Cardioregulatory properties of the abdominal ganglia in Limulus

1970 ◽  
Vol 48 (6) ◽  
pp. 333-341 ◽  
Author(s):  
R. Von Burg ◽  
W. C. Corning
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Heart Function ◽  
Inhibitory Effect ◽  
Bioelectrical Activity ◽  
Inhibitory Influence ◽  
Dorsal Nerves

The abdominal ganglia of the Limulus central nervous system exert a net inhibitory effect on heart rate. This influence is mediated mainly by the dorsal nerves in the first three ganglia. When the dorsal nerves are sectioned, cardioacceleration results; when these nerves are stimulated, a reduction in rate is obtained. However, cardioaccelerators can be unmasked by splitting a ganglion. This selectively removes the inhibitory output, leaving only a cardioaccelerator influence. Inhibition of bioelectrical activity in the intact abdominal ganglia with GABA also resulted in an increased heart rate, confirming their net inhibitory influence on heart function. Possible models of abdominal ganglia organization are discussed.

Isoflurane Depresses Baroreflex Control of Heart Rate in Decerebrate Rats

2002 ◽  
Vol 96 (5) ◽  
pp. 1214-1222 ◽  
Author(s):  
Jong S. Lee ◽  
Don Morrow ◽  
Michael C. Andresen ◽  
Kyoung S. K. Chang
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Baroreflex Sensitivity ◽  
Baroreflex Control ◽  
Beta Adrenoceptor ◽  
Reflex Bradycardia ◽  
Reflex Tachycardia ◽  
Map Data ◽  
Regulatory Sites

Background Isoflurane inhibits baroreflex control of heart rate (HR) by poorly understood mechanisms. The authors examined whether suprapontine central nervous system cardiovascular regulatory sites are required for anesthetic depression. Methods The effects of isoflurane (1 and 2 rat minimum alveolar concentration [MAC]) on the baroreflex control of HR were determined in sham intact and midcollicular-transected decerebrate rats. Intravenous phenylephrine (0.2-12 microg/kg) and nitroprusside (1-60 microg/kg) were used to measure HR responses to peak changes in mean arterial pressure (MAP). Sigmoidal logistic curve fits to HR-MAP data assessed baroreflex sensitivity (HR/MAP), HR range, lower and upper HR plateau, and MAP at half the HR range (BP50). Four groups (two brain intact and two decerebrate) were studied before, during, and after isoflurane. To assess sympathetic and vagal contributions to HR baroreflex, beta-adrenoceptor (1 mg/kg atenolol) or muscarinic (0.5 mg/kg methyl atropine) antagonists were administered systemically. Results Decerebration did not alter resting MAP and HR or baroreflex parameters. Isoflurane depressed baroreflex slope and HR range in brain-intact and decerebrate rats. In both groups, 1 MAC reduced HR range by depressing peak reflex tachycardia. Maximal reflex bradycardia during increases in blood pressure was relatively preserved. Atenolol during 1 MAC did not alter maximum reflex tachycardia. In contrast, atropine during 1 MAC fully blocked reflex bradycardia. Therefore, 1 MAC predominantly depresses sympathetic components of HR baroreflex. Isoflurane at 2 MAC depressed both HR plateaus and decreased BP50 in both groups. Conclusions Isoflurane depresses HR baroreflex control by actions that do not require suprapontine central nervous system sites. Isoflurane actions seem to inhibit HR baroreflex primarily by the sympathetic nervous system.

scholarly journals Fractal fluctuations in the cardiovascular dynamical system : from the autonomic control to the central nervous system influence

2021 ◽  
Author(s):  
Asif Hasan Sharif
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Dynamic Feature ◽  
Scale Free ◽  
Autonomic Nervous ◽  
Factorization Technique ◽  
The Central Nervous System

The fractal component in the complex fluctuations of the human heart rate represents a dynamic feature that is widely observed in diverse fields of natural and artificial systems. It is also of clinical significance as the diminishing of the fractal dynamics appears to correlate with heart disease processes and adverse cardiac events in old age. While the autonomic nervous system directly controls the pacemaker cells of the heart, it does not provide an immediate characterization of the complex heart rate variability (HRV). The central nervous system (CNS) is known to be an important modulator for various cardiac functions. However, its role in the fractal HRV is largely unclear. In this research, human experiments were conducted to study the influence of the central nervous system on fractal dynamics of healthy human HRV. The head up tilt (HUT) maneuver is used to provide a perturbation to the autonomic nervous system. The subsequent fractal effect in the simultaneously recorded electroencephalography and beat-to-beat heart rate data was examined. Using the recently developed multifractal factorization technique, the common multifractality in the data fluctuation was analyzed. An empirical relationship was uncovered which shows the increase (decrease) in HRV multifractality is associated with the increase (decrease) in multifractal correlation between scale-free HRV and the cortical expression of the brain dynamics in 8 out of 11 healthy subjects. This observation is further supported using surrogate analysis. The present findings imply that there is an integrated central-autonomic component underlying the cortical expression of the HRV fractal dynamics. It is proposed that the central element should be incorporated in the fractal HRV analysis to gain a more comprehensive and better characterization of the scale-free HRV dynamics. This study provides the first contribution to the HRV multifractal dynamics analysis in HUT. The multivariate fractal analysis using factorization technique is also new and can be applied in the more general context in complex dynamics research.

scholarly journals Analysis of electrogenesis’ changes in mental retardation persons by using computer electroencephalography

2021 ◽  
Vol 11 (11) ◽  
pp. 249-265
Author(s):  
B. Lobasyuk ◽  
L. Bartsevich ◽  
A. Zamkovaya
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mental Retardation ◽  
Theta Rhythm ◽  
Cognitive Activity ◽  
Control Group ◽  
Bioelectrical Activity ◽  
The Central Nervous System ◽  
Beta Rhythms ◽  
The Brain

Justification. Mental retardation is a persistent decrease in human cognitive activity against the background of organic damage to the central nervous system. Neurophysiological diagnostics, in particular electroencephalography (EEG), most adequately reflects the morpho-functional state of the central nervous system, which is the basis of the mechanisms of mental activity, and the originality of the bioelectrical activity of the brain can be considered as the main indicator that determines a decrease in the level of intellectual development and, thereby, characterizes this state. This provision actualizes the search for highly informative indicators of the originality of the bioelectrical activity of the brain in children with intellectual disabilities. Purspose. With the use of periodometric analysis investigate EEG’s indicators and interhemispheric asymmetry of rhythms amplitudes in MR patients. Materials and methods. The EEG was recorded in a state of calm wakefulness with closed eyes with Neuron-Spectrum-2 electroencephalograph. Differences in indicators were tracked using the calculation of the coefficient of compliance (CC), EEG functional asymmetry coefficients in amplitude were determined, too. Results. It was revealed that in MR patients the amplitudes of the rhythms were greater than in healthy subjects. The greatest increase was determined in theta rhythm in the anterior temporal and posterior temporal leads in the left hemispheres. Duration indices in the delta, theta and alpha ranges of the EEG in mental retardation compared with the control group were increased, and the indices of the duration of beta rhythms - decreased. When analyzing FMPA in MR persons it turned out that in right-handers the negativeness of FMPA indices increased, and in left-handers there was an increase in the positivity of FMPA indices. Conclusions 1. With mental retardation, the amplitudes of the rhythms were greater than in healthy people. The greatest increase was determined in theta rhythm in the anterior temporal and posterior temporal leads in the left hemispheres. 2. The indices of duration in the delta, theta and alpha ranges of the EEG of MR subjects were increased, and the indices of the duration of beta rhythms – decreased. 3. When analyzing FMPA in MR persons, it turned out that in right-handers the negativeness of FMPA indices increased, and in left-handers there was an increase in the positivity of FMPA indices.

β-Neoendorphin inhibits thyrotrophin secretion in rats

1983 ◽  
Vol 104 (4) ◽  
pp. 437-442 ◽  
Author(s):  
Terunori Mitsuma ◽  
Tsuyoshi Nogimori
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Plasma Concentrations ◽  
Inhibitory Effect ◽  
Thyrotrophin Releasing Hormone ◽  
Specific Radioimmunoassay ◽  
Tsh Secretion ◽  
Pretreated Group ◽  
The Central Nervous System ◽  
Tsh Levels

Abstract. The effects of β-neoendorphin on thyrotrophin-releasing hormone (TRH) and thyrotrophin (TSH) secretion in rats were studied. β-neoendorphin (500 μg/kg) was injected iv, and the rats were decapitated serially. TRH, TSH, thyroxine (T4) and 3,3',5-triiodothyronine (T3) were measured by means of a specific radioimmunoassay for each. Hypothalamic immunoreactive TRH (ir-TRH) content increased significantly after β-neoendorphin injection, and plasma concentrations tended to decrease, but not significantly so. Plasma TSH levels decreased significantly in a dose-related manner with a nadir at 40 min. Plasma T4 and T3 levels did not change after the injection. Plasma ir-TRH and TSH responses to cold were significantly inhibited by β-neoendorphin, but the plasma TSH response to TRH was not. Naloxone partially prevented the inhibitory effect of β-neoendorphin on TSH release. In the haloperidol- or 5-hydroxytryptophan-pretreated group, the inhibitory effect of β-neoendorphin on TSH release was prevented, but not in the l-dopa- or para-chlorophenylalanine-pretreated group. These drugs alone did not affect plasma TSH levels at the dose used. These findings suggest that β-neoendorphin acts on the hypothalamus by inhibiting TRH release, which may be modified by amines of the central nervous system.

scholarly journals The Movements of the Proboscis in Glycera Dibranchiata Ehlers

1937 ◽  
Vol 14 (3) ◽  
pp. 290-301
Author(s):  
G. P. WELLS
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Body Wall ◽  
The Body ◽  
Inhibitory Influence ◽  
Spontaneous Movement ◽  
Arenicola Marina ◽  
Glycera Dibranchiata ◽  
The Central Nervous System ◽  
Nervous Conduction

1. The gut of Glycera consists of (a) the buccal tube, (b) the pharynx, containing the jaws with their associated muscles and glands and the principal stomatogastric ganglia, (c) the oesophagus, leading from the pharynx to (d) the intestine, in which digestion occurs. 2. An "isolated extrovert" preparation is described, consisting of the buccal tube, pharynx and oesophagus. The movements of the buccal tube and oesophagus are recorded separately. The preparation has the following properties: (a) The buccal tube shows vigorous, rapid contractions with a somewhat irregular rhythm. These contractions are due to impulses coming forwards from the pharynx, the buccal tube itself having little power of spontaneous movement. (b) The oesophagus shows tone-waves, on which more rapid contractions of small amplitude may be superposed. These contractions and tone-waves are due to impulses originating in the wall of the oesophagus itself. (c) In a few preparations only, synchronous movements of buccal tube and oesophagus were seen. The site of origin of this synchronous activity was not determined. 3. An "extrovert-body wall" preparation is described, in which the movements of the body wall and buccal tube are separately recorded while the normal nervous conduction paths between them remain intact. The preparation has the following properties: (a) In most cases the body wall shows slight movements only, and the buccal tube moves little or not at all. If, however, the buccal tube be cut across close to the mouth, it begins an irregular rhythm of vigorous contractions, due to impulses originating in the pharynx, which usually continues without diminution for hours. The quiescence of the buccal tube before this cut is made indicates that the central nervous system normally exerts an inhibitory influence on the pharynx. (b) In a few preparations, correlated outbursts of contraction in the body wall and buccal tube were seen. These outbursts, which possibly correspond to extrusion movements of the intact worm, are due to impulses originating in the central nervous system. 4. The results are compared with those previously obtained on Arenicola marina, and reported in an earlier paper.

Hypophysectomy alters cardiorespiratory variables: central effects of pituitary endorphins in shock

1981 ◽  
Vol 241 (4) ◽  
pp. H479-H485 ◽  
Author(s):  
J. W. Holaday ◽  
M. O'Hara ◽  
A. I. Faden
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Mean Arterial Pressure ◽  
Hypovolemic Shock ◽  
Cardiovascular Effects ◽  
Central Effects ◽  
Hypophysectomized Rats ◽  
The Central Nervous System

The possible involvement of pituitary endorphins in the pathophysiology of shock was evaluated by measuring cardiorespiratory variables after naloxone injection in conscious hypophysectomized and sham-hypophysectomized rats subjected to controlled hemorrhage. Additionally, the role of the central nervous system (CNS) in mediating the cardiodepressant effects of endorphins in shock was studied. After the induction of hypovolemic shock (20 min at below 40 mmHg), hypophysectomized and sham-hypophysectomized rats received intraventricular (ivt) injections of naloxone HCl (10 micrograms) or an equivalent volume of saline (20 microliters over 20 s). In sham-hypophysectomized rats, both injections significantly elevated mean arterial pressure and pulse pressure; however, the increase produced by naloxone was significantly greater than that produced by saline. By contrast, hypophysectomized rats showed no response to naloxone or saline. Intravenous (iv) administration of naloxone HCl (3 mg/kg) or saline to these same hypophysectomized rats 15 min after ivt administration had no additional cardiovascular effects; as before, only animals with intact pituitaries responded to naloxone. Heart rate and respiration rate were unaffected by ivt or iv naloxone. From these data we suggest that pituitary endorphins contribute to the pathophysiology of hypovolemic shock, at least in part through actions within the CNS.

Stereoselective actions of S-nitrosocysteine in central nervous system of conscious rats

1997 ◽  
Vol 272 (5) ◽  
pp. H2361-H2368 ◽  
Author(s):  
R. L. Davisson ◽  
M. D. Travis ◽  
J. N. Bates ◽  
A. K. Johnson ◽  
S. J. Lewis
Keyword(s):  
Central Nervous System ◽  
Heart Rate ◽  
Nervous System ◽  
Intracerebroventricular Injection ◽  
Conscious Rats ◽  
Arterial Blood ◽  
Recognition Sites ◽  
Pressor Responses ◽  
The Central Nervous System ◽  
Intracerebroventricular Injections

This study examined whether the stereoselective actions of S-nitrosocysteine (SNC) in the central nervous system involves the activation of stereoselective SNC recognition sites. We examined the effects produced by intracerebroventricular injection of the L- and D-isomers of SNC (L- and D-SNC) on mean arterial blood pressure, heart rate, and vascular resistances in conscious rats. We also examined the hemodynamic effects produced by intracerebroventricular injections of 1) L-cystine, the major non-nitric oxide (NO) decomposition product of L-SNC, 2) the parent thiols L- and D-cysteine, and 3) the bulky S-nitrosothiol L-S-nitroso-gamma-glutamylcysteinylglycine [L-S-nitrosoglutathione, (L-SNOG)]. Finally, we examined the decomposition of L- and D-SNC and L-SNOG to NO on their addition to brain homogenates. The intracerebroventricular injection of L-SNC (250-1,000 nmol) produced falls in mean arterial pressure, increases in heart rate, and a dose-dependent pattern of changes in hindquarter, renal, and mesenteric vascular resistances. The intracerebroventricular injections of D-SNC, L-cystine, and L-SNOG produced only minor effects. The intracerebroventricular injection of L-cysteine produced pressor responses and tachycardia, whereas D-cysteine was inactive. L- and D-SNC decomposed equally to NO on addition to brain homogenates. L-SNOG decomposed to similar amounts of NO as L- and D-SNC. These results suggest that SNC may activate stereoselective SNC recognition sites on brain neurons and that S-nitrosothiols of substantially different structure do not stimulate these sites. These recognition sites may be stereoselective membrane-bound receptors for which L-SNC is the unique ligand.

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