Results of simulated mastication suggest existence of a periodontogastric motility reflex

1999 ◽  
Vol 78 (1) ◽  
pp. 29-35
Author(s):  
Mortimer Lorber
Keyword(s):  
Motor Activity ◽  
Gastric Motility ◽  
Periodontal Ligament ◽  
Masticatory Muscles ◽  
Maxillary Molars ◽  
Temporomandibular Joints ◽  
Trigeminal Neurons ◽  
Fasted Rats ◽  
Receptive Relaxation ◽  
Stimulation Of

Various reflexes inhibit gastric motor activity. Might a contrary one permit the oral region to increase gastric motility? Ten fasted rats were allowed to feed for 15 min. Following anesthesia and cannula insertion, antral pressure was recorded during three consecutive 5-min intervals: the baseline, procedure, and postprocedure periods. The procedure involved manually lowering and raising the mandible about once per second, causing repetitive molar occlusion. Doing this when food is in the stomach resembles conditions as the latter part of a meal is consumed. Gastric motor events increased from 1.10 ± 1.67 (mean ± SD) to 5.50 ± 4.12 per 5 min during the procedure (p < 0.05) and 5.80 ± 3.97 in the ensuing period (p < 0.05). The findings suggest an excitatory reflex following stimulation of mechanoreceptors in one or more sites related to mastication: the periodontium, temporomandibular joints, or masticatory muscles. Because rubbing the maxillary molars while the mouth remained constantly open also increased motor events, the periodontium is the most likely location of the receptors. They and associated trigeminal neurons would comprise the reflex's afferent arm. The vagi, perhaps with intermediaries, are its likely efferent arm. In these recently fed rats this reflex acts despite receptive relaxation and enterogastric reflexes to increase distal gastric motor activity.Key words: gastrointestinal motility, mastication, periodontal ligament.

ANTAGONISM BETWEEN INSULIN AND SELECTIVE ADRENERGIC AGONISTS ON THE GLYCOGEN SYNTHETASE AND PHOSPHORYLASE SYSTEMS OF THE ISOLATED RAT DIAPHRAGM

1975 ◽  
Vol 78 (2) ◽  
pp. 392-400
Author(s):  
Arne T. Hostmark ◽  
Ole Grønnerød ◽  
Robert S. Horn
Keyword(s):  
Glycogen Metabolism ◽  
Rat Diaphragm ◽  
Adrenergic Agonists ◽  
Adrenergic Stimulation ◽  
Insulin Effect ◽  
Glycogen Synthetase ◽  
Adrenergic Antagonists ◽  
Fasted Rats ◽  
Isolated Rat ◽  
Stimulation Of

ABSTRACT The antagonism between insulin and selective adrenergic stimulation on the converting systems for glycogen synthetase and phosphorylase has been investigated in the isolated rat diaphragm. Insulin significantly inhibited stimulation by terbutaline and noradrenaline of phosphorylase b to a conversion as well as stimulation of glycogen synthetase I to D conversion by these agents. The inhibition by insulin was stronger on the synthetase system than on the phosphorylase system. The insulin effect was not dependent upon the presence of glucose. In diaphragms from 24 h fasted rats the response of the phosphorylase system to both agonists decreased. Inhibition by insulin of terbutaline stimulated phosphorylase conversion was maintained upon fasting while no effect of insulin against stimulation by noradrenaline could be obtained in diaphragms from fasted rats. The effects of fasting and insulin were not influenced by beta adrenergic antagonists (practolol and butoxamine). The results indicate a difference in sensitivity of the synthetase and phosphorylase systems to insulin and suggest that noradrenaline and terbutaline influence glycogen metabolism by differing mechanisms.

Neural Patterns Associated with Ventilatory Movements in Dragonfly Larvae

1970 ◽  
Vol 52 (1) ◽  
pp. 167-175
Author(s):  
P. J. MILL
Keyword(s):  
Control System ◽  
Motor Activity ◽  
Action Potentials ◽  
Motor Units ◽  
The Other ◽  
Ventilatory Control ◽  
Expiratory Phase ◽  
Segmental Nerve ◽  
Ventral Muscle ◽  
Stimulation Of

1. Rhythmic bursts of motor activity associated with the expiratory phase of ventilation have been recorded from the second lateral segmental nerves of posterior abdominal ganglia in Aeshna and Anax larvae. 2. In Aeshna the rhythmic expiratory bursts contain one, or sometimes two, motor units; whereas in Anax there are almost invariably three units. In both animals only one unit is associated with action potentials in the respiratory dorso-ventral muscle. 3. Motor activity synchronized with the expiratory bursts in the second nerves has been recorded from the other lateral nerves and from the last unpaired nerve. In addition the fifth lateral nerves carry inspiratory bursts. 4. It has been confirmed that stimulation of a first segmental nerve can re-set the ventilatory rhythm by initiating an expiratory burst in the second nerves. The original frequency is immediately resumed on cessation of stimulation. 5. The nature of the ventilatory control system in dragonfly larvae is discussed in relation to other rhythmic systems in the arthropods.

scholarly journals Investigating activity of masticatory muscles in patients with hypermobile temporomandibular joints by using EMG

2015 ◽  
pp. e310-e315 ◽  
Author(s):  
A Davoudi ◽  
A Haghighat ◽  
O Rybalov ◽  
E Shadmehr ◽  
A Hatami
Keyword(s):  
Masticatory Muscles ◽  
Temporomandibular Joints

Effects of galvanic stimulation of the mastoid process on the gastric motility induced by caloric stimulation

1999 ◽  
Vol 26 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Byung Rim Park ◽  
Min Sun Kim ◽  
Moon Young Lee ◽  
Yong Ki Kim ◽  
Suck Chei Choi ◽  
...  
Keyword(s):  
Gastric Motility ◽  
Mastoid Process ◽  
Galvanic Stimulation ◽  
Caloric Stimulation ◽  
Stimulation Of

Employing the T-Scan/BioEMG III Synchronized Technologies to Diagnose and Treat Chronic Occluso-Muscle Disorder

2020 ◽  
pp. 362-514
Author(s):  
Robert B. Kerstein, DMD
Keyword(s):  
Periodontal Ligament ◽  
Temporomandibular Disorder ◽  
Surface Friction ◽  
Masticatory Muscles ◽  
Neural Activation ◽  
Clinical Implementation ◽  
Posterior Teeth ◽  
Occlusal Contact ◽  
Muscle Disorder ◽  
Time Reduction

This chapter discusses chronic occluso-muscle disorder, which is a myogenous subset of temporomandibular disorder (TMD) symptoms resultant from occlusally activated muscle hyperactivity. It also describes the computer-guided occluso-muscle disorder treatment known as disclusion time reduction (DTR), that studies repeatedly show reduces many common muscular temporomandibular disorder symptoms. T-Scan-based research since 1991 has determined that a significant etiologic component of occluso-muscle disorder is prolonged (in time) occlusal surface friction shared between opposing posterior teeth during mandibular excursions, that occurs in both normal chewing function and during parafunction. This friction results in prolonged compressions of the periodontal ligament (PDL) fibers of the involved teeth, which when in excursive opposing occlusal contact, also experience pulpal flexure that leads to pulpal neural activation, which together with the periodontal ligament compressions, trigger excess muscle contractions within the masticatory muscles. It is this unique neuroanatomy that incites and perpetuates many chronic muscular TMD symptomatology, that can be readily resolved in patients that meet the diagnostic criteria for DTR candidacy, using the ICAGD coronoplasty that is performed in the maximum intercuspal position (MIP), without employing treatment splints, deprogrammers, appliances, orthotics, or mandibular repositioning. Additionally, this chapter will highlight the newest disclusion time reduction therapy (DTR) studies that support the clinical implementation of this highly effective measured occlusal treatment for occluso-muscle disorder.

Relation of metabolic events to gastric contractions in the rat

1959 ◽  
Vol 197 (2) ◽  
pp. 269-273 ◽  
Author(s):  
Saovanee Sudsaneh ◽  
Jean Mayer
Keyword(s):  
Intravenous Administration ◽  
Gastric Motility ◽  
Carbohydrate Utilization ◽  
Quiescent Period ◽  
Exposure To Cold ◽  
Gastric Contractions ◽  
Fasted Rats ◽  
Balloon System

A water-filled balloon system was used to study gastric hunger contractions in normal rats. Fasted rats have active hunger contractions alternating with periods of quiescence. The contractions occur at a rate of one or two per minute for 10–15 minutes followed by a quiescent period of 5–10 minutes. Exposure to cold (5°C) and heat (32° and 40°C) inhibited gastric hunger contractions in fasted rats. Intravenous administration of 75 µg glucagon or i.v. injection of 50 µg epinephrine and norepinephrine also inhibited gastric hunger contractions. Cessation of the gastric motility also occurred when 100 µg glucagon or 50 µg epinephrine were given to fed animals pretreated with 2 u insulin. It was found that changes in carbohydrate utilization induced by glucagon preceded the gastric phenomena.

Responses of spinal trigeminal neurons to noxious stimulation of paranasal cavities – a rat model of rhinosinusitis headache

Cephalalgia ◽  
2020 ◽  
pp. 033310242097046
Author(s):  
Michael Koch ◽  
Julika Sertel-Nakajima ◽  
Karl Messlinger
Keyword(s):  
Potassium Chloride ◽  
Dura Mater ◽  
Paranasal Sinuses ◽  
Interstitial Fluid ◽  
Receptive Fields ◽  
Nasal Bone ◽  
Afferent Input ◽  
Noxious Stimulation ◽  
Trigeminal Neurons ◽  
Stimulation Of

Background The pathophysiology of headaches associated with rhinosinusitis is poorly known. Since the generation of headaches is thought to be linked to the activation of intracranial afferents, we used an animal model to characterise spinal trigeminal neurons with nociceptive input from the dura mater and paranasal sinuses. Methods In isoflurane anaesthetised rats, extracellular recordings were made from neurons in the spinal trigeminal nucleus with afferent input from the exposed frontal dura mater. Dural and facial receptive fields were mapped and the paranasal cavities below the thinned nasal bone were stimulated by sequential application of synthetic interstitial fluid, 40 mM potassium chloride, 100 µM bradykinin, 1% ethanol (vehicle) and 100 µm capsaicin. Results Twenty-five neurons with input from the frontal dura mater and responses to chemical stimulation of the paranasal cavities were identified. Some of these neurons had additional receptive fields in the parietal dura, most of them in the face. The administration of synthetic interstitial fluid, potassium chloride and ethanol was not followed by significant changes in activity, but bradykinin provoked a cluster of action potentials in 20 and capsaicin in 23 neurons. Conclusion Specific spinal trigeminal neurons with afferent input from the cranial dura mater respond to stimulation of paranasal cavities with noxious agents like bradykinin and capsaicin. This pattern of activation may be due to convergent input of trigeminal afferents that innervate dura mater and nasal cavities and project to spinal trigeminal neurons, which could explain the genesis of headaches due to disorders of paranasal sinuses.

Relation between duodenal alkaline secretion and motility in fasted and sham-fed dogs

1986 ◽  
Vol 251 (5) ◽  
pp. G591-G596 ◽  
Author(s):  
S. J. Konturek ◽  
P. Thor
Keyword(s):  
Motor Activity ◽  
Vagal Stimulation ◽  
Secretory Activity ◽  
Phase Iii ◽  
Plasma Gastrin ◽  
Marked Rise ◽  
Sham Feeding ◽  
Duodenal Motility ◽  
Alkaline Secretion ◽  
Stimulation Of

A relation between duodenal myoelectric and motor activity and alkaline secretion has been investigated in conscious dogs under basal conditions and following vagal excitation with and without pretreatment with atropine or indomethacin. It was found that duodenal alkaline secretion shows typical periodicity in phase with the myoelectric or motor activity of the duodenum, reaching a peak during phase III and a nadir during phase I of the migrating motor complex (MMC). Sham feeding interrupted the motor and secretory MMC cycle and caused a prolonged increase in duodenal myoelectric or motor activity as well as a sudden and marked rise in duodenal alkaline secretion accompanied by a significant elevation in plasma gastrin and pancreatic polypeptide. Atropine and indomethacin abolished the motor and secretory duodenal cycles and reduced basal alkaline secretion significantly. Atropine abolished, whereas indomethacin increased duodenal myoelectric or motor activity during basal conditions and after vagal stimulation. Neither atropine nor indomethacin abolished sham feeding-induced duodenal alkaline secretion. We conclude that duodenal alkaline secretion fluctuates cyclically in phase with duodenal motility, vagal excitation results in a potent stimulation of duodenal motor and secretory activity, and the mechanism of vagally induced duodenal alkaline secretion is only partly cholinergic and does not involve endogenous generation of prostaglandins.

Stimulation of growth of a colon cancer cell line by gastrin

1986 ◽  
Vol 251 (5) ◽  
pp. G597-G601 ◽  
Author(s):  
C. J. Kusyk ◽  
N. O. McNiel ◽  
L. R. Johnson
Keyword(s):  
Motor Activity ◽  
Cancer Cell Line ◽  
Secretory Activity ◽  
Colon Cancer Cell Line ◽  
Phase Iii ◽  
Marked Rise ◽  
Sham Feeding ◽  
Duodenal Motility ◽  
Alkaline Secretion ◽  
Stimulation Of

A relation between duodenal myoelectric and motor activity and alkaline secretion has been investigated in conscious dogs under basal conditions and following vagal excitation with and without pretreatment with atropine or indomethacin. It was found that duodenal alkaline secretion shows typical periodicity in phase with the myoelectric or motor activity of the duodenum, reaching a peak during phase III and a nadir during phase I of the migrating motor complex (MMC). Sham feeding interrupted the motor and secretory MMC cycle and caused a prolonged increase in duodenal myoelectric or motor activity as well as a sudden and marked rise in duodenal alkaline secretion accompanied by a significant elevation in plasma gastrin and pancreatic polypeptide. Atropine and indomethacin abolished the motor and secretory duodenal cycles and reduced basal alkaline secretion significantly. Atropine abolished, whereas indomethacin increased duodenal myoelectric or motor activity during basal conditions and after vagal stimulation. Neither atropine nor indomethacin abolished sham feeding-induced duodenal alkaline secretion. We conclude that duodenal alkaline secretion fluctuates cyclically in phase with duodenal motility, vagal excitation results in a potent stimulation of duodenal motor and secretory activity, and the mechanism of vagally induced duodenal alkaline secretion is only partly cholinergic and does not involve endogenous generation of prostaglandins.

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