Inhibitory innervation to the guinea pig trachealis muscle

1981 ◽  
Vol 50 (2) ◽  
pp. 374-382 ◽  
Author(s):  
P. Yip ◽  
B. Palombini ◽  
R. F. Coburn
Keyword(s):  
Muscle Tension ◽  
Nerve Fibers ◽  
Sympathetic Trunk ◽  
Dual Nature ◽  
Transmural Stimulation ◽  
Alpha Receptors ◽  
Neural Transmission ◽  
Cervical Trachea ◽  
Trachealis Muscle ◽  
Stimulation Of

The inhibitory innervation of the cervical trachea was studied in situ in anesthetized male guinea pigs. We measured effects of electrical stimulation of vagal motor and sympathetic trunk nerve fibers, during atropine, on trachealis muscle tension. Effects of direct transmural stimulation of trachealis muscle were also determined. We confirmed the dual nature of the inhibitory innervation to this muscle. Vagal motor inhibitory nerves are shown to be preganglionic. Neural transmission at the level of the ganglia is characterized by filtering of high frequency action potentials. The neurotransmitter at the myoneural junction is unidentified but is not norepinephrine. Maximal relaxation accounts for about 20-40% of maximal relaxations seen with transmural stimulation of trachealis muscle in the presence of atropine. Sympathetic trunk nerve fibers are also preganglionic. Neurotransmission at the level of the ganglia is apparently 1:1 at high-action potential frequencies. Norepinephrine released presynaptically has access to smooth muscle beta- but not alpha-receptors. Maximal adrenergic relaxations account for 60-80% of total transmural stimulation relaxations. Transmural stimulation relaxations appear to be accounted for by release of neurotransmitter from sympathetic adrenergic plus vagal nonadrenergic postganglionic nerve fibers.

ATP concentrations and muscle tension increase linearly with muscle contraction

2003 ◽  
Vol 95 (2) ◽  
pp. 577-583 ◽  
Author(s):  
Jianhua Li ◽  
Nicholas C. King ◽  
Lawrence I. Sinoway
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Contraction ◽  
Motor Nerve ◽  
Muscle Tension ◽  
Nerve Fibers ◽  
Ventral Root ◽  
Ventral Roots ◽  
Root Stimulation ◽  
Stimulation Of

Previous studies have suggested that activation of ATP-sensitive P2X receptors in skeletal muscle play a role in mediating the exercise pressor reflex (Li J and Sinoway LI. Am J Physiol Heart Circ Physiol 283: H2636–H2643, 2002). To determine the role ATP plays in this reflex, it is necessary to examine whether muscle interstitial ATP (ATPi) concentrations rise with muscle contraction. Accordingly, in this study, muscle contraction was evoked by electrical stimulation of the L7 and S1 ventral roots of the spinal cord in 12 decerebrate cats. Muscle ATPi was collected from microdialysis probes inserted in the muscle. ATP concentrations were determined by the HPLC method. Electrical stimulation of the ventral roots at 3 and 5 Hz increased mean arterial pressure by 13 ± 2 and 16 ± 3 mmHg ( P < 0.05), respectively, and it increased ATP concentration in contracting muscle by 150% ( P < 0.05) and 200% ( P < 0.05), respectively. ATP measured in the opposite control limb did not rise with ventral root stimulation. Section of the L7 and S1 dorsal roots did not affect the ATPi seen with 5-Hz ventral root stimulation. Finally, ventral roots stimulation sufficient to drive motor nerve fibers did not increase ATP in previously paralyzed cats. Thus ATPi is not largely released from sympathetic or motor nerves and does not require an intact afferent reflex pathway. We conclude that ATPi is due to the release of ATP from contracting skeletal muscle cells.

CATECHOLAMINE ANTAGONISM TO OXYTOCIN-INDUCED MILK-EJECTION

1971 ◽  
Vol 68 (1_Suppla) ◽  
pp. S5-S38 ◽  
Author(s):  
Helmuth Vorherr
Keyword(s):  
Receptor Blockade ◽  
Milk Ejection ◽  
Beta Adrenergic ◽  
Beta Receptor ◽  
Beta Receptors ◽  
Alpha Receptors ◽  
Adrenergic Blockers ◽  
Beta Receptor Blockade ◽  
Second Pain ◽  
Stimulation Of

ABSTRACT In lactating rats and rabbits the mode of antagonism of sympathomimetics, angiotensin or pain toward oxytocin-induced milk-ejection was investigated. In rats intra-arterial (intrafemoral) doses of 0.01–0.02 μg or intravenous (iv) doses of 0.1–0.5 μg of either epinephrine, isoproterenol, norepinephrine, angiotensin or 10 μg of phenylephrine injected simultaneously with, or 30 seconds before an oxytocin dose (10 μU intrafemoral, 300 μU iv) greatly inhibited or suppressed the oxytocin response. A 15 second pain stimulus caused moderate inhibition. With alpha-receptor blockade pain, epinephrine, isoproterenol, norepinephrine, phenylephrine and angiotensin inhibition were, respectively, 70%, 75%, 100%, 40%, 0% and 100%. Under beta-receptor blockade the corresponding values were 14%, 40%, 0%, 70%, 100% and 100%; with simultaneous intrafemoral injections neither catecholamine was inhibitory toward oxytocin. In corresponding rabbit experiments approximately 10-fold higher iv drug dosages were applied and similar results were observed. In both species, combined alpha and beta-receptor blockade nearly eliminated the antagonistic actions of sympathomimetics toward oxytocin, whereas angiotensin inhibition persisted unchanged. The results indicate: 1) Mammary myoepithelial cells contain beta-adrenergic receptors but no alpha-receptors; 2) Inhibition of oxytocin-induced milk-ejection by isoproterenol and phenylephrine is meditated through stimulation of myoepithelial beta-receptors (myoepithelial relaxation) and vascular alpha-receptors (vasoconstriction), respectively; 3) Epinephrine and norepinephrine inhibition of milk-ejection is due to stimulation of vascular alpha-receptors and myoepithelial beta-receptors; 4) Angiotensin effects are unrelated to adrenergic receptor mechanisms; 5) Administration of both alpha and beta-adrenergic blockers is desirable for stabilizing the sensitivity of the oxytocin milk-ejection assay preparation against interference from endogenous or exogenous catecholamines; 6) Other than using adrenergic blockers, pharmacologic doses of oxytocin can correct nursing difficulties in animals and man with hyperfunction of the adrenal-sympathetic system.

scholarly journals Selective stimulation of the ferret abdominal vagus nerve with multi-contact nerve cuff electrodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan A. Shulgach ◽  
Dylan W. Beam ◽  
Ameya C. Nanivadekar ◽  
Derek M. Miller ◽  
Stephanie Fulton ◽  
...  
Keyword(s):  
Vagus Nerve ◽  
Nerve Fibers ◽  
The Body ◽  
Evoked Responses ◽  
Gi Tract ◽  
Selective Stimulation ◽  
Nerve Cuff ◽  
Cuff Electrodes ◽  
Nerve Cuff Electrodes ◽  
Stimulation Of

AbstractDysfunction and diseases of the gastrointestinal (GI) tract are a major driver of medical care. The vagus nerve innervates and controls multiple organs of the GI tract and vagus nerve stimulation (VNS) could provide a means for affecting GI function and treating disease. However, the vagus nerve also innervates many other organs throughout the body, and off-target effects of VNS could cause major side effects such as changes in blood pressure. In this study, we aimed to achieve selective stimulation of populations of vagal afferents using a multi-contact cuff electrode wrapped around the abdominal trunks of the vagus nerve. Four-contact nerve cuff electrodes were implanted around the dorsal (N = 3) or ventral (N = 3) abdominal vagus nerve in six ferrets, and the response to stimulation was measured via a 32-channel microelectrode array (MEA) inserted into the left or right nodose ganglion. Selectivity was characterized by the ability to evoke responses in MEA channels through one bipolar pair of cuff contacts but not through the other bipolar pair. We demonstrated that it was possible to selectively activate subpopulations of vagal neurons using abdominal VNS. Additionally, we quantified the conduction velocity of evoked responses to determine what types of nerve fibers (i.e., Aδ vs. C) responded to stimulation. We also quantified the spatial organization of evoked responses in the nodose MEA to determine if there is somatotopic organization of the neurons in that ganglion. Finally, we demonstrated in a separate set of three ferrets that stimulation of the abdominal vagus via a four-contact cuff could selectively alter gastric myoelectric activity, suggesting that abdominal VNS can potentially be used to control GI function.

Contraction of dog trachealis muscle in vivo: role of alpha-adrenergic receptors

1980 ◽  
Vol 48 (2) ◽  
pp. 329-336 ◽  
Author(s):  
W. H. Beinfield ◽  
J. Seifter
Keyword(s):  
Adrenergic Receptors ◽  
Beta Blockers ◽  
Systemic Arterial Pressure ◽  
Alpha Adrenergic Receptors ◽  
Bilateral Vagotomy ◽  
Cervical Trachea ◽  
Spontaneously Breathing ◽  
Trachealis Muscle

Contraction, relaxation, and longitudinal tension were recorded by isometric strain gauge arches attached to cervical tracheal muscle (CTM) in 60 spontaneously breathing dogs anesthetized with pentobarbital. Intravenous norepinephrine (NE) (3 X 10(-9), 6 X 10(-9), 1.2 X 10(-8), and 2.4 x 10(-8) mol/kg) increased spontaneous mechanical activities (SMA) and caused dose related contraction of CTM in all dogs even though there was no pretreatment with beta-blockers. These activities were first potentiated by propranolol and then prevented by phentolamine. NE briefly decreased SMA and induced CTM relaxation prior to the onset of contraction in one-third of dogs. Propranolol prevented this initial relaxation. CTM responses induced by NE were 1) not significantly altered by atropine, tripelennamine, bilateral vagotomy, curarization, and complete tracheal transection below transducer sites; 2) unrelated to passive constriction of cervical trachea associated with airway elongation; and 3) independent of reflexes initiated by elevations of systemic arterial pressure. The moles per kilogram doses of acetylcholine were found to exceed those of NE when their intravenous administration caused equal CTM contractions in the same dog. These findings are consistent with the existence of alpha-adrenergic receptors in CTM.

Effects of pharyngeal lubrication on the opening of obstructed upper airway

1992 ◽  
Vol 72 (6) ◽  
pp. 2311-2316 ◽  
Author(s):  
H. Miki ◽  
W. Hida ◽  
Y. Kikuchi ◽  
T. Chonan ◽  
M. Satoh ◽  
...  
Keyword(s):  
Hypoglossal Nerve ◽  
Muscle Tone ◽  
Upper Airway ◽  
Intraluminal Pressure ◽  
Lower Airway ◽  
Before And After ◽  
Airway Opening ◽  
Cervical Trachea ◽  
Artificial Surfactant ◽  
Stimulation Of

We examined the effect of electrical stimulation of the hypoglossal nerve and pharyngeal lubrication with artificial surfactant (Surfactant T-A) on the opening of obstructed upper airway in nine anesthetized supine dogs. The upper airway was isolated from the lower airway by transecting the cervical trachea. Upper airway obstruction was induced by applying constant negative pressures (5, 10, 20, and 30 cmH2O) on the rostral cut end of the trachea. Peripheral cut ends of the hypoglossal nerves were electrically stimulated by square-wave pulses at various frequencies from 10 to 30 Hz (0.2-ms duration, 5–7 V), and the critical stimulating frequency necessary for opening the obstructed upper airway was measured at each driving pressure before and after pharyngeal lubrication with artificial surfactant. The critical stimulation frequency for upper airway opening significantly increased as upper airway pressure became more negative and significantly decreased with lubrication of the upper airway. These findings suggest that greater muscle tone of the genioglossus is needed to open the occluded upper airway with larger negative intraluminal pressure and that lubrication of the pharyngeal mucosa with artificial surfactant facilitates reopening of the upper airway.

Functional anatomy of the vagal innervation of the cervical trachea of the dog

2000 ◽  
Vol 89 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Robert L. Coon ◽  
Patrick J. Mueller ◽  
Philip S. Clifford
Keyword(s):  
Smooth Muscle ◽  
Vagus Nerve ◽  
Neural Control ◽  
Muscle Tone ◽  
Cuff Pressure ◽  
Vagal Innervation ◽  
Cervical Trachea ◽  
The Right ◽  
Left Vagus ◽  
Stimulation Of

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea. After establishment of tracheal tone, as indicated by increased cuff pressure, either the right or left vagus nerve was sectioned followed by section of the contralateral vagus. Sectioning the right vagus first resulted in total loss of tone in the cervical trachea, whereas sectioning the left vagus first produced either a partial or no decrease in tracheal tone. After bilateral section of the vagi, cuff pressure was recorded during electrical stimulation of the rostral end of the right or left vagus. At the maximum current strength used, stimulation of the left vagus produced tracheal constriction that averaged 28.5% of the response to stimulation of the right vagus (9.0 ± 1.8 and 31.6 ± 2.5 mmHg, respectively). In conclusion, the musculature of cervical trachea in the dog appears to be predominantly controlled by vagal efferents in the right vagus nerve.

Tetanic hyperpolarization of single medullated nerve fibers in sodium and lithium

1976 ◽  
Vol 231 (4) ◽  
pp. 1033-1038 ◽  
Author(s):  
GM Schoepfle
Keyword(s):  
Steady State ◽  
Interspike Interval ◽  
Nerve Fibers ◽  
Repetitive Stimulation ◽  
Time Dependent ◽  
Potassium Ions ◽  
Current Densities ◽  
Medullated Nerve Fiber ◽  
Sodium And Potassium ◽  
Stimulation Of

Repetitive stimulation of a single medullated nerve fiber of Xenopus yields a succession of postspike voltage-time curves which are nearly coincident until attainment of a voltage that corresponds to that of the maximum attained by the normal postspike undershoot. Initially the interspike potential returns toward a resting level after this brief phase of hyperpolarization. However, as tetanization proceeds, a pattern of hyperpolarization develops with the result that, in the tetanic steady state, there exists a progressive hyperpolarization throughout each interspike interval. Extent of postspike hyperpolarization in terms of a deviation deltaVm from the resting level of membrane potential is approximated by the variation deltaVm = delta[MNa + MK]/[GNa + GK] where MNa and MK are current densities associated with active pumping of sodium and potassium ions and GNa and GK are corresponding time-dependent leak conductances. Tetanic hyperpolarization is reversibly abolished by cyanide and by exposure to lithium Ringer. Eventual reappearance of tetanic hyperpolarization in the presence of lithium Ringer suggests lithium pumping.

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