Control of movements of the stomach and spiral intestine of Raja and Scyliorhinus

1983 ◽  
Vol 63 (3) ◽  
pp. 557-574 ◽  
Author(s):  
J. Z. Young
Keyword(s):  
Vagus Nerve ◽  
Sympathetic Nerves ◽  
Slight Reduction ◽  
High Concentration ◽  
Spiral Intestine ◽  
Cardiac Stomach ◽  
Excitatory Response ◽  
Acetyl Choline ◽  
Spontaneous Contractions ◽  
Stimulation Of

The extrinsic nerves of the stomach of dogfish and skates regulate the frequency and amplitude of contraction by inhibition followed by rebounds. By contrast the nerves of the spiral intestine are excitatory.Stimulation of the vagus nerve of the ray produced slight reduction in the amplitude of spontaneous contractions of the cardiac stomach. Much greater inhibition was produced by stimulation of the sympathetic nerves and was followed by large rebound contractions. These effects were imitated by adrenalin and serotonin which altered the frequency and amplitude of contraction in various ways. These actions were not blocked by either propranalol (1–5 × 10−5 M) or phentolamine (2 × 10−5 M) and indeed were often increased. The excitatory response to adrenalin was not blocked by TTX even after this had blocked the response to the nerve. Responses both to the nerve and adrenaline were blocked by trazodone. Acetyl choline caused some contraction of the stomach but only at high concentration.Muscles of the spiral intestine of Raja or Scyliorhinus were activated by stimulation of their sympathetic nerves and by adrenalin. These responses were not blocked by phentolamine and only reduced by propranalol They were blocked by trazodone. The response to adrenalin continued after the nerve was blocked by TTX. Acetyl choline had very little effect on the spiral intestine.The striking differences between the responses of the stomach and intestine are probably related to the fact that the plexus in the latter contains no nerve cells. The neurons in the stomach are therefore presumbly connected with the inhibition and large rebound contractions.

Increased activity of carotid sinus baroreceptors by sympathetic stimulation and norepinephrine

1981 ◽  
Vol 240 (4) ◽  
pp. H650-H658 ◽  
Author(s):  
E. Tomomatsu ◽  
K. Nishi
Keyword(s):  
Carotid Sinus ◽  
Sympathetic Innervation ◽  
Sympathetic Nerves ◽  
Nerve Endings ◽  
Discharge Frequency ◽  
Sympathetic Stimulation ◽  
High Concentration ◽  
Excitatory Effect ◽  
Pressure Step ◽  
Stimulation Of

Effects of electrical stimulation of sympathetic nerves to the carotid sinus on the discharge of single active baroreceptor fibers of the rabbit were examined in situ and in functionally isolated carotid sinus preparations with an intact sympathetic innervation under controlled conditions of pressure and temperature. Among 30 single units, 18 units responded to sympathetic stimulation of increasing discharge frequency. The excitatory effect of sympathetic stimulation on baroreceptor activity was not abolished by phentolamine (1 mg/kg iv or 10(-6) g/ml in perfusate). In isolated carotid sinus preparations perfused with Krebs-Henseleit solution, various pressure steps were applied to the sinus, and effects of norepinephrine (NE; 10(-9) and 10(-6) g/ml) on activity of nine single baroreceptor units were examined. In the presence of 10(-9) g/ml NE, discharge frequency of all units significantly increased at a given pressure step when compared with the control, whereas NE at a high concentration (10(-6) g/ml) did not produce significant changes in the discharge frequency. It is concluded that NE released by sympathetic nerve endings most likely acts directly on the baroreceptor nerve endings and sensitizes them.

Supersensitivity to l-norepinephrine of the denervated sinoatrial node

1965 ◽  
Vol 208 (2) ◽  
pp. 255-259 ◽  
Author(s):  
David E. Donald ◽  
John T. Shepherd
Keyword(s):  
Vagus Nerve ◽  
Sinoatrial Node ◽  
Sinus Node ◽  
Sympathetic Nerves ◽  
Cardiac Denervation ◽  
Cervical Vagotomy ◽  
Cervical Ganglia ◽  
The Right ◽  
Cardiac Nerves ◽  
Stimulation Of

Following attempted denervation of the heart by the technic of regional neural ablation, dogs with incomplete cardiac denervation were shown to have the same supersensitivity to l-norepinephrine as dogs in which the denervation of the heart was complete. Dogs with chronic bilateral stellate ganglionectomy or those pretreated with reserpine had cardiac acceleration in response to the administration of tyramine or to stimulation of the stellate cardiac nerves, but did not demonstrate supersensitivity to l-norepinephrine. No supersensitivity was seen in dogs with chronic bilateral cervical vagotomy. Excision of the right stellate and caudal cervical ganglia and the immediately adjacent right vagus nerve resulted in supersensitivity to l-norepinephrine. In these animals cardiac acceleration resulted from stimulation of the left stellate cardiac nerves or from the administration of tyramine. The supersensitivity was lost after excision of the sinoatrial node. It is concluded that one can uniquely denervate the sinus node and that dogs so treated will develop supersensitivity to l-norepinephrine despite the presence of functional sympathetic nerves to the rest of the heart.

Gastric motility patterns for digestion and vomiting evoked by sympathetic nerve stimulation and 5-hydroxytryptamine in the dogfish Scyliorhinus canicula

1993 ◽  
Vol 342 (1302) ◽  
pp. 363-380 ◽  
Keyword(s):  
Contractile Activity ◽  
Circular Muscle ◽  
Video Tape ◽  
Spiral Intestine ◽  
Cardiac Stomach ◽  
Scyliorhinus Canicula ◽  
Pyloric Region ◽  
Cardiac Region ◽  
Gastric Pressure ◽  
Stimulation Of

The sympathetic control of motor activity in the stomach of the dogfish Scyliorhinus canicula and its pharmacology was studied in freshly killed animals with the abdominal viscera superfused in situ with elasmobranch Ringer by recording gastric pressure and by quantitative analysis of video-tape recordings of the activity. Little spontaneous activity was seen in the stomach, although in two animals retrograde contractions occurred in the spiral intestine. The effects of electrical stimulation of the splanchnic (sympathetic) nerves varied markedly with frequency. At 4 Hz after a latency of about 1 min there was a slight increase in the overall level of contractile activity in both cardiac and pyloric regions of the stomach, which persisted throughout the stimulation period (5-7 min). At 16 Hz a contraction was visible in the pyloric region within 10 s of the start of stimulation. Over the next 30 s this contraction proceeded cranially becoming more powerful as it swept into the cardiac region. This contraction returned the contents of the pyloric stomach to the cardiac stomach past the valve-like junction between them. This contraction continued into the cardiac stomach and in some animals propelled the contents into the oesophagus. About 2 min after the start of stimulation there followed a series of contractions in both gastric regions, predominantly in the circular muscle. In the cardiac region these contractions occurred alternately in the proximal and distal regions. Occasionally a large contraction passed a bolus of material from the cardiac to the pyloric region. No movements or pressure changes were observed in the stomach after stimulation of the vagus, although contractions were readily induced in the oesophagus. It is proposed that the initial large retrograde contraction provides a mechanism by which the animal can vomit indigestible or accidentally ingested material. In contrast the later motor patterns suggest that this type of activity is involved in more normal digestive functions of mixing food with gastric secretions, trituration and gastric emptying. Evidence is presented which implicates 5-hydroxytryptamine as a principal neurotransmitter involved in the genesis of the retrograde contraction by the splanchnic nerve.

Memoirs: The Autonomic Nervous System of Selachians

1933 ◽  
Vol s2-75 (300) ◽  
pp. 571-624
Author(s):  
JOHN Z. YOUNG
Keyword(s):  
Sympathetic Nerves ◽  
Sympathetic Ganglia ◽  
Cardiac Stomach ◽  
Splanchnic Nerves ◽  
Motor Neurones ◽  
Colon And Rectum ◽  
Motor Cells ◽  
Pyloric Stomach ◽  
Pass Through ◽  
Stimulation Of

1. The rami cornmunicantes of Selachians contain only preganglionic fibres; there are no recurrent grey rami and therefore no sympathetic nerves to the skin, chromatophores, or somatic muscles. This probably accounts for the absence of the sympathetic from the head and tail regions. 2. In accordance with (1) it was found that cutting of the spinal nerves produced no local colour changes in the skin, neither was adrenaline found to have any action on the chromatophores. 3. There are no long pre- or post-ganglionic pathways in the sympathetic and therefore no true sympathetic chains, though the ganglia of adjoining segments are sometimes connected. The arrangement is thus more nearly segmental than that of Teleosts or Tetrapods. 4. No sympathetic ganglia were found in the tail of adult Scyllium or Torpedo, but in embryos of these forms scattered motor neurones were found in connexion with the caudal blood-vessels. 5. Stimulation of the vagus caused movements of the cardiac stomach, of the anterior splanchnic nerves movements of the pylorus and pyloric stomach. Stimulation of the middle and posterior splanchnic nerves caused movements of the intestine, colon, and rectum. Pinching the intestine evoked a characteristic progressive reflex contraction, ending in the extrusion of faeces. 6. The posterior suprarenal bodies differ in the two sexes, those of the male being much the larger, although the number of cells giving the chrome reaction is the same in both. 7. The suprarenal tissue is very plentifully supplied with post-ganglionic fibres, which could be seen actually in connexion with their cell-bodies. The hypothesis of Elliott that the chromophil cells themselves represent post-ganglionics is therefore disproved in this case. 8. The structure of the autonomic neurones is described in detail, especially the methods by which contacts are made between them. 9. No motor cells were found in the vagus ganglion of embryo or adult Scyllium, but they do occur on the post-trematic rami of all the branchial nerves. 10. A small profundus nerve was found to be present in Scyllium, though not in all individuals. 11. There is little evidence for the existence in fish of functionally antagonistic sympathetic and parasympathetic systems, and it is suggested that these systems in Tetrapods represent specializations within a single segmental set of visceral motor fibres, running primarily through the dorsal roots but coming to pass through the ventral roots in those segments in which the roots join.

scholarly journals Phagocytic activity of leukocytes in peptic ulcer and stomach cancer

2021 ◽  
Vol 43 (2) ◽  
pp. 77-77
Author(s):  
G. M. Nikolaev
Keyword(s):  
Peptic Ulcer ◽  
Vagus Nerve ◽  
Stomach Cancer ◽  
Phagocytic Activity ◽  
Sympathetic Nerves ◽  
Perfusion Fluid ◽  
Blood Leukocytes ◽  
Stimulation Of

N.V. Puchkov and G.G. Golodets found that the perfusion fluid collected during stimulation of the frog's sympathetic nerves (sympathy) increased the phagocytic activity of blood leukocytes, and that collected during irritation of the vagus nerve (acetylcholine) decreased ... These data were later confirmed by other researchers (S. M. Titova, R. U. Lipshitz, A. D. Ado et al., Etc.).

A prejunctional mechanism in midbrain periaqueductal gray inhibition of vagal bradycardia in rats

1996 ◽  
Vol 270 (2) ◽  
pp. R373-R382 ◽  
Author(s):  
S. Nosaka ◽  
K. Inui ◽  
S. Murase ◽  
K. Murata
Keyword(s):  
Vagus Nerve ◽  
Acetylcholine Release ◽  
Periaqueductal Gray ◽  
Dependent Manner ◽  
Acetyl Choline ◽  
Aortic Depressor Nerve ◽  
Long Latency ◽  
Peripheral Mechanism ◽  
Vagal Bradycardia ◽  
Stimulation Of

Stimulation of the dorsal part of the midbrain periaqueductal gray matter (dPAG) inhibits baroreflex vagal bradycardia (BVB) via a central mechanism. Here we report that the dPAG suppresses vagal bradycardia also by a peripheral mechanism. In chloralose-urethan-anesthetized, beta-blocked rats, the cervical vagus nerve was cut and the distal cut end was electrically stimulated to induce vagal bradycardia (VIB). Sustained electrical stimulation of the dPAG attenuated VIB in a duration-dependent manner but did not affect bradycardia induced by intravenous acetyl-choline (AIB). The dPAG inhibition of VIB was abolished by C1 transection. Intravenous norepinephrine (NE) reduced VIB but did not affect AIB. Both the dPAG and NE inhibitions of VIB were largely attenuated during intravenous prazosin, a selective alpha 1-receptor antagonist. In contrast, BVB provoked by aortic depressor nerve stimulation was remarkably inhibited by a shortly preceding dPAG stimulation, but this inhibition was not affected by C1 transection. Prazosin treatment did reduced the inhibition, but only moderately. In conclusion, the dPAG has a potential ability to suppress VIB by prejunctionally inhibiting acetylcholine release from cardiac vagus nerve terminals via alpha 1-receptors. However, dPAG stimulation first suppresses BVB largely at a central site, leaving a limited fraction of vagal outflow to be inhibited by a prejunctional mechanism operating with long latency.

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.

Peripheral muscarinic control of norepinephrine release in the cardiovascular system

1980 ◽  
Vol 239 (6) ◽  
pp. H713-H720 ◽  
Author(s):  
E. Muscholl
Keyword(s):  
Physiological Role ◽  
Sympathetic Nerves ◽  
Adrenergic Nerve ◽  
Sequence Of Events ◽  
Adrenergic Response ◽  
Adrenergic Nerve Terminals ◽  
Muscarinic Cholinergic ◽  
Related Compounds ◽  
Stimulation Of

Activation of muscarinic cholinergic receptors located at the terminal adrenergic nerve fiber inhibits the process of exocytotic norepinephrine (NE) release. This neuromodulatory effect of acetylcholine and related compounds has been discovered as a pharmacological phenomenon. Subsequently, evidence for a physiological role of the presynaptic muscarinic inhibition was obtained on organs known to be innervated by the autonomic ground plexus (Hillarp, Acta. Physiol. Scand. 46, Suppl. 157: 1-68, 1959) in which terminal adrenergic and cholinergic axons run side by side. Thus, in the heart electrical vagal stimulation inhibits the release of NE evoked by stimulation of sympathetic nerves, and this is reflected by a corresponding decrease in the postsynaptic adrenergic response. On the other hand, muscarinic antagonists such as atropine enhance the NE release evoked by field stimulation of tissues innervated by the autonomic ground plexus. The presynaptic muscarine receptor of adrenergic nerve terminals probably restricts the influx of calcium ions that triggers the release of NE. However, the sequence of events between recognition of the muscarinic compound by the receptor and the process of exocytosis still remains to be clarified.

Electrical Stimulation of the Vagus Nerve Modulates the Development of Oxygen Epilepsy in Rabbits

2017 ◽  
Vol 47 (3) ◽  
pp. 345-351
Author(s):  
S. Yu. Zhilyaev ◽  
A. N. Moskvin ◽  
T. F. Platonova ◽  
I. T. Demchenko
Keyword(s):  
Electrical Stimulation ◽  
Vagus Nerve ◽  
Stimulation Of
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