Influence of vagus nerves on electrical activity of opossum small intestine

1980 ◽  
Vol 239 (5) ◽  
pp. G406-G410 ◽  
Author(s):  
J. S. Gidda ◽  
R. K. Goyal
Keyword(s):  
Small Intestine ◽  
Small Bowel ◽  
Electrical Activity ◽  
Vagal Stimulation ◽  
Silver Chloride ◽  
Slow Waves ◽  
Vagus Nerves ◽  
Vagal Control ◽  
Frequency Gradient

Experiments were performed in anesthetized opossums to study the nature of vagal control on the small bowel. Electrical activity was recorded in the duodenum, jejunum, and ileum with silver chloride electrodes. Slow waves and spike potentials were observed at all three sites. There was a decreasing frequency gradient of slow waves and the incidence of slow waves with spikes in the aboral direction. Vagotomy had no effect on the electrical activity. Vagal stimulation at threshold stimuli inhibited spike potentials in all three segments of small intestine, but slow waves were not affected. Vagal stimulation after sectioning of the gut proximal to the electrodes converted the response from inhibition to excitation. These studies suggest that a) vagus carries both excitatory and inhibitory influences to the small bowel; b) inhibitory influences are dominant in the intact opossum small intestine; and c) the nature of the response obtained with vagal stimulation may be explained on the basis of the paths taken by inhibitory and excitatory fibers.

Effect of secretin on electrical activity of small intestine

1975 ◽  
Vol 229 (2) ◽  
pp. 484-488 ◽  
Author(s):  
AK Mukhopadhyay ◽  
LR Johnson ◽  
EM Copeland ◽  
NW Weisbrodt
Keyword(s):  
Small Intestine ◽  
Small Bowel ◽  
Electrical Activity ◽  
Slow Wave ◽  
Intravenous Infusion ◽  
Action Potentials ◽  
Slow Waves ◽  
Wave Frequency ◽  
Conscious Dogs ◽  
Total Percentage

The effect of intravenously administered secretin (0.5, 2.0, 6.0 U/kg-h) and intraduodenal acidification (13.2 meq/h HCl) on the electrical activity of the small bowel of three conscious dogs with gastric and duodenal cannulas was observed. Electrical activity was recorded in fasted as well as fed conditions through silver wire electrodes implanted along the entire length of the small bowel. Intravenous infusion of secretin in all dosages and in all dogs delayed the onset of the interdigestive myoelectric complex and reduced the total percentage of slow waves with superimposed spike potentials. Intraduodenal acidification also inhibited the interdigestive myoelectric complex, which developed incompletely with fewer action potentials on slow waves. Secretin did not produce any alteration in the fed pattern of activity, slow-wave frequency, or the caudal migration of the interdigestive myoelectric complex. The present study indicates that the nuerohumoral mechanisms responsible for initiation of the interdigestive myoelectric complex may be different from those responsible for its caudal migration.

GASTROINTESTINAL HYPOMOTILITY IN MAGNESIUM-DEFICIENT SHEEP

1980 ◽  
Vol 60 (2) ◽  
pp. 293-301 ◽  
Author(s):  
L. BUENO ◽  
J. FIORAMONTI ◽  
E. GEUX ◽  
Y. RAISSIGUIER
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Electrical Activity ◽  
Digestive Tract ◽  
Experimental Period ◽  
Proximal Colon ◽  
Slow Waves ◽  
Deficient Diet ◽  
Intravenous Infusions ◽  
Spiking Activity

The electrical activity of the gastrointestinal tract and gallbladder was recorded in four sheep fed a Mg-deficient diet during 10 to 15 days. The mitigating effect of intravenous infusions of MgCl2 was tested at the end of the experimental period in animals presenting hypomagnesemia. Motility of the reticulo-rumen remained unchanged in Mg-deficient sheep except that there was no postprandial increased frequency of contractions. By contrast, the contractions of gallbladder, cecum and proximal colon were reduced in both amplitude and frequency. The amplitude but not the frequency of the antro-duodenal slow-waves was reduced. The amplitude of the regular spiking activity of the small intestine was reduced as well as the number of complexes produced per day. The activity of the spiral colon was correlated to the blood magnesium concentrations but Mg infusion was unable to restore immediately the motor profile of the rest of the gut to its intitial level. This was done within 2–3 days by changes in the diet in three of the four animals. It is concluded that the motility of the whole digestive tract, including the reticulo-rumen, is modified on a Mg-deficient diet and that hypomagnesemia, involved in the atony of the spiral colon, is only one of the factors responsible for the hypomotility.

Migrating spike complex in the small intestine of the fasting cat

1993 ◽  
Vol 265 (4) ◽  
pp. G619-G627
Author(s):  
W. C. De Vos
Keyword(s):  
Small Intestine ◽  
Action Potential ◽  
Electrical Activity ◽  
Slow Wave ◽  
Close Association ◽  
Slow Waves ◽  
Wave Frequency ◽  
Laboratory Animals ◽  
Variable Frequency ◽  
Implanted Electrodes

This study characterizes the migrating spike complex (MSC) in the small intestine of the awake fasting cat and compares the MSC with interdigestive activity in the small intestine of other species. Electrical activity in each of 12 cats with implanted electrodes showed MSCs, bands of spike potentials which attenuated slow-wave frequency and amplitude as the MSCs progressed distally. MSCs occurred at variable frequency with intervals ranging from < 1 min to > 5 h and averaged 51.2 +/- 2.8 (SE) min. MSCs migrated at 1-8 mm/s, accelerating distally; the duration decreased distally such that the length of the bowel in a burst (2-3 cm proximally) was conserved. The MSC was associated with an intense prolonged contraction of duration similar to that of the MSC. Sometimes the MSCs occurred in close association, and when an MSC period was < 5.7 min, the second MSC propagated at a slower rate than the first. Frequently, a brief series of slow wave-associated spikes preceded an MSC. MSCs were not associated with slow waves. The MSC differs in several respects from the migrating myoelectric complex of other laboratory animals and is more appropriately classified in a category that includes giant migrating spikes, prolonged propagated contractions, power contractions, and migrating action potential complexes.

Electrical activity of the longitudinal muscle of dog small intestine studied in vivo using microelectrodes

1960 ◽  
Vol 198 (1) ◽  
pp. 113-118 ◽  
Author(s):  
E. E. Daniel ◽  
A. J. Honour ◽  
A. Bogoch
Keyword(s):  
Small Intestine ◽  
Body Temperature ◽  
Action Potential ◽  
Electrical Activity ◽  
Longitudinal Muscle ◽  
Muscle Cells ◽  
Slow Waves

The electrical activity of longitudinal muscle cells of the small intestine of the dog have been recorded in vivo using microelectrodes. This activity is characterized by periodic slow depolarizations of from 3 to 15 mv starting from potentials of 35–50 mv. The frequency of these slow depolarizations is less in the ileum than in the jejunum and is diminished by reduction in body temperature. Asphyxia diminishes both frequency and amplitude of these slow depolarizations without affecting the resting potentials. Action potential spikes arise from the larger slow depolarizations. The records obtained in this study are compared with previously recorded monopolar extracellular records. It is concluded that the slow waves recorded using extracellular electrodes arise from slow depolarizations of intestinal muscle cells. It is proposed that these slow depolarizations are a coordinating mechanism for motility of the longitudinal muscle of the dog intestine. The mechanism of synchronization of the slow waves themselves remains to be elucidated.

scholarly journals The myogenic component in distention-induced peristalsis in the guinea pig small intestine

2001 ◽  
Vol 280 (3) ◽  
pp. G491-G500 ◽  
Author(s):  
Graeme Donnelly ◽  
Timothy D. Jackson ◽  
Krista Ambrous ◽  
Jing Ye ◽  
Adeel Safdar ◽  
...  
Keyword(s):  
Small Intestine ◽  
Guinea Pig ◽  
Slow Wave ◽  
Action Potentials ◽  
Slow Waves ◽  
Intraluminal Pressure ◽  
Control Activity ◽  
Potential Oscillations ◽  
Frequency Gradient

In an in vitro model for distention-induced peristalsis in the guinea pig small intestine, the electrical activity, intraluminal pressure, and outflow of contents were studied simultaneously to search for evidence of myogenic control activity. Intraluminal distention induced periods of nifedipine-sensitive slow wave activity with superimposed action potentials, alternating with periods of quiescence. Slow waves and associated high intraluminal pressure transients propagated aborally, causing outflow of content. In the proximal small intestine, a frequency gradient of distention-induced slow waves was observed, with a frequency of 19 cycles/min in the first 1 cm and 11 cycles/min 10 cm distally. Intracellular recording revealed that the guinea pig small intestinal musculature, in response to carbachol, generated slow waves with superimposed action potentials, both sensitive to nifedipine. These slow waves also exhibited a frequency gradient. In addition, distention and cholinergic stimulation induced high-frequency membrane potential oscillations (∼55 cycles/min) that were not associated with distention-induced peristalsis. Continuous distention produced excitation of the musculature, in part neurally mediated, that resulted in periodic occurrence of bursts of distally propagating nifedipine-sensitive slow waves with superimposed action potentials associated with propagating intraluminal pressure waves that caused pulsatile outflow of content at the slow wave frequency.

THE RELATIONSHIP BETWEEN ELECTRICAL AND MECHANICAL ACTIVITY OF THE SMALL INTESTINE OF DOG AND MAN

1960 ◽  
Vol 38 (7) ◽  
pp. 777-801 ◽  
Author(s):  
E. E. Daniel ◽  
B. T. Wachter ◽  
A. J. Honour ◽  
A. Bogoch
Keyword(s):  
Small Intestine ◽  
Electrical Activity ◽  
Slow Wave ◽  
Action Potentials ◽  
Extracellular Fluid ◽  
Slow Waves ◽  
Mechanical Activity ◽  
Electrical Currents ◽  
Bipolar Recording ◽  
Balloon Distention

Electrical activity of the small intestine of man and of dogs has been studied using monopolar recording techniques and spread of electrical activity in the small intestine of the dog using a bipolar recording technique. Motility was studied simultaneously. Electrical activity consisted of slow waves and action potentials which occurred when contractions were present. Action potentials were not conducted but slow waves sometimes spread aborally for short distances. Particular attention was paid to the relation of slow waves to action potentials and to motility. No consistent alteration in the frequency or configuration of slow waves was found associated with the occurrence of action potentials and motility, although serotonin or epinephrine altered slow wave frequency slightly. Slow waves usually were increased in amplitude during periods when motility and action potentials were occurring (during eating or balloon propulsion; after the administration of serotonin, neostigmine, physostigmine, or morphine). Slow wave amplitudes usually were diminished when motility was inhibited (by balloon distention; after administration of epinephrine, etc.). Action potentials tended to occur in phase with the slow waves, when the muscle electrode was positive relative to the indifferent electrode, but this was not always so during nonpropulsive contractions. There was also a correlation between the occurrence of distal spread of slow waves over the duodenum and upper jejunum and the ability of the intestine in this region to respond to balloon distention by propulsion.In the dog, body temperature consistently affected slow waves. A decrease of 10 °C diminished their frequencies to less than one-half and diminished their amplitude. Slow waves occurred at similar frequencies and with regular conduction after large doses of nicotine or atropine. Dibenzyline, dichloroisopropyl-norepinephrine, and vagotomy did not markedly alter slow wave frequencies. These findings and those in our studies with microelectrodes indicate that the slow waves are myogenic in origin, and represent electrical currents in the extracellular fluid initiated by periodic depolarizations of muscle cells of the small intestine.

A linked oscillator model of electrical activity of human small intestine

1975 ◽  
Vol 229 (2) ◽  
pp. 384-388 ◽  
Author(s):  
BH Brown ◽  
HL Duthie ◽  
AR Horn ◽  
RH Smallwood
Keyword(s):  
Small Intestine ◽  
Electrical Activity ◽  
Slow Wave ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Electronic Relaxation ◽  
Relaxation Oscillators ◽  
Human Small Intestine ◽  
A Chain ◽  
Frequency Gradient

The electrical slow-wave activity of the human small intestine has been simulated by a chain of 64 coupled electronic relaxation oscillators. The model simulates the frequency gradient of recorded patoentials in the human small intestine and when transected, behaves in a similar way to the transected canine small intestine. The model exhibits a spontaneous effect whereby several adjacent oscillators periodically are in the same state. This effect travels down the model in the time of 20-30 min.

Electrical activity of intestine recorded with pressure electrode

1961 ◽  
Vol 201 (1) ◽  
pp. 209-212 ◽  
Author(s):  
Alex Bortoff
Keyword(s):  
Small Intestine ◽  
Membrane Potential ◽  
Electrical Activity ◽  
Slow Wave ◽  
Spike Activity ◽  
Intestinal Motility ◽  
Wave Activity ◽  
Slow Waves ◽  
Reverse Effect ◽  
Naturally Occurring

The effects of certain autonomic and metabolic drugs on the electrical activity of the small intestine have been investigated, using the pressure electrode. Epinephrine inhibits spike activity and increases the membrane potential, without apparently altering the size of the slow waves. Acetylcholine has the reverse effect. The hyperpolarization produced by epinephrine is followed by a gradual depolarization which exceeds that of the membrane prior to its addition; this is not accompanied by the reappearance of spike activity. Large concentrations of epinephrine produce a waxing and waning of the amplitude of the slow waves. During inhibition by dinitrophenol, both acetylcholine and epinephrine can initiate slow wave activity. An explanation of naturally occurring waxing and waning is suggested, together with a mechanism relating the activity of the two muscle layers during normal intestinal motility.

Patterns of electrical activity in the digestive tract of the conscious cat

1982 ◽  
Vol 48 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Maurice Roche ◽  
Lionel Bueno ◽  
Monique Vagne ◽  
Christian Blourde
Keyword(s):  
Small Intestine ◽  
Electrical Activity ◽  
Digestive Tract ◽  
Slow Wave ◽  
Slow Waves ◽  
Fasting State ◽  
Bipolar Electrodes ◽  
Adult Cats ◽  
Spike Bursts ◽  
Spiking Activity

1. Bipolar electrodes were permanently implanted on the gastric antrum, and on the different portions of the small intestine of each of eleven healthy adult cats receiving one meal daily. All parts of the feline gut exhibited, as in several other species, regular slow waves and alternate periods of quiescence and electrical spiking activity during the recording sessions lasting from 10 to 30 d.2. Patterns of electrical activity characteristic of this species were identified. Both the amplitude and frequency of the antral slow-wave were related to the presence cf superimposed spike bursts during fasting decrease in the antral slow-wave frequency and increase in the length of the duodenal plateau of slow waves after the daily meal were related to its nature.3. In fasted state, the electrical spiking activity of the small intestine occurred as fused spike bursts of large amplitude potentials migrating slowly over short distances only 24 h after feeding. They are interspersed with short periods of irregular spiking activity.4. These findings suggested that, except the distal part of the small intestine which showed an activity which resembled partially the migrating myoelectric complex observed in other species during the fasting state, the motility patterns of the digestive tract in the cat were not comparable to those observed in the dog or sheep. In the cat, mixing of the contents seemed to result from more or less regular spiking activity allowing their propulsion distally. The propagation over distances varying from 200 to 1000 mm of nine to eighteen daily fused spike bursts in the fasting state remains unclear but they are related to the digestive function in accordance with the displacement aborally of their origin in a prolonged fasting condition.

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