scholarly journals Activity of aortic chemoreceptors during electrical stimulation of the stellate ganglion in the cat

1968 ◽  
Vol 199 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Elliott Mills
Keyword(s):  
Electrical Stimulation ◽  
Stellate Ganglion ◽  
Stimulation Of

Effect of changes in myocardial epinephrine stores on plasma norepinephrine gradient across the dog heart

1994 ◽  
Vol 266 (6) ◽  
pp. H2404-H2409 ◽  
Author(s):  
F. Peronnet ◽  
G. Boudreau ◽  
J. de Champlain ◽  
R. Nadeau
Keyword(s):  
Electrical Stimulation ◽  
Adrenal Medulla ◽  
Pulse Width ◽  
Stellate Ganglion ◽  
Plasma Norepinephrine ◽  
Direct Support ◽  
Left Stellate Ganglion ◽  
Ici 118,551 ◽  
Beta 2 ◽  
Stimulation Of

Plasma norepinephrine (NE) concentration ([NE]) gradient across the heart was measured under electrical stimulation of the left stellate ganglion (LSG; 4 Hz, 4 V, 2 ms pulse width, 1 min) in control (Ctrl) and in adrenalectomized (Adrx) dogs, without and with a 10-min epinephrine (Epi) infusion (92 ng.kg-1.min-1), which partly restored myocardial Epi stores in Adrx dogs (2.9 +/- 0.7 ng/g vs. 6.4 +/- 0.7 ng/g in Ctrl dogs) and slightly increased tissue Epi stores in Ctrl dogs (10.5 +/- 1.3 pg/g). Compared with Ctrl dogs (1,069 +/- 172 pg/ml), the [NE] gradient across the heart under stimulation of the LSG was not modified 1 wk after bilateral adrenalectomy (1,190 +/- 122 pg/ml) or after Epi infusion in Ctrl (1,134 +/- 276 pg/ml) and Adrx (1,259 +/- 279 pg/ml) dogs. The beta 2-antagonist ICI-118,551 significantly reduced the stimulation-induced [NE] gradient across the heart in Ctrl dogs (621 +/- 190 and 603 +/- 86 pg/ml without and with a 10-min Epi infusion, respectively) but not in Adrx dogs deprived of tissue Epi (1,345 +/- 345 pg/ml). Partial repletion of myocardial Epi stores in Adrx dogs restored the effect of ICI-118,551 on the stimulation-induced [NE] gradient (776 +/- 121 pg/ml). These results provide direct support of the hypothesis that tissue Epi, which originates from the adrenal medulla and which is released locally along with NE, is the endogenous agonist for presynaptic beta 2-receptors and potentiates NE release.

Responses of medullary raphespinal neurons to electrical stimulation of thoracic sympathetic afferents, vagal afferents, and to other sensory inputs in cats

1991 ◽  
Vol 66 (6) ◽  
pp. 2084-2094 ◽  
Author(s):  
R. W. Blair ◽  
A. R. Evans
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Activity ◽  
Vagal Stimulation ◽  
Discharge Rate ◽  
Stellate Ganglion ◽  
Cell Activity ◽  
Conditioning Stimulus ◽  
Vagal Afferents ◽  
Early Peak ◽  
Stimulation Of

1. Medullary raphespinal neurons antidromically activated from the T2-T5 segments were tested for responses to electrical stimulation of cervical vagal and thoracic sympathetic afferents (by stimulating the left stellate ganglion), somatic probing, auditory stimuli, and visual stimuli in cats anesthetized with alpha-chloralose. A total of 99 neurons in the raphe nuclei were studied; the locations of 76 cells were histologically confirmed. Neurons were located in raphe magnus (RM, 65%), raphe obscurus (RO, 32%), and raphe pallidus (RPa, 4%). The mean conduction velocity of these neurons was 62 +/- 2.9 (SE) m/s with a range of 1.1-121 m/s. 2. A total of 60/99 tested neurons responded to electrical stimulation of sympathetic afferents. Quantitation of responses was obtained for 55 neurons. With one exception, all responsive neurons were excited and exhibited an early burst of spikes with a mean latency of 16 +/- 1.2 ms. From a spontaneous discharge rate of 5.2 +/- 1.2 spikes/s, neuronal activity increased by 2.9 +/- 0.3 spikes/stimulus. In addition to an early peak, 15 neurons (25%) exhibited a late burst of spikes with a latency of 182 +/- 12.9 ms; neuronal activity increased by 5.0 +/- 1.3 spikes/stimulus. Duration of the late peak (130 +/- 18.5 ms) was longer than for the early peak (18 +/- 0.7 ms), but threshold voltages for eliciting each peak were comparable. Sixteen of 29 spontaneously active neurons exhibited a postexcitatory depression of activity that lasted for 163 +/- 19.1 ms. All but one tested neuron in RO responded to stimulation of sympathetic afferents, but 65% of neurons in RM responded to this stimulus. 3. In response to vagal afferent stimulation, 19% of 57 neurons exhibited inhibition only, 11% were only excited, and 9% were either excited or inhibited, depending on the stimulus paradigm used; the remaining 61% of neurons were unresponsive. From a spontaneous rate of 7.9 +/- 3.8 spikes/s, excited cells increased their discharge rate by 1.6 +/- 0.3 spikes/stimulus. Activity of inhibited cells was reduced from 21.3 +/- 5.8 to 7.8 +/- 3.1 spikes/s. The conditioning-test (CT) technique was used to assess 11 neurons' responses. Stellate ganglion stimulation was the test stimulus, and vagal stimulation the conditioning stimulus. Vagal stimulation reduced the neuronal responses to stellate ganglion stimulation by an average of 50% with a CT interval of 60-100 ms, and cell responses returned to control after 300 ms. With spontaneous cell activity, low frequencies of vagal stimulation were generally excitatory, and high frequencies (10-20 Hz) inhibitory.(ABSTRACT TRUNCATED AT 400 WORDS)

ATP as a source of interstitial adenosine in the rat heart

1999 ◽  
Vol 77 (8) ◽  
pp. 579-588 ◽  
Author(s):  
Mojca Lorbar ◽  
Richard A Fenton ◽  
James G Dobson, Jr.
Keyword(s):  
Electrical Stimulation ◽  
Interstitial Fluid ◽  
Contractile Function ◽  
Stellate Ganglion ◽  
Perfused Heart ◽  
Reserpine Treatment ◽  
Rat Hearts ◽  
Perfused Rat Hearts ◽  
Stimulation Of ◽  
Isolated Perfused Rat Hearts

The contribution of neuronal ATP to interstitial adenosine levels was investigated in isolated perfused rat hearts. Ventricular surface transudates, representing interstitial fluid, were analyzed for norepinephrine, ATP, and adenosine. Exocytotic release of norepinephrine was induced by electrical stimulation of cardiac efferents emanating from the stellate ganglion. Ganglion stimulation increased contractility, interstitial norepinephrine, ATP, and adenosine. Interstitial adenosine was 11- to 27-fold higher than interstitial ATP, suggesting that the released ATP is unlikely the only source of adenosine. In the presence of AOPCP (α,β-methyleneadenosine 5'-diphosphate), an ecto-5'-nucleotidase inhibitor, the ganglion-stimulated increase in interstitial ATP and adenosine reached levels similar to those in the absence of AOPCP, also suggesting that adenosine does not derive from extracellular ATP. The perfusate Ca2+ was raised from 1 to 4 mM to determine the importance of the enhanced contractile function on the levels of norepinephrine, ATP, and adenosine. The results were increases in contractility and interstitial norepinephrine, ATP, and adenosine, which were not suppressed with atenolol, indicating a norepinephrine-independent release of ATP and adenosine. Reserpine treatment and administration of guanethidine depleted the catecholamine stores and diminished the catecholamine release, respectively. However, neither agent altered Ca2+-induced increases in ATP and adenosine. It is concluded that the amount of neuronal-derived ATP is low and most likely does not contribute significantly to interstitial levels of adenosine. Furthermore, elevations in interstitial norepinephrine, ATP, and adenosine are associated with neuronal-independent increases in contractile function.Key words: perfused heart, stellate ganglion, co-transmission, calcium, and contractility.

Chronotropic, inotropic, and coronary artery blood flow responses to stimulation of specific canine sympathetic nerves and ganglia

1984 ◽  
Vol 62 (11) ◽  
pp. 1374-1381 ◽  
Author(s):  
R. D. Janes ◽  
D. E. Johnstone ◽  
J. A. Armour
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Coronary Blood Flow ◽  
Stellate Ganglion ◽  
Sympathetic Nerves ◽  
Neural Stimulation ◽  
Intramyocardial Pressure ◽  
Intact Heart ◽  
Cardiac Nerves ◽  
Stimulation Of

Electrical stimulation of the major sympathetic cardiac nerves and ganglia in chloralose-anesthetized, open-chest dogs elicited specific changes in heart rate, coronary blood flow, regional intramyocardial pressure, or intraventricular pressure. The effects produced by stimulation of a cardiac nerve were similar to, but never greater than those produced by stimulation of the ipsilateral stellate ganglion. Coronary blood flow was increased when neural stimulation increased intramyocardial pressure. In contrast, coronary blood flow was not altered significantly when neural stimulation induced tachycardia without increasing intramyocardial pressure. It is concluded that in the intact heart, electrical stimulation of the sympathetic cardiac nerves or ganglia increases coronary blood flow by augmenting intramyocardial pressure, not chronotropism.

scholarly journals Long-term subthreshold electrical stimulation of the left stellate ganglion and a canine model of sudden cardiac death

2004 ◽  
Vol 43 (5) ◽  
pp. 858-864 ◽  
Author(s):  
Moshe Swissa ◽  
Shengmei Zhou ◽  
Ignacio Gonzalez-Gomez ◽  
Che-Ming Chang ◽  
Angela C. Lai ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Sudden Cardiac Death ◽  
Cardiac Death ◽  
Stellate Ganglion ◽  
Canine Model ◽  
Left Stellate Ganglion ◽  
Stimulation Of

Receptor units responding to movement in the octopus mantle

1976 ◽  
Vol 65 (1) ◽  
pp. 1-9
Author(s):  
P. R. Boyle
Keyword(s):  
Electrical Stimulation ◽  
Sensory Feedback ◽  
Stellate Ganglion ◽  
Circular Muscle ◽  
Feedback System ◽  
Solid Support ◽  
Sensory Response ◽  
Afferent Activity ◽  
Form Part ◽  
Stimulation Of

1. A preparation of the mantle of Octopus which is inverted over a solid support and which exposes the stellate ganglion and associated nerves is described. 2. Afferent activity can be recorded from stellar nerves following electrical stimulation of the pallial nerve. The latency and frequency of the phasic sensory response is correlated with the contraction of the mantle musculature. 3. It is proposed that receptors cells located in the muscle, and their activity following mantle contraction, form part of a sensory feedback system in the mantle. Large, multipolar nerve cells that were found between the two main layers of circular muscle in the mantle could be such receptors.

Epinephrine release from the heart during left stellate ganglion stimulation in dogs

1988 ◽  
Vol 254 (4) ◽  
pp. R659-R662 ◽  
Author(s):  
F. Peronnet ◽  
R. Nadeau ◽  
G. Boudreau ◽  
R. Cardinal ◽  
D. Lamontagne ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
High Performance ◽  
Stellate Ganglion ◽  
Blood Samples ◽  
Radioenzymatic Assay ◽  
Left Stellate Ganglion ◽  
Anesthetized Dogs ◽  
Significant Uptake ◽  
Stimulation Of

Plasma epinephrine (E) and norepinephrine (NE) concentrations were measured (radioenzymatic assay) in blood samples simultaneously withdrawn from the aorta (Ao) and coronary sinus (CS) on 10 anesthetized dogs immediately before and during a 1-min period of electrical stimulation of the left stellate ganglion (4 V, 4 ms, 10 Hz). Heart rate and systolic blood pressure significantly increased in response to electrical stimulation (152 +/- 8 to 180 +/- 15 beats/min and 128 +/- 12 to 149 +/- 12 mmHg, mean +/- SE; P less than 0.05). Plasma NE concentrations were not significantly different in the Ao and the CS (432 +/- 110 and 319 +/- 67 pg/ml) before the stimulation, whereas a net removal of E was present across the myocardium (Ao, 172 +/- 61; CS, 71 +/- 22 pg/ml). A large NE spillover in the CS was observed during the stimulation (Ao, 1,555 +/- 513; CS, 10,583 +/- 3,753 pg/ml). A significant output of E from the myocardium was also present (Ao, 165 +/- 42; CS, 291 +/- 74 pg/ml) during the stimulation. Determination of NE and E concentrations by high-performance liquid chromatography in five of the dogs confirmed the observation made with the radioenzymatic assay, i.e., a significant uptake (66%) of blood-borne E was present across the myocardium in the control situation (Ao, 320 +/- 97; CS, 110 +/- 23 pg/ml), whereas plasma E concentrations in the CS (280 +/- 61 pg/ml) were 1.5 times the values found in Ao (184 +/- 56 pg/ml) under electrical stimulation. These observations give further support to the hypothesis that endogenous tissue E can act as a cotransmitter of sympathetic fibers.

Responses of feline medial medullary reticulospinal neurons to cardiac input

1987 ◽  
Vol 58 (5) ◽  
pp. 1149-1167 ◽  
Author(s):  
R. W. Blair
Keyword(s):  
Electrical Stimulation ◽  
Discharge Rate ◽  
Stellate Ganglion ◽  
Visual Input ◽  
Spontaneous Discharge ◽  
Thoracic Spinal Cord ◽  
Afferent Stimulation ◽  
Thoracic Spinal ◽  
To Receive ◽  
Stimulation Of

1. Responses of medial medullary reticulospinal (RS) neurons to electrical stimulation of cardiac sympathetic afferents, probing the epicardium and epicardial application of bradykinin, were determined in cats anesthetized with alpha-chloralose. Conduction velocity of RS cells averaged 67 m/s; these neurons were probably part of the RS motor pathway and the bulbospinal pathway that modulates ascending information. Fifty-three RS neurons had unilateral projections and 18 neurons bilateral projections to the thoracic spinal cord. 2. Maximal electrical stimulation of the left stellate ganglion excited 69% of 97 RS neurons with a mean latency of 15 +/- 1.0 ms. Mean spike discharge rate increased from 4 +/- 1.2 to 93 +/- 8.0 spikes/s for responsive neurons. 3. Epicardial bradykinin (0.04 mg) excited 34%, inhibited 2%, and did not affect 64% of 44 RS cells tested. Excited neurons increased their mean discharge rate from 12.3 +/- 3.6 to 18.2 +/- 4.3 spikes/s, with a latency of 24 +/- 3.0 s, in response to bradykinin. Response duration averaged 43 +/- 2.3 s. Neurons responsive to bradykinin had greater spontaneous discharge rates than unresponsive neurons. Thirteen of 16 RS cells excited by bradykinin were located in the gigantocellular tegmental field (FTG); the other three cells were in the paramedian nucleus (PR). 4. Epicardial bradykinin often elicited changes in aortic pressure. Although some neurons responded to altered blood pressure alone, these responses could not account for responses to bradykinin. Furthermore, the percentage of responsive neurons was similar in experiments with intact nerves as well as those with vagotomy and barodenervation. 5. Touching the epicardium with a blunt probe excited 19 of 60 (32%) RS neurons, and visceral receptive fields were mapped for 12 of these cells. Neurons responded with one to three spikes to probing. RS neurons responsive to probing were scattered throughout the medial reticular formation. 6. RS cells were also tested for somatic, auditory, and visual input. Of 63 neurons responsive to sympathetic afferent stimulation, only one did not receive convergent input from at least one of these sources; 51% received input from each tested source. Neurons responsive to bradykinin were more likely to receive visual input than the general population of neurons. RS neurons unresponsive to sympathetic afferent stimulation were less likely to receive convergent inputs from other sensory modalities.(ABSTRACT TRUNCATED AT 400 WORDS)

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