capsaicin, had higher mechanical thresholds and displayed a slow adaptation to a hyperosmotic stimulus. 5. The anatomical, physiological and pharmacological data provide evidence to support the contention that the vagal ganglionic source of the fibre supplying the airways ultimately dictates its neurochemical and physiological phenotype.The afferent innervation of the airways is derived from the jugular and nodose ganglia of the vagus nerve, and to a lesser extent from the cervical and thoracic spinal ganglia

show abstract

Section: Discussionmentioning

confidence: 99%

Interganglionic segregation of distinct vagal afferent fibre phenotypes in guinea‐pig airways.

Ricco¹,

Kummer²,

Biglari³

et al. 1996

The Journal of Physiology

213

279

View full text Add to dashboard Cite

show abstract

“…These findings suggest that the importance of intrinsic neurons in regulatory functions in the trachea might be lower than in the intestine. In the trachea, the vagal reflex, such as the Hering-Breuer reflex, might also play an important role (Widdicomb and Wells, 1994).…”

Section: Discussionmentioning

confidence: 99%

“…Such endings might be slowly adapting stretch receptors from vagal nerves, as suggested in the cited reports. These endings might be related to the regulation of smooth muscle tone by the vagal reflex (Widdicomb and Wells, 1994). The free nerve endings within the epithelial layer seems to be nonmyelinated nociceptors (C-fiber afferents), which play a role in nociception (Widdicomb and Wells, 1994).…”

Section: Discussionmentioning

confidence: 99%

“…These endings might be related to the regulation of smooth muscle tone by the vagal reflex (Widdicomb and Wells, 1994). The free nerve endings within the epithelial layer seems to be nonmyelinated nociceptors (C-fiber afferents), which play a role in nociception (Widdicomb and Wells, 1994). The branching pattern of the endings seems to provide the morphological basis for the axon reflex, which causes asthma (Barnes, 1986a).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Morphological and quantitative study of the intrinsic nerve plexuses of the canine trachea as revealed by immunohistochemical staining of protein gene product 9.5

Yamamoto¹,

Ootsuka²,

Atoji³

et al. 1998

Anat. Rec.

View full text Add to dashboard Cite

Background: The ganglionated nervous plexuses in the trachea play an important role in the regulation of respiration. Although the tracheal tissue of the dog has frequently been used in physiological and pharmacological studies, little is known about the morphology of the intrinsic nervous plexuses in the dog trachea and quantitative data about the ganglia and nerve cell bodies are lacking. The structure of the nervous plexuses and detailed morphometric data about the intrinsic neurons of the dog have not previously been reported.Methods: The structure of the intrinsic nerves in the dog trachea was examined by a combination method of digestion with KOH and immunohistochemical ataining of protein gene product 9.5. In addition, areas of nerve cell profiles, numbers of nerve cell bodies per ganglion and densities of nerve cell bodies per ganglion were estimated in preparations from five dogs.Results: In the dog trachea, the peritracheal plexus, outer submucosal plexus, inner submucosal plexus, and mucosal plexus were identified from adventitia to epithelium in that order. The peritracheal plexus, situated in the lamina adventitia of the trachea, consisted of thick nerve bundles that were densely distributed in the membranous wall. The peritracheal plexus contained ganglia with round or oval nerve cell bodies. In the trachealis muscle, the intramuscular plexus, which was a well-developed, three-dimensional nervous network, was observed. It did not include ganglia and consisted of inter-and intrafascicular networks. The outer submucosal plexus was observed as small clusters in the inside of the trachealis muscle. A few round nerve cells were observed in the outer submucosal plexus as small clusters. The ganglionated inner submucosal plexus was identified in the superficial layer of the submucosal layer. A finer meshwork, namely, the mucosal plexus, was observed in the lamina propria. Among the entire length of the trachea, we counted 2,134-2,873 ganglia (average, 2,389) and 13,902-24,232 nerve cell bodies (average,18,461) were counted in the peritracheal plexuses of five dogs. The densities of ganglia and nerve cell bodies were high near the carina and low near the thoracic inlet. The number of nerve cell bodies per ganglion was estimated as 6.5-8.8 (average, 7.7). The average maximum area of nerve cell profiles was 522 ؎ 223 m 2 .Conclusions: The structure of the tracheal plexuses in the dog is more complex than those in other smaller animals. The constitution of the plexuses seems to be that of the intestine. The numerous nerve cells in the peritracheal plexus in the adventitia can be expected to play important roles in airway regulation and in the pathogenesis of tracheal collapse.

show abstract

“…Studies with several animal models have shown that rapidly adapting mechanosensitive Ad fibres in the large airways can initiate important defensive reflexes including cough and bronchoconstriction (Widdicombe & Wells, 1994). …”

Section: Discussionmentioning

confidence: 99%

Immunomodulation of afferent neurons in guinea‐pig isolated airway.

Riccio¹,

Myers²,

Undem³

1996

The Journal of Physiology

138

View full text Add to dashboard Cite

1. The trachea, larynx and main bronchi with the right vagus nerve and nodose ganglion were isolated from guinea-pigs passively immunized 24 h previously with serum containing antiovalbumin antibody. 2. The airways were placed in one compartment of a Perspex chamber for recording of isometric tension while the nodose ganglion and attached vagus nerve were pulled into another compartment. Action potentials arriving from single airway afferent nerve endings were monitored extracellularly using a glass microelectrode positioned near neuronal cell bodies in the ganglion. Mechanosensitivity of the nerve endings was quantified using calibrated von Frey filaments immediately before and after exposure to antigen (10 ,ug ml-' ovalbumin). 3. Ten endings responded to the force exerted by the lowest filament (0-078 mN) and were not further investigated. In airways from thirteen immunized guinea-pigs, the mechanical sensitivity of Ad afferent fibres (conduction velocity = 4-3 + 0'6 m s-') was enhanced 4-1 + 0¢9-fold following airway exposure to antigen (P < 0 005). Mechanical sensitivities of afferent fibres (conduction velocity = 4-3 + 0-6 m s-1) from non-immunized control guineapig airways were unaffected by antigen (n = 13). 4. Antigen did not overtly cause action potential generation except in one instance when the receptive field was located over the smooth muscle. This ending also responded to methacholine suggesting that spatial changes in the receptive field, induced by muscle contraction, were responsible for the activation. 5. The mediators responsible for these effects are unknown, although histamine, prostaglandins, leukotrienes and tachykinins do not appear to be essential. The increase in mechanical responsiveness was not associated with the smooth muscle contraction since leukotriene C4, histamine and tachykinins, which all caused a similar contraction to antigen, did not affect mechanical thresholds. Moreover, the antigen-induced increases in excitability persisted beyond the duration of the smooth muscle contraction. 6. These results demonstrate that antigen-antibody-mediated inflammatory processes may enhance the excitability of vagal afferent nerve terminals projecting from the airway and thus may contribute to the pathophysiology of allergic airway diseases.

show abstract

Vagal Reflexes

Cited by 10 publications

References 100 publications

Interganglionic segregation of distinct vagal afferent fibre phenotypes in guinea‐pig airways.

Interganglionic segregation of distinct vagal afferent fibre phenotypes in guinea‐pig airways.

Morphological and quantitative study of the intrinsic nerve plexuses of the canine trachea as revealed by immunohistochemical staining of protein gene product 9.5

Immunomodulation of afferent neurons in guinea‐pig isolated airway.

Contact Info

Product

Resources

About