Role of the various groups of afferent fibers of the mesenteric nerves in vasomotor reflexes

1976 ◽  
Vol 7 (4) ◽  
pp. 306-311
Author(s):  
E. V. Lukoshkova
Keyword(s):  
Afferent Fibers ◽  
Vasomotor Reflexes

1245: Role of C-Afferent Fibers and Monitoring of Intra Vesical Resiniferatoxin Therapy for Patients with Idiopathic Detrusor Overactivity

2004 ◽  
Vol 171 (4S) ◽  
pp. 328-328
Author(s):  
Teruhiko Yokoyama ◽  
Kunihiro Nozaki ◽  
Osamu Fujita ◽  
Miyabi Inoue ◽  
Hiromi Kumon
Keyword(s):  
Detrusor Overactivity ◽  
Idiopathic Detrusor Overactivity ◽  
Afferent Fibers

Role of 5-HT3 receptors and afferent fibers in the effects of mast cell degranulation on colonic motility in rats

1994 ◽  
Vol 107 (4) ◽  
pp. 976-984 ◽  
Author(s):  
Nathalie Castex ◽  
Jean Fioramonti ◽  
Marie JoséFargeas ◽  
Jean More ◽  
Lionel Bueno
Keyword(s):  
Mast Cell ◽  
Colonic Motility ◽  
Mast Cell Degranulation ◽  
Afferent Fibers

Role of ATP in the ROS-mediated laryngeal airway hyperreactivity induced by laryngeal acid-pepsin insult in anesthetized rats

2009 ◽  
Vol 106 (5) ◽  
pp. 1584-1592 ◽  
Author(s):  
Tung-Lung Tsai ◽  
Shyue-Yih Chang ◽  
Ching-Yin Ho ◽  
Yu Ru Kou
Keyword(s):  
Critical Role ◽  
Airway Hyperreactivity ◽  
P2x Receptor ◽  
Major Type ◽  
Radical Scavenger ◽  
Ammonia Vapor ◽  
Anesthetized Rats ◽  
Afferent Fibers ◽  
Laryngeal Airway

The pathogenetic mechanisms of laryngeal airway hyperreactivity (LAH) in patients with extraesophageal reflux are unclear. We recently reported that a laryngeal acid-pepsin insult produces LAH that is mediated through sensitization of the capsaicin-sensitive laryngeal afferent fibers by reactive oxygen species (ROS) in rats. Since ROS may promote the release of ATP from cells, we hypothesized that activation of P2X purinoceptors by ATP subsequent to an increase in ROS induces LAH in an inflamed larynx that has been insulted by acid-pepsin or H2O2 (a major type of ROS). The larynxes of 208 anesthetized rats were functionally isolated while the animals breathed spontaneously. Ammonia vapor was delivered into the larynx to measure laryngeal reflex reactivity. Laryngeal insult with acid-pepsin or H2O2 produced LAH with similar characteristics. The H2O2-induced LAH was prevented by laryngeal pretreatment with dimethylthiourea (a hydroxyl radical scavenger), suggesting a critical role for ROS. The LAH induced by both insults were completely prevented by ATP scavengers (a combination of apyrase and adenosine deaminase) or a P2X receptor antagonist ( iso-pyridoxalphosphate-6-azophenyl-2′,5′-disulfonate). Laryngeal application of a P2X receptor agonist (α,β-methylene-ATP) also produced LAH. An insult with either acid-pepsin or H2O2 similarly promoted an increase in the levels of ATP, lipid peroxidation, and inflammation in the larynx. Our findings suggest that laryngeal insult with acid-pepsin or H2O2 induces inflammation and produces excess ROS in the rat's larynx. The latter may in turn promote the release of ATP to activate P2X receptors, resulting in sensitization of capsaicin-sensitive laryngeal afferent fibers and LAH.

scholarly journals Analysis of Compound Postsynaptic Potentials in the Central Nervous System of the Surf Clam

1967 ◽  
Vol 50 (3) ◽  
pp. 759-778 ◽  
Author(s):  
DeForest Mellon
Keyword(s):  
Individual Component ◽  
Membrane Conductance ◽  
Afferent Input ◽  
Characteristic Mode ◽  
Surf Clam ◽  
Postsynaptic Potentials ◽  
Afferent Fibers ◽  
The Central Nervous System ◽  
Rates Of Decay

Compound postsynaptic potentials, comprising graded excitatory-inhibitory sequences, are the characteristic mode of response to afferent input exhibited by a population of cells in the visceroparietal ganglion of Spisula. Experimentally induced interaction between the phases of the response indicates that the observed sequential invasion represents differences in individual component latencies, rather than the physiological resultant of two separate processes having simultaneous onset but different rates of decay. Excitation is depressed by changes in membrane conductance throughout the duration of the inhibitory phase; moreover, since similar pathways from the periphery initiate both phases, excitatory events are limited to a duration roughly equal in length to the latency for the inhibition. Within this interval repetitive volleys can evoke summation of excitatory events. The inhibitory mechanism is temporally stable, however, and dominates the membrane during repetitive trains of volleys at 1 to 100 per sec. Artificially generated increases in the membrane potential decrease the IPSP while increasing the amplitude of the EPSP. Thus, both phases of the compound response appear to result from events occurring at chemically transmitting synaptic loci. Evidence is presented that these events are driven via collaterals of the same afferent fibers. The behavioral role of these response sequences is uncertain. Analogies, in terms of some observed reflex activity in these clams, appear to exist but presently lack experimental verification.

Role of the Subsequently Activated Receptors in Electro-Acupuncture of the Rat

1981 ◽  
Vol 09 (02) ◽  
pp. 164-170 ◽  
Author(s):  
Kenji Kawakita ◽  
Masaya Hwa
Keyword(s):  
Common Peroneal Nerve ◽  
Muscular Contraction ◽  
Tail Flick ◽  
Acupuncture Analgesia ◽  
Direct Excitation ◽  
Afferent Fibers ◽  
Weak Intensity ◽  
Weak Stimulation ◽  
Subsequent Activation

Role of the subsequently excited receptors elicited by tetanic muscular contraction in electro-acupuncture analgesia was examined. Conditioning stimulation of the nerve (CPN) as well as electro-acupuncture induced a significant delay of the tail flick latencies of the rat with weak intensity of stimulus (1.01-1.5 x DFT), and this effect was abolished after section of the nerve at a point distal to the stimulating electrode. Electrophysiological data indicate that a small amplitude of the A large fiber group's potential was recorded with the intensity range of 1.0-1.5 x DFT. These facts suggest that the analgesic effect induced by weak stimulation is not the result of direct excitation of afferent fibers but the result of subsequent activation of receptors provoked by tetanic muscular contraction. The possible receptors are proposed and their participation in acupuncture analgesia also discussed. CPN = the common peroneal nerve; DFT = dorsal flexion threshold (1.0 x DFT = 1.15 x Tα).

Learned flavor preferences induced by intragastric administration of rewarding nutrients: role of capsaicin-sensitive vagal afferent fibers

2007 ◽  
Vol 293 (2) ◽  
pp. R635-R641 ◽  
Author(s):  
Maria A. Zafra ◽  
Filomena Molina ◽  
Amadeo Puerto
Keyword(s):  
Physiological Saline ◽  
Tween 80 ◽  
Daily Basis ◽  
Preference Learning ◽  
Intragastric Administration ◽  
Flavor Preference ◽  
Afferent Pathways ◽  
Afferent Fibers ◽  
Vagal Afferent

Learned flavor preferences can be established after intragastric nutrient administration by two different behavioral procedures, concurrent and sequential. In a concurrent procedure, two flavored stimuli are offered separately but at the same time on a daily basis: one stimulus is paired with the simultaneous intragastric administration of partially digested food and the other with physiological saline. In sequential learning, the two stimuli are presented during alternate sessions. Neural mechanisms underlying these learning modalities have yet to be fully elucidated. The aim of this study was to examine the role of vagal afferent fibers in the visceral processing of rewarding nutrients during concurrent ( experiment 1) and sequential ( experiment 2) flavor preference learning in Wistar rats. For this purpose, capsaicin, a neurotoxin that destroys slightly myelinated or unmyelinated sensory axons, was applied to the subdiaphragmatic region of the esophagus to selectively damage most of the vagal afferent pathways that originate in the gastrointestinal system. Results showed that capsaicin [1 mg of capsaicin dissolved in 1 ml of vehicle (10% Tween 80 in oil)] blocked acquisition of concurrent but not sequential flavor preference learning. These results are interpreted in terms of a dual neurobiological system involved in processing the rewarding effects of intragastrically administered nutrients. The vagus nerve, specifically capsaicin-sensitive vagal afferent fibers, would only be essential in concurrent flavor preference learning, which requires rapid processing of visceral information.

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