Activation of mouse skin mast cells and cutaneous afferent C-fiber subtypes by bee venom.

In mammals, many Hymenopteran stings are characterized by pain, redness, and swelling - three manifestations consistent with nociceptive nerve fiber activation. The effect of a Western honeybee (Apis mellifera) venom on the activation of sensory C-fibers in mouse skin was studied using an innervated isolated mouse skin preparation that allows for intra-arterial delivery of chemicals to the nerve terminals in the skin. Our data show that honeybee venom stimulated mouse cutaneous nociceptive-like C-fibers, with an intensity (action potential discharge frequency) similar to that seen with a maximally-effective concentration of capsaicin.

High pressure sensor based on intensity-variation using polymer optical fiber.

Silica fiber under high pressure increases the risk of fiber breakage or permanent deformation, which may cause sensor failure due to mechanical strength limitations. High pressure can also induce birefringence in optical fiber. In this study, we present a simple design and low-cost high pressure sensor using polymer optical fiber (POF) based on the intensity-variation technique.

Role of Na1.7 in postganglionic sympathetic nerve function in human and guinea-pig arteries.

Na1.7 plays a crucial role in inducing and conducting action potentials in pain-transducing sensory nociceptor fibres, suggesting that Na1.7 blockers could be effective non-opioid analgesics.

Direct activation of airway sensory C-fibers by SARS-CoV-2 S1 spike protein.

Respiratory viral infection can lead to activation of sensory afferent nerves as indicated by the consequential sore throat, sneezing, coughing, and reflex secretions. In addition to causing troubling symptoms, sensory nerve activation likely accelerates viral spreading. The mechanism how viruses activate sensory nerve terminals during infection is unknown.

Advances in Low-Temperature Dual-Ion Batteries.

Fabricating rechargeable batteries for low-temperature (LT) applications is highly desired at high altitudes/latitudes, aerospace/subsea exploration, and defense. Lithium-ion batteries (LIBs) suffer from severe loss of capacity and energy/power density at sub-zero temperatures caused by the sluggish kinetics. By utilizing both cations and anions as charge carriers, dual-ion batteries (DIBs) become a nascent battery system for LT tolerance by overcoming ion-desolvation during discharge.

K 1/D-type potassium channels inhibit the excitability of bronchopulmonary vagal afferent nerves.

The K 1/D-type potassium current (I ) is an important determinant of neuronal excitability. This study explored whether and how I channels regulate the activation of bronchopulmonary vagal afferent nerves. The single-neuron RT-PCR assay revealed that nearly all mouse bronchopulmonary nodose neurons expressed the transcripts of α-dendrotoxin (α-DTX)-sensitive, I channel-forming K 1.

Role of Na 1.7 in action potential conduction along human bronchial vagal afferent C-fibres.

Background And Purpose: The purpose of this study was to determine the role of Na 1.7 in action potential conduction in C-fibres in the bronchial branches of the human vagus nerve.

Experimental Approach: Bronchial branches of the vagus nerve were dissected from human donor tissue.

[Screening of different metabolites in teenage football players after exercise fatigue].

To investigate the changes of metabolites of teenage football players after exercise-induced fatigue. Twelve male teenage football players (14～16 yrs) were selected as experimental subjects in this study. And an exercise model including aerobic and anaerobic exercise as one group exercise was established by using power bicycle: completion 6 min 150 W load, 60～65 r/min of riding exercise and 30 s of riding exercise which load was the maximum speed set by the tester's weight.

Acute activation of bronchopulmonary vagal nociceptors by type I interferons.

Type I interferon receptors are expressed by the majority of vagal C-fibre neurons innervating the respiratory tract Interferon alpha and beta acutely and directly activate vagal C-fibers in the airways. The interferon-induced activation of C-fibers occurs secondary to stimulation of type 1 interferon receptors Type 1 interferons may contribute to the symptoms as well as the spread of respiratory viral infections by causing coughing and other defensive reflexes associated with vagal C-fibre activation ABSTRACT: We evaluated the ability of type I interferons to acutely activate airway vagal afferent nerve terminals in mouse lungs. Using single cell RT-PCR of lung-specific vagal neurons we found that IFNAR1 and IFNAR2 were expressed in 70% of the TRPV1-positive neurons (a marker for vagal C-fibre neurons) and 44% of TRPV1-negative neurons.

Stimulus intensity-dependent recruitment of Na1 subunits in action potential initiation in nerve terminals of vagal C-fibers innervating the esophagus.

We investigated voltage-gated sodium channel (Na1) subunits that regulate action potential initiation in the nerve terminals of vagal nodose C-fibers innervating the esophagus. Extracellular single fiber recordings were made from the nodose C-fibers, with mechanically sensitive nerve terminals in the isolated innervated guinea pig esophagus. Na1 inhibitors were selectively delivered to the tissue-containing nerve terminals.

Allergen-induced histaminergic and non-histaminergic activation of itch C-fiber nerve terminals in mouse skin.

Acute cutaneous exposure to allergen often leads to itch, but seldom pain. The effect of mast cell activation on cutaneous C-fibers was studied using innervated isolated mouse skin preparation that allows for intra-arterial delivery of chemicals to the nerve terminals in the skin. Allergen (ovalbumin) injection into the isolated skin of actively sensitized mice strongly stimulated chloroquine (CQ)-sensitive C-fibers (also referred to as "itch" nerves); on the other hand, CQ-insensitive C-fibers were activated only modestly, if at all.

Phenotypic distinctions between the nodose and jugular TRPV1-positive vagal sensory neurons in the cynomolgus monkey.

Vagal capsaicin-sensitive afferent C-fibers play an important role in the maintenance of visceral homeostasis and contribute to symptoms in visceral diseases. Based on their developmental origin two functionally distinct types of vagal C-fibers are recognized: those with neurons in the vagal nodose ganglia (derived from epibranchial placodes) and in the vagal jugular ganglia (from neural crest). Studies in nonprimate species demonstrated that the vagal nodose and jugular C-fibers differ in activation profile, neurotrophic regulation, and expression of neurotransmitters.

Targeting C-fibers for peripheral acting anti-tussive drugs.

Activation of vagal C-fibers is likely involved in some types of pathological coughing, especially coughing that is associated with airway inflammation. This is because stimulation of vagal C-fibers leads to strong urge to cough sensations, and because C-fiber terminals can be strongly activated by mediators associated with airway inflammation. The most direct manner in which a given mediator can activate a C-fiber terminal is through interacting with its receptor expressed in the terminal membrane.

KCNQ/M-channels regulate mouse vagal bronchopulmonary C-fiber excitability and cough sensitivity.

Increased airway vagal sensory C-fiber activity contributes to the symptoms of inflammatory airway diseases. The KCNQ/Kv7/M-channel is a well-known determinant of neuronal excitability, yet whether it regulates the activity of vagal bronchopulmonary C-fibers and airway reflex sensitivity remains unknown. Here we addressed this issue using single-cell RT-PCR, patch clamp technique, extracellular recording of single vagal nerve fibers innervating the mouse lungs, and telemetric recording of cough in free-moving mice.

Voltage-Gated Sodium Channels Regulating Action Potential Generation in Itch-, Nociceptive-, and Low-Threshold Mechanosensitive Cutaneous C-Fibers.

We evaluated the effect of voltage-gated sodium channel 1 (Na1) blockers in three nonoverlapping C-fiber subtypes in the mouse skin: chloroquine (CQ)-sensitive C-fibers with high mechanical thresholds- second, CQ-insensitive, capsaicin-sensitive C-fibers with high mechanical thresholds- and CQ and capsaicin-insensitive C-fibers with a very low mechanical threshold-C-LTMs. Na1-blocking drugs were applied to the nerve terminal receptive fields using an innervated isolated dorsal mouse skin-nerve preparation where the drugs are delivered into the skin intra-arterially. We combined these studies with an analysis of the mRNA expression of the -subunits of Na1 in individual dorsal root ganglia neurons labeled from the same region of the skin.

Mrgprs on vagal sensory neurons contribute to bronchoconstriction and airway hyper-responsiveness.

Asthma, accompanied by lung inflammation, bronchoconstriction and airway hyper-responsiveness, is a significant public health burden. Here we report that Mas-related G protein-coupled receptors (Mrgprs) are expressed in a subset of vagal sensory neurons innervating the airway and mediates cholinergic bronchoconstriction and airway hyper-responsiveness. These findings provide insights into the neural mechanisms underlying the pathogenesis of asthma.

Structure of vagal afferent nerve terminal fibers in the mouse trachea.

The structure of primary afferent nerve terminals profoundly influences their function. While the complex vagal airway nerve terminals (stretch receptors, cough receptors and neuroepithelial bodies) were thoroughly characterized, much less is known about the structure of airway nerves that do not form distinct complex terminals (often termed free nerve fibers). We selectively induced expression of GFP in vagal afferent nerves in the mouse by transfection with AAV-GFP virus vector and visualized nerve terminals in the trachea by whole organ confocal imaging.

Distinct Expression of Phenotypic Markers in Placodes- and Neural Crest-Derived Afferent Neurons Innervating the Rat Stomach.

Background: Visceral pain is initiated by activation of primary afferent neurons among which the capsaicin-sensitive (TRPV1-positive) neurons play an important role. The stomach is a common source of visceral pain. Similar to other organs, the stomach receives dual spinal and vagal afferent innervation.

Distinct and common expression of receptors for inflammatory mediators in vagal nodose versus jugular capsaicin-sensitive/TRPV1-positive neurons detected by low input RNA sequencing.

Capsaicin-sensitive sensory C-fibers derived from vagal ganglia innervate the visceral organs, and respond to inflammatory mediators and noxious stimuli. These neurons play an important role in maintenance of visceral homeostasis, and contribute to the symptoms of visceral inflammatory diseases. Vagal sensory neurons are located in two ganglia, the jugular ganglia (derived from the neural crest), and the nodose ganglia (from the epibranchial placodes).

Control of Neurotransmission by NaV1.7 in Human, Guinea Pig, and Mouse Airway Parasympathetic Nerves.

Little is known about the neuronal voltage-gated sodium channels (NaVs) that control neurotransmission in the parasympathetic nervous system. We evaluated the expression of the subunits of each of the nine NaVs in human, guinea pig, and mouse airway parasympathetic ganglia. We combined this information with a pharmacological analysis of selective NaV blockers on parasympathetic contractions of isolated airway smooth muscle.

TRPM8 function and expression in vagal sensory neurons and afferent nerves innervating guinea pig esophagus.

Sensory transduction in esophageal afferents requires specific ion channels and receptors. TRPM8 is a new member of the transient receptor potential (TRP) channel family and participates in cold- and menthol-induced sensory transduction, but its role in visceral sensory transduction is still less clear. This study aims to determine TRPM8 function and expression in esophageal vagal afferent subtypes.

The expression profile of acid-sensing ion channel (ASIC) subunits ASIC1a, ASIC1b, ASIC2a, ASIC2b, and ASIC3 in the esophageal vagal afferent nerve subtypes.

Acid-sensing ion channels (ASICs) have been implicated in esophageal acid sensing and mechanotransduction. However, insufficient knowledge of ASIC subunit expression profile in esophageal afferent nerves hampers the understanding of their role. This knowledge is essential because ASIC subunits form heteromultimeric channels with distinct functional properties.

Selective inhibition of vagal afferent nerve pathways regulating cough using Nav 1.7 shRNA silencing in guinea pig nodose ganglia.

Adeno-associated virus delivery systems and short hairpin RNA (shRNA) were used to selectively silence the voltage-gated sodium channel NaV 1.7 in the nodose ganglia of guinea pigs. The cough reflex in these animals was subsequently assessed.

Comparison of TRPA1-versus TRPV1-mediated cough in guinea pigs.

TRPA1 receptor is activated by endogenous inflammatory mediators and exogenous pollutant molecules relevant to respiratory diseases. Previous studies have implicated TRPA1 as a drug target for antitussive therapy. Here we evaluated the relative efficacy of TRPA1 activation to evoke cough.

IGF2 expression in blood is not associated with its imprinting status in healthy pregnant Chinese women.

Loss of Imprinting (LOI) of IGF2 and over-expressed IGF2 are associated with tumorigenesis. Our previous epidemiological study found a relatively high frequency of IGF2 LOI in healthy mid-gestation pregnant women. The aim of this study is to determine whether the expression of IGF2 is associated with its imprinting status in healthy Chinese pregnant women.