Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

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Durand, M.T.; Mota, A.L.; Barale, A.R.; Castania, J.A.; Fazan, R. Jr.; Salgado, H.C.

2012-01-01

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN). The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 ± 336 to 3695 ± 463 ms) vs SHR (3475 ± 354 to 4494 ± 300 ms); bradycardia = NCR (1618 ± 152 to 1358 ± 185 ms) vs SHR (1911 ± 323 to 1852 ± 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 ± 486 to 6550 ± 847 ms) vs SHR (4849 ± 918 to 4926 ± 646 ms); mesenteric = NCR (5574 ± 790 to 5752 ± 539 ms) vs SHR (5638 ± 648 to 6777 ± 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR

Effects of MK-801 upon local cerebral glucose utilization in conscious rats and in rats anaesthetised with halothane

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Kurumaji, A.; McCulloch, J.

1989-01-01

The effects of MK-801 (0.5 mg/kg i.v.), a non-competitive N-methyl-D-aspartate (NMDA) antagonist, upon local cerebral glucose utilization were examined in conscious, lightly restrained rats and in rats anaesthetised with halothane in nitrous oxide by means of the quantitative autoradiographic [14C]-2-deoxyglucose technique. In the conscious rats, MK-801 produced a heterogenous pattern of altered cerebral glucose utilization with significant increases being observed in 12 of the 28 regions of gray matter examined and significant decreases in 6 of the 28 regions. Pronounced increases in glucose use were observed after MK-801 in the olfactory areas and in a number of brain areas in the limbic system (e.g., hippocampus molecular layer, dentate gyrus, subicular complex, posterior cingulate cortex, and mammillary body). In the cerebral cortices, large reductions in glucose use were observed after administration of MK-801, whereas in the extrapyramidal and sensory-motor areas, glucose use remained unchanged after MK-801 administration in conscious rats. In the halothane-anaesthetised rats, the pattern of altered glucose use after MK-801 differed qualitatively and quantitatively from that observed in conscious rats. In anaesthetised rats, significant reductions in glucose use were noted after MK-801 in 10 of the 28 regions examined, with no area displaying significantly increased glucose use after administration of the drug. In halothane-anaesthetised rats, MK-801 failed to change the rates of glucose use in the olfactory areas, the hippocampus molecular layer, and the dentate gyrus

Noninvasive recording of electrocardiogram in conscious rat: A new device.

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Kumar, Pradeep; Srivastava, Pooja; Gupta, Ankit; Bajpai, Manish

2017-01-01

Electrocardiogram (ECG) is an important tool for the study of cardiac electrophysiology both in human beings and experimental animals. Existing methods of ECG recording in small animals like rat have several limitations and ECG recordings of the anesthetized rat lack validity for heart rate (HR) variability analysis. The aim of the present study was to validate the ECG data from new device with ECG of anesthetized rat. The ECG was recorded on student's physiograph (BioDevice, Ambala) and suitable coupler and electrodes in six animals first by the newly developed device in conscious state and second in anesthetized state (stabilized technique). The data obtained were analyzed using unpaired t -test showed no significant difference ( P < 0.05) in QTc, QRS, and HR recorded by new device and established device in rats. No previous study describes a similar ECG recording in conscious state of rats. Thus, the present method may be a most physiological and inexpensive alternative to other methods. In this study, the animals were not restrained; they were just secured and represent a potential strength of the study.

The effects of apomorphine upon local cerebral glucose utilization in conscious rats and in rats anesthetized with chloral hydrate

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Grome, J J; McCulloch, J

1983-02-01

The effects of the dopaminergic agonist apomorphine (1 mg . kg-1 i.v.) upon local cerebral glucose utilization in 43 anatomically discrete regions of the CNS were examined in conscious, lightly restrained rats and in rats anesthetized with chloral hydrate by means of the quantitative autoradiographic (/sup 14/C)2-deoxyglucose technique. In animals anesthetized with chloral hydrate, glucose utilization was reduced throughout all regions of the CNS from the levels observed in conscious animals, although the magnitude of the reductions in glucose use displayed considerable regional heterogeneity. With chloral hydrate anesthesia, the proportionately most marked reductions in glucose use (by 40-60% from conscious levels) were noted in primary auditory nuclei, thalmaic relay nuclei, and neocortex, and the least pronounced reductions in glucose use (by 15-25% from conscious levels) were observed in limbic areas, some motor relay nuclei, and white matter. In conscious, lightly restrained rats, the administration of apomorphine (1 mg . kg-1) effected significant increased in glucose utilization in 15 regions of the CNS (e.g., subthalamic nucleus, ventral thalamic nucleus, rostral neocortex, substantia nigra, pars reticulata), and significant reductions in glucose utilization in two regions of the CNS (lateral habenular nucleus and anterior cingulate cortex).

Endothelin-1 receptor antagonists protect the kidney against the nephrotoxicity induced by cyclosporine-A in normotensive and hypertensive rats.

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Caires, A; Fernandes, G S; Leme, A M; Castino, B; Pessoa, E A; Fernandes, S M; Fonseca, C D; Vattimo, M F; Schor, N; Borges, F T

2017-12-11

Cyclosporin-A (CsA) is an immunosuppressant associated with acute kidney injury and chronic kidney disease. Nephrotoxicity associated with CsA involves the increase in afferent and efferent arteriole resistance, decreased renal blood flow (RBF) and glomerular filtration. The aim of this study was to evaluate the effect of Endothelin-1 (ET-1) receptor blockade with bosentan (BOS) and macitentan (MAC) antagonists on altered renal function induced by CsA in normotensive and hypertensive animals. Wistar and genetically hypertensive rats (SHR) were separated into control group, CsA group that received intraperitoneal injections of CsA (40 mg/kg) for 15 days, CsA+BOS and CsA+MAC that received CsA and BOS (5 mg/kg) or MAC (25 mg/kg) by gavage for 15 days. Plasma creatinine and urea, mean arterial pressure (MAP), RBF and renal vascular resistance (RVR), and immunohistochemistry for ET-1 in the kidney cortex were measured. CsA decreased renal function, as shown by increased creatinine and urea. There was a decrease in RBF and an increase in MAP and RVR in normotensive and hypertensive animals. These effects were partially reversed by ET-1 antagonists, especially in SHR where increased ET-1 production was observed in the kidney. Most MAC effects were similar to BOS, but BOS seemed to be better at reversing cyclosporine-induced changes in renal function in hypertensive animals. The results of this work suggested the direct participation of ET-1 in renal hemodynamics changes induced by cyclosporin in normotensive and hypertensive rats. The antagonists of ET-1 MAC and BOS reversed part of these effects.

Endothelin-1 receptor antagonists protect the kidney against the nephrotoxicity induced by cyclosporine-A in normotensive and hypertensive rats

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A. Caires

2017-12-01

Full Text Available Cyclosporin-A (CsA is an immunosuppressant associated with acute kidney injury and chronic kidney disease. Nephrotoxicity associated with CsA involves the increase in afferent and efferent arteriole resistance, decreased renal blood flow (RBF and glomerular filtration. The aim of this study was to evaluate the effect of Endothelin-1 (ET-1 receptor blockade with bosentan (BOS and macitentan (MAC antagonists on altered renal function induced by CsA in normotensive and hypertensive animals. Wistar and genetically hypertensive rats (SHR were separated into control group, CsA group that received intraperitoneal injections of CsA (40 mg/kg for 15 days, CsA+BOS and CsA+MAC that received CsA and BOS (5 mg/kg or MAC (25 mg/kg by gavage for 15 days. Plasma creatinine and urea, mean arterial pressure (MAP, RBF and renal vascular resistance (RVR, and immunohistochemistry for ET-1 in the kidney cortex were measured. CsA decreased renal function, as shown by increased creatinine and urea. There was a decrease in RBF and an increase in MAP and RVR in normotensive and hypertensive animals. These effects were partially reversed by ET-1 antagonists, especially in SHR where increased ET-1 production was observed in the kidney. Most MAC effects were similar to BOS, but BOS seemed to be better at reversing cyclosporine-induced changes in renal function in hypertensive animals. The results of this work suggested the direct participation of ET-1 in renal hemodynamics changes induced by cyclosporin in normotensive and hypertensive rats. The antagonists of ET-1 MAC and BOS reversed part of these effects.

Uric acid does not affect the acetylcholine-induced relaxation of aorta from normotensive and deoxycorticosterone acetate-salt hypertensive rats.

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Szasz, Theodora; Watts, Stephanie W

2010-06-01

Uric acid (UA) results from xanthine oxidase (XO) catabolism of xanthine and is the final product of purine catabolism in humans. In this species, hyperuricemia is associated with gout, nephropathy, and increased cardiovascular disease risk. Although the effects of hyperuricemia in vascular biology are overall controversial, UA has been described as an antioxidant and as potentially improving endothelial function. Hypertension is associated with endothelial dysfunction. We hypothesized that UA improves the endothelial function of aorta from deoxycorticosterone acetate (DOCA)-salt hypertensive rats. UA (100 microM) in the presence of the uricase inhibitor oxonic acid (10 microM) did not modify relaxation to acetylcholine (ACh) (1 nM-10 microM) in the aorta from nontreated, sham normotensive, and DOCA-salt hypertensive rats [response to 10 microM ACh for UA versus vehicle, respectively: nontreated = 37 +/- 7 versus 48 +/- 7%, sham = 53 +/- 15 versus 57 +/- 20%, DOCA = 81 +/- 4 versus 85 +/- 2% from 20 microM prostaglandin 2alpha (PGF(2alpha))-induced contraction]. Allopurinol (100 microM), a XO inhibitor, did not significantly alter the ACh-induced relaxation of sham and DOCA aortic rings (response to 10 microM ACh for allopurinol versus vehicle, respectively: sham = 61 +/- 5 versus 68 +/- 9%, DOCA = 87 +/- 6 versus 88 +/- 3% from 20 microM PGF(2alpha)-induced contraction). Uricemia, ranging from unmeasurable to 547 microM in sham and to 506 microM in DOCA rats, was not significantly different between these two groups. The expression and activity of XO, as well as the expression of uricase, were not different between sham and DOCA rat aorta. We conclude that, at least in vitro, UA does not affect the ACh-induced relaxation of normotensive and DOCA-salt hypertensive rats.

Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats

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Roque, Fernanda R.; Soci, Ursula Paula Renó; De Angelis, Katia; Coelho, Marcele A.; Furstenau, Cristina R.; Vassallo, Dalton V.; Irigoyen, Maria Claudia; Oliveira, Edilamar M.

2011-01-01

OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C) and trained (T). An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05). RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 5′-nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion. PMID:22189737

Moderate exercise training promotes adaptations in coronary blood flow and adenosine production in normotensive rats

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Fernanda R. Roque

2011-01-01

Full Text Available OBJECTIVES: Aerobic exercise training prevents cardiovascular risks. Regular exercise promotes functional and structural adaptations that are associated with several cardiovascular benefits. The aim of this study is to investigate the effects of swimming training on coronary blood flow, adenosine production and cardiac capillaries in normotensive rats. METHODS: Wistar rats were randomly divided into two groups: control (C and trained (T. An exercise protocol was performed for 10 weeks and 60 min/day with a tail overload of 5% bodyweight. Coronary blood flow was quantified with a color microsphere technique, and cardiac capillaries were quantified using light microscopy. Adenine nucleotide hydrolysis was evaluated by enzymatic activity, and protein expression was evaluated by western blot. The results are presented as the means ± SEMs (p<0.05. RESULTS: Exercise training increased the coronary blood flow and the myocardial capillary-to-fiber ratio. Moreover, the circulating and cardiac extracellular adenine nucleotide hydrolysis was higher in the trained rats than in the sedentary rats due to the increased activity and protein expression of enzymes, such as E-NTPDase and 59- nucleotidase. CONCLUSIONS: Swimming training increases coronary blood flow, number of cardiac capillaries, and adenine nucleotide hydrolysis. Increased adenosine production may be an important contributor to the enhanced coronary blood flow and angiogenesis that were observed in the exercise-trained rats; collectively, these results suggest improved myocardial perfusion.

Conscious wireless electroretinogram and visual evoked potentials in rats.

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Jason Charng

Full Text Available The electroretinogram (ERG, retina and visual evoked potential (VEP, brain are widely used in vivo tools assaying the integrity of the visual pathway. Current recordings in preclinical models are conducted under anesthesia, which alters neural physiology and contaminates responses. We describe a conscious wireless ERG and VEP recording platform in rats. Using a novel surgical technique to chronically implant electrodes subconjunctivally on the eye and epidurally over the visual cortex, we are able to record stable and repeatable conscious ERG and VEP signals over at least 1 month. We show that the use of anaesthetics, necessary for conventional ERG and VEP measurements, alters electrophysiology recordings. Conscious visual electrophysiology improves the viability of longitudinal studies by eliminating complications associated with repeated anaesthesia. It will also enable uncontaminated assessment of drug effects, allowing the eye to be used as an effective biomarker of the central nervous system.

Effects of nimodipine on learning in normotensive and spontaneously hypertensive rats.

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Meneses, A; Terrón, J A; Ibarra, M; Hong, E

1997-04-01

It is well known that the calcium channel blocker, nimodipine, has beneficial effects on learning in either aged or hypertensive animals and humans. However, no attempts have been made to investigate if nimodipine can reverse the synergistic deleterious effects of aging and hypertension in the same subject. Therefore, this study investigated the effects of stable infusions of nimodipine in the autoshaping learning task using middle-aged normotensive (WKY) and hypertensive (SHR) rats. WKY and SHR of 12 months of age were implanted with osmotic minipumps releasing either vehicle or nimodipine (0.4 mg/kg/day). After 3 weeks of treatment, the animals received autoshaping training sessions during 4 consecutive days. The WKY animals treated with nimodipine exhibited the highest levels of learning during the last session, the rank order being WKY-nimodipine > SHR-nimodipine > WKY-vehicle > SHR-vehicle. These results confirm that nimodipine can reverse the impairing effects of either aging or hypertension on learning; the presence of both conditions, however, might produce more severe dysfunctional changes that cannot be totally reversed by nimodipine.

Opiate antagonist binding sites in discrete brain regions of spontaneously hypertensive and normotensive Wistar-Kyoto rats

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Rahmani, N.H.; Gulati, A.; Bhargava, H.N.

1991-01-01

The binding of 3 H-naltrexone, an opiate receptor antagonist, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. 3 H-Naltrexone bound to membranes of brain regions and spinal cord at a single high affinity site with an apparent dissociation constant value of 3 nM. The highest density of 3 H-naltrexone binding sites were in hippocampus and lowest in the cerebral cortex. The receptor density (B max value) and apparent dissociation constant (K d value) values of 3 H-naltrexone to bind to opiate receptors on the membranes of amygdala, hippocampus, corpus striatum, pons and medulla, midgrain, cortex and spinal cord of WKY and SHR rates did not differ. The B max value of 3 H-naltrexone binding to membranes of hypothalamus of SHR rates was 518% higher than WKY rats but the K d values in the two strains did not differ. It is concluded that SHR rats have higher density of opiate receptors labeled with 3 H-naltrexone in the hypothalamus only, in comparison with WKY rats, and that such a difference in the density of opiate receptors may be related to the elevated blood pressure in SHR rats

Opiate antagonist binding sites in discrete brain regions of spontaneously hypertensive and normotensive Wistar-Kyoto rats

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Rahmani, N.H.; Gulati, A.; Bhargava, H.N. (Univ. of Illinois, Chicago (USA))

1991-01-01

The binding of {sup 3}H-naltrexone, an opiate receptor antagonist, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats was determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. {sup 3}H-Naltrexone bound to membranes of brain regions and spinal cord at a single high affinity site with an apparent dissociation constant value of 3 nM. The highest density of {sup 3}H-naltrexone binding sites were in hippocampus and lowest in the cerebral cortex. The receptor density (B{sub max}value) and apparent dissociation constant (K{sub d} value) values of {sup 3}H-naltrexone to bind to opiate receptors on the membranes of amygdala, hippocampus, corpus striatum, pons and medulla, midgrain, cortex and spinal cord of WKY and SHR rates did not differ. The B{sub max} value of {sup 3}H-naltrexone binding to membranes of hypothalamus of SHR rates was 518% higher than WKY rats but the K{sub d} values in the two strains did not differ. It is concluded that SHR rats have higher density of opiate receptors labeled with {sup 3}H-naltrexone in the hypothalamus only, in comparison with WKY rats, and that such a difference in the density of opiate receptors may be related to the elevated blood pressure in SHR rats.

Blood pressure reducing effects of Phalaris canariensis in normotensive and spontaneously hypertensive rats.

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Passos, Clévia Santos; Carvalho, Lucimeire Nova; Pontes, Roberto Braz; Campos, Ruy Ribeiro; Ikuta, Olinda; Boim, Mirian Aparecida

2012-02-01

The birdseed Phalaris canariensis (Pc) is popularly used as an antihypertensive agent. The aqueous extract of Pc (AEPc) was administered in adult normotensive Wistar rats and spontaneously hypertensive rats (SHR) and in prehypertensive young SHR (SHR(Y), 3 weeks old). Animals received AEPc (400 mg·kg(-1)·day(-1), by gavage) for 30 days, then groups were divided into 2 subgroups: one was treated for another 30 days and the other received water instead of AEPc for 30 days. AEPc reduced systolic blood pressure (SBP) in both adult groups; however, treatment interruption was followed by a gradual return of the SBP to baseline levels. SHR(Y) became hypertensive 30 days after weaning. AEPc minimized the increase in SBP in SHR(Y), but blood pressure rose to levels similar to those in the untreated group with treatment interruption. There were no changes in renal function, diuresis, or Na(+) excretion. Pc is rich in tryptophan, and the inhibition of the metabolism of tryptophan to kynurenine, a potential vasodilator factor, prevented the blood pressure reducing effect of AEPc. Moreover, AEPc significantly reduced sympathoexcitation. Data indicate that the metabolic derivative of tryptophan, kynurenine, may be a mediator of the volume-independent antihypertensive effect of Pc, which was at least in part mediated by suppression of the sympathetic tonus.

Exploratory studies of some Mexican medicinal plants. Cardiovascular effects in rats with and without hypertension.

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Gil Alfonso Magos-Guerrero

2017-09-01

Full Text Available Background: Papaveraceae Argemone mexicana L., Burseraceae Bursera simaruba (L. Sarg., Acanthaceae Justicia spicigera Schltdl. and Selaginellaceae Selaginella lepidophylla (Hook. & Grev. Spring., have been used in Mexican traditional medicine to treat hypertension. The objective of this study was to further characterize the cardiovascular effects of the methanol extracts of such plants. Methods: The medicinal plants were collected and taxonomically identified; the methanol extract of each explored plant were administrated to conscious and unconscious male Wistar rats with and without glucose induced hypertension. The blood pressure and heart rate were evaluated before and after the extract administration. Vascular reactivity experiments were conducted in rat aortic rings obtained from rats with and without sugar induced hypertension, a model widely used to study such effects with cardiovascular agents. Results: After oral administration in normotensive conscious rats all tested extracts decreased the heart rate, such effect was only observed in hypertensive conscious rats after the administration of B. simaruba; only A. mexicana and B. simaruba decreased the blood pressure after oral administration. All extracts administrated by intravenous injection diminished the mean arterial pressure. Dose response curves to cumulative concentrations of all the extracts promote vascular relaxation in precontracted aortas from rats with and without sugar induced hypertension. Conclusions: The present study indicated that B. simaruba is worthy of further investigation as a potential phytotherapeutic agent for treating hypertension. [J Complement Med Res 2017; 6(3.000: 274-279

Blood pressure-renal blood flow relationships in conscious angiotensin II- and phenylephrine-infused rats.

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Polichnowski, Aaron J; Griffin, Karen A; Long, Jianrui; Williamson, Geoffrey A; Bidani, Anil K

2013-10-01

Chronic ANG II infusion in rodents is widely used as an experimental model of hypertension, yet very limited data are available describing the resulting blood pressure-renal blood flow (BP-RBF) relationships in conscious rats. Accordingly, male Sprague-Dawley rats (n = 19) were instrumented for chronic measurements of BP (radiotelemetry) and RBF (Transonic Systems, Ithaca, NY). One week later, two or three separate 2-h recordings of BP and RBF were obtained in conscious rats at 24-h intervals, in addition to separate 24-h BP recordings. Rats were then administered either ANG II (n = 11, 125 ng·kg(-1)·min(-1)) or phenylephrine (PE; n = 8, 50 mg·kg(-1)·day(-1)) as a control, ANG II-independent, pressor agent. Three days later the BP-RBF and 24-h BP recordings were repeated over several days. Despite similar increases in BP, PE led to significantly greater BP lability at the heart beat and very low frequency bandwidths. Conversely, ANG II, but not PE, caused significant renal vasoconstriction (a 62% increase in renal vascular resistance and a 21% decrease in RBF) and increased variability in BP-RBF relationships. Transfer function analysis of BP (input) and RBF (output) were consistent with a significant potentiation of the renal myogenic mechanism during ANG II administration, likely contributing, in part, to the exaggerated reductions in RBF during periods of BP elevations. We conclude that relatively equipressor doses of ANG II and PE lead to greatly different ambient BP profiles and effects on the renal vasculature when assessed in conscious rats. These data may have important implications regarding the pathogenesis of hypertension-induced injury in these models of hypertension.

Dissociation of changes in the permeability of the blood-brain barrier from catecholamine-induced changes in blood pressure of normotensive and spontaneously hypertensive rats

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Sankar, R.; Domer, F.R.; Taylor, B.

1982-01-01

Researchers have studied the effects of the pressor catecholamine, dopamine, and the depressor catecholamine, isoproterenol, on the systemic blood pressure and the permeability of the blood-brain barrier (BBB) to albumin in normotensive (WKY) and spontaneously hypertensive (SHR) rats. The rats were anesthetized with pentobarbital. The permeability of the BBB to protein was measured by the extravasation of radioiodinated serum albumin (RISA). The permeability was decreased by both catecholamines despite the dose-dependent, yet opposite, changes in blood pressure in the WKY rats. The blood pressure response to both of the catecholamines was enhanced in the SHR rats. Isoproterenol caused a decrease in the permeability of the BBB in the SHR but dopamine did not. Results with both WKY and SHR rats are suggestive of an adrenergically-mediated decrease in movement across the BBB of compounds of large molecular weight, regardless of changes in blood pressure

Cardiovascular responses to microinjections of GABA or anesthetics into the rostral ventrolateral medulla of conscious and anesthetized rats

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Lacerda J.E.C.

2003-01-01

Full Text Available The rostral ventrolateral medulla (RVLM contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv anesthetized Wistar rats (300-350 g. In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7. A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl. However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7 or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6 was significantly increased after urethane anesthesia. In contrast, there was no difference between conscious (from 117 ± 4.1 to 92 ± 5.9 mmHg, N = 7 and anesthetized rats (from 123 ± 6.9 to 87 ± 8.7 mmHg, N = 7 when lidocaine (34 nmol/200 nl was microinjected into the RVLM. The heart rate variations were not consistent and only eventually reached significance in conscious or anesthetized rats. The right position of pipettes was confirmed by histology and glutamate microinjection into the RVLM. These findings suggest that in conscious animals the RVLM, in association with the other sympathetic premotor neurons, is responsible for the maintenance of sympathetic vasomotor tone during bilateral RVLM inhibition. Activity of one or more of these premotor neurons outside the RVLM can compensate for the effects of RVLM inhibition. In addition, the effects of lidocaine suggest that fibers passing through the RVLM are involved in the maintenance of blood pressure in conscious animals during RVLM inhibition.

Effects of captopril on cerebral blood flow in normotensive and hypertensive rats

International Nuclear Information System (INIS)

Barry, D.I.; Paulson, O.B.; Jarden, J.O.; Juhler, M.; Graham, D.I.; Strandgaard, S.

1984-01-01

Cerebrovascular effects of the angiotensin converting enzyme inhibitor captopril were examined in normotensive and hypertensive rats. Cerebral blood flow was measured with the intracarotid 133 xenon injection method in halothane-anesthetized animals. The blood-brain barrier permeability of captopril (determined with an integral-uptake method) was negligible, the permeability-surface area product in most brain regions being 1 X 10(-5) cm3/g per second, that is, three to four times lower than that of sodium ion. When administered into the cerebral ventricles to bypass the blood-brain barrier, captopril had no effect on cerebral blood flow: furthermore, cerebral blood flow autoregulation (studied by raising and lowering blood pressure) was identical to that in controls. In contrast, when given intravenously, captopril had a marked effect on cerebral blood flow autoregulation--both the lower and upper limits of autoregulation being shifted to a lower pressure (by about 20 to 30 and 50 to 60 mm Hg, respectively), and the autoregulatory range was shortened by about 40 mm Hg. This effect may be ascribed to inhibition of converting enzyme in the cerebral blood vessels rather than within the brain

An improved strategy for evaluating the extent of chronic arterial baroreceptor denervation in conscious rats

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M. Rodríguez-Martínez

2010-11-01

Full Text Available There is no index or criterion of aortic barodenervation, nor can we differentiate among rats that have suffered chronic sham, aortic or sino-aortic denervation. The objective of this study was to develop a procedure to generate at least one quantitative, reproducible and validated index that precisely evaluates the extent of chronic arterial barodenervation performed in conscious rats. Data from 79 conscious male Wistar rats of about 65-70 days of age with diverse extents of chronic arterial barodenervation and used in previous experiments were reanalyzed. The mean arterial pressure (MAP and the heart rate (HR of all rats were measured systematically before (over 1 h and after three consecutive iv bolus injections of phenylephrine (PHE and sodium nitroprusside (SNP. Four expressions of the effectiveness of barodenervation (MAP lability, PHE ratio, SNP ratio, and SNP-PHE slope were assessed with linear fixed models, three-level average variance, average separation among levels, outlier box plot analysis, and overlapping graphic analysis. The analysis indicated that a neither MAP lability nor SNP-PHE slope was affected by the level of chronic sodium intake; b even though the Box-Cox transformations of both MAP lability [transformed lability index (TLI] and SNP-PHE slope [transformed general sensitivity index (TGSI, {((3-(ΔHRSNP-ΔHRPHE/ΔMAPSNP-ΔMAPPHE-0.4-1/-0.04597}] could be two promising indexes, TGSI proved to be the best index; c TLI and TGSI were not freely interchangeable indexes for this purpose. TGSI ranges that permit differentiation between sham (10.09 to 11.46, aortic (8.40 to 9.94 and sino-aortic (7.68 to 8.24 barodenervated conscious rats were defined.

The Diterpene Sclareol Vascular Effect in Normotensive and Hypertensive Rats.

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Campos, Debora Ribeiro; Celotto, Andrea Carla; Albuquerque, Agnes Afrodite S; Ferreira, Luciana Garros; Monteiro, Ariadne Santana E Neves; Coelho, Eduardo Barbosa; Evora, Paulo Roberto Barbosa

2017-06-29

The diterpene Sclareol has antimicrobial action, cytotoxic and cytostatic effects and anti-tumor activities. However, researches on the cardiovascular system are scarce. This study was designed to investigate the mechanisms involved in the Sclareol cardiovascular effect in normotensive and hypertensive rats. The arterial hypertension was promoted using 2-kidneys 1-clip model in rats. The effect of sclareol on blood pressure was performed by using three dose (10, 20 and 40 mg/kg). Cumulative dose-response curves for Sclareol were determined for endothelium-intact and endothelium-denuded aortic rings in presence or absence of L-NAME and ODQ. The NOx levels were measure in the plasma sample. The Sclareol administration in vivo caused a significant reduction in blood pressure in both groups. In vitro the sclareol promoted relaxation in aorta, with endothelium, pre-contracted to Phe. The inhibitors of the nitric oxide synthase and soluble guanylate cyclase were as efficient as the removal of endothelium, in inhibiting the Sclareol-induced relaxation. Otherwise, it was no change of NOx. Also, for unknown reasons, the Sclareol is not selective for hypertensive animals. The diterpene Sclareol showed in vivo hypotensive and in-vitro vasodilator effects; The chemiluminescence plasmatic NO analysis showed no significant difference between groups and The Sclareol exhibit better effect on normotensive than hypertensive animals to reduce blood pressure. It is concluded that the diterpenes metabolites would be a promising source prototype for the development of new agents in the cardiovascular therapy. O diterpeno Esclareol tem ação antimicrobiana, efeitos citotóxicos e citostáticos e atividades antitumorais. No entanto, pesquisas sobre o sistema cardiovascular são escassas. Este estudo foi desenvolvido para investigar os mecanismos envolvidos no efeito cardiovascular de Esclareol em ratos normotensos e hipertensos. A hipertensão arterial foi promovida utilizando modelo de

Electrocoagulation of the Locus coeruleus and the plasma catecholamine responses to immobilization stress in normotensive and hypertensive rats

International Nuclear Information System (INIS)

Dronjak, S.; Nikolic, J.; Varagic, V.M.

1998-01-01

The Locus coeruleus (LC), the largest noradrenergic nucleus in the brain, plays a major role in behavioral arousal in response to novel or stressful stimuli (Foote et al, 1983). An interesting feature of the LC is the degree of plasticity it displays in response to stress or drug treatment. For example, electrophysiological evidence suggests that sprouting of LC axons may occur following repeated stress (Sakaguchi and Nakamura, 1990). Stress increases LC firing rate and results in increased levels of noradrenaline (Glavin et al, 1983). High concentrations of noradrenergic neurons in LC indicated that this structure might have an integrative role in the blood pressure regulation. Spontaneously hypertensive rats (SHP) are widely used as a model of human essential hypertension. These animals exhibit enhanced sympathetic activity (Brody et al, 1980). It was therefore of interest to study the role of LC in normotensive and spontaneously hypertensive rats, and the effect of unilateral and bilateral electrocoagulation of the LC on the plasma concentration of noradrenaline and adrenaline during immobilization stress. (author)

Initial studies using the RatCAP conscious animal PET tomograph

Energy Technology Data Exchange (ETDEWEB)

Woody, C. [Brookhaven National Laboratory, Upton, NY (United States)]. E-mail: woody@bnl.gov; Vaska, P. [Brookhaven National Laboratory, Upton, NY (United States); Schlyer, D. [Brookhaven National Laboratory, Upton, NY (United States); Pratte, J.-F. [Brookhaven National Laboratory, Upton, NY (United States); Junnarkar, S. [Brookhaven National Laboratory, Upton, NY (United States); Park, S.-J. [Brookhaven National Laboratory, Upton, NY (United States); Stoll, S. [Brookhaven National Laboratory, Upton, NY (United States); Purschke, M. [Brookhaven National Laboratory, Upton, NY (United States); Southekal, S. [Stony Brook University, Stony Brook, NY (United States); Kriplani, A. [Stony Brook University, Stony Brook, NY (United States); Krishnamoorthy, S. [Stony Brook University, Stony Brook, NY (United States); Maramraju, S. [Stony Brook University, Stony Brook, NY (United States); Lee, D. [Brookhaven National Laboratory, Upton, NY (United States); Schiffer, W. [Brookhaven National Laboratory, Upton, NY (United States); Dewey, S. [Brookhaven National Laboratory, Upton, NY (United States); Neill, J. [Long Island University, Brookville, NY (United States); Kandasamy, A. [Brookhaven National Laboratory, Upton, NY (United States); O' Connor, P. [Brookhaven National Laboratory, Upton, NY (United States); Radeka, V. [Brookhaven National Laboratory, Upton, NY (United States); Fontaine, R. [Sherbrooke University, Sherbrooke, Que. (Canada); Lecomte, R. [Sherbrooke University, Sherbrooke, Que. (Canada)

2007-02-01

The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4x8 array of 2.2x2.2x5 mm{sup 3} LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of {approx}14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using {sup 18}F-FDG and {sup 11}C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

Initial studies using the RatCAP conscious animal PET tomograph

International Nuclear Information System (INIS)

Woody, C.; Vaska, P.; Schlyer, D.; Pratte, J.-F.; Junnarkar, S.; Park, S.-J.; Stoll, S.; Purschke, M.; Southekal, S.; Kriplani, A.; Krishnamoorthy, S.; Maramraju, S.; Lee, D.; Schiffer, W.; Dewey, S.; Neill, J.; Kandasamy, A.; O'Connor, P.; Radeka, V.; Fontaine, R.; Lecomte, R.

2007-01-01

The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4x8 array of 2.2x2.2x5 mm 3 LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of ∼14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using 18 F-FDG and 11 C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP

Vitamin D3 deficiency increases DNA damage and modify the expression of genes associated with hypertension in normotensive and hypertensive rats

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Carla Silva Machado

2015-05-01

Full Text Available Vitamin D3 is a lipophilic micronutrient obtained from the diet (salmon, sardines, mackerel and cod liver oil or by the conversion of 7-dehydrocholesterol on skin after exposure to UVB radiation. This vitamin participates in several cellular processes, contributes to the maintenance of calcium concentrations, acts on phosphorus absorption, and is also related to the development and progression of chronic diseases. In hypertension, it is known that vitamin D3 act on renin-angiotensin-aldosterone system, regulates the gene expression and can induce or attenuate oxidative DNA damage. Vitamin D3 deficiency is present in 30-50% of human population (Pilz et al., 2009, and has been associated with increase of chromosomal instability and DNA damage (Nair-Shalliker; Armstrong; Fenech, 2012. Since experimental and clinical studies have suggested a relationship between vitamin D3 and blood pressure, the aim of this study was to evaluate whether vitamin D3 deficiency or supplementation lead to an increase or decrease in DNA damage, regulates the expression of genes associated with hypertension and changes the systolic blood pressure. Spontaneously hypertensive rats (SHR, used as a model of human essential hypertension, and their normotensive controls (Wistar Kyoto – WKY were fed a control diet (vitamin D3 at 1.000 UI/kg, a deficient diet (vitamin D3 at 0 UI/kg or a supplemented diet (vitamin D3 at 10.000 UI/kg for 12 weeks. DNA damage was assessed by comet assay in cardiac muscle tissue and blood tissue, following the methodology proposed by Singh et al. (1988 and Tice et al. (2000; gene expression of 84 genes was assessed by RT2ProfilerTM PCR Array in cardiac muscle tissue; and systolic blood pressure was measured weekly by a noninvasive method using tail plethysmography. In SHR and WKY rats, vitamin D3 deficiency increased DNA damage in the blood tissue and did not change the DNA damage in cardiac muscle tissue; vitamin D3 supplementation maintained the

Zea mays L. extracts modify glomerular function and potassium urinary excretion in conscious rats.

Science.gov (United States)

Velazquez, D V O; Xavier, H S; Batista, J E M; de Castro-Chaves, C

2005-05-01

Diuretic and uricosuric properties have traditionally been attributed to corn silk, stigma/style of Zea mays L. Although the diuretic effect was confirmed, studies of the plant's effects on renal function or solute excretion were lacking. Thus, we studied the effects of corn silk aqueous extract on the urinary excretion of water, Na+, K+, and uric acid. Glomerular and proximal tubular function and Na+ tubular handling were also studied. Conscious, unrestrained adult male rats were housed in individual metabolic cages (IMC) with continuous urine collection for 5 and 3 h, following two protocols. The effects of 25, 50, 200, 350, and 500 mg/kg body wt. corn silk extract on urine volume plus Na+ and K+ excretions were studied in water-loaded conscious rats (2.5 ml/100 g body wt.) in the IMC for 5 h (Protocol 1). Kaliuresis was observed with doses of 350 (100.42 +/- 22.32-120.28 +/- 19.70 microEq/5 h/100 g body wt.; n = 13) and 500 mg/kg body wt. (94.97+/- 29.30-134.32 +/- 39.98 microEq/5h/100 g body wt.; n = 12; pcorn silk extract on urine volume, Na+, K+ and uric acid excretions, and glomerular and proximal tubular function, were measured respectively by creatinine (Cler) and Li+ (ClLi) clearances and Na+ tubular handling, in water-loaded rats (5 ml/100 g body wt.) in the IMC for 3 h (Protocol 2). Clcr (294.6 +/- 73.2, n = 12, to 241.7 +/- 48.0 microl/ min/100 g body wt.; n = 13; pcorn silk aqueous extract is diuretic at a dose of 500 mg/kg body wt. and kaliuretic at doses of 350 and 500 mg/kg body wt. In water-loaded conscious rats (5.0 ml/100 g body wt.), corn silk aqueous extract is kaliuretic at a dose of 500 mg/kg body wt., but glomerular filtration and filtered load decrease without affecting proximal tubular function, Na+, or uric acid excretion.

Effects of a K+ channel blocker on glomerular filtration rate and electrolyte excretion in conscious rats.

Science.gov (United States)

Ludens, J H; Clark, M A; Lawson, J A

1995-06-01

Effects of a K+ channel blocker on glomerular filtration rate and electrolyte excretion in conscious rats were observed. Effects of K+ channel modulation on glomerular filtration rate and electrolyte excretion were studied using the adenosine-triphosphate- (ATP)-sensitive K+ channel blocker 4-morpholinecarboximidine-N-1-adamantyl-N'-cyclohexylhydr ochloride (U-37883A) in conscious rats previously equipped with catheters for clearance studies. In saline-loaded rats, i.v. doses of U-37883A of 1.7, 5.0 and 15 mg/kg increased absolute and fractional Na+ excretion dose-dependently without changing K+ excretion. The glomerular filtration rate remained constant during diuresis. In water-loaded (hypotonic dextrose) rats, free-water clearance studies revealed that the ATP-sensitive K+ channel blocker significantly decreased an index of solute reabsorption (free-water clearance adjusted for chloride clearance) in the diluting segment during peak natriuretic activity. In addition, U-37883A significantly decreased the osmolality of renal papillary interstitial fluid, indicative of an effect in the medullary portion of the diluting segment. Together, these findings suggest that ATP-sensitive K+ channels, possibly those located at the apical boarder, play a pivotal role in Na+ reabsorption in the thick ascending limb of the loop of Henle.

Uric Acid Levels in Normotensive Children of Hypertensive Parents.

Science.gov (United States)

Yildirim, Ali; Keles, Fatma; Kosger, Pelin; Ozdemir, Gokmen; Ucar, Birsen; Kilic, Zubeyir

2015-01-01

This study evaluated uric acid concentrations in normotensive children of parents with hypertension. Eighty normotensive children from families with and without a history of essential hypertension were included. Concentrations of lipid parameters and uric acid were compared. Demographic and anthropometric characteristics were similar in the groups. Systolic and diastolic blood pressure were higher in the normotensive children of parents with hypertension without statistically significant difference (P > 0.05). Uric acid concentrations were higher in the normotensive children of parents with hypertension (4.61 versus 3.57 mg/dL, P pressure were significantly higher in control children aged >10 years (P children with more pronounced difference after age 10 of years (P pressure in the normotensive children of parents. The higher uric acid levels in the normotensive children of hypertensive parents suggest that uric acid may be a predeterminant of hypertension. Monitoring of uric acid levels in these children may allow for prevention or earlier treatment of future hypertension.

Structured triglyceride vehicles for oral delivery of halofantrine: examination of intestinal lymphatic transport and bioavailability in conscious rats

DEFF Research Database (Denmark)

Holm, René; Porter, Christopher J H; Müllertz, Anette

2002-01-01

PURPOSE: To compare the influence of triglyceride vehicle intramolecular structure on the intestinal lymphatic transport and systemic absorption of halofantrine in conscious rats. METHODS: Conscious, lymph cannulated and nonlymph cannulated rats were dosed orally with three structurally different...... triglycerides; sunflower oil, and two structured triglycerides containing different proportion and position of medium-(M) and long-chain (L) fatty acids on the glycerol backbone. The two structured triglycerides were abbreviated MLM and LML to reflect the structural position on the glycerol. The concentration...... animals, and this was most pronounced for the animals dosed with the structured triglycerides. CONCLUSIONS: Using MLM as vehicle increases the portal absorption of halofantrine and results in similar lymphatic transport levels when compared to sunflower oil. Total absorption when assessed as absorption...

Effects of nonhypotensive endotoxemia in conscious rats: Role of prostaglandins

International Nuclear Information System (INIS)

Burnier, M.; Waeber, B.; Aubert, J.F.; Nussberger, J.; Brunner, H.R.

1988-01-01

A nonhypotensive dose of endotoxin was administered to normal conscious rats to evaluate the vascular and humoral effects of endotoxemia per se. Mean blood pressure and heart rate remained stable during the 45 min infusion of Escherichia coli endotoxin. However, a marked increase in plasma renin activity plasma epinephrine and plasma norepinephrine was observed during infusion in endotoxin-treated rats when compared with the vehicle-treated animals. In addition, the blood pressure response to exogenous norepinephrine was significantly reduced during nonhypotensive endotoxemia. Significant changes in regional blood flow distribution, as assessed by radiolabeled microspheres, were observed in endotoxemic rats; in particular a decrease in renal blood flow, and an increase in coronary blood flow were found. The role of prostaglandins in the vascular and humoral alterations induced by nonhypotensive endotoxemia was also examined. Pretreatment with indomethacin (5 mg) prevent the increase in plasma renin activity as well as plasma catecholamine levels. On the contrary, the decreased vascular reactivity and the reduction in renal blood flow observed during endotoxemia were not affected by prostaglandin synthesis inhibition. Thus significant vascular and humoral changes have been found during endotoxemia even in absence of hypotension. The humoral but not the vascular effects of endotoxemia were abolished when prostaglandin synthesis was inhibited

Uric Acid Levels in Normotensive Children of Hypertensive Parents

Directory of Open Access Journals (Sweden)

Ali Yildirim

2015-01-01

Full Text Available This study evaluated uric acid concentrations in normotensive children of parents with hypertension. Eighty normotensive children from families with and without a history of essential hypertension were included. Concentrations of lipid parameters and uric acid were compared. Demographic and anthropometric characteristics were similar in the groups. Systolic and diastolic blood pressure were higher in the normotensive children of parents with hypertension without statistically significant difference (P>0.05. Uric acid concentrations were higher in the normotensive children of parents with hypertension (4.61 versus 3.57 mg/dL, P10 years (P<0.01. Uric acid levels were significantly higher in all children with more pronounced difference after age 10 of years (P<0.001. Positive correlations were found between the level of serum uric acid and age, body weight, body mass index, and systolic and diastolic blood pressure in the normotensive children of parents. The higher uric acid levels in the normotensive children of hypertensive parents suggest that uric acid may be a predeterminant of hypertension. Monitoring of uric acid levels in these children may allow for prevention or earlier treatment of future hypertension.

Uric Acid Levels in Normotensive Children of Hypertensive Parents

OpenAIRE

Yildirim, Ali; Keles, Fatma; Kosger, Pelin; Ozdemir, Gokmen; Ucar, Birsen; Kilic, Zubeyir

2015-01-01

This study evaluated uric acid concentrations in normotensive children of parents with hypertension. Eighty normotensive children from families with and without a history of essential hypertension were included. Concentrations of lipid parameters and uric acid were compared. Demographic and anthropometric characteristics were similar in the groups. Systolic and diastolic blood pressure were higher in the normotensive children of parents with hypertension without statistically significant diff...

Pressor response to L-cysteine injected into the cisterna magna of conscious rats involves recruitment of hypothalamic vasopressinergic neurons.

Science.gov (United States)

Takemoto, Yumi

2013-03-01

The sulfur-containing non-essential amino acid L-cysteine injected into the cisterna magna of adult conscious rats produces an increase in blood pressure. The present study examined if the pressor response to L-cysteine is stereospecific and involves recruitment of hypothalamic vasopressinergic neurons and medullary noradrenergic A1 neurons. Intracisternally injected D-cysteine produced no cardiovascular changes, while L-cysteine produced hypertension and tachycardia in freely moving rats, indicating the stereospecific hemodynamic actions of L-cysteine via the brain. The double labeling immunohistochemistry combined with c-Fos detection as a marker of neuronal activation revealed significantly higher numbers of c-Fos-positive vasopressinergic neurons both in the supraoptic and paraventricular nuclei and tyrosine hydroxylase containing medullary A1 neurons, of L-cysteine-injected rats than those injected with D-cysteine as iso-osmotic control. The results indicate that the cardiovascular responses to intracisternal injection of L-cysteine in the conscious rat are stereospecific and include recruitment of hypothalamic vasopressinergic neurons both in the supraoptic and paraventricular nuclei, as well as of medullary A1 neurons. The findings may suggest a potential function of L-cysteine as an extracellular signal such as neuromodulators in central regulation of blood pressure.

The Labdane Ent-3-Acetoxy-Labda-8(17), 13-Dien-15-Oic Decreases Blood Pressure In Hypertensive Rats

Energy Technology Data Exchange (ETDEWEB)

Simplicio, Janaina A. [Programa de Pós-Graduação em Farmacologia - Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo (USP), Ribeirão Preto, SP (Brazil); Departamento de Enfermagem Psiquiátrica e Ciências Humanas - Laboratório de Farmacologia - Escola de Enfermagem de Ribeirão Preto (USP), Ribeirão Preto, SP (Brazil); Simão, Marilia R.; Ambrosio, Sergio R. [Núcleo de Pesquisa em Ciências e Tecnologia - Universidade de Franca (UNIFRAN), Franca, SP (Brazil); Tirapelli, Carlos R., E-mail: crtirapelli@eerp.usp.br [Departamento de Enfermagem Psiquiátrica e Ciências Humanas - Laboratório de Farmacologia - Escola de Enfermagem de Ribeirão Preto (USP), Ribeirão Preto, SP (Brazil)

2016-06-15

Labdane-type diterpenes induce lower blood pressure via relaxation of vascular smooth muscle; however, there are no studies describing the effects of labdanes in hypertensive rats. The present study was designed to investigate the cardiovascular actions of the labdane-type diterpene ent-3-acetoxy-labda-8(17), 13-dien-15-oic acid (labda-15-oic acid) in two-kidney 1 clip (2K-1C) renal hypertension. Vascular reactivity experiments were performed in aortic rings isolated from 2K-1C and normotensive (2K) male Wistar rats. Nitrate/nitrite (NOx) measurement was performed in aortas by colorimetric assay. Blood pressure measurements were performed in conscious rats. Labda-15-oic acid (0.1-300 µmol/l) and forskolin (0.1 nmol/l - 1 µmol/l) relaxed endothelium-intact and endothelium-denuded aortas from both 2K-1C and 2K rats. Labda-15-oic acid was more effective at inducing relaxation in endothelium-intact aortas from 2K pre-contracted with phenylephrine when compared to the endothelium-denuded ones. Forskolin was more potent than labda-15-oic acid at inducing vascular relaxation in arteries from both 2K and 2K-1C rats. Labda-15-oic acid-induced increase in NOx levels was lower in arteries from 2K-1C rats when compared to 2K rats. Intravenous administration of labda-15-oic acid (0.3-3 mg/kg) or forskolin (0.1-1 mg/kg) induced hypotension in conscious 2K-1C and 2K rats. The present findings show that labda-15-oic acid induces vascular relaxation and hypotension in hypertensive rats.

Evaluation of mechanism for antihypertensive and vasorelaxant effects of hexanic and hydroalcoholic extracts of celery seed in normotensive and hypertensive rats

Directory of Open Access Journals (Sweden)

Faezeh Tashakori-Sabzevar

Full Text Available ABSTRACT Celery (Apium graveolens L., Apiaceae is one of the popular aromatic vegetables and part of the daily diet around the world. In this study, aqueous-ethanolic and hexane extracts of celery seed were prepared and the amount of n-butylphthalide, as an active component, was determined in each extract. Then the effects of hexanic extract on systolic, diastolic, mean arterial blood pressure and heart rate were evaluated in an invasive rat model. The vasodilatory effect and possible mechanisms of above mentioned extracts on aorta ring were also measured. High performance liquid chromatography analysis revealed that hexanic extract contains significantly higher amounts of n-butylphthalide, compared to aqueous-ethanolic extract. The results indicated that hexanic extract significantly decreased the systolic, diastolic, mean arterial blood pressure and heart rate in normotensive and hypertensive rats. Our data revealed that celery seed extract exerts its hypotensive effects through its bradycardic and vasodilatory properties. Moreover, the active components in celery seed extracts could induce their vasodilatory properties through Ca2+ channel blocking activity in endothelial and non-endothelial pathways and particularly by interference with the extra or intracellular calcium.

Humoral Na+-K+ pump inhibitory activity in essential hypertension and in normotensive subjects after acute volume expansion

International Nuclear Information System (INIS)

Pamnani, M.B.; Burris, J.F.; Jemionek, J.F.; Huot, S.J.; Price, M.; Freis, E.D.; Haddy, F.J.

1989-01-01

Plasma from black male patients with essential hypertension was bioassayed for vascular Na+-K+ pump inhibitory activity. Halves of the same rat tail artery were incubated for two hours in boiled plasma supernates from a hypertensive patient and a paired age-, sex-, and race-matched normotensive subject and then ouabain-sensitive 86 Rb uptake was measured. Ouabain-sensitive 86 Rb uptake by their leukocytes was also measured. Eighteen pairs of subjects were studied. The uptakes were not significantly different in the hypertensive patients and control subjects. However, when we selected from the eighteen hypertensive patients, nine with low plasma renin activity on the day of the study, uptakes were reduced in the hypertensive patients relative to the paired control subjects. We also assayed plasma supernates from normotensive black and white male subjects before and after acute volume expansion (2.5 L saline IV + 1.5 L distilled water orally over a three-hour period) and from paired normotensive subjects before and after sham volume expansion and obtained a positive bioassay in the expanded subjects both on intraindividual and interindividual comparisons. These studies demonstrate increased vascular Na+-K+ pump inhibitory activity in the plasma of black male patients with low renin essential hypertension and in the plasma of normotensive subjects after acute volume expansion. The findings suggest that the inhibitory activity in the hypertensive subjects' plasma is related to volume expansion, relative or absolute

Effects of music composed by Mozart and Ligeti on blood pressure and heart rate circadian rhythms in normotensive and hypertensive rats.

Science.gov (United States)

Lemmer, Björn

2008-11-01

There is continuing discussion on the effect of music ("Mozart effect") on numerous functions in man and experimental animals. Radiotelemetry now allows one to monitor cardiovascular functions in freely-moving unrestrained experimental animals. Radiotelemetry was used to monitor systolic and diastolic blood pressure (SBP, DBP), heart rate (HR), and motor activity (MA) in male normotensive WKY and hypertensive SHR animals. Rats were synchronized to a 12 h light (L): 12 h dark (D) regimen in an isolated, ventilated, light-controlled, sound-isolated animal container. Music (Mozart, Symphony # 40; Ligeti, String Quartet # 2) were played for 2 h at 75 dB in the animal cabin starting at the onset of L or D in a cross-over design. Data were collected every 5 min for 24 h under control conditions and during and after music. In addition, plasma concentrations of norepinephrine (NE) were determined in unrestrained animals at 3 h intervals over 24 h. In both WKY and SHR, highly significant circadian rhythms were obtained in SBP, DBP, HR, and MA under control conditions; HR was lower and BP higher in SHR than in WKY. NE was circadian rhythmic in both strains with higher values in D; the increase in NE with immobilization was much more pronounced in SHR than in WKY. The music of Mozart had no effect on either parameter in WKY, neither in L nor in D. In contrast, in SHR, the music of Mozart presented in L significantly decreased HR and left BP unaffected, leading to a small decrease in cardiac output. The music of Ligeti significantly increased BP both in L and in D and reflexively reduced HR in L, the effects being long-lasting over 24 h. Interestingly, white noise at 75 dB had no effect at all on either function in both strains. The effects of both Mozart and Ligeti cannot be attributed to a stress reaction, as stress due to cage switch increased HR and BP both in WKY and SHR. The study clearly demonstrates that music of different character (tempo, rhythm, pitch, tonality) can

Baseline brain energy supports the state of consciousness.

Science.gov (United States)

Shulman, Robert G; Hyder, Fahmeed; Rothman, Douglas L

2009-07-07

An individual, human or animal, is defined to be in a conscious state empirically by the behavioral ability to respond meaningfully to stimuli, whereas the loss of consciousness is defined by unresponsiveness. PET measurements of glucose or oxygen consumption show a widespread approximately 45% reduction in cerebral energy consumption with anesthesia-induced loss of consciousness. Because baseline brain energy consumption has been shown by (13)C magnetic resonance spectroscopy to be almost exclusively dedicated to neuronal signaling, we propose that the high level of brain energy is a necessary property of the conscious state. Two additional neuronal properties of the conscious state change with anesthesia. The delocalized fMRI activity patterns in rat brain during sensory stimulation at a higher energy state (close to the awake) collapse to a contralateral somatosensory response at lower energy state (deep anesthesia). Firing rates of an ensemble of neurons in the rat somatosensory cortex shift from the gamma-band range (20-40 Hz) at higher energy state to energy state. With the conscious state defined by the individual's behavior and maintained by high cerebral energy, measurable properties of that state are the widespread fMRI patterns and high frequency neuronal activity, both of which support the extensive interregional communication characteristic of consciousness. This usage of high brain energies when the person is in the "state" of consciousness differs from most studies, which attend the smaller energy increments observed during the stimulations that form the "contents" of that state.

Increased hepatic nicotine elimination after phenobarbital induction in the conscious rat

International Nuclear Information System (INIS)

Foth, H.; Walther, U.I.; Kahl, G.F.

1990-01-01

Elimination parameters of [14C]nicotine in conscious rats receiving nicotine (0.3 mg/kg) either intravenously or orally were studied. The oral availability of unchanged nicotine, derived by comparison of the respective areas under the concentration vs time curves (AUC), was 89%, indicating low hepatic extraction ratios of about 10%. Pretreatment of rats with phenobarbital (PB) markedly increased hepatic first-pass extraction of nicotine. The oral availability of unchanged nicotine in plasma dropped to 1.4% of the corresponding values obtained from PB-treated rats receiving nicotine iv. After PB pretreatment, the clearance of iv nicotine was increased approximately twofold over controls, much less than the observed more than ninefold increase of hepatic first-pass extraction. It is assumed that extrahepatic metabolism contributed significantly to the rapid removal of nicotine from the plasma. The elimination of cotinine, originating from nicotine administered either po or iv, was significantly increased by PB pretreatment, as determined by the ratio of corresponding AUCs. The pattern of nicotine metabolites in urine also indicated an increase in the rate of cotinine metabolic turnover. The amount of norcotinine in the organic extract of urine paralleled PB microsomal enzyme induction. The ratio between urinary concentrations of the normetabolite and cotinine correlated strongly with the PB-induced state of rat liver. This may be a suitable indicator of PB-inducible hepatic cytochrome P450 isoenzyme(s). Since smoking habits in man are feedback-regulated by nicotine plasma concentrations, a similar increase of nicotine elimination by microsomal enzyme induction in man may be of relevance for tobacco consumption

Effects of mosapride citrate, a 5-HT4-receptor agonist, on gastric distension-induced visceromotor response in conscious rats.

Science.gov (United States)

Seto, Yasuhiro; Yoshida, Naoyuki; Kaneko, Hiroshi

2011-01-01

Mosapride citrate (mosapride), a prokinetic agent with 5-HT(4)-receptor agonistic activity, is known to enhance gastric emptying and alleviate symptoms in patients with functional dyspepsia (FD). As hyperalgesia and delayed gastric emptying play an important role in the pathogenesis of FD, we used in this study balloon gastric distension to enable abdominal muscle contractions and characterized the visceromotor response (VMR) to such distension in conscious rats. We also investigated the effects of mosapride on gastric distension-induced VMR in the same model. Mosapride (3-10 mg/kg, p.o.) dose-dependently inhibited gastric distension-induced VMR in rats. However, itopride even at 100 mg/kg failed to inhibit gastric distension-induced VMR in rats. Additionally, a major metabolite M1 of mosapride, which possesses 5-HT(3)-receptor antagonistic activity, inhibited gastric distension-induced VMR. The inhibitory effect of mosapride on gastric distension-induced visceral pain was partially, but significantly inhibited by SB-207266, a selective 5-HT(4)-receptor antagonist. This study shows that mosapride inhibits gastric distension-induced VMR in conscious rats. The inhibitory effect of mosapride is mediated via activation of 5-HT(4) receptors and blockage of 5-HT(3) receptors by a mosapride metabolite. This finding indicates that mosapride may be useful in alleviating FD-associated gastrointestinal symptoms via increase in pain threshold.

Regulation of Arterial Pressure By The Paraventricular Nucleus in Conscious Rats: Interactions Among Glutamate, GABA, and Nitric Oxide

Directory of Open Access Journals (Sweden)

Marli Cardoso Martins-Pinge

2013-01-01

Full Text Available The paraventricular nucleus (PVN of the hypothalamus is an important site for autonomic and neuroendocrine regulation. Experiments in anesthetized animals and in vitro indicate an interaction among gamma-aminobutyric acid (GABA, nitric oxide (NO and glutamate in the PVN. The cardiovascular role of the PVN and interactions of these neurotransmitters in conscious animals have not been evaluated fully. In chronically instrumented conscious rats, mean arterial pressure (MAP and heart rate (HR responses to microinjections (100 nl in the region of the PVN were tested. Bilateral blockade of ionotropic excitatory amino acid (EAA receptors (kynurenic acid, Kyn in the PVN produced small but significant decreases in MAP and HR. GABAA receptor blockade (bicuculline, Bic, and inhibition of NO synthase (N-(G-monomethyl-L-arginine, L-NMMA each increased MAP and HR. The NO donor sodium nitroprusside (SNP produced depressor responses that were attenuated by Bic. NO synthase inhibition potentiated both pressor responses to the selective EAA agonist, N-methyl-D-aspartic acid (NMDA, and depressor responses to Kyn. Increases in MAP and HR due to Bic were blunted by prior blockade of EAA receptors. Thus, pressor responses to GABA blockade require EAA receptors and GABA neurotransmission contributes to NO inhibition. Tonic excitatory effects of glutamate in the PVN are tonically attenuated by NO. These data demonstrate that, in the PVN of conscious rats, GABA, glutamate and NO interact in a complex fashion to regulate arterial pressure and heart rate under normal conditions.

Angiotensin II and CRF Receptors in the Central Nucleus of the Amygdala Mediate Hemodynamic Response Variability to Cocaine in Conscious Rats

OpenAIRE

Watanabe, Mari A.; Kucenas, Sarah; Bowman, Tamara A.; Ruhlman, Melissa; Knuepfer, Mark M.

2009-01-01

Stress or cocaine evokes either a large increase in systemic vascular resistance (SVR) or a smaller increase in SVR accompanied by an increase in cardiac output (designated vascular and mixed responders, respectively) in Sprague-Dawley rats. We hypothesized that the central nucleus of the amygdala (CeA) mediates this variability. Conscious, freely-moving rats, instrumented for measurement of arterial pressure and cardiac output and for drug delivery into the CeA, were given cocaine (5 mg/kg, ...

Structured triglyceride vehicles for oral delivery of halofantrine: examination of intestinal lymphatic transport and bioavailability in conscious rats.

Science.gov (United States)

Holm, René; Porter, Christopher J H; Müllertz, Anette; Kristensen, Henning G; Charman, William N

2002-09-01

To compare the influence of triglyceride vehicle intramolecular structure on the intestinal lymphatic transport and systemic absorption of halofantrine in conscious rats. Conscious, lymph cannulated and nonlymph cannulated rats were dosed orally with three structurally different triglycerides; sunflower oil, and two structured triglycerides containing different proportion and position of medium-(M) and long-chain (L) fatty acids on the glycerol backbone. The two structured triglycerides were abbreviated MLM and LML to reflect the structural position on the glycerol. The concentration of halofantrine in blood and lymph samples was analyzed by HPLC. Both the lymphatic transport and the total absorption of halofantrine were enhanced by the use the MLM triglyceride. The estimated total absorption of halofantrine in the lymph cannulated animals was higher than in the nonlymph cannulated animals, and this was most pronounced for the animals dosed with the structured triglycerides. Using MLM as vehicle increases the portal absorption of halofantrine and results in similar lymphatic transport levels when compared to sunflower oil. Total absorption when assessed as absorption in the blood plus lymphatic transport for halofantrine after administration in the MLM triglyceride was higher than after administration in sunflower oil.

Long-term pretreatment with desethylamiodarone (DEA) or amiodarone (AMIO) protects against coronary artery occlusion induced ventricular arrhythmias in conscious rats.

Science.gov (United States)

Morvay, Nikolett; Baczkó, István; Sztojkov-Ivanov, Anita; Falkay, György; Papp, Julius Gy; Varró, András; Leprán, István

2015-09-01

The aim of this investigation was to compare the effectiveness of long-term pretreatment with amiodarone (AMIO) and its active metabolite desethylamiodarone (DEA) on arrhythmias induced by acute myocardial infarction in rats. Acute myocardial infarction was induced in conscious, male, Sprague-Dawley rats by pulling a previously inserted loose silk loop around the left main coronary artery. Long-term oral pretreatment with AMIO (30 or 100 mg·(kg body mass)(-1)·day(-1), loading dose 100 or 300 mg·kg(-1) for 3 days) or DEA (15 or 50 mg·kg(-1)·day(-1), loading dose 100 or 300 mg·kg(-1) for 3 days), was applied for 1 month before the coronary artery occlusion. Chronic oral treatment with DEA (50 mg·kg(-1)·day(-1)) resulted in a similar myocardial DEA concentration as chronic AMIO treatment (100 mg·kg(-1)·day(-1)) in rats (7.4 ± 0.7 μg·g(-1) and 8.9 ± 2.2 μg·g(-1)). Both pretreatments in the larger doses significantly improved the survival rate during the acute phase of experimental myocardial infarction (82% and 64% by AMIO and DEA, respectively, vs. 31% in controls). Our results demonstrate that chronic oral treatment with DEA resulted in similar cardiac tissue levels to that of chronic AMIO treatment, and offered an equivalent degree of antiarrhythmic effect against acute coronary artery ligation induced ventricular arrhythmias in conscious rats.

Norepinephrine accumulation by the rat caudal artery in the presence of hypertensive plasma

International Nuclear Information System (INIS)

Freas, W.; Thompson, D.A.; Hart, J.L.; Muldoon, S.M.

1986-01-01

We have partially isolated endogenous factors from canine plasma which inhibit 3 H-norepinephrine (NE) accumulation by the canine saphenous vein. The purpose of this study is to determine if these circulating factors may account for the observed differences in 3 H-NE uptake by hypertensive and normotensive blood vessels. Three models of hypertension were examined in this study. Blood vessels were compared from SHR and WKY rats, deoxycorticosterone acetate (DOCA) and control rats, and reduced renal mass (RRM) and control rats. There was no significant difference in 3 H-NE accumulation between blood vessels obtained from RRM and paired control rats. However, both the SHR and DOCA hypertensive caudal arteries and aorta accumulated significantly more 3 H-NE than their corresponding control tissues. There was not a significant change in 3 H-NE accumulation between hypertensive and control vena cava and mesenteric arteries. Normotensive and hypertensive plasma inhibited 3 H-NE accumulation by the rat caudal artery. However, there was not a correlation between blood pressure of plasma donor rats and accumulation of 3 H-NE. Therefore, although there are differences in 3 H-NE accumulation between hypertensive and normotensive blood vessels, plasma does not contain a factor responsible for this observed difference

Grooming behavior of spontaneously hypertensive rats

NARCIS (Netherlands)

Buuse, M. van den; Jong, Wybren de

1987-01-01

In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

Strain differences in baroceptor reflex in adult Wistar Kyoto rats

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Vitor E. Valenti

2010-01-01

Full Text Available OBJECTIVES: A subset of normotensive Sprague-Dawley rats show lower baroreflex sensitivity; however, no previous study investigated whether there are differences in baroreflex sensitivity within this subset. Our study compared baroreflex sensitivity among conscious rats of this specific subtype. METHODS: Male Wistar Kyoto (WKY rats (16 weeks old were studied. Cannulas were inserted into the abdominal aortic artery through the right femoral artery to measure mean arterial pressure (MAP and heart rate (HR. Baroreflex gain was calculated as the ratio between change in HR and MAP variation (ΔHR/ΔMAP in response to a depressor dose of sodium nitroprusside (SNP, 50 µg/kg, i.v. and a pressor dose of phenylephrine (PE, 8 µg/kg, i.v.. Rats were divided into four groups: 1 low bradycardic baroreflex (LB, baroreflex gain (BG between -1 and -2 bpm/mmHg tested with PE; 2 high bradycardic baroreflex (HB, BG < -2 bpm/mmHg tested with PE; 3 low tachycardic baroreflex (LT, BG between -1 and -2 bpm/mmHg tested with SNP and; 4 high tachycardic baroreflex (HT, BG < -2 bpm/mmHg tested with SNP. Significant differences were considered for p < 0.05. RESULTS: Approximately 37% of the rats showed a reduced bradycardic peak, bradycardic reflex and decreased bradycardic gain of baroreflex while roughly 23% had a decreased basal HR, tachycardic peak, tachycardic reflex and reduced sympathetic baroreflex gain. No significant alterations were noted with regard to basal MAP. CONCLUSION: There is variability regarding baroreflex sensitivity among WKY rats from the same laboratory.

Direct conscious telemetry recordings demonstrate increased renal sympathetic nerve activity in rats with chronic kidney disease

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Ibrahim M Salman

2015-08-01

Full Text Available Chronic kidney disease (CKD is associated with sympathetic hyperactivity and impaired blood pressure control reflex responses, yet direct evidence demonstrating these features of autonomic dysfunction in conscious animals is still lacking. Here we measured renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP using telemetry-based recordings in a rat model of CKD, the Lewis Polycystic Kidney (LPK rat, and assessed responses to chemoreflex activation and acute stress. Male LPK and Lewis control animals (total n=16 were instrumented for telemetric recording of RSNA and MAP. At 12–13 weeks-of-age, resting RSNA and MAP, sympathetic and haemodynamic responses to both peripheral (hypoxia: 10% O2 and central chemoreflex (hypercapnia: 7% CO2 activation and acute stress (open-field exposure, were measured. As indicators of renal function, urinary protein (UPro and creatinine (Ucr levels were assessed. LPK rats had higher resting RSNA (1.2±0.1 vs. 0.6±0.1 µV, p<0.05 and MAP (151±8 vs. 97±2 mmHg, p<0.05 compared to Lewis. MAP was negatively correlated with Ucr (r=-0.80, p=0.002 and positively correlated with RSNA (r=0.66, p=0.014, with multiple linear regression modeling indicating the strongest correlation was with Ucr. RSNA and MAP responses to activation of the central chemoreflex and open-field stress were reduced in the LPK relative to the Lewis (all p<0.05. This is the first description of dual conscious telemetry recording of RSNA and MAP in a genetic rodent model of CKD. Elevated RSNA is likely a key contributor to the marked hypertension in this model, while attenuated RSNA and MAP responses to central chemoreflex activation and acute stress in the LPK indicate possible deficits in the neural processing of autonomic outflows evoked by these sympathoexcitatory pathways.

Impaired cardiac ischemic tolerance in spontaneously hypertensive rats is attenuated by adaptation to chronic and acute stress.

Science.gov (United States)

Ravingerová, T; Bernátová, I; Matejíková, J; Ledvényiová, V; Nemčeková, M; Pecháňová, O; Tribulová, N; Slezák, J

2011-01-01

Chronic hypertension may have a negative impact on the myocardial response to ischemia. On the other hand, intrinsic ischemic tolerance may persist even in the pathologically altered hearts of hypertensive animals, and may be modified by short- or long-term adaptation to different stressful conditions. The effects of long-term limitation of living space (ie, crowding stress [CS]) and brief ischemia-induced stress on cardiac response to ischemia/reperfusion (I/R) injury are not yet fully characterized in hypertensive subjects. The present study was designed to test the influence of chronic and acute stress on the myocardial response to I/R in spontaneously hypertensive rats (SHR) compared with their effects in normotensive counterparts. In both groups, chronic, eight-week CS was induced by caging five rats per cage in cages designed for two rats (200 cm(2)/rat), while controls (C) were housed four to a cage in cages designed for six animals (480 cm(2)/rat). Acute stress was evoked by one cycle of I/R (5 min each, ischemic preconditioning) before sustained I/R in isolated Langendorff-perfused hearts of normotensive and SHR rats. At baseline conditions, the effects of CS were manifested only as a further increase in blood pressure in SHR, and by marked limitation of coronary perfusion in normotensive animals, while no changes in heart mechanical function were observed in any of the groups. Postischemic recovery of contractile function, severity of ventricular arrhythmias and lethal injury (infarction size) were worsened in the hypertrophied hearts of C-SHR compared with normotensive C. However, myo-cardial stunning and reperfusion-induced ventricular arrhythmias were attenuated by CS in SHR, which was different from deterioration of I/R injury in the hearts of normotensive animals. In contrast, ischemic preconditioning conferred an effective protection against I/R in both groups, although the extent of anti-infarct and anti-arrhythmic effects was lower in SHR. Both

Serum 25-hydroxy Vitamin D Level In Preeclamptic And Normotensive Pregnancies

International Nuclear Information System (INIS)

Umar, N.; Shahzad, F.; Akmal, A.; Tauseef, A.; Sabir, S.; Shumaela Kanwal, S.; Zulfiqar, S.

2016-01-01

Objective:To compare serum 25-hydroxy vitamin D level between preeclamptic and normotensive pregnancies. Study Design: Cross-sectional analytical study. Place and Duration of Study: Department of Physiology, Federal Postgraduate Medical Institute, Shaikh Zayed Hospital, Lahore, in collaboration with Sir Ganga Ram Hospital and Lady Willingdon Hospital, Lahore, from March 2012 to April 2012. Methodology: Thirty registered preeclamptic patients with systolic and diastolic blood pressure > 140/90 mm Hg on more than two occasions, 6 hours apart, and proteinuria at least 300 mg in 24-hour urine collection; and 30 normotensive uncomplicated pregnant women matched for age, gestational age, parity and BMI were included by convenient sampling technique. Vitamin D levels of less than 50 n mol/l (< 20 ng/ml) was the cutoff point. Spearman's rank correlation of vitamin D with systolic blood pressure and arterial pressure in both preeclamptic and normotensive pregnant women was presented in a tabulated form. Results: Vitamin D deficiency was found in 95 percent of preeclamptic and normotensive pregnant women. The difference of vitamin D level between the two groups was not found significant. Although there was an inverse correlation between serum vitamin D and systolic blood pressure and arterial pressure in preeclamptic group, but this was not statistically significant. Conclusion: Vitamin D deficiency does not seem to be affected by the state of preeclamptic and normotensive pregnancy. The correlation of systolic blood pressure and arterial pressure and vitamin D needs to be explored further by increasing the sample size. (author)

Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study

Energy Technology Data Exchange (ETDEWEB)

Rodríguez-Pérez, A.S.; López-Rodríguez, J.F.; Calvo-Turrubiartes, M.Z. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico); Saavedra-Alanís, V.M. [Molecular Biology Laboratory, Department of Biochemistry, San Luis Potosí (Mexico); Llamazares-Azuara, L. [Autonomous University of San Luis Potosí, Renal Laboratory, Faculty of Medicine, San Luis Potosí (Mexico); Rodríguez-Martínez, M. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico)

2013-10-02

This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP−LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group ∼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.

Plasma Triglyceride and Cholesterol Levels in Normotensive and ...

African Journals Online (AJOL)

Plasma Triglyceride and Cholesterol Levels in Normotensive and Hypertensive Pregnant and Parturient Nigerian Women. Kashope D. Thomas, Oyebola G. Adeosun, Norah O. Akinola, Uche Onwudiegwu, Alexander T. Owolabi ...

Role of Renal Nerves in the Treatment of Renovascular Hypertensive Rats with L-Arginine

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Sonia Alves Gouvea

2014-01-01

Full Text Available The purpose was to determine the role of renal nerves in mediating the effects of antihypertensive treatment with L-arginine in a renovascular hypertension model. The 2K1C (two-kidney one-clip model hypertensive rats were submitted to bilateral surgical-pharmacological renal denervation. The animals were subdivided into six experimental groups: normotensive control rats (SHAM, 2K1C rats, 2K1C rats treated with L-arginine (2K1C + L-arg, denervated normotensive (DN rats, denervated 2K1C (2K1C + DN rats, and denervated 2K1C + L-arg (2K1C + DN + L-arg rats. Arterial blood pressure, water intake, urine volume, and sodium excretion were measured. The 2K1C rats exhibited an increase in the mean arterial pressure (MAP (from 106 ± 3 to 183 ± 5.8 mmHg, P<0.01, whereas L-arg treatment induced a reduction in the MAP (143 ± 3.4 mmHg without lowering it to the control level. Renal nerve denervation reduced the MAP to normotensive levels in 2K1C rats with or without chronic L-arg treatment. L-arg and denervation induced increases in water intake and urine volume, and L-arg caused a significant natriuretic effect. Our results suggest that renal sympathetic activity participates in the genesis and the maintenance of the hypertension and also demonstrate that treatment with L-arg alone is incapable of normalizing the MAP and that the effect of such treatment is not additive with the effect of kidney denervation.

Exercise scintirenography in normotensive young offspring of essential hypertensives

International Nuclear Information System (INIS)

Kong Fanzhen; Zhang Chenggang; Zhao Deshan

2004-01-01

Objective: To observe whether there is potential renal function decline in normotensive young offspring of essential hypertensives and to probe into the possible mechanism giving rise to it, providing some clues to the study of the pathogenic and hereditary mechanism of essential hypertension. Methods: Using 99 Tc m -DTPA as the imaging agent, authors performed rest and exercise scintirenography in normotensive young offspring of essential hypertensives [NOH, 31 cases, 14 males, 17 females; mean age: (23.2 ± 4.1) years], normotensive young off-spring of non-hypertensives [NON, 31 cases, 20 males, 11 females; mean age: (23.1±3.6) years], some of the hypertensive parents [21 cases, 5 males, 16 females; mean age: (53.0 ± 5.61) years] and old non-hypertensive subjects [10 cases, 6 males, 4 females; mean age: (53.7 ± 5.2) years]. The results were analyzed with the software of SPSS 10.0 for Windows. Results: Though all of the rest renal function indexes from NOH were within the normal range, there were significant differences between most of those indexes from NOH and those from NON, e. g., t p and MTT from NOH were significantly delayed than those from NON; exercise made these differences more significant, and after exercise, glomerular filtration rate (GFR) and RI were significantly lower, and 20/P was significantly higher. There were 4, 5, 2 cases showing abnormal exercise scintirenography in NOH, hypertensive parents and old non-hypertensive subjects, respectively, but none in NON group. Conclusions: There is potential renal function decline in normotensive young offspring of essential hypertensives. The kidney may play an important role in the pathogenic and hereditary mechanism of essential hypertension

Effects of dihydropyridines on tension and calcium-45 influx in isolated mesenteric resistance vessels from spontaneously hypertensive and normotensive rats

International Nuclear Information System (INIS)

Cauvin, C.; Hwang, O.; Yamamoto, M.; van Breemen, C.

1987-01-01

Contractile tension responses to norepinephrine and depolarizing potassium (80 mM K+), as well as calcium-45 influx stimulated by these agents, were studied in isolated mesenteric resistance vessels (each 100 microM internal diameter) from spontaneously hypertensive rats (SHRs) and from normotensive Wistar Kyoto rats (WKYs). Inhibitory effects of 2 dihydropyridine Ca++ antagonists, PN 200-110 (isradipine) and nisoldipine, on these parameters were also determined. Contractile responses to 80 mM K+ were inhibited by both Ca++ antagonists with the same potency and efficacy in SHR compared with WKY vessels (PN 200-110 IC50 = 2.8 +/- 1.3 X 10(-8) M in SHRs and 2.5 +/- 1.5 X 10(-8) M in WKYs; nisoldipine IC50 = 1.1 +/- 0.4 X 10(-8) M in SHRs and 1.2 +/- 0.9 X 10(-8) M in WKYs). However, contractile responses to norepinephrine (10(-4) M) were inhibited less potently by nisoldipine in SHR vessels (IC50 = 2.2 +/- 0.3 X 10(-9) M) compared with WKY vessels (IC50 = 1.6 +/- 0.6 X 10(-10) M). Similarly, PN 200-110 tended to be less (but not significantly less) potent in SHR vessels (IC50 = 3.3 +/- 1.8 X 10(-8) M) than in WKY vessels (IC50 = 3.4 +/- 0.9 X 10(-9) M); its efficacy was significantly depressed in the SHR vessels (by approximately 20%). When norepinephrine-stimulated calcium-45 influx was determined in the presence of these Ca++ antagonists, a similar profile emerged with respect to a comparison of SHR and WKY vessels. These results support a previously hypothesized alteration in receptor-activated Ca++ influx pathways in SHR mesenteric resistance vessels

Perinatal L-arginine and antioxidant supplements reduce adult blood pressure in spontaneously hypertensive rats

NARCIS (Netherlands)

Racasan, S; Braam, B; van der Giezen, DM; Goldschmeding, R; Boer, P; Koomans, HA; Joles, JA

Embryo cross-transplantation and cross-fostering between spontaneously hypertensive rats (SHR) and normotensive rats (WKY) suggest that perinatal environment modulates the genetically determined phenotype. In SHR the balance between NO and reactive oxygen species (ROS) is disturbed. We hypothesized

Unprovoked atrial tachyarrhythmias in aging spontaneously hypertensive rats: the role of the autonomic nervous system.

Science.gov (United States)

Scridon, Alina; Gallet, Clément; Arisha, Moussa M; Oréa, Valérie; Chapuis, Bruno; Li, Na; Tabib, Alain; Christé, Georges; Barrès, Christian; Julien, Claude; Chevalier, Philippe

2012-08-01

Experimental models of unprovoked atrial tachyarrhythmias (AT) in conscious, ambulatory animals are lacking. We hypothesized that the aging, spontaneously hypertensive rat (SHR) may provide such a model. Baseline ECG recordings were acquired with radiotelemetry in eight young (14-wk-old) and eight aging (55-wk-old) SHRs and in two groups of four age-matched Wistar-Kyoto (WKY) rats. Quantification of AT and heart rate variability (HRV) analysis were performed based on 24-h ECG recordings in unrestrained rats. All animals were submitted to an emotional stress protocol (air-jet). In SHRs, carbamylcholine injections were also performed. Spontaneous AT episodes were observed in all eight aging SHRs (median, 91.5; range, 4-444 episodes/24 h), but not in young SHRs or WKY rats. HRV analysis demonstrated significantly decreased low frequency components in aging SHRs compared with age-matched WKY rats (P aging (P = 0.01) SHRs compared with normotensive controls. In aging SHRs, emotional stress significantly reduced the number of arrhythmic events, whereas carbamylcholine triggered AT and significantly increased atrial electrical instability. This study reports the occurrence of unprovoked episodes of atrial arrhythmia in hypertensive rats, and their increased incidence with aging. Our results suggest that autonomic imbalance with relative vagal hyperactivity may be responsible for the increased atrial arrhythmogenicity observed in this model. We also provide evidence that, in this model, the sympatho-vagal imbalance preceded the occurrence of arrhythmia. These results indicate that aging SHRs may provide valuable insight into the understanding of atrial arrhythmias.

Increased transient receptor potential canonical type 3 channels in vasculature from hypertensive rats

DEFF Research Database (Denmark)

Liu, Daoyan; Yang, Dachun; He, Hongbo

2009-01-01

We tested the hypothesis that transient receptor potential canonical type 3 (TRPC3) channels are increased in vascular smooth muscle cells and aortic tissue from spontaneously hypertensive rats (SHR) compared with normotensive Wistar Kyoto rats. Expression of TRPC3 was analyzed by immunohistochem...

The conscious access hypothesis: Explaining the consciousness.

Science.gov (United States)

Prakash, Ravi

2008-01-01

The phenomenon of conscious awareness or consciousness is complicated but fascinating. Although this concept has intrigued the mankind since antiquity, exploration of consciousness from scientific perspectives is not very old. Among myriad of theories regarding nature, functions and mechanism of consciousness, off late, cognitive theories have received wider acceptance. One of the most exciting hypotheses in recent times has been the "conscious access hypotheses" based on the "global workspace model of consciousness". It underscores an important property of consciousness, the global access of information in cerebral cortex. Present article reviews the "conscious access hypothesis" in terms of its theoretical underpinnings as well as experimental supports it has received.

Agential Self-consciousness : beyond conscious agency

NARCIS (Netherlands)

Bos, G.H.

2013-01-01

Although we perform many of our actions without much consciousness of these, occasionally we are explicitly conscious that we are doing something for a reason. Such consciousness I call ‘agential self-consciousness’. Since ages we have understood such agential self-consciousness in terms of the

1,25 (OH)2 vitamin D3-induced 45Ca uptake in vascular myocytes cultured from spontaneously hypertensive and normotensive rats

International Nuclear Information System (INIS)

Xue, Hong; McCarron, D.A.; Bukoski, R.D.

1991-01-01

The effect of 1,25 (OH) 2 vitamin D 3 on basal 45 Ca uptake was examined in vasvular smooth muscle cells cultured from mesenteric arteries of spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) normotensive rats. Basal uptake of 45 Ca was significantly greater in myocytes of WKY than SHR at 5, 10, 30 and 60 min incubation with the isotope. Incubation with 1 ng/ml 1,25 (OH) 2 vitamin D 3 for 48 hr increased basal 45 Ca uptake between 1-10 min in SHR and between 5-10 min in WKY. The dose-response relationship indicated that cells from both strains are equally sensitive to the calciotropic effects of 1,25 (OH) 2 vitamin D 3 with half-maximal stimulation occurring at approximately 0.3-0.4 ng/ml. In cells of both strains maximal stimulation of 45 Ca uptake was achieved only after a 12-24 hr period of incubation with hormone and pretreatment with cycloheximide inhibited 1,24 (OH) 2 vitamin D 3 -enhanced 45 Ca uptake. Although 45 Ca binding by extracellular matrix material was significantly greater in WKY than SHR, 1,25 (OH) 2 vitamin D 3 had no effect on the amount of matrix 45 Ca binding in either strain

EVALUATIN OF ANTIHYPERTENSIVE ACTIVITY OF SONCHUS ASPER L. IN RATS.

Science.gov (United States)

Mushtaq, Muhammad Naveed; Akhtar, Muhammad Shoaib; Alamgeer; Ahmad, Taseer; Khan, Hafeez Ullah; Maheen, Safirah; Ahsan, Haseeb; Naz, Huma; Asif, Hira; Younis, Waqas; Tabassum, Nazia

2016-01-01

The present investigation was carried out to evaluate the effect of aerial parts of Sonchus asper L. in normotensive, glucose and egg feed diet induced hypertensive rats. Aqueous-methanolic extract of Sonchus asper in 250, 500 and 1000 mg/kg doses was studied in normotensive and glucose induced hypertensive rats using the non-invasive technique. The results obtained showed that the extract has significantly (p < 0.5 - p < 0.001) decreased the blood pressure and heart rate in dose dependent manner. The dose 1000 mg/kg of the extract produced the maximum antihypertensive effect and was selected for further experiments. The extract was found to prevent the rise in blood pressure of egg and glucose fed rats as compared to control group in 21 days study. The LD50 of the plant extract was 3500 mg/kg b.w. in mice and sub-chronic toxicity study showed that there was no significant alteration in the blood chemistry of the extract treated rats. It is conceivable, therefore, that the aqueous-methanolic extract of Sonchus asper has exerted considerable antihypertensive activity in rats and has duly supported traditional medicinal use of plant in hypertension.

Normotensive sodium loading in conscious dogs: Regulation of renin secretion during beta receptor blockade

DEFF Research Database (Denmark)

Bie, Peter; Mølstrøm, Simon; Wamberg, Søren

2009-01-01

Cl (20 micromol/kg/min for 180 min, NaLoad) during regular or low-sodium diet (0.03 mmol/kg/d, LowNa) with and without metoprolol (2 mg/kg plus 0.9 mg/kg/h). Vasopressin V2 receptors were blocked by Otsuka compound OPC31260 to facilitate clearance measurements. Body fluid volume was maintained by servo-controlled...... that in this setting, renin secretion and renin-dependent sodium excretion are controlled by via the renal nerves and therefore eliminated or reduced by blocking the action of norepinephrine on the juxtaglomerular cells with the beta1-receptor antagonist metoprolol. This was tested in conscious dogs by infusion of Na...... irrespective of diet. In conclusion, PRC depended on dietary sodium and beta1-adrenergic control as expected; however, the acute sodium-driven decrease in PRC at constant MAP and GFR was unaffected by beta1-receptor blockade demonstrating that renin may be regulated without changes in MAP, GFR, or beta1...

Electroacupuncture Delays Hypertension Development through Enhancing NO/NOS Activity in Spontaneously Hypertensive Rats

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Hye Suk Hwang

2011-01-01

Full Text Available Using spontaneously hypertensive rats (SHR, this study investigated whether electroacupuncture (EA could reduce early stage hypertension by examining nitric oxide (NO levels in plasma and nitric oxide synthase (NOS levels in the mesenteric resistance artery. EA was applied to the acupuncture point Governor Vessel 20 (GV20 or to a non-acupuncture point in the tail twice weekly for 3 weeks under anesthesia. In conscious SHR and normotensive Wistar Kyoto (WKY rats, blood pressure was determined the day after EA treatment by the tail-cuff method. We measured plasma NO concentration, and evaluated endothelial NO syntheses (eNOS and neuronal NOS (nNOS protein expression in the mesenteric artery. Systolic blood pressure (SBP and diastolic blood pressure (DBP were lower after 3 weeks of GV20 treatment than EA at non-acupuncture point and no treatment control in SHR. nNOS expression by EA was significantly different between both WKY and no treatment SHR control, and EA at GV20 in SHR. eNOS expression was significantly high in EA at GV 20 compared with no treatment control. In conclusion, EA could attenuate the blood pressure elevation of SHR, along with enhancing NO/NOS activity in the mesenteric artery in SHR.

The conscious access hypothesis: Explaining the consciousness

OpenAIRE

Prakash, Ravi

2008-01-01

The phenomenon of conscious awareness or consciousness is complicated but fascinating. Although this concept has intrigued the mankind since antiquity, exploration of consciousness from scientific perspectives is not very old. Among myriad of theories regarding nature, functions and mechanism of consciousness, off late, cognitive theories have received wider acceptance. One of the most exciting hypotheses in recent times has been the ?conscious access hypotheses? based on the ?global workspac...

Comparison of the hemodynamic effects of etomidate between hypertensive and normotensive patients

Directory of Open Access Journals (Sweden)

Hayrettin Daşkaya

2014-06-01

Full Text Available Objective: Comparison of the hemodynamic effect of ethomidate induction in normotensive and hypertensive patients. Methods: Forty ASA 1-2 patients were included. After informed consent were obtained, patients were divided into two group; Group H: Hypertensive patients, Group N: Normotensive patients. Fentanile and midazolam were administrated for premedication. Anesthesia induction was performed by etomidate 0.3 mg/kg and rocuronium 0.6 mg/kg. Arterial pressures and heart rates were measured at certain intervals: control, pre-intubation and 1, 3 and 5 min post-intubation. Myoclonic movements and hemodynamic parameters were noted by an anesthetist who was masked to the groups. Results: Hemodynamic parameters were higher in hypertensive patients but were in clinically tolerable limits. Conclusion: No hemodynamic instability was observed in anesthesia induction with ethomidate in neither hypertensive nor normotensive patients. J Clin Exp Invest 2014; 5 (2: 164-168

Nesfatin-1 activates cardiac vagal neurons of nucleus ambiguus and elicits bradycardia in conscious rats.

Science.gov (United States)

Brailoiu, G Cristina; Deliu, Elena; Tica, Andrei A; Rabinowitz, Joseph E; Tilley, Douglas G; Benamar, Khalid; Koch, Walter J; Brailoiu, Eugen

2013-09-01

Nesfatin-1, a peptide whose receptor is yet to be identified, has been involved in the modulation of feeding, stress, and metabolic responses. More recently, increasing evidence supports a modulatory role for nesfatin-1 in autonomic and cardiovascular activity. This study was undertaken to test if the expression of nesfatin-1 in the nucleus ambiguus, a key site for parasympathetic cardiac control, may be correlated with a functional role. As we have previously demonstrated that nesfatin-1 elicits Ca²⁺ signaling in hypothalamic neurons, we first assessed the effect of this peptide on cytosolic Ca²⁺ in cardiac pre-ganglionic neurons of nucleus ambiguus. We provide evidence that nesfatin-1 increases cytosolic Ca²⁺ concentration via a Gi/o-coupled mechanism. The nesfatin-1-induced Ca²⁺ rise is critically dependent on Ca²⁺ influx via P/Q-type voltage-activated Ca²⁺ channels. Repeated administration of nesfatin-1 leads to tachyphylaxis. Furthermore, nesfatin-1 produces a dose-dependent depolarization of cardiac vagal neurons via a Gi/o-coupled mechanism. In vivo studies, using telemetric and tail-cuff monitoring of heart rate and blood pressure, indicate that microinjection of nesfatin-1 into the nucleus ambiguus produces bradycardia not accompanied by a change in blood pressure in conscious rats. Taken together, our results identify for the first time that nesfatin-1 decreases heart rate by activating cardiac vagal neurons of nucleus ambiguus. Our results indicate that nesfatin-1, one of the most potent feeding peptides, increases cytosolic Ca²⁺ by promoting Ca²⁺ influx via P/Q channels and depolarizes nucleus ambiguus neurons; both effects are Gi/o-mediated. In vivo studies indicate that microinjection of nesfatin-1 into nucleus ambiguus produces bradycardia in conscious rats. This is the first report that nesfatin-1 increases the parasympathetic cardiac tone. © 2013 International Society for Neurochemistry.

Conscious sensation, conscious perception and sensorimotor theories of consciousness

OpenAIRE

Gamez, David

2014-01-01

This article explores the hypothesis that the differences between our conscious sensations (color, sound, smell, etc.) could be linked to the different ways in which our senses process and structure information. It is also proposed that the organization of our conscious sensations into a conscious perception of a three-dimensional world could be linked to our mastery of sensorimotor contingencies. These hypotheses are supported by a number of observations, including the appearance of consciou...

Placental oxidative stress and maternal endothelial function in pregnant women with normotensive fetal growth restriction.

Science.gov (United States)

Yoshida, Atsumi; Watanabe, Kazushi; Iwasaki, Ai; Kimura, Chiharu; Matsushita, Hiroshi; Wakatsuki, Akihiko

2018-04-01

The purpose of this study was to investigate the relationship between placental oxidative stress and maternal endothelial function in pregnant women with normotensive fetal growth restriction (FGR). We examined serum concentrations of oxygen free radicals (d-ROMs), maternal angiogenic factor (PlGF), and sFlt-1, placental oxidative DNA damage, and maternal endothelial function in 17 women with early-onset preeclampsia (PE), 18 with late-onset PE, 14 with normotensive FGR, and 21 controls. Flow-mediated vasodilation (FMD) was assessed as a marker of maternal endothelial function. Immunohistochemical analysis was performed to measure the proportion of placental trophoblast cell nuclei staining positive for 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage. Maternal serum d-ROM, sFlt-1 concentrations, and FMD did not significantly differ between the control and normotensive FGR groups. The proportion of nuclei staining positive for 8-OHdG was significantly higher in the normotensive FGR group relative to the control group. Our findings demonstrate that, despite the presence of placental oxidative DNA damage as observed in PE patients, pregnant women with normotensive FGR show no increase in the concentrations of sFlt-1 and d-ROMs, or a decrease in FMD.

Blood Pressure Interventions Affect Acute and Four-Week Diesel Exhaust Induced Pulmonary Injury in Healthy and Hypertensive Rats

Science.gov (United States)

Rationale: We recently showed that inhalation exposure of normotensive Wistar Kyoto (WKY) rats to whole diesel exhaust (DE) elicits changes in cardiac gene expression that broadly mimics expression in spontaneously hypertensive (SH) rats without DE. We hypothesized that pharmacol...

Detection of acute myocardial infarction in spontaneously hypertensive rats by /sup 99m/Tc-Pyrrolidino methyl tetracycline

Energy Technology Data Exchange (ETDEWEB)

Zmbova, B; Tadzer, I; Stakic, D; Bogdanova, V; Stojanova, D

1983-01-01

The myocardial infarct induced by isoproterenol in spontaneously hypertensive rats accumulates higher activities of /sup 99/sup(m)Tc-PM tetracycline compared with the cardiac infarct in normotensive rats caused by the same method. The isoproterenol model of the myocardial necrosis was induced in intact rats without opening the thorax and is a convenient method for experimental radioisotope studies.

Arterial stiffness in normotensive and hypertensive subjects: Frequency in community pharmacies.

Science.gov (United States)

Rodilla Sala, Enrique; Adell Alegre, Manuel; Giner Galvañ, Vicente; Perseguer Torregrosa, Zeneida; Pascual Izuel, Jose Maria; Climent Catalá, María Teresa

2017-12-07

Arterial stiffness (AS) is a well-recognized target organ lesion. This study aims to determine: 1) the frequency of AS in community pharmacies; 2) if stiffened subjects identified by brachial oscillometry have more CV risk factors than normal subjects, and 3) the dependence of stiffness on using either age-adjusted values or a fixed threshold. Observational, cross-sectional study in 32 community pharmacies of the Valencia Community, between November/2015 and April/2016. Stiffness was as pulse wave velocity (PWV) measured with a semi-automatic, validated device (Mobil-O-Graph ® , IEM), followed by a 10-item questionnaire. Mean age of the 1,427 consecutive recruited patients was 56.6 years. Overall proportion of patients with AS was 17.4% with age-adjusted PWV (9.4% in normotensives, 28.3% in hypertensives). Multivariate logistic regression showed independent association of stiffness in normotensives with male gender, obesity, higher pulse pressure and heart rate, in hypertensives, with higher pulse pressure and lower age. AS was globally found in 20.5% of subjects, defining stiffness by PWV>10m/s (6.2% in normotensives, 40.2% in hypertensives). It was associated with higher age and pulse pressure in both groups. Concordance in classifying stiffness was 74.6%. Frequency of AS varied between 17.4-20.5%. Age-adjusted stiffness is associated in normotensives with male gender, pulse pressure, obesity and heart rate, in hypertensives with pulse pressure and inversely to age. Stiffness by 10m/s is determined by higher pulse pressure and higher age. Both definitions of PWV are not interchangeable. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Influence of a multideficient diet from northeastern Brazil on resting blood pressure and baroreflex sensitivity in conscious, freely moving rats

Directory of Open Access Journals (Sweden)

F.M.F. Monteiro

2001-02-01

Full Text Available The "regional basic diet" or RBD is a multideficient diet (providing 8% protein which is known to produce dietary deficiencies in some populations in northeastern Brazil. The present study investigated the effects of RBD-induced malnutrition on resting blood pressure and baroreflex sensitivity in conscious rats. Malnourished rats were obtained by feeding dams the RBD during mating and pregnancy (RBD-1 group or during nursing and a 10-day period after weaning (RBD-2 group. At 90 days of age, only RBD-2 rats weighed significantly (P<0.001 less than control rats born to dams fed a standard commercial diet (23% protein during pregnancy and nursing. Baseline mean arterial pressure and heart rate of both RBD-1 and RBD-2 rats were comparable to those of controls. The slopes for both reflex bradycardia and tachycardia (bpm/mmHg induced by intravenous phenylephrine and sodium nitroprusside, respectively, were unchanged in either RBD-1 (-2.08 ± 0.11 and -3.10 ± 0.43, respectively or RBD-2 (-2.32 ± 0.30 and -3.73 ± 0.53, respectively rats, when compared to controls (-2.09 ± 0.10 and -3.17 ± 0.33, respectively. This study shows that, after a prolonged period of nutritional recovery, the patterns of resting blood pressure and baroreflex sensitivity of both pre- and postnatally malnourished rats were similar to those of controls. The decreased body weight and the tendency to increased reflex tachycardia in RBD-2 rats may suggest that this type of maternal malnutrition during lactation is more critical than during pregnancy.

Mechanisms of phytoestrogen biochanin A-induced vasorelaxation in renovascular hypertensive rats

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Seok Choi

2014-12-01

Conclusion: These results suggest that the enhanced relaxation caused by biochanin A in aortic rings from hypertensive rats is endothelium dependent. Vascular smooth muscle K+ channels may be involved in biochanin A-induced relaxation in aortae from hypertensive and normotensive rats. In addition, an endothelium-derived activation of voltage-dependent K+ channels contributes, at least in part, to the relaxant effect of biochanin A in renovascular hypertension.

Ultrafine Particulate Matter Combined With Ozone Exacerbates Lung Injury in Mature Adult Rats With Cardiovascular Disease.

Science.gov (United States)

Wong, Emily M; Walby, William F; Wilson, Dennis W; Tablin, Fern; Schelegle, Edward S

2018-05-01

Particulate matter (PM) and ozone (O3) are dominant air pollutants that contribute to development and exacerbation of multiple cardiopulmonary diseases. Mature adults with cardiovascular disease (CVD) are particularly susceptible to air pollution-related cardiopulmonary morbidities and mortalities. The aim was to investigate the biologic potency of ultrafine particulate matter (UFPM) combined with O3 in the lungs of mature adult normotensive and spontaneously hypertensive (SH) Wistar-Kyoto rats. Conscious, mature adult male normal Wistar-Kyoto (NW) and SH rats were exposed to one of the following atmospheres: filtered air (FA); UFPM (∼ 250 μg/m3); O3 (1.0 ppm); or UFPM + O3 (∼ 250 μg/m3 + 1.0 ppm) combined for 6 h, followed by an 8 h FA recovery period. Lung sections were evaluated for lesions in the large airways, terminal bronchiolar/alveolar duct regions, alveolar parenchyma, and vasculature. NW and SH rats were similarly affected by the combined-pollutant exposure, displaying severe injury in both large and small airways. SH rats were particularly susceptible to O3 exposure, exhibiting increased injury scores in terminal bronchioles and epithelial degeneration in large airways. UFPM-exposure groups had minimal histologic changes. The chemical composition of UFPM was altered by the addition of O3, indicating that ozonolysis promoted compound degradation. O3 increased the biologic potency of UFPM, resulting in greater lung injury following exposure. Pathologic manifestations of CVD may confer susceptibility to air pollution by impairing normal lung defenses and responses to exposure.

Proximal-tubule-like epithelium in Bowman's capsule in spontaneously hypertensive rats. Changes with age.

OpenAIRE

Haensly, W. E.; Granger, H. J.; Morris, A. C.; Cioffe, C.

1982-01-01

Kidneys were samples from male spontaneously hypertensive rats (SHR) and normotensive rats (WKY) in four groups. Renal tissues were examined in 64 rats: 6 SHR and 6 WKY rats 8 and 16 weeks of age and 10 SHR and 10 WKY rats 32 and 64 weeks of age. Tissue samples were fixed, processed, and stained by routine histologic procedures. The parietal layer of Bowman's capsule in 100-115 renal corpuscles from right to left kidney sections was classified as squamous or cuboidal epithelium. The cuboidal ...

Left ventricular structure and function in black normotensive type 2 ...

African Journals Online (AJOL)

Keywords: Black normotensive patients, left ventricular function, type 2 DM. Résumé ... sickle cell disease and structural heart disease were excluded ... Pulmonary venous flow (PVF) velocity ... had abnormal ECG pattern compared with 30%.

Effect of 1,25(OH)2 vitamin D3 and ionized Ca2+ on 45Ca uptake by primary cultures of aortic myocytes of spontaneously hypertensive and Wistar Kyoto normotensive rats

International Nuclear Information System (INIS)

Bukoski, R.D.; Xue, H.; McCarron, D.A.

1987-01-01

The effect of several regulators of whole animal Ca 2+ homeostasis on 45 Ca uptake by primary cultures of aortic myocytes isolated from spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rats was examined. Exposure of confluent cells to 1.0, 1.25 or 1.50 mM ionized Ca 2+ in serum-free medium for seven days resulted in increased 45 Ca uptake at the higher concentrations of Ca 2+ in cells of the SHR but not the WKY. 1,25 (OH)2 vitamin D3 (1 ng/ml) for 7 days caused enhanced influx in cells from both the SHR and WKY while parathyroid hormone (1-34) (1 ng/ml) was without effect. The data indicate that humoral factors that serve to regulate whole animal Ca 2+ homeostasis may also play a role in the regulation of Ca 2+ metabolism of the vascular smooth muscle cell

Elevated levels of protein AMBP in cerebrospinal fluid of women with preeclampsia compared to normotensive pregnant women

NARCIS (Netherlands)

C. Van Den Berg (Caroline); J.J. Duvekot (Hans); C. Güzel (Coşkun); Hansson, S.R. (Stefan R.); T.G. de Leeuw (Tom); E.A.P. Steegers (Eric); Versendaal, J. (Johannes); T.M. Luider (Theo); M.P. Stoop (Marcel)

2017-01-01

textabstractPurpose: To investigate the cerebrospinal fluid (CSF) proteome of patients with preeclampsia (PE) and normotensive pregnant women, in order to provide a better understanding of brain involvement in PE. Experimental design: Ninety-eight CSF samples (43 women with PE and 55 normotensive

A biphasic response of urinary prostaglandin E2 excretion to water deprivation in conscious diabetes insipidus Brattleboro rats

DEFF Research Database (Denmark)

Kanters, J K; Holstein-Rathlou, N H; Christensen, P

1989-01-01

The effects of water deprivation on the urinary excretion rate of prostaglandin E2 (PGE2) were examined in conscious Brattleboro rats. In order to study the time course of the changes in the PGE2 excretory rate, urine was collected in 6 periods, Control: 0-1 hour (h.). 1: 3-4.5 h., 8-10 h., III: 12......-15 h., IV: 24-28 h. and V: 32-36 h. after removal of water and food. It was found that the PGE2 excretion rate changed in a biphasic pattern. During the first 2 experimental periods it increased. Thereafter it decreased towards the control value. There was an increase in PGE2 excretion with urinary...

Exercise Blood Pressure and the Risk for Future Hypertension Among Normotensive Middle‐Aged Adults

OpenAIRE

Berger, Assaf; Grossman, Ehud; Katz, Moshe; Kivity, Shaye; Klempfner, Robert; Segev, Shlomo; Goldenberg, Ilan; Sidi, Yehezkel; Maor, Elad

2015-01-01

Background The aim of the present study was to examine whether exercise blood pressure can be used to predict the development of hypertension in normotensive middle‐aged adults. Methods and Results We investigated 7082 normotensive subjects who were annually screened in a tertiary medical center and completed maximal treadmill exercise tests at each visit. After the initial 3 years, subjects were divided into approximate quartiles according to their average exercise systolic and diastolic blo...

Homing in on consciousness: Why is a dream conscious?

Science.gov (United States)

Porte, Helene Sophrin

2016-01-01

Morsella et al. argue convincingly that consciousness is for adaptive voluntary action. What, then, is consciousness in a dream for? Two prior questions present themselves. In a dream, how do contents get into the conscious field? What are the properties of consciousness in a dream?

Preserved consciousness in vegetative and minimal conscious states

DEFF Research Database (Denmark)

Kondziella, Daniel; Nielsen, Christian Thomas Friberg; Frokjaer, Vibe G

2016-01-01

Active, passive and resting state paradigms using functional MRI (fMRI) or EEG may reveal consciousness in the vegetative (VS) and the minimal conscious state (MCS). A meta-analysis was performed to assess the prevalence of preserved consciousness in VS and MCS as revealed by fMRI and EEG.......0001)) and to show preserved functional cortical connectivity during passive paradigms (55% vs 26%; OR 3.53 (95% CI 2.49 to 4.99; ppreserved consciousness more often than active paradigms (38% vs 24%; OR 1.98 (95% CI 1.54 to 2.54; p... were insufficient for statistical evaluation. In conclusion, active paradigms may underestimate the degree of consciousness as compared to passive paradigms. While MCS patients show signs of preserved consciousness more frequently in both paradigms, roughly 15% of patients with a clinical diagnosis...

Consciousness.

Science.gov (United States)

Sejnowski, Terrence J

2015-01-01

No one did more to draw neuroscientists' attention to the problem of consciousness in the twentieth century than Francis Crick, who may be better known as the co-discoverer (with James Watson) of the structure of DNA. Crick focused his research on visual awareness and based his analysis on the progress made over the last fifty years in uncovering the neural mechanisms underlying visual perception. Because much of what happens in our brains occurs below the level of consciousness and many of our intuitions about unconscious processing are misleading, consciousness remains an elusive problem. In the end, when all of the brain mechanisms that underlie consciousness have been identified, will we still be asking: "What is consciousness?" Or will the question shift, just as the question "What is life?" is no longer the same as it was before Francis Crick?

Cerebrovascular CO2 reactivity in normotensive and hypertensive man

DEFF Research Database (Denmark)

Tominaga, S; Strandgaard, S; Uemura, K

1976-01-01

Cerebrovascular reactivity to CO2 inhalation and voluntary hyperventilation was studied in seven normotensive subjects and nine hypertensive patients without clinical or angiographical signs of arteriosclerosis. Cerebral blood flow (CBF) was measured by the intracarotid 133Xe clearance method...... and calculated as the initial slope index. Three to five CBF measurements were made in each patient in the PaCO2 range of 20 to 55 mm Hg. No difference was observed in reactivity between hypertensive and normotensive patients, either during CO2 inhalation or during hyperventilation. The shape of the CBF:PaCO2...... curve suggested a decrease in reactivity below a PaCO2 of 30 to 35 mm Hg in both groups. Above a PaCO2 of 35 mm Hg, exponential regression analysis yielded a mean reactivity of 6 +/- 2%, whereas below a PaCO2 of 30 mm Hg it was about 2%. The rise in CBF during CO2 inhalation was not influenced...

[Self-consciousness, consciousness of the other and dementias].

Science.gov (United States)

Gil, Roger

2007-06-01

Studies of self-consciousness in dementia concern essentially anosognosia or the loss of insight. However, Self-consciousness is multifaceted: it includes awareness of the body, perceptions, one's own history, identity, and one's own projects. Self-consciousness is linked to consciousness of others i.e. to social cognition supported by identification of others, but also by comprehension of facial expression of emotions, comprehension and expression of emotional prosody, pragmatic abilities, ability to infer other's people's mental states, thoughts, and feelings (theory of mind and empathy), knowledge of social norms and rules, social reasoning. The subtypes of dementias (and namely Alzheimer's disease and frontotemporal dementia) affect heterogeneously the different aspects of the self-and other-consciousness. Further studies are needed for a better knowledge of the complex relationship between Self-consciousness, social cognition, decision making and neuropsychiatric symptoms and behavioral disturbances occurring in demented patients.

Uric acid concentrations are associated with insulin resistance and birthweight in normotensive pregnant women.

Science.gov (United States)

Laughon, S Katherine; Catov, Janet; Roberts, James M

2009-12-01

We sought to investigate whether uric acid concentrations are increased in pregnant women with insulin resistance and to correlate both with fetal growth. Uric acid, glucose, and insulin were measured in plasma at 20.4 (+/-2.0) weeks' gestation in 263 women. The association between uric acid and insulin resistance, as estimated using the homeostasis model assessment (HOMA), was analyzed and related to birthweights. In 212 (80.6%) women who remained normotensive throughout pregnancy, HOMA increased 1.23 U per 1-mg/dL increase in uric acid (95% confidence interval, 1.07-1.42; P=.003). Infants born to normotensive women in the upper quartile of uric acid and lowest HOMA quartile weighed 435.6 g less than infants of women with highest uric acid and HOMA quartiles (Pinsulin resistance in midpregnancy. Hyperuricemia was associated with lower birthweight in normotensive women, and this effect was attenuated by insulin resistance.

Relationship of Heme Oxygenase-1 (HO-1 Level with Onset and Severity in Normotensive Pregnancy and Severe Preeclampsia

Directory of Open Access Journals (Sweden)

John Johannes Wantania

2016-08-01

Full Text Available Background: Preeclampsia still becomes a major problem in pregnancies. Various evidences showed that heme oxygenase-1 (HO-1 is very important in pregnancy. This study aims to understand the relationship of heme oxygenase-1 level with onset and severity in normotensive pregnancy and severe preeclampsia. Methods: This is a cross sectional analytic comparative study, the subjects consisted of 26 patients with normotensive pregnancies and 26 patients with severe preeclampsia. Blood samples from women with < 34 / ≥ 34 weeks’ normotensive pregnancies and women with severe preeclampsia were taken. HO-1 ELISA kit used to quantitate heme oxygenase-1 level in samples. Results: The level of heme oxygenase-1 in normotensive pregnant women < 34 weeks lower than severe preeclampsia pregnant women < 34 weeks (3.28 ± 0.46 ng/mL vs 4.20 ± 0.64 ng/mL, p=0.003, respectively. The median level of heme oxygenase-1 in normotensive pregnant women ≥ 34 weeks was 2.96 (2.41–4.39 ng/mL, while severe preeclampsia pregnant women ≥ 34 weeks was 3.52 (2.88–5.43 ng/mL, (p=0.040. The median level of heme oxygenase-1 in normotensive pregnant women was 3.04 (2.41–4.39 ng/mL, while severe preeclampsia pregnant women was 3.68 (2.88–5.67 ng/mL, (p=0.001. Conclusions: There is correlation between the incidence of severe preeclampsia with heme oxygenase-1 level in < 34 and ≥ 34 weeks of pregnancy. There is a significant difference between the level of heme oxygenase-1 in pregnant women with severe preeclampsia and in women with normotensive pregnancy. 

Cross-sectional study of antioxidant status in normotensive and ...

African Journals Online (AJOL)

concentration of all antioxidants except uric acid were significantly lower during pregnancy when compared with controls (t= 2.06; p<0.01). In the normotensive group of pregnant women, vitamin C was the only antioxidant that showed significant higher concentration when the second trimester concentration and third ...

Increased atrial natriuretic factor receptor density in cultured vascular smooth muscle cells of the spontaneously hypertensive rat

International Nuclear Information System (INIS)

Khalil, F.; Fine, B.; Kuriyama, S.; Hatori, N.; Nakamura, A.; Nakamura, M.; Aviv, A.

1987-01-01

To explore the role of the atrial natriuretic factor (ANF) system in the pathophysiology of hypertension we examined the binding kinetics of synthetic ANF to cultured vascular smooth muscle cells (VSMCs) derived from the spontaneously hypertensive rat (SHR) and two normotensive controls-the Wistar Kyoto (WKY) and American Wistar (W). The number of maximal binding sites (Bmax) per cell (mean +/- SEM; X10(3] were: SHR = 278.0 +/- 33.0, WKY = 28.3 +/- 7.1 and W = 26.6 +/- 4.2. The differences between the SHR and normotensive strains were significant at p less than 0.001. The equilibrium dissociation constant (Kd; X 10(-9)M) was higher in SHR VSMCs (0.94 +/- 0.14) than in WKY (0.22 +/- 0.09; p less than 0.01) and W (0.39 +/- 0.14; p less than 0.02) cells. The plasma levels of the immunoreactive ANF were higher in SHR than the normotensive controls. We suggest that the relatively greater ANF receptor density in cultured VSMCs of the SHR represents a response to the in vitro environment which is relatively more deficient in ANF for VSMCs of the SHR as compared with the normotensive rats. Thus, the capacity of the SHR VSMC to regulate ANF receptor density appears to be independent of the blood pressure level

Evaluation of purinergic mechanism for the treatment of voiding dysfunction: a study in conscious spinal cord-injured rats.

Science.gov (United States)

Lu, Shing-Hwa; Groat, William C de; Lin, Alex T L; Chen, Kuang-Kuo; Chang, Luke S

2007-10-01

To investigate the effect of a selective P2X(3-)P2X(2/3) purinergic receptor antagonist (a-317491) on detrusor hyperreflexia in conscious chronic spinal cord-injured female rats. Six chronic spinal cord-transected female Sprague-Dawley rats (290-336 g) were used in this study. Spinal transection at the T8-T9 segmental level was performed using aseptic techniques under halothane anesthesia. Fourteen to 16 weeks after spinal transection, A-317491, a selective P2X(3-)P2X(2/3) purinergic receptor antagonist, was administered intravenously in cystometry studies at increasing doses of 0.03, 0.1, 0.3, 1, 3, 10 and 30 micromol/kg at 40-50 minute intervals. Cystometrograms (CMGs) were performed before and after the administration of each dose of the drug. The continuous filling of CMGs revealed a large number of small-amplitude (> 8 cmH(2)O), non-voiding contractions (NVCs) (average, 9.7 per voiding cycle) preceding voiding contractions (mean amplitude, 31 cmH(2)O; duration, 2.5 minutes), which occurred at an interval of 539 seconds and at a pressure threshold of 5.7 cmH(2)O. When tested in a range of doses (0.03-30 micromol/kg, intravenous), A-317491 in doses between 1 and 30 micromol/kg significantly (p spinal cord injury in rats.

Effect of hypertensive rat plasma on ion transport of cultured vascular smooth muscle

International Nuclear Information System (INIS)

Magargal, W.W.; Overbeck, H.W.

1986-01-01

We layered fresh, unprocessed plasma from healthy rats with early (less than or equal to 7 days) or benign, chronic (greater than 3 wk) one-kidney, one-clip hypertension and from paired one-kidney normotensive control rats over confluent primary-cultured rat aortic smooth muscle cells. Plasma from all rats increased cellular ouabain-sensitive 86 Rb + uptake and sodium content and decreased ouabain-insensitive 86 Rb + uptake compared with uptakes and content in the presence of balanced salt solution (P less than 0.01). Cells incubated in the presence of plasma from rats with early (P less than 0.02) or chronic hypertension (P less than 0.01) had significantly reduced ouabain-sensitive 86 Rb + uptake when compared with cells incubated in normotensive plasma, but their intracellular Na+ contents were not lower. We no longer detected this uptake difference when chronic hypertensives drank 0.9% NaCl instead of water. Plasma from hypertensive rats also altered ouabain-insensitive 86 Rb + uptake by the cultured cells. These findings of this new, reproducible, and specific assay system support the hypothesis that plasma factors inhibit the membrane sodium-potassium pump in vascular smooth muscle cells in this form of hypertension. The abnormality occurs in both early and chronic stages, but may not be related to sodium intake. The data also provide evidence for plasma factors in hypertension altering membrane K+ permeability

Logical Evaluation of Consciousness: For Incorporating Consciousness into Machine Architecture

OpenAIRE

Padhy, C. N.; Panda, R. R.

2010-01-01

Machine Consciousness is the study of consciousness in a biological, philosophical, mathematical and physical perspective and designing a model that can fit into a programmable system architecture. Prime objective of the study is to make the system architecture behave consciously like a biological model does. Present work has developed a feasible definition of consciousness, that characterizes consciousness with four parameters i.e., parasitic, symbiotic, self referral and reproduction. Prese...

Fruits intake and cardiovascular function in normotensive young adults

African Journals Online (AJOL)

This study assessed the effect of increase fruits intake on cardiovascular health as specified by blood pressure and pulse rate. It is a 4 week study involving 70 apparently healthy normotensive students, between the ages of 20–30 years. They were recruited from the Department of Physiology, College of Medicine, Ambrose ...

Circadian blood pressure rhythm in normotensive offspring of hypertensive parents.

Science.gov (United States)

Toker, Rabia Tutuncu; Yildirim, Ali; Demir, Tevfik; Ucar, Birsen; Kilic, Zubeyir

2015-01-01

The aim of this study was to explore the circadian blood pressure (BP) rhythm using ambulatory BP monitoring (ABPM) in normotensive children with a family history of essential hypertension. Group 1 consisted of children with hypertensive mothers and/or fathers (n = 20), Group 2 consisted of children with hypertensive grandparents (n = 20), and Group 3 consisted of children with normotensive parents (n = 20). All participating children underwent a 24-h ABPM and echocardiography. Significantly higher systolic burden was found in children with hypertensive parents (p children with a family history of hypertension, a positive correlation between nocturnal systolic BP and LVMI was found, and increasing nocturnal BP values were associated with increasing LVMI (p children with a family history of hypertension, target-organ damage may precede the clinical detection of hypertension, and in those with a nocturnal non-dipper status, a more marked effect on LVMI may occur.

Impact of emotion on consciousness: positive stimuli enhance conscious reportability.

Directory of Open Access Journals (Sweden)

Kristine Rømer Thomsen

2011-04-01

Full Text Available Emotion and reward have been proposed to be closely linked to conscious experience, but empirical data are lacking. The anterior cingulate cortex (ACC plays a central role in the hedonic dimension of conscious experience; thus potentially a key region in interactions between emotion and consciousness. Here we tested the impact of emotion on conscious experience, and directly investigated the role of the ACC. We used a masked paradigm that measures conscious reportability in terms of subjective confidence and objective accuracy in identifying the briefly presented stimulus in a forced-choice test. By manipulating the emotional valence (positive, neutral, negative and the presentation time (16 ms, 32 ms, 80 ms we measured the impact of these variables on conscious and subliminal (i.e. below threshold processing. First, we tested normal participants using face and word stimuli. Results showed that participants were more confident and accurate when consciously seeing happy versus sad/neutral faces and words. When stimuli were presented subliminally, we found no effect of emotion. To investigate the neural basis of this impact of emotion, we recorded local field potentials (LFPs directly in the ACC in a chronic pain patient. Behavioural findings were replicated: the patient was more confident and accurate when (consciously seeing happy versus sad faces, while no effect was seen in subliminal trials. Mirroring behavioural findings, we found significant differences in the LFPs after around 500 ms (lasting 30 ms in conscious trials between happy and sad faces, while no effect was found in subliminal trials. We thus demonstrate a striking impact of emotion on conscious experience, with positive emotional stimuli enhancing conscious reportability. In line with previous studies, the data indicate a key role of the ACC, but goes beyond earlier work by providing the first direct evidence of interaction between emotion and conscious experience in the human

Artificial consciousness and the consciousness-attention dissociation.

Science.gov (United States)

Haladjian, Harry Haroutioun; Montemayor, Carlos

2016-10-01

Artificial Intelligence is at a turning point, with a substantial increase in projects aiming to implement sophisticated forms of human intelligence in machines. This research attempts to model specific forms of intelligence through brute-force search heuristics and also reproduce features of human perception and cognition, including emotions. Such goals have implications for artificial consciousness, with some arguing that it will be achievable once we overcome short-term engineering challenges. We believe, however, that phenomenal consciousness cannot be implemented in machines. This becomes clear when considering emotions and examining the dissociation between consciousness and attention in humans. While we may be able to program ethical behavior based on rules and machine learning, we will never be able to reproduce emotions or empathy by programming such control systems-these will be merely simulations. Arguments in favor of this claim include considerations about evolution, the neuropsychological aspects of emotions, and the dissociation between attention and consciousness found in humans. Ultimately, we are far from achieving artificial consciousness. Copyright © 2016 Elsevier Inc. All rights reserved.

The benefits of endurance training in cardiomyocyte function in hypertensive rats are reversed within four weeks of detraining.

Science.gov (United States)

Carneiro-Júnior, Miguel Araujo; Quintão-Júnior, Judson Fonseca; Drummond, Lucas Rios; Lavorato, Victor Neiva; Drummond, Filipe Rios; da Cunha, Daise Nunes Queiroz; Amadeu, Marco Aurélio; Felix, Leonardo Bonato; de Oliveira, Edilamar Menezes; Cruz, Jader Santos; Prímola-Gomes, Thales Nicolau; Mill, José Geraldo; Natali, Antonio José

2013-04-01

The aim of the present study was to verify the effects of low-intensity endurance training and detraining on the mechanical and molecular properties of cardiomyocytes from spontaneously hypertensive rats (SHRs). Male SHRs and normotensive control Wistar rats at 16-weeks of age were randomly divided into eight groups of eight animals: NC8 and HC8 (normotensive and hypertensive control for 8weeks); NT8 and HT8 (normotensive and hypertensive trained at 50-60% of maximal exercise capacity for 8weeks); NC12 and HC12 (normotensive and hypertensive control for 12weeks); NDT and HDT (normotensive and hypertensive trained for 8weeks and detrained for 4weeks). The total exercise time until fatigue (TTF) was determined by a maximal exercise capacity test. Resting heart rate (RHR) and systolic arterial pressure (SAP) were measured. After the treatments, animals were killed by cervical dislocation and left ventricular myocytes were isolated by enzymatic dispersion. Isolated cells were used to determine intracellular global Ca(2+) ([Ca(2+)]i) transient and cardiomyocyte contractility (1Hz; ~25°C). [Ca(2+)]i regulatory proteins were measured by Western blot, and the markers of pathologic cardiac hypertrophy by quantitative real-time polymerase chain reaction (q-RT-PCR). Exercise training augmented the TTF (NC8, 11.4±1.5min vs. NT8, 22.5±1.4min; HC8, 11.7±1.4min vs. HT8, 24.5±1.3min; Pendurance training induces positive benefits to left ventricular myocyte mechanical and molecular properties, which are reversed within 4weeks of detraining. Copyright © 2013 Elsevier Ltd. All rights reserved.

Hemodynamic characterization of chronic bile duct-ligated rats: effect of pentobarbital sodium

International Nuclear Information System (INIS)

Lee, S.S.; Girod, C.; Braillon, A.; Hadengue, A.; Lebrec, D.

1986-01-01

Systemic and splanchnic hemodynamics of the chronic bile duct-ligated rat were characterized by radioactive microspheres. Conscious and pentobarbital sodium-anesthetized, bile duct-ligated and sham-operated rats had cardiac output and regional organ blood flows determined. The conscious bile duct-ligated rat compared with the sham-operated showed a hyperdynamic circulation with an increased cardiac output and portal tributary blood flow. Pentobarbital sodium anesthesia induced marked hemodynamic changes in both sham-operated and bile duct-ligated rats. The latter group was especially sensitive to its effects; thus, comparison of cardiac output and portal tributary blood flow between anesthetized bile duct-ligated and sham-operated rats showed no significant differences. The authors conclude that the rat with cirrhosis due to chronic bile duct ligation is an excellent model for hemodynamic investigations but should be studied in the conscious state, since pentobarbital sodium anesthesia eliminated the hyperdynamic circulation

Erythrocyte sodium concentration and 86Rb uptake in weanling Dahl rats

International Nuclear Information System (INIS)

McCormick, C.P.; Hennessy, J.F.; Rauch, A.L.; Buckalew, V.M. Jr.

1989-01-01

Alterations in Na, K ATPase pump activity as well as erythrocyte (RBC) intracellular sodium concentration (Nai) have been demonstrated in humans and rats with established hypertension. The contribution of hypertension itself to these changes is unclear. Accordingly, we investigated RBC ion transport and plasma ouabain-like factor (OLF) in four- to five-week old normotensive Dahl salt-sensitive (DS) and salt-resistant (DR) rats on low salt diet. Although both strains were normotensive, systolic blood pressure (SBP) of DS (123 ± 2 mm Hg) was higher than that of DR (116 ± 1 mm Hg). No interstrain difference was evident in RBC pump activity measured as ouabain-sensitive 86rubidium ( 86 Rb) uptake (DS = 0.277 ± .030 and DR = 0.271 ± .029 mumol/10(9)RBC/h) even though RBC Nai was greater in DS than DR (14.9 ± 2.0 v 10.7 ± 1.0 mEq/L; P less than 0.05). Plasma OLF was higher in DS than DR (28.9 ± 4.7 v 16.5 ± 2.3 pmol/mL; P less than 0.05), but did not correlate with RBC pump activity in either strain. RBC Nai was directly correlated with pump activity in DS (r = 0.84, P less than 0.01) and demonstrated a trend to correlate in DR (r = 0.71, P = 0.07). RBC Nai was also directly correlated with SBP in DR (r = 0.73, P less than 0.05) and DS (r = 0.70, P = 0.05). We conclude that RBC Nai is genetically determined in Dahl rats and is elevated in normotensive DS who are at risk for hypertension development

Decreased α1-adrenergic receptor-mediated inositide hydrolysis in neurons from hypertensive rat brain

International Nuclear Information System (INIS)

Feldstein, J.B.; Gonzales, R.A.; Baker, S.P.; Sumners, C.; Crews, F.T.; Raizada, M.K.

1986-01-01

The expression of α 1 -adrenergic receptors and norepinephrine (NE)-stimulated hydrolysis of inositol phospholipid has been studied in neuronal cultures from the brains of normotensive (Wistar-Kyoto, WKY) and spontaneously hypertensive (SH) rats. Binding of 125 I-1-[β-(4-hydroxyphenyl)-ethyl-aminomethyl] tetralone (HEAT) to neuronal membranes was 68-85% specific and was rapid. Competition-inhibition experiments with various agonists and antagonists suggested that 125 I-HEAT bound selectively to α 1 -adrenergic receptors. Specific binding of 125 I-HEAT to neuronal membranes from SH rat brain cultures was 30-45% higher compared with binding in WKY normotensive controls. This increase was attributed to an increase in the number of α 1 -adrenergic receptors on SH rat brain neurons. Incubation of neuronal cultures of rat brain from both strains with NE resulted in a concentration-dependent stimulation of release of inositol phosphates, although neurons from SH rat brains were 40% less responsive compared with WKY controls. The decrease in responsiveness of SH rat brain neurons to NE, even though the α 1 -adrenergic receptors are increased, does not appear to be due to a general defect in membrane receptors and postreceptor signal transduction mechanisms. This is because neither the number of muscarinic-cholinergic receptors nor the carbachol-stimulated release of inositol phosphates is different in neuronal cultures from the brains of SH rats compared with neuronal cultures from the brains of WKY rats. These observations suggest that the increased expression of α 1 -adrenergic receptors does not parallel the receptor-mediated inositol phosphate hydrolysis in neuronal cultures from SH rat brain

Organizational consciousness.

Science.gov (United States)

Pees, Richard C; Shoop, Glenda Hostetter; Ziegenfuss, James T

2009-01-01

The purpose of this paper is to develop a conceptual understanding of organizational consciousness that expands the discussion of organizational analysis, and use a case study to apply it in the analysis of a merger between an academic health center and a regional medical center. The paper draws on the experiences and insights of scholars who have been exploring complex organizational issues in relationship with consciousness. Organizational consciousness is the organization's capacity for reflection; a centering point for the organization to "think" and find the degree of unity across systems; and a link to the organization's identity and self-referencing attributes. It operates at three stages: reflective, social, and collective consciousness. Translating abstract concepts such as consciousness to an organizational model is complex and interpretive. For now, the idea of organizational consciousness remains mostly a theoretical concept. Empirical evidence is needed to support the theory. Faced with complicated and compelling issues for patient care, health care organizations must look beyond the analysis of structure and function, and be vigilant in their decisions on where important issues sit on the ladder of competing priorities. Organizational consciousness keeps the organization's attention focused on purpose and unifies the collective will to succeed. If the paper can come to understand how consciousness operates in organizations, and learn how to apply it in organizational decisions, the pay-off could be big in terms of leading initiatives for change. The final goal is to use what is learned to improve organizational outcomes.

Serum oxidized low density lipoprotein levels in preeclamptic and normotensive pregnants.

Science.gov (United States)

Kozan, A; Yildirmak, S Turkmen; Mihmanli, V; Ayabakan, H; Cicek, Y G; Kalaslioglu, V; Doean, S; Cebeci, H Cerci

2015-01-01

BACKGROUNDS/AIM: The aim of the study was to determine serum lipids and oxidized low density lipoprotein (ox-LDL) levels in preeclamptic pregnants and compare with those of normotensives. Ox-LDL levels were determined by enzyme linked immunosorbent assay (ELISA); total cholesterol, hight density lipoprotein (HDL)-cholesterol and triglyceride levels were measured by enzymatic colorimetric assay in 26 normotensive and 27 preeclamptic pregnants. LDL and very low density lipoprotein (VLDL) cholesterol was calculated by Friedwald formula. Serum levels of Ox-LDL (U/L), total-cholesterol (mg/dL), HDL-cholesterol (mg/dL), LDL-cholesterol (mg/dL), triglyceride (mg/dL), and VLDL-cholesterol (mg/dL) in normotensive and preeclamptic pregnants were found as 130±60 and 133±69; 248±49 and 248±81; 67±14 and 61±16; 147±61 and 135±59; 207±76 and 256±87; 41±15 and 50±17, respectively. Mean values of Ox-LDL and other lipid parameters were higher than the upper limits of their reference ranges in both of groups. However no significant differences were found in Ox-LDL, total, HDL and LDL-cholesterol levels between two groups. However, the levels of triglyceride and VLDL-cholesterol were significantly higher in preeclampsia group. The present results suggest that the levels of serum Ox-LDL and other lipid parameters rise as a result of pregnancy rather than as a result of preeclampsia.

Parameters of Blood Flow in Great Arteries in Hypertensive ISIAH Rats with Stress-Dependent Arterial Hypertension.

Science.gov (United States)

Seryapina, A A; Shevelev, O B; Moshkin, M P; Markel', A L

2016-08-01

Magnetic resonance angiography was used to examine blood flow in great arteries of hypertensive ISIAH and normotensive Wistar rats. In hypertensive ISIAH rats, increased vascular resistance in the basin of the abdominal aorta and renal arteries as well as reduced fraction of total renal blood flow were found. In contrast, blood flow through both carotid arteries in ISIAH rats was enhanced, which in suggests more intensive blood supply to brain regulatory centers providing enhanced stress reactivity of these rats characterized by stress-dependent arterial hypertension.

Electroencephalography in normotensive and hypertensive pregnancies and subsequent quality of life

NARCIS (Netherlands)

I.A. Brussé (Ingrid); J.J. Duvekot (Hans); I. Meester (Ivette); G. Jansen (Gerard); D. Rizopoulos (Dimitris); E.A.P. Steegers (Eric); G.H. Visser (Gerhard H.)

2016-01-01

textabstractObjectives: To compare electroencephalography (EEG) findings during pregnancy and postpartum in women with normotensive pregnancies and pregnancies complicated by hypertensive disorders. Also the health related quality of life postpartum was related to these EEG findings. Materials and

Prevention and intervention studies with telmisartan, ramipril and their combination in different rat stroke models.

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Christa Thoene-Reineke

Full Text Available OBJECTIVES: The effects of AT1 receptor blocker, telmisartan, and the ACE inhibitor, ramipril, were tested head-to head and in combination on stroke prevention in hypertensive rats and on potential neuroprotection in acute cerebral ischemia in normotensive rats. METHODS: Prevention study: Stroke-prone spontaneously hypertensive rats (SHR-SP were subjected to high salt and randomly assigned to 4 groups: (1 untreated (NaCl, n = 24, (2 telmisartan (T; n = 27, (3 ramipril (R; n = 27 and (4 telmisartan + ramipril (T+R; n = 26. Drug doses were selected to keep blood pressure (BP at 150 mmHg in all groups. Neurological signs and stroke incidence at 50% mortality of untreated SHR-SP were investigated. Intervention study: Normotensive Wistar rats were treated s.c. 5 days prior to middle cerebral artery occlusion (MCAO for 90 min with reperfusion. Groups (n = 10 each: (1 sham, (2 vehicle (V; 0.9% NaCl, (3 T (0.5 mg/kg once daily, (4 R (0.01 mg/kg twice daily, (5 R (0.1 mg/kg twice daily or (6 T (0.5 mg/kg once daily plus R (0.01 mg/kg twice daily. Twenty-four and 48 h after MCAO, neurological outcome (NO was determined. Forty-eight h after MCAO, infarct volume by MRI, neuronal survival, inflammation factors and neurotrophin receptor (TrkB were analysed. RESULTS: Stroke incidence was reduced, survival was prolonged and neurological outcome was improved in all treated SHR-SP with no differences between treated groups. In the acute intervention study, T and T+R, but not R alone, improved NO, reduced infarct volume, inflammation (TNFα, and induced TrkB receptor and neuronal survival in comparison to V. CONCLUSIONS: T, R or T+R had similar beneficial effects on stroke incidence and NO in hypertensive rats, confirming BP reduction as determinant factor in stroke prevention. In contrast, T and T+R provided superior neuroprotection in comparison to R alone in normotensive rats with induced cerebral ischemia.

Changes in maternal serum thioredoxin (TRX) levels after delivery in preeclamptic and normotensive pregnant women.

Science.gov (United States)

Vitoratos, Nicolaos; Vlahos, Nikos F; Economou, Emanuel; Panoulis, Konstatninos; Creatsas, George

2012-01-01

To investigate changes of maternal plasma thioredoxin (TRX) levels after delivery in preeclamptic and normotensive pregnant women. Ten normotensive women (group A) were compared to 17 women with severe preeclampsia (group B). TRX levels were assessed in maternal plasma, immediately after delivery and 12-16 weeks postpartum. There were no differences in plasma TRX levels between the two groups immediately antepartum (p = 0.095). A significant reduction in plasma TRX levels was found immediately following delivery only in normotensive group (117.76 ± 37.19 ng/mL vs. 43.45 ± 21.11 ng/mL, p = 0.002), but not in women with preeclampsia (80.42 ± 59.95 ng/mL vs. 53.82 ± 44.34 ng/mL, p = 0.12). Plasma TRX levels remained unchanged in women with preeclampsia (80.42 ± 59.95 ng/mL vs. 55.37 ± 52.23 ng/mL, p = 0.2) at 12-14 weeks postpartum.

The Measurement of Consciousness: A Framework for the Scientific Study of Consciousness

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David eGamez

2014-07-01

Full Text Available Scientists studying consciousness are attempting to identify correlations between measurements of consciousness and the physical world. Consciousness can only be measured through first-person reports, which raises problems about the accuracy of first-person reports, the possibility of non-reportable consciousness and the causal closure of the physical world. Many of these issues could be resolved by assuming that consciousness is entirely physical or functional. However, this would sacrifice the theory-neutrality that is a key attraction of a correlates-based approach to the study of consciousness. This paper puts forward a different solution that uses a framework of definitions and assumptions to explain how consciousness can be measured. This addresses the problems associated with first-person reports and avoids the issues with the causal closure of the physical world. This framework is compatible with most of the current theories of consciousness and it leads to a distinction between two types of correlates of consciousness.

What Explains Consciousness? Or…What Consciousness Explains?

Science.gov (United States)

Dulany, Donelson E.

2014-01-01

In this invited commentary I focus on the topic addressed in three papers: De Sousa's (2013[1617]) Toward an Integrative Theory of Consciousness, a monograph with Parts 1 & 2, as well as commentaries by Pereira (2013a[59]) and Hirstein (2013[42]). All three are impressively scholarly and can stand—and shout—on their own. But theory of consciousness? My aim is to slice that topic into the two fundamentally different kinds of theories of consciousness, say what appears to be an ideology, out of behaviourism into cognitivism, now also influencing the quest for an “explanation of consciousness” in cognitive neuroscience. I will then say what can be expected given what we know of the complexity of brain structure, the richness of a conscious “vocabulary”, and current technological limits of brain imaging. This will then turn to the strategy for examining “what consciousness explains”—metatheory, theories, mappings, and a methodology of competitive support, a methodology especially important where there are competing commitments. There are also increasingly common identifications of methodological bias in, along with failures to replicate, studies reporting unconscious controls in decision, social priming—as there have been in perception, learning, problem solving, etc. The literature critique has provided evidence taken as reducing, and in some cases eliminating, a role for conscious controls—a position consistent with that ideology out of behaviourism into cognitivism. It is an ideological position that fails to recognize the fundamental distinction between theoretical and metaphysical assertions. PMID:24891796

Sodium homeostasis in lymphocytes and blood pressure alterations before and during salt restriction in normotensives and in essential hypertensives

DEFF Research Database (Denmark)

Jest, P; Pedersen, K E; Klitgaard, N A

1986-01-01

Blood pressure, lymphocytic sodium content and sodium efflux were studied in hypertensive and normotensive subjects during salt restriction. Diastolic blood pressure decreased significantly in both groups. In essential hypertension the initial high lymphocyte sodium content decreased during salt...... mechanisms with regard to lymphocyte sodium metabolism differs between hypertensive and normotensive subjects....

Essential hypertensive controlled and normotensive patients. If there are differences?

Directory of Open Access Journals (Sweden)

V. V. Syvolap

2016-10-01

Full Text Available Ambulatory blood pressure monitoring (ABPM is a modern method of blood pressure (BP investigation recommended by international scientific associations for diagnostics of essential hypertension (EH. However, there are some methodological aspects which are not regulated. Particularly, ABPM parameters have not yet established for those patients in different age groups and pathologies. The aim of the study was to determine peculiarities of ABPM parameters in treated controlled hypertensive and normotensive patients. Materials and methods. 71 patients were included into the study and divided into two groups according to the level of 24-h systolic BP (SBP and 24-h diastolic BP (DBP. There were 50 controlled patients with EH in the first group and 21 normotensive individuals without EH in the second group. Results. In EH patients and normotensive individuals we had statistician difference of such parameters, like the hypertension time index (TI of day SBP parameters (20 (8–31 % vs. 8 (4–18 %; р=0.040; of the square index (SI of hypertension (24 (11–41 mm2/h vs. 8 (2–23 mm2/h; р=0.021; of the square index normalized (SIN of hypertension (1.4 (0.6–2.4 U vs. 0.4 (0.1–1.2 U; р=0.018, and the morning surge of SBP (45±14 mm Hg vs. 37±14 mm Hg; р=0.028, respectively. There is no different in other ABPM parameters. Conclusion. The present data shows that treated controlled hypertensive patients and individuals without EH have statistician difference only in daily SBP of hypertensive indexes (TI, SI, SIN and the morning surge of SBP. The other ABPM parameters, included new one, such as the arterial stiffness index, did not represent statistical difference between groups.

Levodopa acts centrally to induce an antinociceptive action against colonic distension through activation of D2 dopamine receptors and the orexinergic system in the brain in conscious rats

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Toshikatsu Okumura

2016-02-01

Subcutaneously (80 mg/rat or intracisternally (2.5 μg/rat administered levodopa significantly increased the threshold of colonic distension-induced AWR in conscious rats. The dose difference to induce the antinociceptive action suggests levodopa acts centrally to exert its antinociceptive action against colonic distension. While neither sulpiride, a D2 dopamine receptor antagonist, nor SCH23390, a D1 dopamine receptor antagonist by itself changed the threshold of colonic distension-induced AWR, the intracisternally injected levodopa-induced antinociceptive action was significantly blocked by pretreatment with subcutaneously administered sulpiride but not SCH23390. Treatment with intracisternal SB334867, an orexin 1 receptor antagonist, significantly blocked the subcutaneously administered levodopa-induced antinociceptive action. These results suggest that levodopa acts centrally to induce an antinociceptive action against colonic distension through activation of D2 dopamine receptors and the orexinergic system in the brain.

Conscious Belief

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David Pitt

2016-04-01

Full Text Available Tim Crane maintains that beliefs cannot be conscious because they persist in the absence of consciousness. Conscious judgments can share their contents with beliefs, and their occurrence can be evidence for what one believes; but they cannot be beliefs, because they don’t persist. I challenge Crane’s premise that belief attributions to the temporarily unconscious are literally true. To say of an unconscious agent that she believes that p is like saying that she sings well. To say she sings well is to say that when she sings, her singing is good. To say that she believes that p is (roughly to say that when she consciously considers the content that p she consciously affirms (believes it. I also argue that the phenomenal view of intentional content Crane appears to endorse prima facie commits him to the view, at least controversial, perhaps incoherent, that there is unconscious phenomenology (the intentional contents of unconscious beliefs.

Effects of fasting on Blood pressure in normotensive males

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Fatima Samad

2016-07-01

Full Text Available Muslims all over the world fast in the holy month of Ramadan. Fasting means abstinence from drinking any liquids, eating, smoking and taking anything parenterally.  It is intermittent in nature from the start of dawn to end at dusk. Fasting has various physiological effects on different biological parameters of the human body. Previous studies that look at effect of Ramadan fasting on blood pressure have focused mainly on hypertensive patients and patients with already established heart disease.(1,2There is very limited data regarding the effect of fasting on the normal population. (3,4 A few previous studies have advocated a hypotensive role of fasting.(5 In our study published in Journal of Ayub Medical College Abbottabad (JAMC in 2015, “Effects of Ramadan Fasting on Blood pressure in normotensive males”, we investigated the effect of Ramadan fasting on blood pressure of normotensive men. We conducted a repeated measure observational study in Karachi, Pakistan on 70 individuals who were normotensive, non-smokers between the ages of 18–50 years. . Blood pressure, pulse, BMI of each participant was recorded one week before the start of Ramadan and in the first, second and third week of Ramadan. The results of our study show that intermittent fasting has a hypotensive effect in normotensive males as proven in animal models and certain human population. There was an average drop of 8/3 mmHg and while the results are significant, their clinical relevance needs to be analysed. Studies on animal models have suggested atrial natriuretic peptide, catecholamines, opiates and body mass index as possible reasons for the decrease in blood pressure due to fasting.(3, 6  Dewanti et al suggested that the cause of drop in blood pressure was the drop in BMI however in our study we found that a drop in BMI only occurred before Iftar towards the end of the fast. There was no significant drop in post-Iftar BMI although there was a significant drop in blood

Tx2-6 toxin of the Phoneutria nigriventer spider potentiates rat erectile function☆

Science.gov (United States)

Nunes, K.P.; Costa-Gonçalves, A.; Lanza, L.F.; Cortes, S.F.; Cordeiro, M.N.; Richardson, M.; Pimenta, A.M.C.; Webb, R.C.; Leite, R.; De Lima, M.E.

2011-01-01

The venom of the spider Phoneutria nigriventer contains several toxins that have bioactivity in mammals and insects. Accidents involving humans are characterized by various symptoms including penile erection. Here we investigated the action of Tx2-6, a toxin purified from the P. nigriventer spider venom that causes priapism in rats and mice. Erectile function was evaluated through changes in intracavernosal pressure/mean arterial pressure ratio (ICP/MAP) during electrical stimulation of the major pelvic ganglion (MPG) of normotensive and deoxycorticosterone-acetate (DOCA)-salt hypertensive rats. Nitric oxide (NO) release was detected in cavernosum slices with fluorescent dye (DAF-FM) and confocal microscopy. The effect of Tx2-6 was also characterized after intracavernosal injection of a non-selective nitric oxide synthase (NOS) inhibitor, L-NAME. Subcutaneous or intravenous injection of Tx2-6 potentiated the elevation of ICP/MAP induced by ganglionic stimulation. L-NAME inhibited penile erection and treatment with Tx2-6 was unable to reverse this inhibition. Tx2-6 treatment induced a significant increase of NO release in cavernosum tissue. Attenuated erectile function of DOCA-salt hypertensive rats was fully restored after toxin injection. Tx2-6 enhanced erectile function in normotensive and DOCA-salt hypertensive rats, via the NO pathway. Our studies suggest that Tx2-6 could be important for development of new pharmacological agents for treatment of erectile dysfunction. PMID:18397797

Exercise Blood Pressure and the Risk for Future Hypertension Among Normotensive Middle‐Aged Adults

Science.gov (United States)

Berger, Assaf; Grossman, Ehud; Katz, Moshe; Kivity, Shaye; Klempfner, Robert; Segev, Shlomo; Goldenberg, Ilan; Sidi, Yehezkel; Maor, Elad

2015-01-01

Background The aim of the present study was to examine whether exercise blood pressure can be used to predict the development of hypertension in normotensive middle‐aged adults. Methods and Results We investigated 7082 normotensive subjects who were annually screened in a tertiary medical center and completed maximal treadmill exercise tests at each visit. After the initial 3 years, subjects were divided into approximate quartiles according to their average exercise systolic and diastolic blood pressure responses (≤158; 158 to 170; 170 to 183; ≥183 mm Hg for systolic blood pressure and ≤73; 73 to 77; 77 to 82; ≥82 mm Hg for diastolic blood pressure). Mean age of the study population was 48±9 years and 73% were men. Average baseline resting blood pressure was 120/77±12/7 mm Hg. During a follow‐up of 5±3 years, 1036 (14.6%) subjects developed hypertension. The cumulative probability of new‐onset hypertension at 5 years was significantly increased with increasing quartiles of exercise systolic blood pressure (5%, 9%, 17%, and 35%, respectively; Pexercise either systolic or diastolic blood pressures were independently associated with respective 11% (Phypertension. Conclusions In normotensive middle‐aged individuals, blood pressure response to exercise is associated with future development of hypertension. PMID:25904593

Nonneurocognitive Extended Consciousness

Science.gov (United States)

Wojcik, Kevin; Chemero, Anthony

2012-01-01

One of the attributes necessary for Watson to be considered human is that it must be conscious. From Rachlin's (2012) point of view, that of teleological behaviorism, consciousness refers to the organization of behavioral complexity in which overt behavior is distributed widely over time. Consciousness is something that humans do, or achieve, in…

Cardiovascular reactivity in young adults with hypertensive and normotensive parents: A gender based comparative study

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Anjali Verma

2017-01-01

Full Text Available Introduction: Essential hypertension begins due to mutation of specific genes that contribute to the risk of developing hypertension. Genetic contribution was recognized 25 years ago, now formulated from time to time. Some studies have also proven that the hypertension in father had strong contribution in their individual than mother. The aim of the study is to compare the cardiovascular reactivity in male and female subjects with hypertensive and normotensive parents. Materials and methods: This comparative study was conducted in physiology department of Teerthanker Mahaveer medical college and research center, Moradabad. The research work was initiated after taken the ethical clearance from the ethical committee of the college. Three different stressors: cold pressor task, cycling and videogame were used. Total 120 subjects were taken for the study in which 77 were male and 43 were female. Result: Male subjects of normotensive parents had slightly higher HR rate (mean: 76.73/min compared to the female subjects (mean: 75/min with p value >0.05. Female subjects of hypertensive parents had higher HR rate (mean: 82.72/min compared to the male subjects (mean: 73.95/min with p value <0.001. Conclusion: Male subjects with normotensive parents had higher resting HR, SBP &DBP than Female subjects with normotensive parents, but the difference was significant only in SBP. Female subjects with hypertensive parents group was showing higher resting HR than male subjects with hypertensive parents group, remains higher after stress also with insignificant difference. Thus, subjects with hypertensive parents showing increased CVR to stress are more likely to develop future hypertension, and the risk is greater for male subjects.

Effects of 3,4-methylenedioxymethamphetamine (MDMA) and its main metabolites on cardiovascular function in conscious rats.

Science.gov (United States)

Schindler, Charles W; Thorndike, Eric B; Blough, Bruce E; Tella, Srihari R; Goldberg, Steven R; Baumann, Michael H

2014-01-01

The cardiovascular effects produced by 3,4-methylenedioxymethamphetamine (MDMA; 'Ecstasy') contribute to its acute toxicity, but the potential role of its metabolites in these cardiovascular effects is not known. Here we examined the effects of MDMA metabolites on cardiovascular function in rats. Radiotelemetry was employed to evaluate the effects of s.c. administration of racemic MDMA and its phase I metabolites on BP, heart rate (HR) and locomotor activity in conscious male rats. MDMA (1-20 mg·kg(-1)) produced dose-related increases in BP, HR and activity. The peak effects on HR occurred at a lower dose than peak effects on BP or activity. The N-demethylated metabolite, 3,4-methylenedioxyamphetamine (MDA), produced effects that mimicked those of MDMA. The metabolite 3,4-dihydroxymethamphetamine (HHMA; 1-10 mg·kg(-1)) increased HR more potently and to a greater extent than MDMA, whereas 3,4-dihydroxyamphetamine (HHA) increased HR, but to a lesser extent than HHMA. Neither dihydroxy metabolite altered motor activity. The metabolites 4-hydroxy-3-methoxymethamphetamine (HMMA) and 4-hydroxy-3-methoxyamphetamine (HMA) did not affect any of the parameters measured. The tachycardia produced by MDMA and HHMA was blocked by the β-adrenoceptor antagonist propranolol. Our results demonstrate that HHMA may contribute significantly to the cardiovascular effects of MDMA in vivo. As such, determining the molecular mechanism of action of HHMA and the other hydroxyl metabolites of MDMA warrants further study. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Water-avoidance stress enhances gastric contractions in freely moving conscious rats: role of peripheral CRF receptors.

Science.gov (United States)

Nozu, Tsukasa; Kumei, Shima; Takakusaki, Kaoru; Okumura, Toshikatsu

2014-05-01

Stress alters gastrointestinal motility through central and peripheral corticotropin-releasing factor (CRF) pathways. Accumulating evidence has demonstrated that peripheral CRF is deeply involved in the regulation of gastric motility, and enhances gastric contractions through CRF receptor type 1 (CRF1) and delays gastric emptying (GE) through CRF receptor type 2 (CRF2). Since little is known whether water-avoidance stress (WAS) alters gastric motility, the present study tried to clarify this question and the involvement of peripheral CRF receptor subtypes in the mechanisms. We recorded intraluminal gastric pressure waves using a perfused manometric method. The rats were anesthetized and the manometric catheter was inserted into the stomach 4-6 days before the experiments. We assessed the area under the manometric trace as the motor index (MI), and compared this result with those obtained 1 h before and after initiation of WAS in nonfasted conscious rats. Solid GE for 1 h was also measured. WAS significantly increased gastric contractions. Intraperitoneal (ip) administration of astressin (100 μg/kg, 5 min prior to stress), a nonselective CRF antagonist, blocked the response to WAS. On the other hand, pretreatment (5 min prior to stress) with neither astressin2-B (200 μg/kg, ip), a selective CRF2 antagonist, nor urocortin 2 (30 μg/kg, ip), a selective CRF2 agonist, modified the response to WAS. These drugs did not alter the basal MI. WAS did not change GE. WAS may activate peripheral CRF1 but not CRF2 signaling and stimulates gastric contractions without altering GE.

Chaos in blood flow control in genetic and renovascular hypertensive rats

DEFF Research Database (Denmark)

Yip, K P; Holstein-Rathlou, N H; Marsh, D J

1991-01-01

Hydrostatic pressure and flow in renal proximal tubules oscillate at 30-40 mHz in normotensive rats anesthetized with halothane. The oscillations originate in tubuloglomerular feedback, a mechanism that provides local blood flow regulation. Instead of oscillations, spontaneously hypertensive rats...... (SHR) have aperiodic tubular pressure fluctuations; the pattern is suggestive of deterministic chaos. Normal rats made hypertensive by clipping one renal artery had similar aperiodic tubular pressure fluctuations in the unclipped kidney, and the fraction of rats with irregular fluctuations increased...... with time after the application of the renal artery clip. Statistical measures of deterministic chaos were applied to tubular pressure data. The correlation dimension, a measure of the dimension of the phase space attractor generating the time series, indicated the presence of a low-dimension strange...

Central cardiovascular action of urotensin II in spontaneously hypertensive rats.

Science.gov (United States)

Lin, Yingzi; Tsuchihashi, Takuya; Matsumura, Kiyoshi; Fukuhara, Masayo; Ohya, Yusuke; Fujii, Koji; Iida, Mitsuo

2003-10-01

We have previously reported that urotensin II acts on the central nervous system to increase blood pressure in normotensive rats. In the present study, we have determined the central cardiovascular action of urotensin II in spontaneously hypertensive rats (SHR). Intracerebroventricular (ICV) injection of urotensin II elicited a dose-dependent increase in blood pressure in both SHR and normotensive Wistar-Kyoto rats (WKY). The changes in mean arterial pressure induced by ICV urotensin II at doses of 1 and 10 nmol in the WKY were 8 +/- 2 and 23 +/- 3 mmHg, respectively. ICV administration of urotensin II caused significantly greater increases in blood pressure in SHR (16 +/- 3 mmHg at 1 nmol and 35 +/- 3 mmHg at 10 nmol, respectively) compared with those in WKY. Urotensin II (10 nmol) elicited significant and comparable increases in heart rate in SHR (107 +/- 10 bpm) and WKY (101 +/- 21 bpm). Plasma epinephrine concentrations after ICV administration of 10 nmol urotensin II were 203 +/- 58 pmol/ml in SHR and 227 +/- 47 pmol/ml in WKY, which tended to be higher than those in artificial cerebrospinal fluid-injected rats (73+/- 7 and 87 +/- 28 pmol/ml, respectively, p GPR 14 was expressed extensively in the glial cells within the brainstem, hypothalamus, and thalamus. These results suggest that central urotensin II may play a role in the pathogenesis of hypertension in SHR. Since GPR 14 was expressed in the glial cells of the brain, urotensin II may act as a neuromodulator to regulate blood pressure.

Low Plasma Volume in Normotensive Formerly Preeclamptic Women Predisposes to Hypertension.

Science.gov (United States)

Scholten, Ralph R; Lotgering, Fred K; Hopman, Maria T; Van Dijk, Arie; Van de Vlugt, Maureen; Janssen, Mirian C H; Spaanderman, Marc E A

2015-11-01

Formerly preeclamptic women are at risk for cardiovascular disease. Low plasma volume may reflect latent hypertension and potentially links preeclampsia with chronic cardiovascular disease. We hypothesized that low plasma volume in normotensive formerly preeclamptic women predisposes to hypertension. We longitudinally studied n=104 formerly preeclamptic women in whom plasma volume was measured 3 to 30 months after the preeclamptic pregnancy. Cardiovascular variables were assessed at 2 points in time (3-30 months postpartum and 2-5 years thereafter). Study population was divided into low plasma volume (≤1373 mL/m(2)) and normal plasma volume (>1373 mL/m(2)). Primary end point was hypertension at the second visit: defined as ≥140 mm Hg systolic or ≥90 mm Hg diastolic. Secondary outcome of this study was change in traditional cardiovascular risk profile between visits. Variables correlating univariately with change in blood pressure between visits were introduced in regression analysis. Eighteen of 104 (17%) formerly preeclamptic women who were normotensive at first visit had hypertension at second evaluation 2 to 5 years later. Hypertension developed more often in women with low plasma volume (10/35 [29%]) than in women with normal plasma volume (8/69 [12%]; odds ratio, 3.2; 95% confidence interval, 1.4-8.6). After adjustments, relationship between plasma volume status and subsequent hypertension persisted (adjusted odds ratio, 3.0; 95% confidence interval, 1.1-8.5). Mean arterial pressure at second visit correlated inverse linearly with plasma volume (r=-0.49; Phypertension within 5 years. Women with low plasma volume have higher chance to develop hypertension than women with normal plasma volume. Clinically, follow-up of blood pressure seems warranted in women with history of preeclampsia, even when initially normotensive. © 2015 American Heart Association, Inc.

Electroencephalography in Normotensive and Hypertensive Pregnancies and Subsequent Quality of Life.

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Brussé, Ingrid A; Duvekot, Johannes J; Meester, Ivette; Jansen, Gerard; Rizopoulos, Dimitris; Steegers, Eric A P; Visser, Gerhard H

2016-01-01

To compare electroencephalography (EEG) findings during pregnancy and postpartum in women with normotensive pregnancies and pregnancies complicated by hypertensive disorders. Also the health related quality of life postpartum was related to these EEG findings. An observational case-control study in a university hospital in the Netherlands. Twenty-nine normotensive and 58 hypertensive pregnant women were included. EEG's were recorded on several occasions during pregnancy and 6-8 weeks postpartum. Postpartum, the women filled out health related quality of life questionnaires. Main outcome measures were qualitative and quantitative assessments on EEG, multidimensional fatigue inventory, Short Form (36) Health Survey and EuroQoL visual analogue scale. In women with severe preeclampsia significantly lower alpha peak frequency, more delta and theta activity bilaterally and a higher EEG Sum Score were seen. Postpartum, these women showed impaired mental health, mental fatigue and social functioning, which could not be related to the EEG findings. Severe preeclamptic patients show more EEG abnormalities and have impaired mental wellbeing postpartum, but these findings are not correlated.

Electroencephalography in Normotensive and Hypertensive Pregnancies and Subsequent Quality of Life.

Directory of Open Access Journals (Sweden)

Ingrid A Brussé

Full Text Available To compare electroencephalography (EEG findings during pregnancy and postpartum in women with normotensive pregnancies and pregnancies complicated by hypertensive disorders. Also the health related quality of life postpartum was related to these EEG findings.An observational case-control study in a university hospital in the Netherlands. Twenty-nine normotensive and 58 hypertensive pregnant women were included. EEG's were recorded on several occasions during pregnancy and 6-8 weeks postpartum. Postpartum, the women filled out health related quality of life questionnaires. Main outcome measures were qualitative and quantitative assessments on EEG, multidimensional fatigue inventory, Short Form (36 Health Survey and EuroQoL visual analogue scale.In women with severe preeclampsia significantly lower alpha peak frequency, more delta and theta activity bilaterally and a higher EEG Sum Score were seen. Postpartum, these women showed impaired mental health, mental fatigue and social functioning, which could not be related to the EEG findings.Severe preeclamptic patients show more EEG abnormalities and have impaired mental wellbeing postpartum, but these findings are not correlated.

Exogenous and endogenous angiotensin‐II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow

Science.gov (United States)

Emans, Tonja W.; Janssen, Ben J.; Pinkham, Maximilian I.; Ow, Connie P. C.; Evans, Roger G.; Joles, Jaap A.; Malpas, Simon C.; Krediet, C. T. Paul

2016-01-01

Key points Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary.We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats.This method provides stable and continuous measurements of cortical tissue oxygen tension (PO2) for more than 2 weeks and can reproducibly detect acute changes in cortical oxygenation.Exogenous angiotensin‐II reduced renal cortical tissue PO2 more than equi‐pressor doses of phenylephrine, probably because it reduced renal oxygen delivery more than did phenylephrine.Activation of the endogenous renin–angiotensin system in transgenic Cyp1a1Ren2 rats reduced cortical tissue PO2; in this model renal hypoxia precedes the development of structural pathology and can be reversed acutely by an angiotensin‐II receptor type 1 antagonist.Angiotensin‐II promotes renal hypoxia, which may in turn contribute to its pathological effects during development of chronic kidney disease. Abstract We hypothesised that both exogenous and endogenous angiotensin‐II (AngII) can decrease the partial pressure of oxygen (PO2) in the renal cortex of unrestrained rats, which might in turn contribute to the progression of chronic kidney disease. Rats were instrumented with telemeters equipped with a carbon paste electrode for continuous measurement of renal cortical tissue PO2. The method reproducibly detected acute changes in cortical oxygenation induced by systemic hyperoxia and hypoxia. In conscious rats, renal cortical PO2 was dose‐dependently reduced by intravenous AngII. Reductions in PO2 were significantly greater than those induced by equi‐pressor doses of phenylephrine. In anaesthetised rats, renal oxygen consumption was not affected, and filtration fraction was increased only in the AngII infused animals. Oxygen delivery decreased by 50% after infusion of AngII and renal blood flow (RBF) fell by 3.3 ml min−1

Chronic type 1 diabetes in spontaneously hypertensive rats leads to exacerbated cardiac fibrosis.

Science.gov (United States)

Black, Mary Jane; D'Amore, Angelo; Auden, Alana; Stamp, Laura; Osicka, Tanya; Panagiotopoulos, Sianna; Jerums, George

2010-01-01

Diabetes in human subjects is often associated with hypertension. The aim of this study was to examine the development of cardiac fibrosis following induction of type 1 diabetes in genetically hypertensive rats. Diabetes was induced by streptozotocin (STZ) injection in 8-week-old normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) for a duration of 16 or 24 weeks. Aged-matched, nondiabetic WKY and SHRs were used as controls. At termination of treatment, the rats were anaesthetized, hearts arrested in diastole and perfusion fixed. A comprehensive examination of cardiac fibrosis throughout the right and left ventricles was undertaken in picrosirius red-stained sections, using image analysis and by undertaking collagen type I and type III immunohistochemistry. Induction of diabetes in the SHRs led to a marked increase in the levels of interstitial fibrosis in the left ventricle plus septum (LV+S) at both 16 and 24 weeks duration (59% and 43% increase, respectively) and also in the right ventricle after 24 weeks duration of diabetes (35% increase compared to the nondiabetic SHR). Exacerbated perivascular fibrosis was also observed in the LV+S in the diabetic-hypertensive rats at the later time point. These effects of induction of diabetes were not observed in the normotensive strain. Our findings clearly demonstrate elevations in cardiac fibrosis when type 1 diabetes is combined with hypertension. Our findings thus stress the importance of closely monitoring both blood pressure and glucose levels in type 1 diabetic patients in order to prevent myocardial collagen deposition. Copyright © 2010 Elsevier Inc. All rights reserved.

Consciousness without a cortex, but what kind of consciousness is this? [Open Peer Commentary

NARCIS (Netherlands)

Coenen, A.M.L.

2007-01-01

Merker suggests that the thalamocortical system is not an essential system for consciousness, but, instead, that the midbrain reticular system is responsible for consciousness. Indeed, the latter is a crucial system for consciousness, when consciousness is regarded as the waking state. However, when

Conscious Leadership.

Science.gov (United States)

Ward, Suzanne F; Haase, Beth

2016-11-01

Health care leaders need to use leadership methodologies that support safe patient care, satisfy employees, and improve the bottom line. Conscious leaders help create desirable personal and professional life experiences for themselves using specific tools that include mindfulness, context, and the observer-self, and they strive to help their employees learn to use these tools as well. In perioperative nursing, conscious leaders create an environment in which nurses are supported in their aim to provide the highest level of patient care and in which transformations are encouraged to take place; this environment ultimately promotes safety, contributes to fulfilling and meaningful work, and enhances a facility's financial viability. This article discusses some of the key concepts behind conscious leadership, how perioperative leaders can reach and maintain expanded consciousness, and how they can best assist their staff members in their own evolution to a more mindful state. Copyright © 2016 AORN, Inc. Published by Elsevier Inc. All rights reserved.

Exercise blood pressure and the risk for future hypertension among normotensive middle-aged adults.

Science.gov (United States)

Berger, Assaf; Grossman, Ehud; Katz, Moshe; Kivity, Shaye; Klempfner, Robert; Segev, Shlomo; Goldenberg, Ilan; Sidi, Yehezkel; Maor, Elad

2015-04-22

The aim of the present study was to examine whether exercise blood pressure can be used to predict the development of hypertension in normotensive middle-aged adults. We investigated 7082 normotensive subjects who were annually screened in a tertiary medical center and completed maximal treadmill exercise tests at each visit. After the initial 3 years, subjects were divided into approximate quartiles according to their average exercise systolic and diastolic blood pressure responses (≤158; 158 to 170; 170 to 183; ≥183 mm Hg for systolic blood pressure and ≤73; 73 to 77; 77 to 82; ≥82 mm Hg for diastolic blood pressure). Mean age of the study population was 48 ± 9 years and 73% were men. Average baseline resting blood pressure was 120/77 ± 12/7 mm Hg. During a follow-up of 5 ± 3 years, 1036 (14.6%) subjects developed hypertension. The cumulative probability of new-onset hypertension at 5 years was significantly increased with increasing quartiles of exercise systolic blood pressure (5%, 9%, 17%, and 35%, respectively; Pexercise either systolic or diastolic blood pressures were independently associated with respective 11% (Phypertension. In normotensive middle-aged individuals, blood pressure response to exercise is associated with future development of hypertension. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Serum levels of vascular endothelial growth factor in preeclamptic and normotensive pregnancy.

Science.gov (United States)

Hunter, A; Aitkenhead, M; Caldwell, C; McCracken, G; Wilson, D; McClure, N

2000-12-01

The purpose of these studies was first to determine if vascular endothelial growth factor (VEGF), a vascular permeability agent, is increased in the serum of women with preclinical and clinical preclampsia (PE), and second to determine how these levels change after delivery. Twenty preeclamptic and 25 normotensive women at term consented to have blood taken pre- and post-delivery. Ten preeclamptic, 10 gestational hypertensive, and 28 normotensive women had blood collected respectively at 12, 20, and 30 weeks gestation and predelivery. Serum was extracted from all samples, and VEGF concentrations were determined by radioimmunoassay. Predelivery, the median serum VEGF concentration in the preeclamptic group was 51.7 ng/mL, and in the control group the concentration was 13.9 ng/mL (P<0.0001). Serum VEGF concentrations fell within 24 hours of delivery in both groups, which resulted in median values of 3.8 ng/mL and 3.2 ng/mL respectively (P<0.3). At 12 and 20 weeks, there was no significant difference between the serum VEGF concentrations in the 3 groups (P<0.3, 0.052 respectively). At 30 weeks, prior to the onset of clinical PE, the serum VEGF levels in the eventual preeclamptic group were elevated significantly compared with the gestational hypertensive and normotensive groups (P<0.001). Predelivery serum VEGF concentrations were significantly elevated in the preeclamptic group and were similar to those in the first study (P<0.0001). These findings suggest that VEGF may be important in the pathophysiology of PE and has the potential to act as a preclinical marker for the condition.

Moral significance of phenomenal consciousness.

Science.gov (United States)

Levy, Neil; Savulescu, Julian

2009-01-01

Recent work in neuroimaging suggests that some patients diagnosed as being in the persistent vegetative state are actually conscious. In this paper, we critically examine this new evidence. We argue that though it remains open to alternative interpretations, it strongly suggests the presence of consciousness in some patients. However, we argue that its ethical significance is less than many people seem to think. There are several different kinds of consciousness, and though all kinds of consciousness have some ethical significance, different kinds underwrite different kinds of moral value. Demonstrating that patients have phenomenal consciousness--conscious states with some kind of qualitative feel to them--shows that they are moral patients, whose welfare must be taken into consideration. But only if they are subjects of a sophisticated kind of access consciousness--where access consciousness entails global availability of information to cognitive systems--are they persons, in the technical sense of the word employed by philosophers. In this sense, being a person is having the full moral status of ordinary human beings. We call for further research which might settle whether patients who manifest signs of consciousness possess the sophisticated kind of access consciousness required for personhood.

Attention and Olfactory Consciousness

OpenAIRE

Keller, Andreas

2011-01-01

Understanding the relation between attention and consciousness is an important part of our understanding of consciousness. Attention, unlike consciousness, can be systematically manipulated in psychophysical experiments and a law-like relation between attention and consciousness is waiting to be discovered. Most attempts to discover the nature of this relation are focused on a special type of attention: spatial visual attention. In this review I want to introduce another type of attention to ...

Reduction in brain immunoreactive corticotropin-releasing factor (CRF) in spontaneously hypertensive rats

International Nuclear Information System (INIS)

Hashimoto, K.; Hattori, T.; Murakami, K.; Suemaru, S.; Kawada, Y.; Kageyama, J.; Ota, Z.

1985-01-01

The brain CRF concentration of spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY) was examined by rat CRF radioimmunoassay. Anti-CRF serum was developed by immunizing rabbits with synthetic rat CRF. Synthetic rat CRF was also used as tracer and standard. The displacement of 125 I-rat CRF by serially diluted extracts of male Wistar rats hypothalamus, thalamus, midbrain, pons, medulla oblongata, cerebral cortex, cerebellum and neurointermediate lobe was parallel to the displacement of synthetic rat CRF. In both WKY and SHR the highest levels of CRF immunoreactivity were shown by the hypothalamus and neurointermediate lobe, and considerable CRF immunoreactivity was also detected in other brain regions. The CRF immunoreactivity in the hypothalamus, neurointermediate lobe, midbrain, medulla oblongata and cerebral cortex was significantly reduced in SHR and it may suggest that CRF abnormality may be implicated in the reported abnormalities in the pituitary-adrenal axis, autonomic response and behavior of SHR

Ambulatory blood pressure monitoring and microalbuminuria in normotensive subjects with insulin-dependent diabetes mellitus

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Cohen Cesar Nissan

2000-01-01

Full Text Available OBJECTIVE: To assess the association between microalbuminuria with ambulatory blood pressure monitoring in normotensive individuals with insulin-dependent diabetes mellitus. METHODS: Thirty-seven patients underwent determination of the rate of urinary excretion of albumin through radioimmunoassay and ambulatory blood pressure monitoring. Their mean age was 26.5±6.7 years, and the mean duration of their disease was 8 (1-34 years. Microalbuminuria was defined as urinary excretion of albumin > or = 20 and 50% and diastolic pressure load > 30% during sleep was associated with microalbuminuria (p=0.008. The pressure drop during sleep did not differ between the groups. CONCLUSION: Microalbuminuric normotensive insulin-dependent diabetic patients show greater mean pressure value and pressure load during ambulatory blood pressure monitoring, and these variables correlate with urinary excretion of albumin.

Intracolonic hydrogen sulfide lowers blood pressure in rats.

Science.gov (United States)

Tomasova, Lenka; Dobrowolski, Leszek; Jurkowska, Halina; Wróbel, Maria; Huc, Tomasz; Ondrias, Karol; Ostaszewski, Ryszard; Ufnal, Marcin

2016-11-30

Research suggests that hydrogen sulfide (H 2 S) is an important biological mediator involved in various physiological processes including the regulation of arterial blood pressure (BP). Although H 2 S is abundant in the colon, the effects of gut-derived H 2 S on the circulatory system have not yet been investigated. We studied the effects of intracolonic administration of Na 2 S, a H 2 S donor, on systemic hemodynamics. Hemodynamics were recorded in anesthetized, normotensive Wistar Kyoto and spontaneously hypertensive rats at baseline and after intracolonic injection of either saline (controls) or Na 2 S·9H 2 O saline solution at a dose range of 10-300 mg/kg of BW. The H 2 S donor produced a significant, dose-dependent decrease in mean arterial blood pressure (MABP), which lasted several times longer than previously reported after parenteral infusions (>90 min). The effect was more pronounced in hypertensive than in normotensive rats. The Na 2 S-induced decrease in MABP was reduced by pretreatment with glibenclamide, an inhibitor of ATP-sensitive potassium-channels. Na 2 S did not affect mesenteric vein blood flow. Rats treated with Na 2 S showed increased portal blood levels of thiosulfate and sulfane sulfur, products of H 2 S oxidation. In contrast, rats treated with neomycin, an antibiotic, showed significantly decreased levels of thiosulfate and sulfane sulfur, and a tendency for greater hypotensive response to Na 2 S. The H 2 S donor decreased heart rate but did not affect ECG morphology and QTc interval. In conclusion the gut-derived H 2 S may contribute to the control of BP and may be one of the links between gut microbiota and hypertension. Furthermore, gut-derived H 2 S may be a therapeutic target in hypertension. Copyright © 2016 Elsevier Inc. All rights reserved.

Tubulo-glomerular feedback response: enhancement in adult spontaneously hypertensive rats and effects of anaesthetics

DEFF Research Database (Denmark)

Leyssac, P P; Holstein-Rathlou, N H

1989-01-01

. Maximum TGF pressure response was 28.6% greater in SHR than in the normotensive rats (13.3 vs. 9.5 mm Hg; p less than 0.025). The sensitivity, as estimated from the slope of the feedback curve at the Tp [f'(Tp)] was 87% greater in SHR than in WKY. There was no significant difference between...

Dynamic modeling of renal blood flow in Dahl hypertensive and normotensive rats

DEFF Research Database (Denmark)

Knudsen, Torben; Elmer, Henrik; Knudsen, Morten H

2004-01-01

A method is proposed in this paper which allows characterization of renal autoregulatory dynamics and efficiency using quantitative mathematical methods. Based on data from rat experiments, where arterial blood pressure and renal blood flow are measured, a quantitative model for renal blood flow...

Increased left ventricular mass in normotensive type 1 diabetic patients with diabetic nephropathy

DEFF Research Database (Denmark)

Sato, A; Tarnow, L; Parving, H H

1998-01-01

in normotensive type 1 diabetic patients with and without nephropathy. RESEARCH DESIGN AND METHODS: M-mode and Doppler echocardiography was performed in 17 type 1 diabetic patients with nephropathy (albuminuria [median (range)], 345 (135-2,846) mg/24 h) and compared with 34 normotensive, normoalbuminuric (10 [3......-30] mg/24 h) type 1 diabetic patients matched for arterial blood pressure (mean +/- SD) ([134/77] +/- [13/7] vs. [129/78] +/- [12/7] mmHg), age (40 +/- 11 vs. 42 +/- 10 years), duration of diabetes (28 +/- 7 vs. 28 +/- 6 years), and BMI (24.2 +/- 4.2 vs. 24.6 +/- 2.4 kg/m2). RESULTS: Left ventricular......OBJECTIVE: Diabetic nephropathy increases the risk of premature cardiovascular disease and sudden death, particularly in type 1 diabetic patients. One possible mechanism for this risk may be left ventricular hypertrophy. In our study, we aimed to evaluate left ventricular structure and function...

Abnormal endothelium-dependent microvascular dilator reactivity in pregnancies complicated by normotensive intrauterine growth restriction

NARCIS (Netherlands)

Koopmans, C.M.; Blaauw, Judith; van Pampus, Maria; Rakhorst, G.; Aarnoudse, J.G.

OBJECTIVE: Normotensive intrauterine growth restriction and preeclampsia share a similar placenta pathophysiology, whereas maternal clinical manifestations differ. Clinical symptoms of preeclampsia are partly attributed to vascular endothelial dysfunction, but it is unclear whether this phenomenon

Consciousness and the "Causal Paradox"

OpenAIRE

Velmans, Max

1996-01-01

Viewed from a first-person perspective consciousness appears to be necessary for complex, novel human activity - but viewed from a third-person perspective consciousness appears to play no role in the activity of brains, producing a "causal paradox". To resolve this paradox one needs to distinguish consciousness of processing from consciousness accompanying processing or causing processing. Accounts of consciousness/brain causal interactions switch between first- and third-person perspectives...

Inhibition of Extracellular Signal-Regulated Kinases Ameliorates Hypertension-Induced Renal Vascular Remodeling in Rat Models

Directory of Open Access Journals (Sweden)

Li Jing

2011-11-01

Full Text Available The aim of this study is to investigate the effect of the extracellular signal-regulated kinases 1/2 (ERK1/2 inhibitor, PD98059, on high blood pressure and related vascular changes. Blood pressure was recorded, thicknesses of renal small artery walls were measured and ERK1/2 immunoreactivity and erk2 mRNA in renal vascular smooth muscle cells (VSMCs and endothelial cells were detected by immunohistochemistry and in situ hybridization in normotensive wistar kyoto (WKY rats, spontaneously hypertensive rats (SHR and PD98059-treated SHR. Compared with normo-tensive WKY rats, SHR developed hypertension at 8 weeks of age, thickened renal small artery wall and asymmetric arrangement of VSMCs at 16 and 24 weeks of age. Phospho-ERK1/2 immunoreactivity and erk2 mRNA expression levels were increased in VSMCs and endothelial cells of the renal small arteries in the SHR. Treating SHR with PD98059 reduced the spontaneous hypertension-induced vascular wall thickening. This effect was associated with suppressions of erk2 mRNA expression and ERK1/2 phosphorylation in VSMCs and endothelial cells of the renal small arteries. It is concluded that inhibition of ERK1/2 ameliorates hypertension induced vascular remodeling in renal small arteries.

Spot urine protein measurements in normotensive pregnancies, pregnancies with isolated proteinuria and preeclampsia.

Science.gov (United States)

Kattah, Andrea; Milic, Natasa; White, Wendy; Garovic, Vesna

2017-10-01

We performed a prospective, longitudinal study of pregnant women presenting to their first obstetrics visits to characterize the changes in spot urine protein-to-creatinine (UPCR) and albumin-to-creatinine ratios (UACR) in normotensive pregnancies, as well as identify clinical characteristics associated with isolated proteinuria and preeclampsia. We measured spot urinary albumin, protein, and creatinine at the first prenatal visit, end of the second trimester, and at delivery. In the normotensive pregnancies ( n = 142), we found that from the beginning of pregnancy to delivery, UACR increased by a median [interquartile range (IQR)] of 14.7 mg/g Cr (3.74-51.8) and UPCR by 60 mg/g Cr (30-130) ( P 300 mg/g Cr in the absence of hypertension) was identified in 19/142 (13.4%) normotensive pregnancies. Increases in systolic and diastolic blood pressure from early pregnancy to delivery and increases in UACR from early to midpregnancy were associated with isolated proteinuria at delivery. Twelve women developed preeclampsia. Nulliparity, early, and midpregnancy diastolic blood pressures were strongly associated with the development of preeclampsia, but early changes in UACR were not. In conclusion, women who develop isolated proteinuria at delivery have a larger increase in blood pressure than women without proteinuria and have a "microalbuminuric" phase earlier in gestation, unlike women who develop preeclampsia. These findings suggest a different mechanism of urine protein excretion in women with isolated proteinuria as compared with women with preeclampsia, where proteinuria has a more abrupt onset. Copyright © 2017 the American Physiological Society.

Effects of intravenous bumetanide administration on renal haemodynamics and proximal and distal tubular sodium reabsorption in conscious rats

Energy Technology Data Exchange (ETDEWEB)

Shalmi, M.; Petersen, J.S.; Christensen, S. (Department of pharmacology, University of Copenhagen (Denmark))

1989-01-01

The renal effects of 0.02-62.5 mg/kg bumetanide given as intravenous bolus injections were studied in water diuretic conscious rats. Clearances of {sup 14}C-tetraethylammonium, {sup 3}H-inulin and lithium were used as markers for renal plasma flow (RPF), glomerular filtion rate (GFR) and proximal tubular output, respectively. Bumetanide caused biphasic, transient and dose-independent changes in the renal haemodynamics without significant alterations of the filtration fraction. At dose-levels above 0.02 mg/kg bumetanide increased urine flow, absolute and fractional Na excretion as well as the indices for fractional output of Na from the proximal tubules (C{sub Li}/C{sub I}n) and the distal nephron segments (C{sub Na}/C{sub Li}). The changes in C{sub Li}/C{sub In} became maximal at doses above 0.5 mg/kg, whereas C{sub Na}/C{sub Li} was increased with the dose up to 12.5 mg/kg. Paradoxically, doses above 12.5 mg/kg were less natriuretic due to a decrease of C{sub Na}/C{sub Li}. It is concluded that in rats bumetanide is an effective although short-acting diuretic when administered intravenously. When comparing peak responses bumetanide is equipotent to furosemide but has a lower maximal efficacy. Judged from the changes in fractional lithium excretion, the natriuretic effect of bumetanide is effected by inhibition of Na reabsorption in the proximal tubule in addition to the well-known effect on the distal nephron segment. (author).

Neuroimaging of consciousness

Energy Technology Data Exchange (ETDEWEB)

Cavanna, Andrea Eugenio [Birmingham Univ. (United Kingdom). Dept. of Neuropsychiatry; UCL Institute of Neurology, London (United Kingdom). Sobell Dept. of Motor, Neuroscience and Movement Disorders; Nani, Andrea [Birmingham Univ. (United Kingdom). Research Group BSMHFT; Blumenfeld, Hal [Yale University School of Medicine, New Haven, CT (United States). Depts. of Neurology, Neurobiology and Neurosurgery; Laureys, Steven (ed.) [Liege Univ. (Belgium). Cyclotron Research Centre

2013-07-01

An important reference work on a multidisciplinary and rapidly expanding area. Particular focus on the relevance of neuroimaging for the diagnosis and treatment of common neuropsychiatric disorders affecting consciousness. Written by world-class experts in the field. Relevant for clinicians, researchers, and scholars across different specialties. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This book presents the state of the art in neuroimaging exploration of the brain correlates of the alterations in consciousness across these conditions, with a particular focus on the potential applications for diagnosis and management. Although the book has a practical approach and is primarily targeted at neurologists, neuroradiologists, and psychiatrists, a wide range of researchers and health care professionals will find it an essential reference that explains the significance of neuroimaging of consciousness for clinical practice. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This

Neuroimaging of consciousness

International Nuclear Information System (INIS)

Cavanna, Andrea Eugenio; UCL Institute of Neurology, London; Nani, Andrea; Blumenfeld, Hal; Laureys, Steven

2013-01-01

An important reference work on a multidisciplinary and rapidly expanding area. Particular focus on the relevance of neuroimaging for the diagnosis and treatment of common neuropsychiatric disorders affecting consciousness. Written by world-class experts in the field. Relevant for clinicians, researchers, and scholars across different specialties. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This book presents the state of the art in neuroimaging exploration of the brain correlates of the alterations in consciousness across these conditions, with a particular focus on the potential applications for diagnosis and management. Although the book has a practical approach and is primarily targeted at neurologists, neuroradiologists, and psychiatrists, a wide range of researchers and health care professionals will find it an essential reference that explains the significance of neuroimaging of consciousness for clinical practice. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This

Continuous measurement of the blood pressure response of normotensives and hypertensives during reading

NARCIS (Netherlands)

Näring, G.W.B.; Schaap, C.; DeMey, H.; Staak, C. van der

1996-01-01

Experiments on the response of blood pressure (BP) to speech were critically reviewed. Based on this review, it was concluded that evidence to support the assumption that the BP response to speech is higher for hypertensives than for normotensives is insufficient. The present investigation addressed

The Science of Consciousness

CERN Multimedia

CERN. Geneva

2015-01-01

We not only act in the world but we consciously perceive it. The interactions of myriad of neuronal and sub-neuronal processes that are responsible for visual behaviors also give rise to the daily movie screened for our benefit in the privacy of our own skull. I will discuss the empirical progress that has been achieved over the past several decades in characterizing the behavioral and the neuronal correlates of consciousness in human and non-human animals and in dissociating selective visual attention from visual consciousness. I will introduce Tononi’s integrated Information Theory (IIT) that explains in a principled manner which physical systems are capable of conscious, subjective experience. The theory explains many empirical facts about consciousness and its pathologies in humans. It can also be extrapolated to more difficult cases, such as fetuses, mice, or bees. The theory predicts that many, seemingly complex, systems are not conscious, in particular digital computers running software, even if thes...

Norepinephrine-evoked salt-sensitive hypertension requires impaired renal sodium chloride cotransporter activity in Sprague-Dawley rats.

Science.gov (United States)

Walsh, Kathryn R; Kuwabara, Jill T; Shim, Joon W; Wainford, Richard D

2016-01-15

Recent studies have implicated a role of norepinephrine (NE) in the activation of the sodium chloride cotransporter (NCC) to drive the development of salt-sensitive hypertension. However, the interaction between NE and increased salt intake on blood pressure remains to be fully elucidated. This study examined the impact of a continuous NE infusion on sodium homeostasis and blood pressure in conscious Sprague-Dawley rats challenged with a normal (NS; 0.6% NaCl) or high-salt (HS; 8% NaCl) diet for 14 days. Naïve and saline-infused Sprague-Dawley rats remained normotensive when placed on HS and exhibited dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide. NE infusion resulted in the development of hypertension, which was exacerbated by HS, demonstrating the development of the salt sensitivity of blood pressure [MAP (mmHg) NE+NS: 151 ± 3 vs. NE+HS: 172 ± 4; P salt-sensitive animals, increased NE prevented dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide, suggesting impaired NCC activity contributes to the development of salt sensitivity [peak natriuresis to hydrochlorothiazide (μeq/min) Naïve+NS: 9.4 ± 0.2 vs. Naïve+HS: 7 ± 0.1; P salt-sensitive component of NE-mediated hypertension, while chronic ANG II type 1 receptor antagonism significantly attenuated NE-evoked hypertension without restoring NCC function. These data demonstrate that increased levels of NE prevent dietary sodium-evoked suppression of the NCC, via an ANG II-independent mechanism, to stimulate the development of salt-sensitive hypertension. Copyright © 2016 the American Physiological Society.

Effects of curative treatment emphasizing endurance training on the performance and blood pressure of hypertensive and normotensives

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Worms, F.

1981-01-01

The problem of normal values of blood pressure after exercise taking into account the blood pressure at the end of the exercise test is discussed. Hypertensives showed a lower working capacity than normotensives. In normotensives, however, systolic blood pressure at the end of an exercise correlated well with the working capacity. After the endurance cure submaximal blood pressure was markedly lower in hypertensives with a striking dependence on the level of initial values. Systolic blood pressure at the end of an exercise test was not changed significantly. Most probably it is not possible to overcome this malregulation in hypertensives by endurance training alone.

Normotensive blood pressure in pregnancy: the role of salt and aldosterone.

Science.gov (United States)

Gennari-Moser, Carine; Escher, Geneviève; Kramer, Simea; Dick, Bernhard; Eisele, Nicole; Baumann, Marc; Raio, Luigi; Frey, Felix J; Surbek, Daniel; Mohaupt, Markus G

2014-02-01

A successful pregnancy requires an accommodating environment. Salt and water availability are critical for plasma volume expansion. Any changes in sodium intake would alter aldosterone, a hormone previously described beneficial in pregnancy. To date, it remains ambiguous whether high aldosterone or high salt intake is preferable. We hypothesized that increased aldosterone is a rescue mechanism and appropriate salt availability is equally effective in maintaining a normotensive blood pressure (BP) phenotype in pregnancy. We compared normotensive pregnant women (n=31) throughout pregnancy with young healthy female individuals (n=31-62) and performed salt sensitivity testing within the first trimester. Suppression of urinary tetrahydro-aldosterone levels by salt intake as measured by gas chromatography-mass spectrometry and urinary sodium excretion corrected for creatinine, respectively, was shifted toward a higher salt intake in pregnancy (Ppregnancy, neither high urinary tetrahydro-aldosterone nor sodium excretion was correlated with higher BP. In contrast, in nonpregnant women, systolic BP rose with aldosterone (Ppregnancy without causing aldosterone-induced hypertension. Second, salt seems to aid in BP lowering in pregnancy for reasons incompletely elucidated, yet involving renin suppression and potentially placental sensing mechanisms. Further research should identify susceptible individuals and clarify effector mechanisms.

Consciousness and neural plasticity

DEFF Research Database (Denmark)

changes or to abandon the strong identity thesis altogether. Were one to pursue a theory according to which consciousness is not an epiphenomenon to brain processes, consciousness may in fact affect its own neural basis. The neural correlate of consciousness is often seen as a stable structure, that is...

Conscious motor processing and movement self-consciousness: two dimensions of personality that influence laparoscopic training.

Science.gov (United States)

Malhotra, Neha; Poolton, Jamie M; Wilson, Mark R; Fan, Joe K M; Masters, Rich S W

2014-01-01

Identifying personality factors that account for individual differences in surgical training and performance has practical implications for surgical education. Movement-specific reinvestment is a potentially relevant personality factor that has a moderating effect on laparoscopic performance under time pressure. Movement-specific reinvestment has 2 dimensions, which represent an individual's propensity to consciously control movements (conscious motor processing) or to consciously monitor their 'style' of movement (movement self-consciousness). This study aimed at investigating the moderating effects of the 2 dimensions of movement-specific reinvestment in the learning and updating (cross-handed technique) of laparoscopic skills. Medical students completed the Movement-Specific Reinvestment Scale, a psychometric assessment tool that evaluates the conscious motor processing and movement self-consciousness dimensions of movement-specific reinvestment. They were then trained to a criterion level of proficiency on a fundamental laparoscopic skills task and were tested on a novel cross-handed technique. Completion times were recorded for early-learning, late-learning, and cross-handed trials. Propensity for movement self-consciousness but not conscious motor processing was a significant predictor of task completion times both early (p = 0.036) and late (p = 0.002) in learning, but completion times during the cross-handed trials were predicted by the propensity for conscious motor processing (p = 0.04) rather than movement self-consciousness (p = 0.21). Higher propensity for movement self-consciousness is associated with slower performance times on novel and well-practiced laparoscopic tasks. For complex surgical techniques, however, conscious motor processing plays a more influential role in performance than movement self-consciousness. The findings imply that these 2 dimensions of movement-specific reinvestment have a differential influence in the learning and updating

Inner Consciousness Tindakan Nabi

Directory of Open Access Journals (Sweden)

Moh. Helmi Umam

2015-09-01

Full Text Available The article is written to examine deeds and actions of the Prophet Muhammad (peace be upon him within inner consciousness analysis of Husserl’s phenomenology. The article is formulated to explore the significance of phenomenology of religious study, Prophet’s deeds as well as his inner consciousness, and inner consciousness analysis of Prophet’s deeds. This article is written using phenomenological method, i.e. a comprehensive interpretation about the source of information or object’s phenomenon as long as it can be traced. Inner consciousness of Prophet’s actions sees that his deeds in deciding important religious pronouncements were results of long-term memory based on divine and social argumentations, which have came into Prophet’s consciousness as a human.

The Neurogenetic Correlates of Consciousness

Science.gov (United States)

Grandy, John K.

2013-09-01

The neurogenetic correlates of consciousness (NgCC) is a new field of consciousness studies that focuses on genes that have an effect on or are involved in the continuum of neuron-based consciousness. A framework of consciousness based on the neural correlates of consciousness (NCC) has already been established by Francis Crick and Christof Kock. In this work I propose that there are NgCC underlying the NCC which are both active during the conscious experience. So how are genes involved? There are two significant connections between DNA and neurons that are involved in the conscious experience. First, any brain system can be adversely affected by underlying genetic abnormalities which can be expressed in an individual at birth, in adulthood, or later in life. Second, the DNA molecule does not lay dormant while the neuron runs on autopilot. DNA is active in translating and transcribing RNA and protein products that are utilized during neuron functioning. Without these products being continuously produced by the DNA during a conscious experience the neurons would cease to function correctly and be rendered unable to provide a continuum of human consciousness. Consequently, in addition to NCC, NgCC must be factored in when appreciating a conscious event. In this work I will discuss and explain some NgCC citing several examples.

Exogenous and endogenous angiotensin-II decrease renal cortical oxygen tension in conscious rats by limiting renal blood flow.

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Emans, Tonja W; Janssen, Ben J; Pinkham, Maximilian I; Ow, Connie P C; Evans, Roger G; Joles, Jaap A; Malpas, Simon C; Krediet, C T Paul; Koeners, Maarten P

2016-11-01

Our understanding of the mechanisms underlying the role of hypoxia in the initiation and progression of renal disease remains rudimentary. We have developed a method that allows wireless measurement of renal tissue oxygen tension in unrestrained rats. This method provides stable and continuous measurements of cortical tissue oxygen tension (PO2) for more than 2 weeks and can reproducibly detect acute changes in cortical oxygenation. Exogenous angiotensin-II reduced renal cortical tissue PO2 more than equi-pressor doses of phenylephrine, probably because it reduced renal oxygen delivery more than did phenylephrine. Activation of the endogenous renin-angiotensin system in transgenic Cyp1a1Ren2 rats reduced cortical tissue PO2; in this model renal hypoxia precedes the development of structural pathology and can be reversed acutely by an angiotensin-II receptor type 1 antagonist. Angiotensin-II promotes renal hypoxia, which may in turn contribute to its pathological effects during development of chronic kidney disease. We hypothesised that both exogenous and endogenous angiotensin-II (AngII) can decrease the partial pressure of oxygen (PO2) in the renal cortex of unrestrained rats, which might in turn contribute to the progression of chronic kidney disease. Rats were instrumented with telemeters equipped with a carbon paste electrode for continuous measurement of renal cortical tissue PO2. The method reproducibly detected acute changes in cortical oxygenation induced by systemic hyperoxia and hypoxia. In conscious rats, renal cortical PO2 was dose-dependently reduced by intravenous AngII. Reductions in PO2 were significantly greater than those induced by equi-pressor doses of phenylephrine. In anaesthetised rats, renal oxygen consumption was not affected, and filtration fraction was increased only in the AngII infused animals. Oxygen delivery decreased by 50% after infusion of AngII and renal blood flow (RBF) fell by 3.3 ml min -1 . Equi-pressor infusion of

Measuring consciousness in dreams: the lucidity and consciousness in dreams scale.

Science.gov (United States)

Voss, Ursula; Schermelleh-Engel, Karin; Windt, Jennifer; Frenzel, Clemens; Hobson, Allan

2013-03-01

In this article, we present results from an interdisciplinary research project aimed at assessing consciousness in dreams. For this purpose, we compared lucid dreams with normal non-lucid dreams from REM sleep. Both lucid and non-lucid dreams are an important contrast condition for theories of waking consciousness, giving valuable insights into the structure of conscious experience and its neural correlates during sleep. However, the precise differences between lucid and non-lucid dreams remain poorly understood. The construction of the Lucidity and Consciousness in Dreams scale (LuCiD) was based on theoretical considerations and empirical observations. Exploratory factor analysis of the data from the first survey identified eight factors that were validated in a second survey using confirmatory factor analysis: INSIGHT, CONTROL, THOUGHT, REALISM, MEMORY, DISSOCIATION, NEGATIVE EMOTION, and POSITIVE EMOTION. While all factors are involved in dream consciousness, realism and negative emotion do not differentiate between lucid and non-lucid dreams, suggesting that lucid insight is separable from both bizarreness in dreams and a change in the subjectively experienced realism of the dream. Copyright © 2012 Elsevier Inc. All rights reserved.

Quantitation of uveoscleral outflow in normotensive and glaucomatous Beagles by 3H-labeled dextran

International Nuclear Information System (INIS)

Barrie, K.P.; Gum, G.G.; Samuelson, D.A.; Gelatt, K.N.

1985-01-01

In uveoscleral outflow, aqueous humor leaves the anterior chamber and passes caudally through the trabecular meshwork and the sclerociliary cleft to enter the supraciliary and suprachoroidal spaces. The fluid is then absorbed by choroidal and scleral circulations. Using 3 H-labeled dextran, uveoscleral outflow was quantitated in normotensive and glaucomatous Beagles under general anesthesia. The intrascleral plexus was isolated and 3 H-labeled dextran was injected into the anterior chamber. Intrascleral plexus contents were sampled every 5 minutes over a 30- to 60-minute period. The eyes were enucleated, sectioned, and prepared for scintillation counting. Uveoscleral outflow accounted for 15% and 3% of the total aqueous humor outflow in the normotensive dogs and in the advanced glaucomatous dogs, respectively. In the advanced glaucomatous Beagle, conventional and uveoscleral outflow pathways were reduced and contributed to the etiopathogenesis of glaucoma

Science, conscience, consciousness.

Science.gov (United States)

Hennig, Boris

2010-01-01

Descartes' metaphysics lays the foundation for the special sciences, and the notion of consciousness ("conscientia") belongs to metaphysics rather than to psychology. I argue that as a metaphysical notion, "consciousness" refers to an epistemic version of moral conscience. As a consequence, the activity on which science is based turns out to be conscientious thought. The consciousness that makes science possible is a double awareness: the awareness of what one is thinking, of what one should be doing, and of the possibility of a gap between the two.

The biological function of consciousness

Directory of Open Access Journals (Sweden)

Brian eEarl

2014-08-01

Full Text Available This research is an investigation of whether consciousness—one’s ongoing experience—influences one’s behavior and, if so, how. Analysis of the components, structure, properties, and temporal sequences of consciousness has established that, (1 contrary to one’s intuitive understanding, consciousness does not have an active, executive role in determining behavior; (2 consciousness does have a biological function; and (3 consciousness is solely information in various forms. Consciousness is associated with a flexible response mechanism (FRM for decision-making, planning, and generally responding in nonautomatic ways. The FRM generates responses by manipulating information and, to function effectively, its data input must be restricted to task-relevant information. The properties of consciousness correspond to the various input requirements of the FRM; and when important information is missing from consciousness, functions of the FRM are adversely affected; both of which indicate that consciousness is the input data to the FRM. Qualitative and quantitative information (shape, size, location, etc., is incorporated into the input data by a qualia array of colors, sounds, and so on, which makes the input conscious. This view of the biological function of consciousness provides an explanation why we have experiences; why we have emotional and other feelings, and why their loss is associated with poor decision-making; why blindsight patients do not spontaneously initiate responses to events in their blind field; why counter-habitual actions are only possible when the intended action is in mind; and the reason for inattentional blindness.

An information integration theory of consciousness

Directory of Open Access Journals (Sweden)

Tononi Giulio

2004-11-01

Full Text Available Abstract Background Consciousness poses two main problems. The first is understanding the conditions that determine to what extent a system has conscious experience. For instance, why is our consciousness generated by certain parts of our brain, such as the thalamocortical system, and not by other parts, such as the cerebellum? And why are we conscious during wakefulness and much less so during dreamless sleep? The second problem is understanding the conditions that determine what kind of consciousness a system has. For example, why do specific parts of the brain contribute specific qualities to our conscious experience, such as vision and audition? Presentation of the hypothesis This paper presents a theory about what consciousness is and how it can be measured. According to the theory, consciousness corresponds to the capacity of a system to integrate information. This claim is motivated by two key phenomenological properties of consciousness: differentiation – the availability of a very large number of conscious experiences; and integration – the unity of each such experience. The theory states that the quantity of consciousness available to a system can be measured as the Φ value of a complex of elements. Φ is the amount of causally effective information that can be integrated across the informational weakest link of a subset of elements. A complex is a subset of elements with Φ>0 that is not part of a subset of higher Φ. The theory also claims that the quality of consciousness is determined by the informational relationships among the elements of a complex, which are specified by the values of effective information among them. Finally, each particular conscious experience is specified by the value, at any given time, of the variables mediating informational interactions among the elements of a complex. Testing the hypothesis The information integration theory accounts, in a principled manner, for several neurobiological observations

A low-carbohydrate/high-fat diet reduces blood pressure in spontaneously hypertensive rats without deleterious changes in insulin resistance

OpenAIRE

Bosse, John D.; Lin, Han Yi; Sloan, Crystal; Zhang, Quan-Jiang; Abel, E. Dale; Pereira, Troy J.; Dolinsky, Vernon W.; Symons, J. David; Jalili, Thunder

2013-01-01

Previous studies reported that diets high in simple carbohydrates could increase blood pressure in rodents. We hypothesized that the converse, a low-carbohydrate/high-fat diet, might reduce blood pressure. Six-week-old spontaneously hypertensive rats (SHR; n = 54) and Wistar-Kyoto rats (WKY; n = 53, normotensive control) were fed either a control diet (C; 10% fat, 70% carbohydrate, 20% protein) or a low-carbohydrate/high-fat diet (HF; 20% carbohydrate, 60% fat, 20% protein). After 10 wk, SHR-...

Consciousness in non-epileptic attack disorder.

Science.gov (United States)

Reuber, Markus; Kurthen, M

2011-01-01

Non-epileptic attack disorder (NEAD) is one of the most important differential diagnoses of epilepsy. Impairment of consciousness is the key feature of non-epileptic attacks (NEAs). The first half of this review summarises the clinical research literature featuring observations relating to consciousness in NEAD. The second half places this evidence in the wider context of the recent discourse on consciousness in neuroscience and the philosophy of mind. We argue that studies of consciousness should not only distinguish between the 'level' and `content' of consciousness but also between 'phenomenal consciousness' (consciousness of states it somehow "feels to be like") and 'access consciousness' (having certain 'higher' cognitive processes at one's disposal). The existing evidence shows that there is a great intra- and interindividual variability of NEA experience. However, in most NEAs phenomenal experience - and, as a precondition for that experience, vigilance or wakefulness - is reduced to a lesser degree than in those epileptic seizures involving impairment of consciousness. In fact, complete loss of "consciousness" is the exception rather than the rule in NEAs. Patients, as well as external observers, may have a tendency to overestimate impairments of consciousness during the seizures.

Consciousness extended

DEFF Research Database (Denmark)

Carrara-Augustenborg, Claudia

2012-01-01

There is no consensus yet regarding a conceptualization of consciousness able to accommodate all the features of such complex phenomenon. Different theoretical and empirical models lend strength to both the occurrence of a non-accessible informational broadcast, and to the mobilization of specific...... brain areas responsible for the emergence of the individual´s explicit and variable access to given segments of such broadcast. Rather than advocating one model over others, this chapter proposes to broaden the conceptualization of consciousness by letting it embrace both mechanisms. Within...... such extended framework, I propose conceptual and functional distinctions between consciousness (global broadcast of information), awareness (individual´s ability to access the content of such broadcast) and unconsciousness (focally isolated neural activations). My hypothesis is that a demarcation in terms...

Is Consciousness Reality or Illusion ? A Non-Dualist Interpretation of Consciousness

Science.gov (United States)

Schwarz, Eric

2004-08-01

This paper proposes a way to approach the "hard problem" of consciousness. First, we present a typology of the main models developed in the litterature to understand consciousness. Most of them adopt a physicalist ontology and a functionalist epistemology. We then present the main features of a metamodel we have elaborated to interpret nonlinear systems evolving toward complexity and autonomy. This systemic metamodel is a general framework that can later be used to make models of specific systems. As an extension of the mechanist paradigm, it is based on three primordial categories objects, relations and wholes or systems. In the last part, we apply it to the cases of the logic of life and the nature of consciousness. Both can be interpreted by the metamodel, in particular, by the autopoiesis proposed by Maturana and Varela for life and self-reference for consciousness.

Multicomponent exercise decreases blood pressure, heart rate and double product in normotensive and hypertensive older patients with high blood pressure.

Science.gov (United States)

Coelho-Júnior, Hélio José; Asano, Ricardo Yukio; Gonçalvez, Ivan de Oliveira; Brietzke, Cayque; Pires, Flávio Oliveira; Aguiar, Samuel da Silva; Feriani, Daniele Jardim; Caperuto, Erico Chagas; Uchida, Marco Carlos; Rodrigues, Bruno

2018-02-26

The present study aimed to investigate the effects of a 6-month multicomponent exercise program on blood pressure, heart rate, and double product of uncontrolled and controlled normotensive and hypertensive older patients. The study included 183 subjects, 97 normotensives, of which 53 were controlled normotensives (CNS), and 44 uncontrolled normotensives (UNS), as well as 86 hypertensives, of which 43 were controlled hypertensives (CHS), and 43 uncontrolled hypertensives (UHS). Volunteers were recruited and blood pressure and heart rate measurements were made before and after a 6-month multicomponent exercise program. The program of physical exercise was performed twice a week for 26 weeks. The physical exercises program was based on functional and walking exercises. Exercise sessions were performed at moderate intensity. The results indicated that UHS showed a marked decrease in systolic (-8.0mmHg), diastolic (-11.1mmHg), mean (-10.1mmHg), and pulse pressures, heart rate (-6.8bpm), and double product (-1640bpmmmHg), when compared to baseline. Similarly, diastolic (-5.5mmHg) and mean arterial (-4.8mmHg) pressures were significantly decreased in UNS. Concomitantly, significant changes could be observed in the body mass index (-0.9kg/m 2 ; -1.5kg/m 2 ) and waist circumference (-3.3cm; only UHS) of UNS and UHS, which may be associated with the changes observed in blood pressure. In conclusion, the data of the present study indicate that a 6-month multicomponent exercise program may lead to significant reductions in blood pressure, heart rate, and double product of normotensive and hypertensive patients with high blood pressure values. Copyright © 2018 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Intentionality and Consciousness

NARCIS (Netherlands)

Ierna, Carlo; Jacquette, Dale

2018-01-01

In this chapter I concentrate on the notion of intentionality and its relation to consciousness. Ever since its re-introduction into contemporary philosophy in the works of Franz Brentano, intentionality has been associated in various ways with consciousness. In the continental and analytic

Water and exchangeable sodium in Goldblatt two-kidney, two-clip hypertensive rats

International Nuclear Information System (INIS)

Mac Cormack, W.P.; Roson, M.I.; Maquieira, M.K.; Mendez, M.A.; Santoro, F.M.; Morera, S.; de la Riva, I.J.

1986-01-01

Exchangeable 22 Na (ExNa), total body water (TBW) and the inulin space (InSp) were determined in two-kidney, two-clip (2K-2C) hypertensive and sham operated (normotensive) control rats 6-8 weeks after surgery. TBW (ml/kg lean body weight) was the same in hypertensive and sham rats. In contrast, ExNa (mEq/kglbw) and InSp (ml/kglbw) significantly increased (p less than 0.01) in rats whose hypertension did not exceed 170 mmHg. Consequently, sham, moderate hypertensive (less than 170 mmHg) and severe hypertensive (less than 170 mmHg) animals showed equal TBW but differed in body water distribution in that moderately hypertensive animals displayed a redistribution of water in favor of the extracellular space

Consciousness: function and definition.

Science.gov (United States)

Niedermeyer, E

1994-07-01

The term "consciousness" plays an enormous role in the clinical assessment of patients and also in psychophysiological considerations. It has often been said that consciousness is a term that defies definition. This lack of definability, however, might be more apparent than real. In the multitude of facets, three main components can be singled out: a) vigilance, b) mental contents and c) selective attention. Vigilance, not to be equated with consciousness, is most amenable to electrophysiological studies. The stages of sleep have fairly well standardized EEG correlates, unlike the comatose states. The overflowing wealth of mental contents is constantly adjusted to momentary needs by the mechanism of selective attention. Awareness is a subcomponent and differs from both vigilance and consciousness. Emotionality is particularly important among the variety of further subcomponents. The time factor must be taken into account in order to understand the dynamics and fluctuations of consciousness.

Neural Darwinism and consciousness.

Science.gov (United States)

Seth, Anil K; Baars, Bernard J

2005-03-01

Neural Darwinism (ND) is a large scale selectionist theory of brain development and function that has been hypothesized to relate to consciousness. According to ND, consciousness is entailed by reentrant interactions among neuronal populations in the thalamocortical system (the 'dynamic core'). These interactions, which permit high-order discriminations among possible core states, confer selective advantages on organisms possessing them by linking current perceptual events to a past history of value-dependent learning. Here, we assess the consistency of ND with 16 widely recognized properties of consciousness, both physiological (for example, consciousness is associated with widespread, relatively fast, low amplitude interactions in the thalamocortical system), and phenomenal (for example, consciousness involves the existence of a private flow of events available only to the experiencing subject). While no theory accounts fully for all of these properties at present, we find that ND and its recent extensions fare well.

Hypertension, Prehypertension and Normotension among Police Personnel in a District of West Bengal, India.

Science.gov (United States)

Mallik, Debabrata; Mukhopadhyay, Dipta Kanti; Kumar, Pranav; Sinhababu, Apurba

2014-11-01

We conducted the present study to assess the prevalence of hypertension, prehypertension, normotension and the associated factors along with awareness, treatment and control of hypertension among police personnel in Bankura, West Bengal, India. We collected information on individual, lifestyle, service-related and anthropometric characteristics of 1817 police personnel. We also measured blood pressure (BP) and plasma glucose level of the participants. Individuals were classified as hypertensive (BP ≥ 140/ 90 mmHg), prehypertensive (BP 120-139/ 80-89 mmHg) and normotensive (BP < 120/ 80 mmHg) on the basis of BP and their prevalence were expressed in percentages. Relation of individual, lifestyle, service-related and anthropometric characteristics with hypertension and/or prehypertension was examined with binary logistic regression. Prevalence of hypertension, prehypertension and normotension are 41.9%, 42.9% and 15.2% respectively. Even one-quarter of below 40 years subjects have hypertension. Mean BP remains in the prehypertensive range. Prevalence of hypertension and mean BP increases with age. Cardiovascular risk factors show clustering in higher age and with hypertension. Older age group, male gender, abdominal obesity, diabetes and service length are positively associated with hypertension and/or prehypertension. Around 40% of hypertensive knew their status, three-quarter of aware subjects received treatment and only one-third of treated subjects have controlled BP (< 140/ 90 mmHg). High prevalence of hypertension and prehypertension, high mean BP, mean age above 40 years and clustering of other risk factors pose a greater risk of cardiovascular morbidity in the current study population.

Enhanced vasomotion of cerebral arterioles in spontaneously hypertensive rats

Science.gov (United States)

Lefer, D. J.; Lynch, C. D.; Lapinski, K. C.; Hutchins, P. M.

1990-01-01

Intrinsic rhythmic changes in the diameter of pial cerebral arterioles (30-70 microns) in anesthetized normotensive and hypertensive rats were assessed in vivo to determine if any significant differences exist between the two strains. All diameter measurements were analyzed using a traditional graphic analysis technique and a new frequency spectrum analysis technique known as the Prony Spectral Line Estimator. Graphic analysis of the data revealed that spontaneously hypertensive rats (SHR) possess a significantly greater fundamental frequency (5.57 +/- 0.28 cycles/min) of vasomotion compared to the control Wistar-Kyoto normotensive rats (WKY) (1.95 +/- 0.37 cycles/min). Furthermore, the SHR cerebral arterioles exhibited a significantly greater amplitude of vasomotion (10.07 +/- 0.70 microns) when compared to the WKY cerebral arterioles of the same diameter (8.10 +/- 0.70 microns). Diameter measurements processed with the Prony technique revealed that the fundamental frequency of vasomotion in SHR cerebral arterioles (6.14 +/- 0.39 cycles/min) was also significantly greater than that of the WKY cerebral arterioles (2.99 +/- 0.42 cycles/min). The mean amplitudes of vasomotion in the SHR and WKY strains obtained by the Prony analysis were found not to be statistically significant in contrast to the graphic analysis of the vasomotion amplitude of the arterioles. In addition, the Prony system was able to consistently uncover a very low frequency of vasomotion in both strains of rats that was typically less than 1 cycle/min and was not significantly different between the two strains. The amplitude of this slow frequency was also not significantly different between the two strains. The amplitude of the slow frequency of vasomotion (less than 1 cycle/min) was not different from the amplitude of the higher frequency (2-6 cycles/min) vasomotion by Prony or graphic analysis. These data suggest that a fundamental intrinsic defect exists in the spontaneously hypertensive rat

Role of central and peripheral opiate receptors in the effects of fentanyl on analgesia, ventilation and arterial blood-gas chemistry in conscious rats

Science.gov (United States)

Henderson, Fraser; May, Walter J.; Gruber, Ryan B.; Discala, Joseph F.; Puscovic, Veljko; Young, Alex P.; Baby, Santhosh M.; Lewis, Stephen J.

2015-01-01

This study determined the effects of the peripherally restricted µ-opiate receptor (µ-OR) antagonist, naloxone methiodide (NLXmi) on fentanyl (25 µg/kg, i.v.)-induced changes in (1) analgesia, (2) arterial blood gas chemistry (ABG) and alveolar-arterial gradient (A-a gradient), and (3) ventilatory parameters, in conscious rats. The fentanyl-induced increase in analgesia was minimally affected by a 1.5 mg/kg of NLXmi but was attenuated by a 5.0 mg/kg dose. Fentanyl decreased arterial blood pH, pO2 and sO2 and increased pCO2 and A-a gradient. These responses were markedly diminished in NLXmi (1.5 mg/kg)-pretreated rats. Fentanyl caused ventilatory depression (e.g., decreases in tidal volume and peak inspiratory flow). Pretreatment with NLXmi (1.5 mg/kg, i.v.) antagonized the fentanyl decrease in tidal volume but minimally affected the other responses. These findings suggest that (1) the analgesia and ventilatory depression caused by fentanyl involve peripheral µ-ORs and (2) NLXmi prevents the fentanyl effects on ABG by blocking the negative actions of the opioid on tidal volume and A-a gradient. PMID:24284037

Impact of Emotion on Consciousness

DEFF Research Database (Denmark)

Thomsen, Kristine Rømer; Lou, Hans Olav Christensen; Jønsson, Morten

2011-01-01

Emotion and reward have been proposed to be closely linked to conscious experience, but empirical data are lacking. The anterior cingulate cortex (ACC) plays a central role in the hedonic dimension of conscious experience; thus potentially a key region in interactions between emotion...... and consciousness. Here we tested the impact of emotion on conscious experience, and directly investigated the role of the ACC. We used a masked paradigm that measures conscious reportability in terms of subjective confidence and objective accuracy in identifying the briefly presented stimulus in a forced......-choice test. By manipulating the emotional valence (positive, neutral, negative) and the presentation time (16 ms, 32 ms, 80 ms) we measured the impact of these variables on conscious and subliminal (i.e. below threshold) processing. First, we tested normal participants using face and word stimuli. Results...

Psychotherapy, consciousness, and brain plasticity

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Daniel eCollerton

2013-09-01

Full Text Available Purely psychological treatments for emotional distress produce lasting, measureable, and reproducible changes in cognitive and emotional consciousness and brain function. How these changes come about illustrates the interplay between brain and consciousness. Studies of the effects of psychotherapy highlight the holistic nature of consciousness. Pre and post treatment functional Magnetic Resonance Imaging localises the brain changes following psychotherapy to frontal, cingulate, and limbic circuits, but emphasise that these areas support a wide range of conscious experiences. Multivoxel Pattern Analysis of distributed changes in function across these brain areas may be able to provide the ability to distinguish between different states of consciousness.

Blood Pressure Regulation by the Rostral Ventrolateral Medulla in Conscious Rats: Effects of Hypoxia, Hypercapnia, Baroreceptor Denervation, and Anesthesia

Science.gov (United States)

Wenker, Ian C.; Abe, Chikara; Viar, Kenneth E.; Stornetta, Daniel S.

2017-01-01

in the medulla oblongata, which may operate as a switchboard for differential, behavior-appropriate activation of selected sympathetic efferents. Based largely on experimentation in anesthetized or reduced preparations, a rostrally located subset of C1 neurons may contribute to both BP stabilization and dysregulation (hypertension). Here, we used Archaerhodopsin-based loss-of-function optogenetics to explore the contribution of these neurons to BP in conscious rats. The results suggest that C1 neurons contribute little to resting BP under normoxia or hypercapnia, C1 neuron discharge is restrained continuously by arterial baroreceptors, and C1 neuron activation is critical to stabilize BP under hypoxia or anesthesia. This optogenetic approach could also be useful to explore the role of C1 neurons during specific behaviors or in hypertensive models. PMID:28363984

Objects of consciousness

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Donald David Hoffman

2014-06-01

Full Text Available Current models of visual perception typically assume that human vision estimates true properties of physical objects, properties that exist even if unperceived. However, recent studies of perceptual evolution, using evolutionary games and genetic algorithms, reveal that natural selection often drives true perceptions to extinction when they compete with perceptions tuned to fitness rather than truth: Perception guides adaptive behavior; it does not estimate a preexisting physical truth. Moreover, shifting from evolutionary biology to quantum physics, there is reason to disbelieve in preexist-ing physical truths: Certain interpretations of quantum theory deny that dynamical properties of physical objects have defi-nite values when unobserved. In some of these interpretations the observer is fundamental, and wave functions are com-pendia of subjective probabilities, not preexisting elements of physical reality. These two considerations, from evolutionary biology and quantum physics, suggest that current models of object perception require fundamental reformulation. Here we begin such a reformulation, starting with a formal model of consciousness that we call a conscious agent. We develop the dynamics of interacting conscious agents, and study how the perception of objects and space-time can emerge from such dynamics. We show that one particular object, the quantum free particle, has a wave function that is identical in form to the harmonic functions that characterize the asymptotic dynamics of conscious agents; particles are vibrations not of strings but of interacting conscious agents. This allows us to reinterpret physical properties such as position, momentum, and energy as properties of interacting conscious agents, rather than as preexisting physical truths. We sketch how this approach might extend to the perception of relativistic quantum objects, and to classical objects of macroscopic scale.

Influence of Prostanoids in the Diuretic and Natriuretic Effects of Extracts and Kaempferitrin from Bauhinia forficata Link Leaves in Rats.

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de Souza, Priscila; da Silva, Luisa Mota; Boeing, Thaise; Somensi, Lincon Bordignon; Cechinel-Zanchett, Camile Cecconi; Campos, Adriana; Krueger, Clarissa de Medeiros Amorim; Bastos, Jairo Kenupp; Cechinel-Filho, Valdir; Andrade, Sérgio Faloni de

2017-10-01

Although Bauhinia forficata Link is popularly used in Brazil to induce diuresis, no scientific investigation has focused on demonstrating its efficacy in preclinical trials. For that, normotensive male Wistar and spontaneously hypertensive rats were used to test the effect of extracts and kaempferitrin obtained from Bauhinia forficata leaves in the experimental model of diuresis. Cumulative urine volume, Na + and K + excretion, calcium, creatinine, prostaglandin E 2 , pH, density, and conductivity were measured at the end of the experiment (after 8 or 24 h). The treatment with aqueous infusion, methanolic extract, trichloromethane, or ethyl acetate-butanolic fractions significantly increase urinary volume and electrolytes levels when orally given to rats, without altering the pH or density parameters. Kaempferitrin induced diuretic, natriuretic, but not kaliuretic effects in both normotensive and hypertensive rats. In addition, kaempferitrin enhanced urinary creatinine and prostaglandin E 2 excretion, without modifying calcium levels. Kaempferitrin-induced diuresis was unaffected by previous treatment with a nonselective inhibitor of nitric oxide synthase and neither with a nonselective muscarinic receptor antagonist. On the other hand, a cyclooxygenase inhibitor was able to decrease its effect when compared with vehicle-treated rats, suggesting that the diuretic and natriuretic properties from kaempferitrin are associated with endogenous prostanoids generation. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Effect of tempol and tempol plus catalase on intra-renal haemodynamics in spontaneously hypertensive stroke-prone (SHSP) and Wistar rats.

Science.gov (United States)

Ahmeda, Ahmad F; Rae, Mark G; Al Otaibi, Mohammed F; Anweigi, Lamyia M; Johns, Edward J

2017-05-01

Vasoconstriction within the renal medulla contributes to the development of hypertension. This study investigated the role of reactive oxygen species (ROS) in regulating renal medullary and cortical blood perfusion (MBP and CBP respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar rats. CBP and MBP were measured using a laser-Doppler flow meter before and after intra-renal infusion of tempol, the superoxide dismutase (SOD) mimetic or tempol plus catalase, the hydrogen peroxide-degrading enzyme. Tempol infusion significantly elevated blood perfusion within the renal medulla (MBP) in both SHRSP (by 43 ± 7%, P catalase and tempol were co-infused, MBP was again significantly increased in SHRSP (by 57 ± 6%, P < 0.001) and Wistar rats (by 33 ± 6%, P < 0.001), with a significantly greater increase in perfusion being induced in the SHRSP relative to the Wistar rats (P < 0.01). Notably, this increase was significantly greater than in those animals infused with tempol alone (P < 0.01). These results suggest that ROS plays a proportionally greater role in reducing renal vascular compliance, particularly within the renal medulla, in normotensive and hypertensive animals, with effects being greater in the hypertensive animals. This supports the hypothesis that SHRSP renal vasculature might be subjected to elevated level of oxidative stress relative to normotensive animals.

Attention Networks and Consciousness

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Michael ePosner

2012-03-01

Full Text Available The term consciousness is an important one in the vernacular of the western literature in many fields. It is no wonder that scientists have assumed that consciousness will be found as a component of the human brain and that we will come to understand its neural basis. However, there is rather little in common between consciousness as the neurologist would use it to diagnose the vegetative state, how the feminist would use it to support raising male consciousness of the economic plight of women and as the philosopher would use it when defining the really hard question of the subjective state of awareness induced by sensory qualities. When faced with this kind of problem it is usual to subdivide the term into more manageable perhaps partly operational definitions. Three meanings that capture aspects of consciousness are: (1 the neurology of the state of mind allowing coherent orientation to time and place (2 the selection of sensory or memorial information for awareness and (3 the voluntary control over overt responses. In each of these cases the mechanisms of consciousness overlap with one or more of the attentional networks that have been studied with the methods of cognitive neuroscience. In this paper we explore t

The neurochemical correlate of consciousness: exploring neurotransmitter systems underlying conscious vision

NARCIS (Netherlands)

van Loon, A.M.

2014-01-01

How and where does our brain integrated the information that we get into our eyes into a unifying percept and into a conscious experience? Although different neural correlates of consciousness (NCC) have been proposed, depending on the kind of neural signals recorded, the type of manipulation used,

Effects of clenbuterol on insulin resistance in conscious obese Zucker rats.

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Pan, S J; Hancock, J; Ding, Z; Fogt, D; Lee, M; Ivy, J L

2001-04-01

The present study was conducted to determine the effect of chronic administration of the long-acting beta(2)-adrenergic agonist clenbuterol on rats that are genetically prone to insulin resistance and impaired glucose tolerance. Obese Zucker rats (fa/fa) were given 1 mg/kg of clenbuterol by oral intubation daily for 5 wk. Controls received an equivalent volume of water according to the same schedule. At the end of the treatment, rats were catheterized for euglycemic-hyperinsulinemic (15 mU insulin. kg(-1). min(-1)) clamping. Clenbuterol did not change body weight compared with the control group but caused a redistribution of body weight: leg muscle weights increased, and abdominal fat weight decreased. The glucose infusion rate needed to maintain euglycemia and the rate of glucose disappearance were greater in the clenbuterol-treated rats. Furthermore, plasma insulin levels were decreased, and the rate of glucose uptake into hindlimb muscles and abdominal fat was increased in the clenbuterol-treated rats. This increased rate of glucose uptake was accompanied by a parallel increase in the rate of glycogen synthesis. The increase in muscle glucose uptake could not be ascribed to an increase in the glucose transport protein GLUT-4 in clenbuterol-treated rats. We conclude that chronic clenbuterol treatment reduces the insulin resistance of the obese Zucker rat by increasing insulin-stimulated muscle and adipose tissue glucose uptake. The improvements noted may be related to the repartitioning of body weight between tissues.

[Consciousness and the electroencephalogram].

Science.gov (United States)

Faber, J; Vladyka, V; Subrt, O

1991-08-01

In the course of 12 years the authors subjected to clinical EEG and stereo-EEG (SEEG) 72 patients (66 epileptics with the diagnosis of psychomotor epilepsy and grand mal) and six psychotic patients suffering from schizophrenia. With the exception of five epileptics and two psychotic patients all subjects had epileptic foci in the amygdalohippocampal complex (AHK). After coagulation of these foci marked improvement of the fits and the mental state occurred in half the patients. During EEG and SEEG recording the authors used different activation methods (hyperventilation through the nose and mouth, sleep, listening to music) and above all direct electric stimulation (ES) of one of the AHK. Secondary epileptic foci had, as a rule, more spikes and a lower threshold for ES than primary ones which contained more delta and slow theta waves. The ES led as a rule to an emotional response, such as anxiety and fear, more rarely to illusions, depersonalization and oneiroid hallucinations and twice to a hedonic response of non-sexual character. The purpose of ES was to assess the site from where it is possible to start the original aura or typical parox. The authors considered these foci, consistent with data in the literature, as the leading focus and it was subsequently coagulated. The authors investigated the reactivity and vigility by the patient's response to sound (the patient had to press a button) and by an interview with the patient. It was revealed that in isolated discharges of the spikes and waves in the scalp electrodes, i.e. in the neocortex, reactivity is lacking. In isolated discharges in the AHK the reactivity was satisfactory, but as a rule anxiety developed. It is thus possible to divide consciousness into emotional consciousness with its site in the AHK, i.e. in the limbic system, and rational consciousness which is a function of the neocrotical system. Congenital changes of consciousness such as vigility or sleep are described as "states" of consciousness

Minimally conscious state or cortically mediated state?

Science.gov (United States)

Naccache, Lionel

2018-04-01

Durable impairments of consciousness are currently classified in three main neurological categories: comatose state, vegetative state (also recently coined unresponsive wakefulness syndrome) and minimally conscious state. While the introduction of minimally conscious state, in 2002, was a major progress to help clinicians recognize complex non-reflexive behaviours in the absence of functional communication, it raises several problems. The most important issue related to minimally conscious state lies in its criteria: while behavioural definition of minimally conscious state lacks any direct evidence of patient's conscious content or conscious state, it includes the adjective 'conscious'. I discuss this major problem in this review and propose a novel interpretation of minimally conscious state: its criteria do not inform us about the potential residual consciousness of patients, but they do inform us with certainty about the presence of a cortically mediated state. Based on this constructive criticism review, I suggest three proposals aiming at improving the way we describe the subjective and cognitive state of non-communicating patients. In particular, I present a tentative new classification of impairments of consciousness that combines behavioural evidence with functional brain imaging data, in order to probe directly and univocally residual conscious processes.

Conscience and consciousness: a definition.

Science.gov (United States)

Vithoulkas, G; Muresanu, D F

2014-03-15

While consciousness has been examined extensively in its different aspects, like in philosophy, psychiatry, neurophysiology, neuroplasticity, etc., conscience though it is an equal important aspect of the human existence, which remains an unknown to a great degree as an almost transcendental aspect of the human mind. It has not been examined as thoroughly as consciousness and largely remains a "terra incognita" for its neurophysiology, brain topography, etc. Conscience and consciousness are part of a system of information that governs our experience and decision making process. The intent of this paper is to define these terms, to discuss about consciousness from both neurological and quantum physics point of view, the relationship between the dynamics of consciousness and neuroplasticity and to highlight the relationship between conscience, stress and health.

Interference Control Modulations Over Conscious Perception

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Itsaso Colás

2017-05-01

Full Text Available The relation between attention and consciousness has been a controversial topic over the last decade. Although there seems to be an agreement on their distinction at the functional level, no consensus has been reached about attentional processes being or not necessary for conscious perception. Previous studies have explored the relation of alerting and orienting systems of attention and conscious perception, but the impact of the anterior executive attention system on conscious access remains unexplored. In the present study, we investigated the behavioral interaction between executive attention and conscious perception, testing control mechanisms both at stimulus-level representation and after error commission. We presented a classical Stroop task, manipulating the proportion of congruent and incongruent trials, and analyzed the effect of reactive and proactive control on the conscious perception of near-threshold stimuli. Reactive control elicited under high proportion congruent conditions influenced participants’ decision criterion, whereas proactive control elicited under low proportion congruent conditions was ineffective in modulating conscious perception. In addition, error commission affected both perceptual sensitivity to detect near-threshold information and response criterion. These results suggest that reactivation of task goals through reactive control strategies in conflict situations impacts decision stages of conscious processing, whereas interference control elicited by error commission impacts both perceptual sensitivity and decision stages of conscious processing. We discuss the implications of our results for the gateway hypothesis about attention and consciousness, as they showed that interference control (both at stimulus-level representation and after error commission can modulate the conscious access of near-threshold stimuli.

Angiotensin II and CRF receptors in the central nucleus of the amygdala mediate hemodynamic response variability to cocaine in conscious rats.

Science.gov (United States)

Watanabe, Mari A; Kucenas, Sarah; Bowman, Tamara A; Ruhlman, Melissa; Knuepfer, Mark M

2010-01-14

Stress or cocaine evokes either a large increase in systemic vascular resistance (SVR) or a smaller increase in SVR accompanied by an increase in cardiac output (designated vascular and mixed responders, respectively) in Sprague-Dawley rats. We hypothesized that the central nucleus of the amygdala (CeA) mediates this variability. Conscious, freely-moving rats, instrumented for measurement of arterial pressure and cardiac output and for drug delivery into the CeA, were given cocaine (5 mg/kg, iv, 4-6 times) and characterized as vascular (n=15) or mixed responders (n=10). Subsequently, we administered cocaine after bilateral microinjections (100 nl) of saline or selective agents in the CeA. Muscimol (80 pmol), a GABA(A) agonist, or losartan (43.4 pmol), an AT(1) receptor antagonist, attenuated the cocaine-induced increase in SVR in vascular responders, selectively, such that vascular responders were no longer different from mixed responders. The corticotropin releasing factor (CRF) antagonist, alpha-helical CRF(9-41) (15.7 pmol), abolished the difference between cardiac output and SVR in mixed and vascular responders. We conclude that greater increases in SVR observed in vascular responders are dependent on AT(1) receptor activation and, to a lesser extent on CRF receptors. Therefore, AT(1) and CRF receptors in the CeA contribute to hemodynamic response variability to intravenous cocaine.

Creative Consciousness

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Ashok Natarajan

2013-09-01

Full Text Available Consciousness is creative. That creativity expresses in myriad ways – as moments in time in which decades of progress can be achieved overnight, as organizational innovations of immense power for social accomplishment; as creative social values that further influence the evolution of organizations and society; as the creativity of individuality in the leader, genius, artist and inventor; as social creativity that converts raw human experience into civilization; as cultural creativity that transforms human relationships into sources of rich emotional capacity; and as value-based educational creativity that can awaken and nurture young minds to develop and discover their own inherent capacity for knowledge in freedom. Through such moments do society and humanity evolve. Education is society’s most advanced institution for conscious social evolution. Values are the essence of society’s knowledge for highest accomplishment. Education that imparts values is an evolutionary social organization that can hasten the emergence of that creative consciousness.

Consciousness cannot be separated from function.

Science.gov (United States)

Cohen, Michael A; Dennett, Daniel C

2011-08-01

Numerous theories of consciousness hold that there are separate neural correlates of conscious experience and cognitive function, aligning with the assumption that there are 'hard' and 'easy' problems of consciousness. Here, we argue that any neurobiological theory based on an experience/function division cannot be empirically confirmed or falsified and is thus outside the scope of science. A 'perfect experiment' illustrates this point, highlighting the unbreachable boundaries of the scientific study of consciousness. We describe a more nuanced notion of cognitive access that captures personal experience without positing the existence of inaccessible conscious states. Finally, we discuss the criteria necessary for forming and testing a falsifiable theory of consciousness. Copyright © 2011 Elsevier Ltd. All rights reserved.

Coherence in consciousness: paralimbic gamma synchrony of self-reference links conscious experiences

DEFF Research Database (Denmark)

Lou, Hans C; Gross, Joachim; Biermann-Ruben, Katja

2010-01-01

. In minimal self-reference subjective experiences are self-aware in the weak sense that there is something it feels like for the subject to experience something. In autonoetic consciousness, consciousness emerges, by definition, by retrieval of memories of personally experienced events (episodic memory...

Perceptual consciousness overflows cognitive access.

Science.gov (United States)

Block, Ned

2011-12-01

One of the most important issues concerning the foundations of conscious perception centers on the question of whether perceptual consciousness is rich or sparse. The overflow argument uses a form of 'iconic memory' to argue that perceptual consciousness is richer (i.e., has a higher capacity) than cognitive access: when observing a complex scene we are conscious of more than we can report or think about. Recently, the overflow argument has been challenged both empirically and conceptually. This paper reviews the controversy, arguing that proponents of sparse perception are committed to the postulation of (i) a peculiar kind of generic conscious representation that has no independent rationale and (ii) an unmotivated form of unconscious representation that in some cases conflicts with what we know about unconscious representation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Phentolamine tests and catecholamine levels in normotensive CVA patients.

Science.gov (United States)

Favazza, A R

1974-11-01

Ten normotensive patients diagnosed as having a CVA had Regitine tests and urinary VMA and catecholamine determinations during the first day of hospitalization. The VMA and catecholamine levels were all within normal limits (except for one elevated VMA level) but did not correlate well with each other. The average response to phentolamine was an average drop in blood pressure of 30mm. Hg systolic and 19 mm. Hg diastolic. Mechanisms by which hypertensive states or cerebral damage might effect blood pressure are discussed. It is suggested that CNS damage might induce a vasolabile or hypersensitive state via connections and consequent alterations in the autonomic vasomotor system.

Distorted temporal consciousness and preserved knowing consciousness in confabulation: a case study.

Science.gov (United States)

La Corte, Valentina; George, Nathalie; Pradat-Diehl, Pascale; Barba, Gianfranco Dalla

2011-01-01

In this study we describe a patient, TA, who developed a chronic amnesic-confabulatory syndrome, following rupture of a right internal carotid siphon aneurysm. Our aim was to elucidate as fully as possible the nature of TA's impairment and to test the hypothesis of confabulation as reflecting a dysfunction of Temporal Consciousness, i.e., to become aware of something as part of a personal past, present or future. TA's confabulations were present in answers to questions tapping Temporal Consciousness, i.e., autobiographical episodic memory, orientation in time and place, and foresight of personal future. In contrast, confabulations were not observed in answers to questions tapping Knowing Consciousness, i.e., to become aware of something as a meaning or as an element of impersonal knowledge. In fact, he had normal access to semantic knowledge, including foresight of impersonal future. TA's brain MRI showed lesions involving the right hippocampus, parahippocampal gyrus, fornix, mammillary bodies, and thalamus. Moreover TA showed sub-cortical lesions involving the caudate and putamen nuclei bilaterally, a lesion site not commonly described in amnesic-confabulatory syndrome. We suggest that this pattern of results is better accounted for within the framework of the Memory, Consciousness and Temporality Theory and reflects a specific distortion of Temporal Consciousness.

Electrophysiological evidence for phenomenal consciousness.

Science.gov (United States)

Revonsuo, Antti; Koivisto, Mika

2010-09-01

Abstract Recent evidence from event-related brain potentials (ERPs) lends support to two central theses in Lamme's theory. The earliest ERP correlate of visual consciousness appears over posterior visual cortex around 100-200 ms after stimulus onset. Its scalp topography and time window are consistent with recurrent processing in the visual cortex. This electrophysiological correlate of visual consciousness is mostly independent of later ERPs reflecting selective attention and working memory functions. Overall, the ERP evidence supports the view that phenomenal consciousness of a visual stimulus emerges earlier than access consciousness, and that attention and awareness are served by distinct neural processes.

Measuring the level and content of consciousness during epileptic seizures: the Ictal Consciousness Inventory.

Science.gov (United States)

Cavanna, A E; Mula, M; Servo, S; Strigaro, G; Tota, G; Barbagli, D; Collimedaglia, L; Viana, M; Cantello, R; Monaco, F

2008-07-01

Ictal alterations of the level of general awareness and subjective content of consciousness play a pivotal role in the clinical phenomenology of epilepsy, and reflect the pathological involvement of different neurobiological substrates. However, no self-reported measures have been proposed for patients experiencing altered conscious states during seizures. This study describes the development and validation of a new scale for the quantitative assessment of the level and content of ictal consciousness, the Ictal Consciousness Inventory (ICI). The ICI is a 20-item questionnaire generated on the basis of interviews with patients, literature review, and consultation with experts. It was tested on a sample of 110 patients attending three different epilepsy clinics in Northern Italy, who also completed standardized clinical scales. Standard psychometric methods were used to demonstrate that this scale satisfies criteria for acceptability, reliability, and validity. The ICI is proposed as a user-friendly and clinically sound instrument for the measurement of ictal alterations of consciousness in patients with epilepsy.

Nonlinear analysis of renal autoregulation in rats using principal dynamic modes

DEFF Research Database (Denmark)

Marmarelis, V Z; Chon, K H; Holstein-Rathlou, N H

1999-01-01

This article presents results of the use of a novel methodology employing principal dynamic modes (PDM) for modeling the nonlinear dynamics of renal autoregulation in rats. The analyzed experimental data are broadband (0-0.5 Hz) blood pressure-flow data generated by pseudorandom forcing and colle......This article presents results of the use of a novel methodology employing principal dynamic modes (PDM) for modeling the nonlinear dynamics of renal autoregulation in rats. The analyzed experimental data are broadband (0-0.5 Hz) blood pressure-flow data generated by pseudorandom forcing...... and collected in normotensive and hypertensive rats for two levels of pressure forcing (as measured by the standard deviation of the pressure fluctuation). The PDMs are computed from first-order and second-order kernel estimates obtained from the data via the Laguerre expansion technique. The results...

Consciousness, biology and quantum hypotheses.

Science.gov (United States)

Baars, Bernard J; Edelman, David B

2012-09-01

Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is "a difference that makes a difference" at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

Consciousness, biology and quantum hypotheses

Science.gov (United States)

Baars, Bernard J.; Edelman, David B.

2012-09-01

Natural phenomena are reducible to quantum events in principle, but quantum mechanics does not always provide the best level of analysis. The many-body problem, chaotic avalanches, materials properties, biological organisms, and weather systems are better addressed at higher levels. Animals are highly organized, goal-directed, adaptive, selectionist, information-preserving, functionally redundant, multicellular, quasi-autonomous, highly mobile, reproducing, dissipative systems that conserve many fundamental features over remarkably long periods of time at the species level. Animal brains consist of massive, layered networks of specialized signaling cells with 10,000 communication points per cell, and interacting up to 1000 Hz. Neurons begin to divide and differentiate very early in gestation, and continue to develop until middle age. Waking brains operate far from thermodynamic equilibrium under delicate homeostatic control, making them extremely sensitive to a range of physical and chemical stimuli, highly adaptive, and able to produce a remarkable range of goal-relevant actions. Consciousness is “a difference that makes a difference” at the level of massive neuronal interactions in the most parallel-interactive anatomical structure of the mammalian brain, the cortico-thalamic (C-T) system. Other brain structures are not established to result in direct conscious experiences, at least in humans. However, indirect extra-cortical influences on the C-T system are pervasive. Learning, brain plasticity and major life adaptations may require conscious cognition. While brains evolved over hundreds of millions of years, and individual brains grow over months, years and decades, conscious events appear to have a duty cycle of ∼100 ms, fading after a few seconds. They can of course be refreshed by inner rehearsal, re-visualization, or attending to recurrent stimulus sources. These very distinctive brain events are needed when animals seek out and cope with new

Comparison of the effects of sodium bicarbonate jet prophylaxis on blood pressure in normotensive individuals and patients with controlled hypertension: a controlled clinical trial.

Science.gov (United States)

Ferreira, Camila Lopes; De Marco, Andrea Carvalho; Lazzari, Thiago Rodrigues; Amorim, José Benedito Oliveira; Santamaria, Mauro Pedrine; Jardini, Maria Aparecida Neves

2017-01-01

This study assessed the blood pressure (BP) of normotensive subjects and subjects with pharmacologically controlled hypertension after sodium bicarbonate jet prophylaxis. Forty subjects were divided into 2 groups: a normotensive control group (n = 20) and a hypertensive group (n = 20). Blood pressure measurements were conducted at 4 timepoints: prior to the dental prophylaxis (T0), immediately after treatment (Ti), 15 minutes after treatment (T15), and 30 minutes after treatment (T30). The systolic BP (SBP) values for both groups were significantly increased at Ti (P < 0.05) and returned to their initial state at T15. Both groups also showed a significant increase in diastolic BP (DBP) values at Ti (P < 0.05); however, the basal conditions in hypertensive subjects were not restored until T30, whereas the values for normotensive subjects were restored at T15. The results indicated that systemic BP changed significantly after sodium bicarbonate jet prophylaxis in both study groups; while initial SBP values were restored by 15 minutes in both groups, the return to initial DBP values took longer in the hypertensive group than in the normotensive group.

Correlation of CRP Levels in Third Trimester with Fetal Birth Weight in Preeclamptic and Normotensive Pregnant Women

International Nuclear Information System (INIS)

Ali, Z.; Bukhari, F. A.; Zargham, U.; Khakan, S.; Zaki, S.; Tauseef, A.

2015-01-01

Objective: To evaluate the levels of C-reactive protein, an inflammatory marker in preeclamptic and normotensive pregnant women and to determine its correlation with fetal birth weight. Study Design: Cross-sectional analytical study. Place and Duration of Study: Unit of Obstetrics and Gynaecology, Shaikh Zayed Hospital and Gynaecological Unit II of Jinnah Hospital, Lahore, from December 2011 to May 2012. Methodology: The participants included 60 cases with preeclampsia and 60 normotensive pregnant women, all in their third trimester. All the participants were in the age group of 20 - 40 years and had a BMI range of 18 - 25. High sensitive C-reactive protein (hsCRP) levels were measured by Enzyme Link Immunosorbent Assay. Statistical analysis was done using SPSS (version 15). The values were considered significant at 0.05 level of significance. Results: C-reactive protein levels were significantly high (p < 0.001) in the preeclamptic group with a median value of 8.8 (0.3 - 25.5) as compared to 5.4 (0.24 - 9.8) mg/l in the normotensive women. The birth weight of babies was also significantly low in the preeclamptic group. The high CRP levels were negatively correlated with fetal birth weight in preeclamptic group. Conclusion: Elevated C-reactive protein levels in the preeclamptic pregnant women is a part of an exaggerated maternal systemic inflammatory response, and correlates with low fetal birth weight. (author)

Effect of low-dose valsartan on proteinuria in normotensive immunoglobulin A nephropathy with minimal proteinuria: a randomized trial.

Science.gov (United States)

Jo, Young-Il; Na, Ha-Young; Moon, Ju-Young; Han, Sang-Woong; Yang, Dong-Ho; Lee, Sang-Ho; Park, Hyeong-Cheon; Choi, Hoon-Young; Lim, So-Dug; Kie, Jeong-Hae; Lee, Yong-Kyu; Shin, Sug-Kyun

2016-03-01

Immunoglobulin A nephropathy (IgAN) is a generally progressive disease, even in patients with favorable prognostic features. In this study, we aimed to investigate the antiproteinuric effect and tolerability of low-dose valsartan (an angiotensin II receptor blocker) therapy in normotensive IgAN patients with minimal proteinuria of less than 0.5 to 1.0 g/day. Normotensive IgAN patients, who had persistent proteinuria with a spot urine protein-to-creatinine ratio of 0.3 to 1.0 mg/mg creatinine, were recruited from five hospitals and randomly assigned to either 40 mg of valsartan as the low-dose group or 80 mg of valsartan as the regular-dose group. Clinical and laboratory data were collected at baseline, and at 4, 8, 12, and 24 weeks after valsartan therapy. Forty-three patients (low-dose group, n = 23; regular-dose group, n = 20) were enrolled in the study. Proteinuria decreased significantly not only in the regular-dose group but also in the low-dose group. The change in urine protein-to-creatinine ratio at week 24 was -41.3% ± 26.1% (p valsartan can significantly reduce proteinuria without causing any intolerability in normotensive IgAN patients with minimal proteinuria.

Cortisol level and hemodynamic changes during tooth extraction at hypertensive and normotensive patients.

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Agani, Zana Bajrami; Benedetti, Alberto; Krasniqi, Vjosa Hamiti; Ahmedi, Jehona; Sejfija, Zana; Loxha, Mergime Prekazi; Murtezani, Arben; Rexhepi, Aida Namani; Ibraimi, Zana

2015-04-01

The patients that are subjects to oral-surgical interventions produce large amounts of steroids in comparison with healthy patients which are not a subject to any dental intervention. The aim of research was to determine the level of stress hormone cortisol in serum, arterial blood pressure and arterial pulse, and to compare the effectiveness of the usage of lidocaine with adrenalin in comparison with lidocaine without adrenalin during the tooth extraction. This clinical research includes patients with indication of tooth extraction divided in hypertensive and normotensive patients. There is no important statistical distinction between groups, for the cortisol levels before, during and after tooth extraction regardless of the type of anesthetic used, while we registered higher values of systolic and diastolic values at hypertensive patients, regardless of the type of anesthetic. There is significant systolic and diastolic blood pressure rise in both groups of patients hypertensive and normotensive patients, (regardless of anesthetic used with or without vasoconstrictor), who underwent tooth extraction. The special emphasize is attributed to hypertensive patients where these changes are more significant. As per cortisol level and pulse rate, our results indicate no significant statistical difference in between groups.

Neurobiology of consciousness: an overview.

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Delacour, J

1997-05-01

The aim of this review is to connect the phenomenology of consciousness to its neurobiology. A survey of the recent literature revealed the following points. (1) Comprehensive descriptions of consciousness, of its subjective as well as of its objective aspects, are both possible and necessary for its scientific study. An intentionality-modeling structure (an unified and stable ego refers to objects or to itself in the framework of a stable, reproducible, predictable world) accounts for the main features. (2) The material basis of consciousness can be clarified without recourse to new properties of matter or to quantum physics. Current neurobiology appears to be able to handle the problem. In fact, the neurobiology of consciousness is already in progress, and has achieved substantial results. At the system level, its main sources of data are: the neurophysiology of sleep-wakefulness, brain imaging of mental representations, attention and working memory, the neuropsychology of frontal syndrome, and awareness-unawareness dissociations in global amnesia and different forms of agnosia. At an intermediate level of organization, the mechanisms of consciousness may be the formation of a certain kind of neural assembly. (3) Further research may focus on neuropsychology and neurophysiology of object perception and recognition as a natural model of intentionality, perception of time, body schema, interhemispheric communications, 'voluntary' acts and mental images. The synthetic and dynamic views provided by brain imaging may be decisive for discovering the neural correlates of the integrative aspects of consciousness. (4) The neurobiological approach may, beyond the finding of cellular and molecular mechanisms, improve the general concepts of consciousness, overcome their antinomies and, against epiphenomenalism, definitely establish the reality of consciousness.

Disorders of consciousness and communication. Ethical motivations and communication-enabling attributes of consciousness.

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Tamburrini, Guglielmo; Mattia, Donatella

2011-01-01

Envisaged extensions of a functional magnetic resonance imaging (fMRI) technique allowing communication with patients affected by disorders of consciousness are here examined in connection with subjective symptom reporting, informed consent, and continued medical care decision-making. The principles of medical beneficence, personal autonomy protection, and the right to participate in social life are isolated as appropriate sources of ethical motivations for the use of fMRI-enabled communication. Consciousness requirements for each communication context are identified on the basis of qualitative distinctions between the access, phenomenal, and narrative varieties of consciousness. Ethically motivated uses of fMRI-enabled communication are hierarchically organized in terms of progressively more demanding consciousness requirements for successful communication. The outcomes of this analysis can be used to curb unrealistic expectations of these new scientific developments, and to promote mutual trust between medical doctors, patient surrogates and families.

Perceptual integration without conscious access.

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Fahrenfort, Johannes J; van Leeuwen, Jonathan; Olivers, Christian N L; Hogendoorn, Hinze

2017-04-04

The visual system has the remarkable ability to integrate fragmentary visual input into a perceptually organized collection of surfaces and objects, a process we refer to as perceptual integration. Despite a long tradition of perception research, it is not known whether access to consciousness is required to complete perceptual integration. To investigate this question, we manipulated access to consciousness using the attentional blink. We show that, behaviorally, the attentional blink impairs conscious decisions about the presence of integrated surface structure from fragmented input. However, despite conscious access being impaired, the ability to decode the presence of integrated percepts remains intact, as shown through multivariate classification analyses of electroencephalogram (EEG) data. In contrast, when disrupting perception through masking, decisions about integrated percepts and decoding of integrated percepts are impaired in tandem, while leaving feedforward representations intact. Together, these data show that access consciousness and perceptual integration can be dissociated.

Consciousness, Psychology, and Education: A Speculative Essay.

Science.gov (United States)

1980

This monograph explores implications of the psychology of consciousness for education. The psychology of consciousness encompasses the relationships among behavior, experience, and states of consciousness. It is interpreted to include different states of consciousness, paranormal phenomena, mystical experiences, dreams, psychic healing, and other…

Localisation of selected Ca2+-transport systems in rat's heart and kidney and their modulation by stress

International Nuclear Information System (INIS)

Zacikova, L.

2000-01-01

This thesis deals with the identification of selected calcium transport systems and their modulation by immobilization stress in rat heart and kidney. In our experiments we used normotensive (Sprague-Dawley, Wistar-Kyoto) and hypertensive (SHR) strains. We compared mRNA levels, protein expression and activity of the Na + /Ca 2+ exchanger from hearts of control animals, animals subjected to a single (once) or repeated (seven times) immobilization stress and from animals treated continually with cortisol. We have observed that immobilization stress increased both, gene expression and protein message of the Na + /Ca 2 + exchanger in rat cardiac left, but not right ventricle. This effect is not mediated through the glucocorticoid responsive element. We have found that cortisol decreased activity of the N a +/Ca 2+ exchanger without changing expression and protein amount of this transport system. IP3 receptor of type I and 2 was detected on mRNA levels in rat cardiac atria. Very small amounts of these receptors were observed in rat cardiac ventricles. Since it was difficult to detect these amounts in ventricles, we used 'seminested' PCR to verify expression of IP 3 R1 and 2 in cardiac ventricles. The highest levels of IP 3 R1 and 2 were expressed in left atria. Immobilization stress significantly increased mRNA IP 3 R1 and 2 in rat cardiac atria. We observed both, mRNA and type 1 IP 3 receptor's protein in renal medulla, but not in renal cortex. We have found that this receptor was approximately twice as abundant in normotensive as in genetically hypertensive rat kidney. Immobilization stress significantly down-regulated IP 3 R1 in renal medulla, but not in renal cortex. To investigate the role of NAADP in signaling we measured 45 Ca 2+ release from rat cardiac microsomes. We examined concentration and time dependence of 45 Ca 2+ release from rat cardiac microsomes. All these results could contribute to the understanding of Ca 2+ modulation in cardiac and kidney under

The Emerging Physics of Consciousness

CERN Document Server

Tuszynski, Jack A

2006-01-01

Consciousness remains one of the major unsolved problems in science. How do the feelings and sensations making up conscious experience arise from the concerted actions of nerve cells and their associated synaptic and molecular processes? Can such feelings be explained by modern science, or is there an entirely different kind of explanation needed? And how can this seemingly intractable problem be approached experimentally? How do the operations of the conscious mind emerge out of the specific interactions involving billions of neurons? This book seeks answers to these questions on the underlying assumption that consciousness can be understood using the intellectual potential of modern physics and other sciences. There are a number of theories of consciousness, some based on classical physics while others require the use of quantum concepts. The latter ones have drawn criticism from the parts of the scientific establishment while simultaneously claiming that classical approaches are doomed to failure. The cont...

Consciousness and the Invention of Morel

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Lampros ePerogamvros

2013-03-01

Full Text Available A scientific study of consciousness should take into consideration both objective and subjective measures of conscious experiences. To this date, very few studies have tried to integrate third-person data, or data about the neurophysiological correlates of conscious states, with first-person data, or data about subjective experience. Inspired by Morel’s invention (Casares, 1940, a literary machine capable of reproducing sensory-dependent external reality, this article suggests that combination of virtual reality techniques and brain reading technologies, that is, decoding of conscious states by brain activity alone, can offer this integration. It is also proposed that the multimodal, simulating and integrative capacities of the dreaming brain render it an 'endogenous' Morel's machine, which can potentially be used in studying consciousness, but not always in a reliable way. Both the literary machine and dreaming could contribute to a better understanding of conscious states.

Rats

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Alexey Kondrashov

2012-01-01

Full Text Available We aimed to perform a chemical analysis of both Alibernet red wine and an alcohol-free Alibernet red wine extract (AWE and to investigate the effects of AWE on nitric oxide and reactive oxygen species production as well as blood pressure development in normotensive Wistar Kyoto (WKY and spontaneously hypertensive rats (SHRs. Total antioxidant capacity together with total phenolic and selected mineral content was measured in wine and AWE. Young 6-week-old male WKY and SHR were treated with AWE (24,2 mg/kg/day for 3 weeks. Total NOS and SOD activities, eNOS and SOD1 protein expressions, and superoxide production were determined in the tissues. Both antioxidant capacity and phenolic content were significantly higher in AWE compared to wine. The AWE increased NOS activity in the left ventricle, aorta, and kidney of SHR, while it did not change NOS activity in WKY rats. Similarly, increased SOD activity in the plasma and left ventricle was observed in SHR only. There were no changes in eNOS and SOD1 expressions. In conclusion, phenolics and minerals included in AWE may contribute directly to increased NOS and SOD activities of SHR. Nevertheless, 3 weeks of AWE treatment failed to affect blood pressure of SHR.

Soluble CD30 in normotensive pregnant women with isolated fetal intrauterine growth restriction: a comparison with preeclamptic women.

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Laskowska, Marzena; Laskowska, Katarzyna; Oleszczuk, Jan

2010-11-01

This study investigated the serum concentration of soluble CD30 (sCD30) in pregnant women with isolated fetal intrauterine growth restriction, in pregnancies complicated by preeclampsia with and without accompanying intrauterine growth restriction, and in normotensive healthy pregnant controls. Lower serum concentrations of sCD30 were observed in the group of normotensive pregnant women with a growth-restricted fetus in comparison with the group of healthy pregnant controls, and also in comparison with both preeclamptic groups of pregnant women with and without fetal growth restriction. The concentration of sCD30 in maternal serum from preeclamptic women did not differ in comparison with values from healthy controls or pregnancies complicated by isolated fetal intrauterine growth restriction. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

The mystery of consciousness

CERN Document Server

Searle, John R

1997-01-01

It has long been one of the most fundamental problems of philosophy, and it is now, John Searle writes, "the most important problem in the biological sciences": What is consciousness? Is my inner awareness of myself something separate from my body? In what began as a series of essays in The New York Review of Books, John Searle evaluates the positions on consciousness of such well-known scientists and philosophers as Francis Crick, Gerald Edelman, Roger Penrose, Daniel Dennett, David Chalmers, and Israel Rosenfield. He challenges claims that the mind works like a computer, and that brain functions can be reproduced by computer programs. With a sharp eye for confusion and contradiction, he points out which avenues of current research are most likely to come up with a biological examination of how conscious states are caused by the brain. Only when we understand how the brain works will we solve the mystery of consciousness, and only then will we begin to understand issues ranging from artificial intelligence...

Consciousness Is a Thing, Not a Process

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Susan Pockett

2017-12-01

Full Text Available The central dogma of cognitive psychology is ‘consciousness is a process, not a thing’. Hence, the main task of cognitive neuroscientists is generally seen as working out what kinds of neural processing are conscious and what kinds are not. I argue here that the central dogma is simply wrong. All neural processing is unconscious. The illusion that some of it is conscious results largely from a failure to separate consciousness per se from a number of unconscious processes that normally accompany it—most particularly focal attention. Conscious sensory experiences are not processes at all. They are things: specifically, spatial electromagnetic (EM patterns, which are presently generated only by ongoing unconscious processing at certain times and places in the mammalian brain, but which in principle could be generated by hardware rather than wetware. The neurophysiological mechanisms by which putatively conscious EM patterns are generated, the features that may distinguish conscious from unconscious patterns, the general principles that distinguish the conscious patterns of different sensory modalities and the general features that distinguish the conscious patterns of different experiences within any given sensory modality are all described. Suggestions for further development of this paradigm are provided.

Science of consciousness and the hard problem

Energy Technology Data Exchange (ETDEWEB)

Stapp, H.P.

1996-05-22

Quantum theory is essentially a rationally coherent theory of the interaction of mind and matter, and it allows our conscious thoughts to play a causally efficacious and necessary role in brain dynamics. It therefore provides a natural basis, created by scientists, for the science of consciousness. As an illustration it is explained how the interaction of brain and consciousness can speed up brain processing, and thereby enhance the survival prospects of conscious organisms, as compared to similar organisms that lack consciousness. As a second illustration it is explained how, within the quantum framework, the consciously experienced {open_quotes}I{close_quotes} directs the actions of a human being. It is concluded that contemporary science already has an adequate framework for incorporating causally efficacious experimential events into the physical universe in a manner that: (1) puts the neural correlates of consciousness into the theory in a well defined way, (2) explains in principle how the effects of consciousness, per se, can enhance the survival prospects of organisms that possess it, (3) allows this survival effect to feed into phylogenetic development, and (4) explains how the consciously experienced {open_quotes}I{close_quotes} can direct human behaviour.

8 Questions About the Conscious Mind

NARCIS (Netherlands)

Dooremalen, A.J.P.W.

Can the mind function separately from the brain? Can machines have conscious minds? Is Google Maps part of the conscious mind? Hans Dooremalen provides answers to these three and five other questions about the conscious mind in an easy to read introduction to the philosophy of mind.

Phenomenal and access consciousness in olfaction.

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Stevenson, Richard J

2009-12-01

Contemporary literature on consciousness, with some exceptions, rarely considers the olfactory system. In this article the characteristics of olfactory consciousness, viewed from the standpoint of the phenomenal (P)/access (A) distinction, are examined relative to the major senses. The review details several qualitative differences in both olfactory P consciousness (shifts in the felt location, universal synesthesia-like and affect-rich experiences, and misperceptions) and A consciousness (recovery from habituation, capacity for conscious processing, access to semantic and episodic memory, learning, attention, and in the serial-unitary nature of olfactory percepts). The basis for these differences is argued to arise from the functions that the olfactory system performs and from the unique neural architecture needed to instantiate them. These data suggest, at a minimum, that P and A consciousness are uniquely configured in olfaction and an argument can be made that the P and A distinction may not hold for this sensory system.

On the evolution of conscious attention.

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Haladjian, Harry Haroutioun; Montemayor, Carlos

2015-06-01

This paper aims to clarify the relationship between consciousness and attention through theoretical considerations about evolution. Specifically, we will argue that the empirical findings on attention and the basic considerations concerning the evolution of the different forms of attention demonstrate that consciousness and attention must be dissociated regardless of which definition of these terms one uses. To the best of our knowledge, no extant view on the relationship between consciousness and attention has this advantage. Because of this characteristic, this paper presents a principled and neutral way to settle debates concerning the relationship between consciousness and attention, without falling into disputes about the meaning of these terms. A decisive conclusion of this approach is that extreme views on the relationship between consciousness and attention must be rejected, including identity and full dissociation views. There is an overlap between the two within conscious attention, but developing a full understanding of this mechanism requires further empirical investigations.

Long-term treatment with nebivolol improves arterial reactivity and reduces ventricular hypertrophy in spontaneously hypertensive rats.

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Guerrero, Estela; Voces, Felipe; Ardanaz, Noelia; Montero, María José; Arévalo, Miguel; Sevilla, María Angeles

2003-09-01

The aim of this study was to assess the effects of long-term nebivolol therapy on high blood pressure, impaired endothelial function in aorta, and damage observed in heart and conductance arteries in spontaneously hypertensive rats (SHR). For this purpose, SHR were treated for 9 weeks with nebivolol (8 mg/kg per day). Untreated SHR and Wistar Kyoto rats were used as hypertensive and normotensive controls, respectively. The left ventricle/body weight ratio was used as an index of cardiac hypertrophy, and to evaluate vascular function, responses induced by potassium chloride, noradrenaline, acetylcholine, and sodium nitroprusside were tested on aortic rings. Aortic morphometry and fibrosis were determined in parallel by a quantitative technique. Systolic blood pressure, measured by the tail-cuff method, was lower in treated SHR than in the untreated group (194 +/- 3 versus 150 +/- 4 mm Hg). The cardiac hypertrophy index was significantly reduced by the treatment. In aortic rings, treatment with nebivolol significantly reduced the maximal response to both KCl and NA in SHR. In vessels precontracted with phenylephrine relaxant, activity due to acetylcholine was higher in normotensive rats than in SHR and the treatment significantly improved this response. The effect of sodium nitroprusside on aortic rings was similar in all groups. Medial thickness and collagen content were significantly reduced in comparison with SHR. In conclusion, the chronic antihypertensive effect of nebivolol in SHR was accompanied by an improvement in vascular structure and function and in the cardiac hypertrophy index.

A mathematical model of embodied consciousness

NARCIS (Netherlands)

Rudrauf, D.; Bennequin, D.; Granic, I.; Landini, G.; Friston, K.; Williford, K.

2017-01-01

We introduce a mathematical model of embodied consciousness, the Projective Consciousness Model (PCM), which is based on the hypothesis that the spatial field of consciousness (FoC) is structured by a projective geometry and under the control of a process of active inference. The FoC in the PCM

Plasmatic levels of N-terminal pro-atrial natriuretic peptide in preeclamptic patients and healthy normotensive pregnant women.

Science.gov (United States)

Reyna-Villasmil, Eduardo; Mejia-Montilla, Jorly; Reyna-Villasmil, Nadia; Mayner-Tresol, Gabriel; Herrera-Moya, Pedro; Fernández-Ramírez, Andreina; Rondón-Tapía, Marta

2018-05-11

To compare plasma N-terminal pro-atrial natriuretic peptide concentrations in preeclamptic patients and healthy normotensive pregnant women. A cases-controls study was done with 180 patients at Hospital Central Dr. Urquinaona, Maracaibo, Venezuela, that included 90 preeclamptic patients (group A; cases) and 90 healthy normotensive pregnant women selected with the same age and body mass index similar to group A (group B; controls). Blood samples were collected one hour after admission and prior to administration of any medication in group A to determine plasma N-terminal pro-atrial natriuretic peptide and other laboratory parameters. Plasma N-terminal pro-atrial natriuretic peptide concentrations in group A (mean 1.01 [0.26] pg/mL) showed a significant difference when compared with patients in group B (mean 0.55 [0.07] pg/mL; P<.001]. There was no significant correlation with systolic and diastolic blood pressure values in preeclamptic patients (P=ns). A cut-off value of 0.66ng/mL had an area under the curve of 0.93, sensitivity of 87.8%, specificity of 83.3%, a positive predictive value of 84.0% and a negative predictive value of 87.2%, with a diagnostic accuracy of 85.6%. Preeclamptic patients have significantly higher concentrations of plasma N-terminal pro-atrial natriuretic peptide compared with healthy normotensive pregnant women, with high predictive values for diagnosis. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Toward a computational theory of conscious processing.

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Dehaene, Stanislas; Charles, Lucie; King, Jean-Rémi; Marti, Sébastien

2014-04-01

The study of the mechanisms of conscious processing has become a productive area of cognitive neuroscience. Here we review some of the recent behavioral and neuroscience data, with the specific goal of constraining present and future theories of the computations underlying conscious processing. Experimental findings imply that most of the brain's computations can be performed in a non-conscious mode, but that conscious perception is characterized by an amplification, global propagation and integration of brain signals. A comparison of these data with major theoretical proposals suggests that firstly, conscious access must be carefully distinguished from selective attention; secondly, conscious perception may be likened to a non-linear decision that 'ignites' a network of distributed areas; thirdly, information which is selected for conscious perception gains access to additional computations, including temporary maintenance, global sharing, and flexible routing; and finally, measures of the complexity, long-distance correlation and integration of brain signals provide reliable indices of conscious processing, clinically relevant to patients recovering from coma. Copyright © 2013 Elsevier Ltd. All rights reserved.

Diastolic dysfunction is associated with insulin resistance, but not with aldosterone level in normotensive offspring of hypertensive families.

Science.gov (United States)

Zizek, Bogomir; Poredos, Pavel; Trojar, Andrej; Zeljko, Tadej

2008-01-01

We investigated left ventricular (LV) morphology and function in association with insulin level/insulin resistance (IR) and aldosterone level in normotensive offspring of subjects with essential hypertension (familial trait, FT). The study encompassed 76 volunteers of whom 44 were normotensive with FT (aged 28-39 years) and 32 age-matched controls without FT. LV mass and function were measured using conventional echocardiography and tissue Doppler imaging. LV diastolic function was reported as peak septal annular velocities (E(m) and E(m)/A(m) ratio) in tissue Doppler imaging. Fasting insulin and aldosterone were determined. In subjects with FT, the LV mass was higher than in controls (92.14 +/- 24.02 vs. 70.08 +/- 20.58 g; p < 0.001). The study group had a worse LV diastolic function than control subjects (lower E(m) and E(m)/A(m) ratio; p < 0.001). In subjects with FT, the E(m)/A(m) ratio was independently associated with IR (partial p = 0.029 in multivariate model, R(2) = 0.51), but not with LV mass. The aldosterone level was comparable in both groups. In normotensive individuals with FT, LV morphological and functional abnormalities were found. LV dysfunction but not an increase in LV mass is associated with IR. The aldosterone level is probably not responsible for the development of early hypertensive heart disease. (c) 2008 S. Karger AG, Basel.

Obese Hypertensive Men Have Plasma Concentrations of C-Reactive Protein Similar to That of Obese Normotensive Men

DEFF Research Database (Denmark)

Asferg, Camilla L; Andersen, Ulrik B; Linneberg, Allan

2014-01-01

BACKGROUND: Low-grade chronic inflammation is a characteristic feature of obesity, the most important lifestyle risk factor for hypertension. Elevated plasma concentrations of the inflammatory biomarker C-reactive protein (CRP) are associated with an increased risk of hypertension, but elevated...... plasma CRP concentrations are also closely associated with obesity. It is uncertain whether CRP is directly involved in the pathogenesis of hypertension or is only a marker of other pathogenic processes closely related to obesity. METHODS: We studied 103 obese men (body mass index (BMI) ≥ 30.0 kg/m(2......)); 63 of these men had 24-hour ambulatory blood pressure (ABP) ≥ 130/80 mm Hg and comprised the obese hypertensive (OHT) group. The 40 remaining obese men had 24-hour ABP obese normotensive (ONT) group. Our control group comprised 27 lean normotensive (LNT) men. All...

Consciousness and Attention: On sufficiency and necessity

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Jeroen J A Van Boxtel

2010-12-01

Full Text Available Recent research has slowly corroded a belief that selective attention and consciousness are so tightly entangled that they cannot be individually examined. In this review, we summarize psychophysical and neurophysiological evidence for a dissociation between top-down attention and consciousness. The evidence includes recent findings that show subjects can attend to perceptually invisible objects. More contentious is the finding that subjects can become conscious of an isolated object, or the gist of the scene in the near absence of top-down attention; we critically re-examine the possibility of ‘complete’ absence of top-down attention. We also cover the recent flurry of studies that utilized independent manipulation of attention and consciousness. These studies have shown paradoxical effects of attention, including examples where top-down attention and consciousness have opposing effects, leading us to strengthen and revise our previous views. Neuroimaging studies with EEG, MEG and fMRI are uncovering the distinct neuronal correlates of selective attention and consciousness in dissociative paradigms. These findings point to a functional dissociation: attention as analyzer and consciousness as synthesizer. Separating the effects of selective visual attention from those of visual consciousness is of paramount importance to untangle the neural substrates of consciousness from those for attention.

Pain and consciousness.

Science.gov (United States)

Garcia-Larrea, Luis; Bastuji, Hélène

2017-10-12

The aversive experience we call "pain" results from the coordinated activation of multiple brain areas, commonly described as a "pain matrix". This is not a fixed arrangement of structures but rather a fluid system composed of several interacting networks: A 'nociceptive matrix' includes regions receiving input from ascending nociceptive systems, and ensures the bodily characteristics of physical pain. A further set of structures receiving secondary input supports the 'salience' attributes of noxious stimuli, triggers top-down cognitive controls, and -most importantly- ensures the passage from pre-conscious nociception to conscious pain. Expectations and beliefs can still modulate the conscious experience via activity in supramodal regions with widespread cortical projections such as the ventral tegmental area. Intracortical EEG responses in humans show that nociceptive cortical processing is initiated in parallel in sensory, motor and limbic areas; it progresses rapidly to the recruitment of anterior insular and fronto-parietal networks, and finally to the activation of perigenual, posterior cingulate and hippocampal structures. Functional connectivity between sensory and high-level networks increases during the first second post-stimulus, which may be determinant for access to consciousness. A model is described, progressing from unconscious sensori-motor and limbic processing of spinothalamic and spino-parabrachial input, to an immediate sense of awareness supported by coordinated activity in sensorimotor and fronto-parieto-insular networks, and leading to full declarative consciousness through integration with autobiographical memories and self-awareness, involving posterior cingulate and medial temporal areas. This complete sequence is only present during full vigilance states. We contend, however, that even in unconscious subjects, repeated limbic and vegetative activation by painful stimuli via spino-amygdalar pathways can generate implicit memory traces and

Philosophy Iceberg of the Universe Consciousness Energy (The Theory of the Universe Consciousness Energy Expression

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Georgii Chuzhyk

2017-02-01

Full Text Available We offer an evolutionary and alternative solution to the problem of the Universe. The theory involves the formation of the Universe by means of all the sequences of energies and energy of consciousness with gradual structural wrapping by energy shells recording and accumulating them; formation of the core dispatch centers performing energetic and informational communication with a single rhythm among all space objects that form civilizations. We outline a way of human consciousness formation. The theory explains how the first objectively appeared sparks of human consciousness energy were evolving, accumulating and being recorded, formed the Earth’s noosphere in its core dispatch center. The consciousness energy structure has not yet been discovered and that inhibits the science, which is wary of those who define it as a stream of multi-super large reflection objectively reflecting the highest degree of manifestation of civilization collective creativity, named by John Wheeler as a substance of the information — “It from Bit.” Core dispatching centers of all cosmic objects consciousness energies such as the Earth are combined into the Universe core dispatcher center of which called the Cosmic Consciousness. Many hundreds of billions of years the Cosmic Consciousness absorbed and only recorded the sequences, experience of which ended strictly following the laws of nature, formed a unique quality — for each new sequence by its energetic and informational signal it can highlight, express from its archive the evolution of similar Roadmap, which had been already passed by a similar sequence. The Cosmic Consciousness indirectly provides the most important thing in the Universe — not interfering, it retains all its evolutionary integrity and harmony. All of them constantly and continuously follow and check it through bioinformational communication, without deviation move toward their goal. Life of the Earth civilization is also moving

A narrative method for consciousness research

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José-Luis eDíaz

2013-11-01

Full Text Available Some types of first person narrations of mental processes that constitute phenomenological parliaments and texts, such as internal monologue statements, epitomize the best expressions and representations of human consciousness available and therefore may be used to model phenomenological streams of consciousness. The type of autonomous monologue in which an author or narrator declares actual mental processes in a think aloud manner seems particularly suitable for modeling streams of consciousness. A narrative method to extract and depict conscious processes, operations, contents, and states from an acceptable phenomenological text would require three subsequent steps: operational criteria for producing and/or selecting a phenomenological text, a system for detecting text items that are indicative of conscious contents and processes, and a procedure for representing such items in formal dynamic system devices such as Petri nets. The requirements and restrictions of each of these steps are presented, analyzed, and applied to phenomenological texts in the following manner: (1 The relevance of introspective language and narrative analyses to consciousness research and the idea that specific narratives are of paramount interest for such investigation is justified; (2 Some of the obstacles and constraints to attain plausible consciousness inferences from narrative texts and the methodological requirements to extract and depict items relevant to consciousness contents and operations from a suitable phenomenological text are examined; (3 A preliminary exercise of the proposed method is used to analyze and chart a classical interior monologue excerpted from James Joyce’s Ulysses, a masterpiece of the stream-of-consciousness literary technique and, finally, an inter-subjective evaluation for inter-observer agreement of mental attributions of another phenomenological text (an excerpt from the Intimate Journal of Miguel de Unamuno is presented using some

A narrative method for consciousness research.

Science.gov (United States)

Díaz, José-Luis

2013-01-01

Some types of first-person narrations of mental processes that constitute phenomenological accounts and texts, such as internal monolog statements, epitomize the best expressions and representations of human consciousness available and therefore may be used to model phenomenological streams of consciousness. The type of autonomous monolog in which an author or narrator declares actual mental processes in a think aloud manner seems particularly suitable for modeling streams of consciousness. A narrative method to extract and depict conscious processes, operations, contents, and states from an acceptable phenomenological text would require three subsequent steps: operational criteria for producing and/or selecting a phenomenological text, a system for detecting text items that are indicative of conscious contents and processes, and a procedure for representing such items in formal dynamic system devices such as Petri nets. The requirements and restrictions of each of these steps are presented, analyzed, and applied to phenomenological texts in the following manner: (1) the relevance of introspective language and narrative analyses to consciousness research and the idea that specific narratives are of paramount interest for such investigation is justified; (2) some of the obstacles and constraints to attain plausible consciousness inferences from narrative texts and the methodological requirements to extract and depict items relevant to consciousness contents and operations from a suitable phenomenological text are examined; (3) a preliminary exercise of the proposed method is used to analyze and chart a classical interior monolog excerpted from James Joyce's Ulysses, a masterpiece of the stream-of-consciousness literary technique and, finally, (4) an inter-subjective evaluation for inter-observer agreement of mental attributions of another phenomenological text (an excerpt from the Intimate Journal of Miguel de Unamuno) is presented using some mathematical tools.

A narrative method for consciousness research

Science.gov (United States)

Díaz, José-Luis

2013-01-01

Some types of first-person narrations of mental processes that constitute phenomenological accounts and texts, such as internal monolog statements, epitomize the best expressions and representations of human consciousness available and therefore may be used to model phenomenological streams of consciousness. The type of autonomous monolog in which an author or narrator declares actual mental processes in a think aloud manner seems particularly suitable for modeling streams of consciousness. A narrative method to extract and depict conscious processes, operations, contents, and states from an acceptable phenomenological text would require three subsequent steps: operational criteria for producing and/or selecting a phenomenological text, a system for detecting text items that are indicative of conscious contents and processes, and a procedure for representing such items in formal dynamic system devices such as Petri nets. The requirements and restrictions of each of these steps are presented, analyzed, and applied to phenomenological texts in the following manner: (1) the relevance of introspective language and narrative analyses to consciousness research and the idea that specific narratives are of paramount interest for such investigation is justified; (2) some of the obstacles and constraints to attain plausible consciousness inferences from narrative texts and the methodological requirements to extract and depict items relevant to consciousness contents and operations from a suitable phenomenological text are examined; (3) a preliminary exercise of the proposed method is used to analyze and chart a classical interior monolog excerpted from James Joyce’s Ulysses, a masterpiece of the stream-of-consciousness literary technique and, finally, (4) an inter-subjective evaluation for inter-observer agreement of mental attributions of another phenomenological text (an excerpt from the Intimate Journal of Miguel de Unamuno) is presented using some mathematical tools

Consistency between recognition and behavior creates consciousness

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Keita Inaba

2004-08-01

Full Text Available What is consciousness? Is it possible to create consciousness mechanically? Various studies have been performed in the fields of psychology and cerebral science to answer these questions. As of yet, however, no researchers have proposed a model capable of explaining the mind-body problem described by Descartes or replicating a consciousness as advanced as that of human beings. Ancient people believed that the consciousness resided in a Homunculus, a human in miniature who lived in the brain. It is no mystery that the ancients came up with such an idea; for consciousness has always been veiled in mystery, beyond the reach of our explorative powers. We can assert, however, that consciousness does not "live" in us, but "exists" in us. Insofar as the processes occurring inside the human brain are a product of the physical activity of the neurons that reside there, we believe that it should be possible to define consciousness systematically.

Consciousness and biological evolution.

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Lindahl, B I

1997-08-21

It has been suggested that if the preservation and development of consciousness in the biological evolution is a result of natural selection, it is plausible that consciousness not only has been influenced by neural processes, but has had a survival value itself; and it could only have had this, if it had also been efficacious. This argument for mind-brain interaction is examined, both as the argument has been developed by William James and Karl Popper and as it has been discussed by C.D. Broad. The problem of identifying mental phenomena with certain neural phenomena is also addressed. The main conclusion of the analysis is that an explanation of the evolution of consciousness in Darwinian terms of natural selection does not rule out that consciousness may have evolved as a mere causally inert effect of the evolution of the nervous system, or that mental phenomena are identical with certain neural phenomena. However, the interactionistic theory still seems, more plausible and more fruitful for other reasons brought up in the discussion.

Chronic photoperiod disruption does not increase vulnerability to focal cerebral ischemia in young normotensive rats.

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Ku Mohd Noor, Ku Mastura; Wyse, Cathy; Roy, Lisa A; Biello, Stephany M; McCabe, Christopher; Dewar, Deborah

2017-11-01

Photoperiod disruption, which occurs during shift work, is associated with changes in metabolism or physiology (e.g. hypertension and hyperglycaemia) that have the potential to adversely affect stroke outcome. We sought to investigate if photoperiod disruption affects vulnerability to stroke by determining the impact of photoperiod disruption on infarct size following permanent middle cerebral artery occlusion. Adult male Wistar rats (210-290 g) were housed singly under two different light/dark cycle conditions ( n = 12 each). Controls were maintained on a standard 12:12 light/dark cycle for nine weeks. For rats exposed to photoperiod disruption, every three days for nine weeks, the lights were switched on 6 h earlier than in the previous photoperiod. T 2 -weighted magnetic resonance imaging was performed at 48 h after middle cerebral artery occlusion. Disruption of photoperiod in young healthy rats for nine weeks did not alter key physiological variables that can impact on ischaemic damage, e.g. blood pressure and blood glucose immediately prior to middle cerebral artery occlusion. There was no effect of photoperiod disruption on infarct size after middle cerebral artery occlusion. We conclude that any potentially adverse effect of photoperiod disruption on stroke outcome may require additional factors such as high fat/high sugar diet or pre-existing co-morbidities.

DMN Operational Synchrony Relates to Self-Consciousness: Evidence from Patients in Vegetative and Minimally Conscious States.

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Fingelkurts, Andrew A; Fingelkurts, Alexander A; Bagnato, Sergio; Boccagni, Cristina; Galardi, Giuseppe

2012-01-01

The default mode network (DMN) has been consistently activated across a wide variety of self-related tasks, leading to a proposal of the DMN's role in self-related processing. Indeed, there is limited fMRI evidence that the functional connectivity within the DMN may underlie a phenomenon referred to as self-awareness. At the same time, none of the known studies have explicitly investigated neuronal functional interactions among brain areas that comprise the DMN as a function of self-consciousness loss. To fill this gap, EEG operational synchrony analysis [1, 2] was performed in patients with severe brain injuries in vegetative and minimally conscious states to study the strength of DMN operational synchrony as a function of self-consciousness expression. We demonstrated that the strength of DMN EEG operational synchrony was smallest or even absent in patients in vegetative state, intermediate in patients in minimally conscious state and highest in healthy fully self-conscious subjects. At the same time the process of ecoupling of operations performed by neuronal assemblies that comprise the DMN was highest in patients in vegetative state, intermediate in patients in minimally conscious state and minimal in healthy fully self-conscious subjects. The DMN's frontal EEG operational module had the strongest decrease in operational synchrony strength as a function of selfconsciousness loss, when compared with the DMN's posterior modules. Based on these results it is suggested that the strength of DMN functional connectivity could mediate the strength of self-consciousness expression. The observed alterations similarly occurred across EEG alpha, beta1 and beta2 frequency oscillations. Presented results suggest that the EEG operational synchrony within DMN may provide an objective and accurate measure for the assessment of signs of self-(un)consciousness in these challenging patient populations. This method therefore, may complement the current diagnostic procedures for

A framework for investigating animal consciousness.

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Droege, Paula; Braithwaite, Victoria A

2015-01-01

An assessment of consciousness in nonverbal animals requires a framework for research that extends testing methods beyond subjective report. This chapter proposes a working definition of consciousness in terms of temporal representation that provides the critical link between internal phenomenology and external behavior and neural structure. Our claim is that consciousness represents the present moment as distinct from the past and the future in order to flexibly respond to stimuli. We discuss behavioral and neural evidence that indicates the capacity for both flexible response and temporal representation, and we illustrate these capacities in fish, a taxonomic group that challenges human intuitions about consciousness.

Changes in serum aldosterone are associated with changes in obesity-related factors in normotensive overweight and obese young adults.

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Cooper, Jennifer N; Fried, Linda; Tepper, Ping; Barinas-Mitchell, Emma; Conroy, Molly B; Evans, Rhobert W; Mori Brooks, Maria; Woodard, Genevieve A; Sutton-Tyrrell, Kim

2013-10-01

Recent data suggest excess circulating aldosterone promotes cardiometabolic decline. Weight loss may lower aldosterone levels, but little longitudinal data is available in normotensive adults. We aimed to determine whether, independent of changes in sodium excretion, reductions in serum aldosterone are associated with favorable changes in obesity-related factors in normotensive overweight/obese young adults. We studied 285 overweight/obese young adult participants (body mass index ≥ 25 andobesity-related factors were measured at baseline, 6, 12 and 24 months. Weight loss was significant at 6 (7%), 12 (6%) and 24 months (4%; all Pobesity-related factors are associated with reductions in aldosterone in young adults with no risk factors besides excess weight, an important finding, given aldosterone's emergence as an important cardiometabolic risk factor.

Phenomenology without conscious access is a form of consciousness without top-down attention

OpenAIRE

Koch, Christof; Tsuchiya, Naotsugu

2007-01-01

We agree with Block's basic hypothesis postulating the existence of phenomenal consciousness without cognitive access. We explain such states in terms of consciousness without top-down, endogenous attention and speculate that their correlates may be a coalition of neurons that are consigned to the back of cortex, without access to working memory and planning in frontal cortex.

Peripheral Vascular Resistance Impairment during Isometric Physical Exercise in Normotensive Offspring of Hypertensive Parents

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Natália Portela

Full Text Available Abstract Background: A family history of hypertension is associated with vascular and autonomic abnormalities, as well as an impaired neurohemodynamic response to exercise. Objective: To test the hypothesis that normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise. Methods: The study included 37 normotensive volunteers of both sexes who were sedentary, eutrophic, and nonsmokers, comprising 23 with (FH+; 24 ± 3 years and 14 without (FH-; 27 ± 5 years a family history of hypertension. Blood pressure, heart rate (DIXTAL®, forearm blood flow (Hokanson®, and peripheral vascular resistance were simultaneously measured for 3 minutes during rest and, subsequently, for 3 minutes during an isometric exercise at 30% of maximal voluntary contraction (Jamar®. Results: At rest, the FH+ and FH- groups present similar mean blood pressure (83 ± 7 versus 83 ± 5 mmHg, p = 0.96, heart rate (69 ± 8 bpm versus 66 ± 7 bpm, p = 0.18, forearm blood flow (3 ± 1 mL/min/100 mL versus 2.7 ± 1 mL/min/100 mL, p = 0.16, and peripheral vascular resistance (30 ± 9 units versus 34±9 units, p = 0.21, respectively. Both groups showed a significant and similar increase in mean blood pressure (∆ = 15 ± 7 mmHg versus 14 ± 7 mmHg, p = 0.86, heart rate (∆ = 12 ± 8 bpm versus 13 ± 7 bpm, p = 0.86, and forearm blood flow (∆ = 0.8 ± 1.2 mL/min/100 mL versus 1.4 ± 1.1 mL/min/100 mL, p = 0.25, respectively, during exercise. However, individuals in the FH+ group showed no reduction in peripheral vascular resistance during exercise, which was observed in the FH- group (∆ = -0.4 ± 8.6 units versus -7.2 ± 6.3 units, p = 0.03. Conclusion: Normotensive individuals with a family history of hypertension present an impaired peripheral vascular resistance response to exercise.

Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats.

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Li, Peng; Huang, Pei-Pei; Yang, Yun; Liu, Chi; Lu, Yan; Wang, Fang; Sun, Wei; Kong, Xiang-Qing

2017-01-01

Li P, Huang P, Yang Y, Liu C, Lu Y, Wang F, Sun W, Kong X. Renal sympathetic denervation attenuates hypertension and vascular remodeling in renovascular hypertensive rats. J Appl Physiol 122: 121-129, 2017. First published October 14, 2016; doi:10.1152/japplphysiol.01019.2015-Sympathetic activity is enhanced in patients with essential or secondary hypertension, as well as in various hypertensive animal models. Therapeutic targeting of sympathetic activation is considered an effective antihypertensive strategy. We hypothesized that renal sympathetic denervation (RSD) attenuates hypertension and improves vascular remodeling and renal disease in the 2-kidney, 1-clip (2K1C) rat model. Rats underwent 2K1C modeling or sham surgery; then rats underwent RSD or sham surgery 4 wk later, thus resulting in four groups (normotensive-sham, normotensive-RSD, 2K1C-sham, and 2K1C-RSD). Norepinephrine was measured by ELISA. Echocardiography was used to assess heart function. Fibrosis and apoptosis were assessed by Masson and TUNEL staining. Changes in mean arterial blood pressure in response to hexamethonium and plasma norepinephrine levels were used to evaluate basal sympathetic nerve activity. The 2K1C modeling success rate was 86.8%. RSD reversed the elevated systolic blood pressure induced by 2K1C, but had no effect on body weight. Compared with rats in the 2K1C-sham group, rats in the 2K1C-RSD group showed lower left ventricular mass/body weight ratio, interventricular septal thickness in diastole, left ventricular end-systolic diameter, and left ventricular posterior wall thickness in systole, whereas fractional shortening and ejection fraction were higher. Right kidney apoptosis and left kidney hypertrophy were not changed by RSD. Arterial fibrosis was lower in animals in the 2K1C-RSD group compared with those in the 2K1C-sham group. RSD reduced plasma norepinephrine and basal sympathetic activity in rats in the 2K1C-RSD group compared with rats in the 2K1C-sham group. These

Synchronization among Mechanisms of Renal Autoregulation is Reduced in Hypertensive Rats

DEFF Research Database (Denmark)

Sosnovtseva, Olga; Pavlov, A. N.; Mosekilde, Erik

2007-01-01

, and a slower (20-40 mHz) oscillation in tubuloglomerular feedback (TGF). These mechanisms interact; the TGF mode modulates both the amplitude and the frequency of the myogenic mode. Nephrons also communicate with each other using vascular signals triggered by membrane events in arteriolar smooth muscle cells...... in SHR is a state of partial synchronization with entrainment between neighboring nephrons for only one of the modes. Modulation of the myogenic mode by the TGF mode is much stronger in hypertensive than in normotensive rats. Synchronization among nephrons forms the basis for an integrated reaction...

Mythology, Weltanschauung, symbolic universe and states of consciousness

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Gert Malan

2016-07-01

Full Text Available This article investigates whether different religious (mythological worldviews can be described as alternative and altered states of consciousness (ASCs. Differences between conscious and unconscious motivations for behaviour are discussed before looking at ASCs, Weltanschauung and symbolic universes. Mythology can be described both as Weltanschauung and symbolic universe, functioning on all levels of consciousness. Different Weltanschauungen constitute alternative states of consciousness. Compared to secular worldviews, religious worldviews may be described as ASCs. Thanks to our globalised modern societies, the issue is even more complex, as alternate modernities lead to a symbolic multiverse, with individuals living in a social multiverse. Keyowrds: mythology; Weltanschauung; worldview; symbolic universe; states of consciousness; altered states of consciousness; alternative states of consciousness; symbolic multiverse; social multiverse

On the neural mechanisms subserving consciousness and attention

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Catherine eTallon-Baudry

2012-01-01

Full Text Available Consciousness, as described in the experimental literature, is a multi-faceted phenomenon, that impinges on other well-studied concepts such as attention and control. Do consciousness and attention refer to different aspects of the same core phenomenon, or do they correspond to distinct functions? One possibility to address this question is to examine the neural mechanisms underlying consciousness and attention. If consciousness and attention pertain to the same concept, they should rely on shared neural mechanisms. Conversely, if their underlying mechanisms are distinct, then consciousness and attention should be considered as distinct entities. This paper therefore reviews neurophysiological facts arguing in favor or against a tight relationship between consciousness and attention. Three neural mechanisms that have been associated with both attention and consciousness are examined (neural amplification, involvement of the fronto-parietal network, and oscillatory synchrony, to conclude that the commonalities between attention and consciousness at the neural level may have been overestimated. Last but not least, experiments in which both attention and consciousness were probed at the neural level point toward a dissociation between the two concepts. It therefore appears from this review that consciousness and attention rely on distinct neural properties, although they can interact at the behavioral level. It is proposed that a "cumulative influence model", in which attention and consciousness correspond to distinct neural mechanisms feeding a single decisional process leading to behavior, fits best with available neural and behavioral data. In this view, consciousness should not be considered as a top-level executive function but should rather be defined by its experiential properties.

Cajal and consciousness. Introduction.

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Marijuán, P C

2001-04-01

One hundred years after Santiago Ramón Cajal established the bases of modern neuroscience in his masterpiece Textura del sistema nervioso del hombre y de los vertebrados, the question is stated again: What is the status of consciousness today? The responses in this book, by contemporary leading figures of neuroscience, evolution, molecular biology, computer science, and quantum physics, collectively compose a fascinating conceptual landscape. Both the evolutionary emergence of consciousness and its development towards the highest level may be analyzed by a wealth of new theories and hypotheses, including Cajal's prescient ones. Some noticeable gaps remain, however. Celebrating the centennial of Textura is a timely occasion to reassess how close--and how far--our system of the sciences is to explaining consciousness.

EFFECTS OF RAMADAN FASTING ON BLOOD PRESSURE IN NORMOTENSIVE MALES.

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Samad, Fatima; Qazi, Fahd; Pervaiz, Mohammad B; Kella, Danesh K; Mansoor, Maryah; Osmani, Bushra Z; Mir, Fazia; Kadir, Muhammad Masood

2015-01-01

Research has been done to investigate the effect of intermittent complete fasting on human physiological parameters but the effect of fasting on blood pressure remains relatively unexplored. Research in animal models suggests a hypotensive effect with an undetermined mechanism. Muslims worldwide fast daily from dawn to dusk throughout the Islamic month of Ramadan. This study was to investigate the proposed hypotensive effect of Ramadan fasting in males over A period of 20 days and to study the relationship of the pattern of blood pressure variation with body mass index change. A repeated measures observational study design was implemented with convenient sampling. Study group included 40 normotensive, non-smoker males with no known comorbidities between the ages of 18-40 who fasted daily in the month of Ramadan. One set of BP readings, each, was taken one week before the start of Ramadan and on the 7th, 14th and 21st day of Ramadan which included pre and post Iftar measurements along with other variables. Data was analysed by repeated measures ANOVA using SPSS. The differences were compared with critical values generated by Tukey's Method. There was a significant drop in systolic BP of 7.61 mmHg before Iftar, 2.72 mm-Hg after Iftar (peffect of Ramadan on diastolic BP (p<0.005), the drop being 3.19 mmHg. The drop in body mass index was significant only before Iftar at 0.3 kg/m2 (p<0.005). Pulse rate showed a significant drop of 7.79 bpm before Iftar and a significant rise of 3.96 bpm (p<0.005). Intermittent fasting causes a drop in both systolic and diastolic blood pressure in normotensive males.

Environmentally conscious patent histories

Science.gov (United States)

Crouch, Dennis D.; Crouch, Henry L.

2004-02-01

There is a need for investigators, legislators, and business leaders to understand the magnitude of innovation and discovery in the field of environmentally conscious technologies (ECTs). Knowledge of the "big picture" is important to providing a national and global account of actual environmental stewardship over the last twenty-five years. A recitation of the Environmental Protection Agency (EPA) supported Acts which have been enacted into law reveals one facet of the multifaceted dynamic of environmental consciousness. The popular discussion and debate, as well as partisan lobbying, which created the political forces leading to environmentally conscious legislation is another facet. A third facet is the corporate response to the threats and opportunities predicted by CEO"s and others through environmental scanning. This paper examines changes in environmentally conscious inventive effort by comparing data from United States Patents issued from 1976 through 2003. Patents are useful tool for measuring technological innovation because they are publicly available records of innovative activity. Although not all inventions result in patent applications, the monopoly rights granted on the invention give the inventor a strong incentive to obtain patents on any viable product or process. Among the results, we found a significant increase in patents relating to environmentally conscious products and processes during the period in question. Specifically, a dramatic increase in patent activity was seen for the decade of the 1990"s. Surprisingly, the patenting rate from 2000 to 2003 seems to have stabilized. Additionally public discussion of ECTs appears to have a positive impact on patent filings.

Functional neuroanatomy of disorders of consciousness.

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Di Perri, Carol; Stender, Johan; Laureys, Steven; Gosseries, Olivia

2014-01-01

Our understanding of the mechanisms of loss and recovery of consciousness, following severe brain injury or during anesthesia, is changing rapidly. Recent neuroimaging studies have shown that patients with chronic disorders of consciousness and subjects undergoing general anesthesia present a complex dysfunctionality in the architecture of brain connectivity. At present, the global hallmark of impaired consciousness appears to be a multifaceted dysfunctional connectivity pattern with both within-network loss of connectivity in a widespread frontoparietal network and between-network hyperconnectivity involving other regions such as the insula and ventral tegmental area. Despite ongoing efforts, the mechanisms underlying the emergence of consciousness after severe brain injury are not thoroughly understood. Important questions remain unanswered: What triggers the connectivity impairment leading to disorders of consciousness? Why do some patients recover from coma, while others with apparently similar brain injuries do not? Understanding these mechanisms could lead to a better comprehension of brain function and, hopefully, lead to new therapeutic strategies in this challenging patient population. © 2013.

Autophagic signaling and proteolytic enzyme activity in cardiac and skeletal muscle of spontaneously hypertensive rats following chronic aerobic exercise.

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Elliott M McMillan

Full Text Available Hypertension is a cardiovascular disease associated with deleterious effects in skeletal and cardiac muscle. Autophagy is a degradative process essential to muscle health. Acute exercise can alter autophagic signaling. Therefore, we aimed to characterize the effects of chronic endurance exercise on autophagy in skeletal and cardiac muscle of normotensive and hypertensive rats. Male Wistar Kyoto (WKY and spontaneously hypertensive rats (SHR were assigned to a sedentary condition or 6 weeks of treadmill running. White gastrocnemius (WG of hypertensive rats had higher (p<0.05 caspase-3 and proteasome activity, as well as elevated calpain activity. In addition, skeletal muscle of hypertensive animals had elevated (p<0.05 ATG7 and LC3I protein, LAMP2 mRNA, and cathepsin activity, indicative of enhanced autophagic signaling. Interestingly, chronic exercise training increased (p<0.05 Beclin-1, LC3, and p62 mRNA as well as proteasome activity, but reduced (p<0.05 Beclin-1 and ATG7 protein, as well as decreased (p<0.05 caspase-3, calpain, and cathepsin activity. Left ventricle (LV of hypertensive rats had reduced (p<0.05 AMPKα and LC3II protein, as well as elevated (p<0.05 p-AKT, p-p70S6K, LC3I and p62 protein, which collectively suggest reduced autophagic signaling. Exercise training had little effect on autophagy-related signaling factors in LV; however, exercise training increased (p<0.05 proteasome activity but reduced (p<0.05 caspase-3 and calpain activity. Our results suggest that autophagic signaling is altered in skeletal and cardiac muscle of hypertensive animals. Regular aerobic exercise can effectively alter the proteolytic environment in both cardiac and skeletal muscle, as well as influence several autophagy-related factors in skeletal muscle of normotensive and hypertensive rats.

Characterization of Human Torso Vascular Morphometry in Normotensive and Hypotensive Trauma Patients

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2017-09-01

20454 CT  THORAX  W  IV  CONTRAST 5/1/11  19:10 49 American  IndianF 120 73 DOD  normotensive 20455 CT  THORAX  W  IV  CONTRAST 5...70. Muscle Health/Sarcopenia Bone Health 6 0 o   72. Obesity  –  Fat  Characteriza4on   unroll   unroll   CT  images   SubQ...one of the following: American Indian (4), Asian (33), African American (145), Hispanic (30), Other (39), Pacific Islander (1), Caucasian (1395), or

[Functional pathophysiology of consciousness].

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Jellinger, Kurt A

2009-01-01

Consciousness (Latin conscientia "moral conscience"), according to the English philosopher John Locke (1632-1704) [103], is the awareness of all that occurs in the mind of a person, whereas the American philosopher John Searle (2000) defined it as "inner qualitative, subjective states and processes of awareness". In modern science it is defined as a continuous state of full awareness of the Self and one's relationship to the external and internal environment, describing the degree of wakefulness in which an organism recognizes stimuli. This widely discussed biological term for complex neuronal processes that allow an individuum to recognize itself and its environment and to act accordingly, has been and still is the subject of much research in philosophy and natural/neuroscience. Its definition is often used for awareness and recognition, too. While the Egyptians in the papyrus Edwin Smith already recognized the brain as the seat of consciousness, René Descartes (1644 [36]) believed its special structure should be "a small gland in the middle", but the anatomical structures and physiological processes involved in consciousness were elucidated only in the middle of the 20th century. Neuronal substrates include several functional networks that are hierarchically organized and cooperate functionally. The lowest level is the mesencephalic formatio reticularis and its projections to the thalamus that were identified als ascending reticular system (ARAS) by the classical experiments of Moruzzi and Magoun, whereas later analyses of patients with impaired consciousness provided further insights. The mesencephalic ARAS as motor of the function of higher structures projects 1. via the reticular thalamus diffusely to the cortex, 2. via hypothalamus to the basal forebrain and limbic system, and 3. to the medial raphe of the brainstem and locus coeruleus and their diffuse cortical projections. The reticular system is stimulated directly and indirectly via numerous collaterals

How neuroscience will change our view on consciousness.

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Lamme, Victor A F

2010-09-01

Is there consciousness in machines? Or in animals? What happens to consciousness when we are asleep, or in vegetative state? These are just a few examples of the many questions about consciousness that are troubling scientists and laypersons alike. Moreover, these questions share a striking feature: They seem to have been around forever, yet neither science nor philosophy has been able to provide an answer. Why is that? In my view, the main reason is that the study of consciousness is dominated by what we know from introspection and behavior. This has fooled us into thinking that we know what we are conscious of. The scientific equivalent of this is Global Workspace theory. But in fact we don't know what we are conscious of, as I will explain from a simple experiment in visual perception. Once we acknowledge that, it is clear that we need other evidence about the presence or absence of a conscious sensation than introspection or behavior. Assuming the brain has something to do with it, I will demonstrate how arguments from neuroscience, together with theoretical and ontological arguments, can help us resolve what the exact nature of our conscious sensation is. It turns out that we see much more than we think, and that Global Workspace theory is all about access but not about seeing. The exercise is an example of how neuroscience will move us away from psychological intuitions about consciousness, and hence depict a notion of consciousness that may go against our deepest conviction: "My consciousness is mine, and mine alone." It's not.

Spatial frequency tuning during the conscious and non-conscious perception of emotional facial expressions—an intracranial ERP study

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Verena eWillenbockel

2012-07-01

Full Text Available Previous studies have shown that complex visual stimuli, such as emotional facial expressions, can influence brain activity independently of the observers’ awareness. Little is known yet, however, about the informational correlates of consciousness—i.e., which low-level information correlates with brain activation during conscious vs. non-conscious perception. Here, we investigated this question in the spatial frequency (SF domain. We examined which SFs in disgusted and fearful facial expressions modulate activation in the insula and amygdala over time and as a function of awareness, using a combination of intracranial event-related potentials (ERPs, SF Bubbles (Willenbockel et al., 2010a, and Continuous Flash Suppression (CFS; Tsuchiya and Koch, 2005. Patients implanted with electrodes for epilepsy monitoring viewed face photographs (13° x 7° that were randomly SF filtered trial-by-trial. In the conscious condition, the faces were visible; in the non-conscious condition, they were rendered invisible using CFS. Data were analyzed by performing multiple linear regressions on the SF filters from each trial and the transformed ERP amplitudes across time. The resulting classification images suggest that many SFs are involved in the conscious and non-conscious perception of emotional expressions, with those between 6 and 10 cycles per face width being particularly important early on. The results also revealed qualitative differences between the awareness conditions for both regions. Non-conscious processing relied on low SFs more and was faster than conscious processing. Overall, our findings are consistent with the idea that different pathways are employed for the processing of emotional stimuli under different degrees of awareness. The present study represents a first step to mapping with a high temporal resolution how SF information flows through the emotion-processing network and to shedding light on the informational correlates of

Characteristics of central binding sites for [3H] DAMGO in spontaneously hypertensive rats

International Nuclear Information System (INIS)

Gulati, A.; Bhargava, H.N.

1990-01-01

The binding of [ 3 H] DAMGO, a highly selective ligand for μ-opiate receptors, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats were determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. [ 3 H] DAMGO bound to membranes of brain regions and spinal cord at a single high affinity site. The receptor density (B max value) and apparent dissociation constant (K d value) of [ 3 H] DAMGO to bind to membranes of hippocampus, corpus striatum, pons and medulla, cortex and spinal cord of WKY and SHR rats did not differ. The B max value of [ 3 H] DAMGO in membranes of hypothalamus and midbrain of SHR rats was significantly higher than in WKY rats but the K d values in the two strains did not differ. On the other hand, the B max value of [ 3 H] DAMGO in membranes of amygdala of SHR rats was lower than that of WKY rats but the K d values in the two strains were similar

Social Construction of National Reality: Chinese Consciousness versus Hong Kong Consciousness

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Fu-Lai Tony Yu

2017-08-01

Full Text Available The struggle to break away from the parent state and claim for independence often results in political unrest, terrorist activities and even ethnic cleansing. In East Asia, the hostilities between people from Hong Kong and mainland China also intensify rapidly in recent years. The late 2000s and early 2010s witness a surge in anti-Mainlander sentiment in Hong Kong and a call for self-determination, resulting in a series of political upheavals. In literatures, irredentist and secessionist advocators generally defend themselves in terms of common blood, race and culture. None of them regards the issue from human agency theory. This paper has two objectives. Firstly, based largely on the works of Max Weber, W.I. Thomas, Alfred Schutz and Peter Berger, this paper constructs a theoretical framework, namely, the social construction of national reality, which allows us to explain the origin of national identity and the reason for people to call for autonomy or secession. It will argue that collective consciousness originates from everyday life experience taken for granted during socialization. Individuals make sense of the external world. Experiences taken for granted become the actor’s stock of knowledge. A common scheme of knowledge shared by the community serves to differentiate in-group (nationals and out-group (foreigners. Collective consciousness thus defines national identity and hence a nation. Unless people (both in-group and out-group interact with and learn from each other, different stocks of knowledge taken for granted will create conflict. This theory is applied to explain growing Sinophobia in Hong Kong. The confrontation between traditional Chinese consciousness and emerging Hong Kong consciousness undermines the peaceful coexistence among Hongkongers and Mainlanders, unless both parties redefine their stock of knowledge via dynamic learning. The paper concludes that in order to reduce the conflicts in the regions, understanding the

The consciousness state space (CSS)-a unifying model for consciousness and self.

Science.gov (United States)

Berkovich-Ohana, Aviva; Glicksohn, Joseph

2014-01-01

Every experience, those we are aware of and those we are not, is embedded in a subjective timeline, is tinged with emotion, and inevitably evokes a certain sense of self. Here, we present a phenomenological model for consciousness and selfhood which relates time, awareness, and emotion within one framework. The consciousness state space (CSS) model is a theoretical one. It relies on a broad range of literature, hence has high explanatory and integrative strength, and helps in visualizing the relationship between different aspects of experience. Briefly, it is suggested that all phenomenological states fall into two categories of consciousness, core and extended (CC and EC, respectively). CC supports minimal selfhood that is short of temporal extension, its scope being the here and now. EC supports narrative selfhood, which involves personal identity and continuity across time, as well as memory, imagination and conceptual thought. The CSS is a phenomenological space, created by three dimensions: time, awareness and emotion. Each of the three dimensions is shown to have a dual phenomenological composition, falling within CC and EC. The neural spaces supporting each of these dimensions, as well as CC and EC, are laid out based on the neuroscientific literature. The CSS dynamics include two simultaneous trajectories, one in CC and one in EC, typically antagonistic in normal experiences. However, this characteristic behavior is altered in states in which a person experiences an altered sense of self. Two examples are laid out, flow and meditation. The CSS model creates a broad theoretical framework with explanatory and unificatory power. It constructs a detailed map of the consciousness and selfhood phenomenology, which offers constraints for the science of consciousness. We conclude by outlining several testable predictions raised by the CSS model.

Is Phenomenal Consciousness a Complex Structure?

OpenAIRE

Stieg, Chuck

2004-01-01

Evolutionary explanations of psychological phenomena have become widespread. This paper examines a recent attempt by Nichols and Grantham (2000) to circumvent the problem of epiphenomenalism in establishing the selective status of consciousness. Nichols and Grantham (2000) argue that a case can be made for the view that consciousness is an adaptation based on its complexity. I set out this argument and argue that it fails to establish that phenomenal consciousness is a complex system. It ...

Measurement of glomerular filtration rate in the conscious rat.

Science.gov (United States)

Pestel, Sabine; Krzykalla, Volker; Weckesser, Gerhard

2007-01-01

Glomerular filtration rate (GFR) is an important parameter for studying drug-induced impairments on renal function in rats. The GFR is calculated from the concentration of creatinine and blood urea nitrogen (BUN) in serum and in urine, respectively. Following current protocols serum and urine samples must be taken from the same animal. Thus, in order to determine time-dependent effects it is necessary to use for each time point one separated group of animals. We developed a statistical test which allows analyzing the GFR from two different groups of animals: one used for repeated serum and the other one used for repeated urine analysis. Serum and urine samples were taken from two different sets of rats which were otherwise treated identically, i.e. drug doses, routes of administration (per os or per inhalation) and tap water loading. For each dose group GFR mean, standard deviation and statistical analysis to identify differences between the dose groups were determined. After determination of the optimal time points for measurements, the effect on GFR of the three reference compounds, furosemide, hydrochlorothiazide and formoterol, was calculated. The results showed that the diuretic drugs furosemide and hydrochlorothiazide decreased the GFR and the antidiuretic drug formoterol increased the GFR, as counter regulation on urine loss or urine retention, respectively. A mathematical model and the corresponding algorithm were developed, which can be used to calculate the GFR, and to test for differences between groups from two separated sets of rats, one used for urine, and the other one for serum analysis. This new method has the potential to reduce the number of animals needed and to improve the quality of data generated from various groups of animals in renal function studies.

Neural plasticity lessons from disorders of consciousness

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Athena eDemertzi

2011-02-01

Full Text Available Communication and intentional behavior are supported by the brain’s integrity at a structural and a functional level. When widespread loss of cerebral connectivity is brought about as a result of a severe brain injury, in many cases patients are not capable of conscious interactive behavior and are said to suffer from disorders of consciousness (e.g., coma, vegetative state /unresponsive wakefulness syndrome, minimally conscious states. This lesion paradigm has offered not only clinical insights, as how to improve diagnosis, prognosis and treatment, but also put forward scientific opportunities to study the brain’s plastic abilities. We here review interventional and observational studies performed in severely brain-injured patients with regards to recovery of consciousness. The study of the recovered conscious brain (spontaneous and/or after surgical or pharmacologic interventions, suggests a link between some specific brain areas and the capacity of the brain to sustain conscious experience, challenging at the same time the notion of fixed temporal boundaries in rehabilitative processes. Altered functional connectivity, cerebral structural reorganization as well as behavioral amelioration after invasive treatments will be discussed as the main indices for plasticity in these challenging patients. The study of patients with chronic disorders of consciousness may, thus, provide further insights not only at a clinical level (i.e., medical management and rehabilitation but also from a scientific-theoretical perspective (i.e., the brain’s plastic abilities and the pursuit of the neural correlate of consciousness.

George Herbert Mead on consciousness: antidote to Cartesian absurdities?

DEFF Research Database (Denmark)

Willert, Søren

The article explicates George Herbert Mead's theory of consciousness as presented in Mind, Self and Society. According to Mead, the term consciousness may refer to three different sets of phenomena: (1) the environment as implied by our goal-directed action; Mead names this consciousness aspect...... experience; it is shared by humans and subhuman animals alike; (2) consciousness of environmental experience; Mead names this consciousness aspect awareness; it is exclusively human; (3) the peculiar sensed qualities attaching to consciousness, equalling what is today named qualia. Descartes......-inspired psychology makes the third consciousness aspect all-important. Within Mead's framework for a darwinistically inspired psycholgy, it becomes theoretically insignificant....

Early life stress sensitizes the renal and systemic sympathetic system in rats.

Science.gov (United States)

Loria, Analia S; Brands, Michael W; Pollock, David M; Pollock, Jennifer S

2013-08-01

We hypothesized that maternal separation (MS), an early life stress model, induces a sensitization of the sympathetic system. To test this hypothesis, we evaluated the renal and systemic sympathetic system in 12- to 14-wk-old male control or MS rats with the following parameters: 1) effect of renal denervation on conscious renal filtration capacity, 2) norepinephrine (NE) content in key organs involved in blood pressure control, and 3) acute systemic pressor responses to adrenergic stimulation or ganglion blockade. MS was performed by separating pups from their mothers for 3 h/day from day 2 to 14; controls were nonhandled littermates. Glomerular filtration rate (GFR) was examined in renal denervated (DnX; within 2 wk) or sham rats using I¹²⁵-iothalamate plasma clearance. MS-DnX rats showed significantly increased GFR compared with MS-SHAM rats (3.8 ± 0.4 vs. 2.4 ± 0.2 ml/min, respectively, P renal nerves regulate GFR in MS rats. NE content was significantly increased in organ tissues from MS rats (P renal and systemic sympathetic system. Conscious MS rats displayed a significantly greater increase in mean arterial pressure (MAP) in response to NE (2 μg/kg ip) and a greater reduction in MAP in response to mecamylamine (2 mg/kg ip, P renal and systemic sympathetic system ultimately impairing blood pressure regulation.

Consciousness in Non-Epileptic Attack Disorder

OpenAIRE

Reuber, M.; Kurthen, M.

2011-01-01

Non-epileptic attack disorder (NEAD) is one of the most important differential diagnoses of epilepsy. Impairment of\\ud consciousness is the key feature of non-epileptic attacks (NEAs). The first half of this review summarises the clinical research\\ud literature featuring observations relating to consciousness in NEAD. The second half places this evidence in the wider context\\ud of the recent discourse on consciousness in neuroscience and the philosophy of mind. We argue that studies of consci...

Does perceptual learning require consciousness or attention?

Science.gov (United States)

Meuwese, Julia D I; Post, Ruben A G; Scholte, H Steven; Lamme, Victor A F

2013-10-01

It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness: Two distinct brain processes. Trends in Cognitive Sciences, 11, 16-22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are different. Trends in Cognitive Sciences, 7, 12-18, 2003]. Attention and consciousness converge when conscious visual percepts are attended and hence become available for conscious report. In such a view, a lack of reportability can have two causes: the absence of attention or the absence of a conscious percept. This raises an important question in the field of perceptual learning. It is known that learning can occur in the absence of reportability [Gutnisky, D. A., Hansen, B. J., Iliescu, B. F., & Dragoi, V. Attention alters visual plasticity during exposure-based learning. Current Biology, 19, 555-560, 2009; Seitz, A. R., Kim, D., & Watanabe, T. Rewards evoke learning of unconsciously processed visual stimuli in adult humans. Neuron, 61, 700-707, 2009; Seitz, A. R., & Watanabe, T. Is subliminal learning really passive? Nature, 422, 36, 2003; Watanabe, T., Náñez, J. E., & Sasaki, Y. Perceptual learning without perception. Nature, 413, 844-848, 2001], but it is unclear which of the two ingredients-consciousness or attention-is not necessary for learning. We presented textured figure-ground stimuli and manipulated reportability either by masking (which only interferes with consciousness) or with an inattention paradigm (which only interferes with attention). During the second session (24 hr later), learning was assessed neurally and behaviorally, via differences in figure-ground ERPs and via a detection task. Behavioral and neural learning effects were found for stimuli presented in the inattention paradigm and not for masked stimuli. Interestingly, the behavioral learning effect only became apparent when performance feedback was given on the task to measure learning

Philosophical foundations of artificial consciousness.

Science.gov (United States)

Chrisley, Ron

2008-10-01

Consciousness is often thought to be that aspect of mind that is least amenable to being understood or replicated by artificial intelligence (AI). The first-personal, subjective, what-it-is-like-to-be-something nature of consciousness is thought to be untouchable by the computations, algorithms, processing and functions of AI method. Since AI is the most promising avenue toward artificial consciousness (AC), the conclusion many draw is that AC is even more doomed than AI supposedly is. The objective of this paper is to evaluate the soundness of this inference. The results are achieved by means of conceptual analysis and argumentation. It is shown that pessimism concerning the theoretical possibility of artificial consciousness is unfounded, based as it is on misunderstandings of AI, and a lack of awareness of the possible roles AI might play in accounting for or reproducing consciousness. This is done by making some foundational distinctions relevant to AC, and using them to show that some common reasons given for AC scepticism do not touch some of the (usually neglected) possibilities for AC, such as prosthetic, discriminative, practically necessary, and lagom (necessary-but-not-sufficient) AC. Along the way three strands of the author's work in AC--interactive empiricism, synthetic phenomenology, and ontologically conservative heterophenomenology--are used to illustrate and motivate the distinctions and the defences of AC they make possible.

Consciousness: a unique way of processing information.

Science.gov (United States)

Marchetti, Giorgio

2018-02-08

In this article, I argue that consciousness is a unique way of processing information, in that: it produces information, rather than purely transmitting it; the information it produces is meaningful for us; the meaning it has is always individuated. This uniqueness allows us to process information on the basis of our personal needs and ever-changing interactions with the environment, and consequently to act autonomously. Three main basic cognitive processes contribute to realize this unique way of information processing: the self, attention and working memory. The self, which is primarily expressed via the central and peripheral nervous systems, maps our body, the environment, and our relations with the environment. It is the primary means by which the complexity inherent to our composite structure is reduced into the "single voice" of a unique individual. It provides a reference system that (albeit evolving) is sufficiently stable to define the variations that will be used as the raw material for the construction of conscious information. Attention allows for the selection of those variations in the state of the self that are most relevant in the given situation. Attention originates and is deployed from a single locus inside our body, which represents the center of the self, around which all our conscious experiences are organized. Whatever is focused by attention appears in our consciousness as possessing a spatial quality defined by this center and the direction toward which attention is focused. In addition, attention determines two other features of conscious experience: periodicity and phenomenal quality. Self and attention are necessary but not sufficient for conscious information to be produced. Complex forms of conscious experiences, such as the various modes of givenness of conscious experience and the stream of consciousness, need a working memory mechanism to assemble the basic pieces of information selected by attention.

Intuitive decisions on the fringes of consciousness

Directory of Open Access Journals (Sweden)

Mark C. Price

2008-01-01

Full Text Available Decision making research often dichotomises between more deliberative, cognitive processes and more heuristic, intuitive and emotional processes. We argue that within this two-systems framework (e.g., Kahneman, 2002 there is ambiguity over how to map the System 1/System 2 axis, and the notion of intuitive processing, onto the distinction between conscious and non-conscious processes. However the convergent concepts of experience-based metacognitive judgements (Koriat, 2007 and of fringe consciousness (Mangan, 1993 can clarify intuitive processing as an informative extit{conscious feeling} without conscious access to the antecedents of the feeling. We stress that these intuitive feelings can be used to guide behaviour in a controlled and contextually sensitive manner that would not be permitted by purely non-conscious influences on behaviour. An outline is provided for how to empirically recognise these intuitive feelings. This is illustrated with an example from research on implicit learning where intuitive feelings may play an important role in peoples' decisions and judgements. Finally we suggest that our approach to understanding intuitive feelings softens rather than reinforces the two-systems dichotomy.

Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

Energy Technology Data Exchange (ETDEWEB)

De Ciuceis, Carolina; Porteri, Enzo; Rizzoni, Damiano; Boari, Gianluca E.M.; Rosei, Enrico Agabiti [University of Brescia, Clinica Medica, Department of Clinical and Experimental Sciences, Brescia (Italy); Cornali, Claudio; Mardighian, Dikran; Fontanella, Marco M. [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Pinardi, Chiara [Spedali Civili, Medical Physics Unit, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); Rodella, Luigi F.; Rezzani, Rita [University of Brescia, Section of Anatomy, Department of Clinical and Experimental Sciences, Brescia (Italy); Gasparotti, Roberto [University of Brescia, Section of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy); University of Brescia, Section of Neuroradiology, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, Brescia (Italy)

2014-12-15

The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients. Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients. Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01). Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences. (orig.)

Characteristics of central binding sites for ( sup 3 H) DAMGO in spontaneously hypertensive rats

Energy Technology Data Exchange (ETDEWEB)

Gulati, A.; Bhargava, H.N. (Univ. of Illinois, Chicago (USA))

1990-01-01

The binding of ({sup 3}H) DAMGO, a highly selective ligand for {mu}-opiate receptors, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats were determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. ({sup 3}H) DAMGO bound to membranes of brain regions and spinal cord at a single high affinity site. The receptor density (B{sub max} value) and apparent dissociation constant (K{sub d} value) of ({sup 3}H) DAMGO to bind to membranes of hippocampus, corpus striatum, pons and medulla, cortex and spinal cord of WKY and SHR rats did not differ. The B{sub max} value of ({sup 3}H) DAMGO in membranes of hypothalamus and midbrain of SHR rats was significantly higher than in WKY rats but the K{sub d} values in the two strains did not differ. On the other hand, the B{sub max} value of ({sup 3}H) DAMGO in membranes of amygdala of SHR rats was lower than that of WKY rats but the K{sub d} values in the two strains were similar.

[Cognitive neuroscience of consciousness: from theory to bedside].

Science.gov (United States)

Naccache, Lionel

2013-05-01

The exploration of the neural bases of consciousness (both conscious states and conscious mental contents) has progressed significantly over the last 15 years, in particular concerning the investigation of conscious access during perception. These advancements stem both from original neuropsychological studies, and from the rapid development of functional brain-imaging tools and methods. Only since recently these discoveries lead to medical applications aiming at improving the evaluation and follow-up of patients suffering from impairments of functional communication and/or of consciousness (comatose, vegetative, minimally conscious states, or paralyzed patients such as the "locked in" syndrome or similar conditions). By contributing to possible improvements of diagnosis and prognosis evaluations of these complex medical situations, these new tools open new perspectives associated with noteworthy ethical, social and philosophic implications.

Reflective self-awareness and conscious states

DEFF Research Database (Denmark)

Kjaer, Troels W; Nowak, Markus; Lou, Hans C

2002-01-01

A recent meta-analysis has shown precuneus, angular gyri, anterior cingulate gyri, and adjacent structures to be highly metabolically active in support of resting consciousness. We hypothesize that these regions constitute a functional network of reflective self-awareness thought to be a core...... function of consciousness. Seven normal volunteers were asked to think intensely on how they would describe the personality traits and physical appearance of themselves and a neutral reference person known to all the subjects (the Danish Queen). During each of the four conditions cerebral blood flow...... during reflective self-awareness. The commonality between the neural networks of the resting conscious state and self-awareness reflects the phenomenological concept of a fundamental contribution of reflective self-awareness to the contents and coherence of the conscious state....

A NEW ANIMAL-MODEL FOR HUMAN PREECLAMPSIA - ULTRA-LOW-DOSE ENDOTOXIN INFUSION IN PREGNANT RATS

NARCIS (Netherlands)

FAAS, MM; SCHUILING, GA; BALLER, JFW; VISSCHER, CA; BAKKER, WW

OBJECTIVE: An animal model for preeclampsia was developed by means of an ultra-low-dose endotoxin infusion protocol in conscious pregnant rats. STUDY DESIGN: Rats received a permanent jugular vein cannula on day 0 of pregnancy, through which endotoxin (1.0 mu/kg body weight) (n = 10) or saline

Moringa oleifera-rich diet and T cell calcium signaling in spontaneously hypertensive rats.

Science.gov (United States)

Attakpa, E S; Bertin, G A; Chabi, N W; Ategbo, J-M; Seri, B; Khan, N A

2017-11-24

Moringa oleifera is a plant whose fruits, roots and leaves have been advocated for traditional medicinal uses. The physicochemical analysis shows that Moringa oleifera contains more dietary polyunsaturated fatty acids (PUFA) than saturated fatty acids (SFA). The consumption of an experimental diet enriched with Moringa oleifera extracts lowered blood pressure in spontaneously hypertensive rats (SHR), but not in normotensive Wistar-Kyoto (WKY) rats as compared to rats fed an unsupplemented control diet. Anti-CD3-stimulated T cell proliferation was diminished in both strains of rats fed the Moringa oleifera. The experimental diet lowered secretion of interleukin-2 in SHR, but not in WKY rats compared with rats fed the control diet. Studies of platelets from patients with primary hypertension and from SHR support the notion that the concentration of intracellular free calcium [Ca(2+)](i) is modified in both clinical and experimental hypertension. We observed that the basal, [Ca(2+)](i) was lower in T cells of SHR than in those of WKY rats fed the control diet. Feeding the diet with Moringa oleifera extracts to WKY rats did not alter basal [Ca(2+)](i) in T cells but increased basal [Ca(2+)](i) in SHR. Our study clearly demonstrated that Moringa oleifera exerts antihypertensive effects by inhibiting the secretion of IL-2 and modulates T cell calcium signaling in hypertensive rats.

Nabokov's impressionistic expression of free consciousness

Directory of Open Access Journals (Sweden)

Lončar-Vujnović Mirjana

2009-01-01

Full Text Available The most interesting thing about Nabokov's narrative technique is the way in which he always manages to impress the presence of the implied author on the reader's consciousness without making direct intrusion intonation. Narration through the confined consciousness of an individual is really, it seems, only a springboard for Nabokov. He takes an impressionistic device (consciously or unconsciously, it makes no difference and pushes it to its limits without technically violating the point of view to which he has committed himself.

The Methodology of Psychological Research of Ecological Consciousness

Directory of Open Access Journals (Sweden)

Irina A. Shmeleva

2009-01-01

Full Text Available The paper examines the methodological principles of the psychological study of ecological consciousness as one of the urgent interdisciplinary problems of XX–XXI century, caused by the aggravation of global ecological problems and the need for the realization of the “sustainable development”ideas. Ecological consciousness is considered as multilayered, dynamic, reflexive element of human consciousness, incorporating multivariate, holistic aspects of interaction of the human being as the H.S. and the Humanity representative with the environment and the Planet. The possibility of the more active introduction of Russian psychology in the process is argued for in connection with the existing conceptual approaches, which compose the methodological basis for ecological consciousness research. Among these approaches are considered: the principles of holistic study of the human being by B. Ananyev, the methodology of system psychological description by V. Gansen and G. Sukhodolsky, the idea of reflexivity of consciousness by S. Rubinstein, the humanitarian- ecological imperative of the development of consciousness by V. Zinchenko, the theory of relations by V. Myasishev, consideration of ecological consciousness as relation to nature by S. Deryabo and V. Yasvin, theories of consciousness by V. Petrenko, V. Allakhverdov and other Russian psychologists. The value component of ecological consciousness is distinguished as the most significant. The possibility of applying the Values’ theory of the by S. Schwartz for studying the ecological values is discussed along with the prognostic potential of the universalism value.

Evidence that logical reasoning depends on conscious processing.

Science.gov (United States)

DeWall, C Nathan; Baumeister, Roy F; Masicampo, E J

2008-09-01

Humans, unlike other animals, are equipped with a powerful brain that permits conscious awareness and reflection. A growing trend in psychological science has questioned the benefits of consciousness, however. Testing a hypothesis advanced by [Lieberman, M. D., Gaunt, R., Gilbert, D. T., & Trope, Y. (2002). Reflection and reflexion: A social cognitive neuroscience approach to attributional inference. Advances in Experimental Social Psychology, 34, 199-249], four studies suggested that the conscious, reflective processing system is vital for logical reasoning. Substantial decrements in logical reasoning were found when a cognitive load manipulation preoccupied conscious processing, while hampering the nonconscious system with consciously suppressed thoughts failed to impair reasoning (Experiment 1). Nonconscious activation (priming) of the idea of logical reasoning increased the activation of logic-relevant concepts, but failed to improve logical reasoning performance (Experiments 2a-2c) unless the logical conclusions were largely intuitive and thus not reliant on logical reasoning (Experiment 3). Meanwhile, stimulating the conscious goal of reasoning well led to improvements in reasoning performance (Experiment 4). These findings offer evidence that logical reasoning is aided by the conscious, reflective processing system.

Opposing effects of attention and consciousness on afterimages.

Science.gov (United States)

van Boxtel, Jeroen J A; Tsuchiya, Naotsugu; Koch, Christof

2010-05-11

The brain's ability to handle sensory information is influenced by both selective attention and consciousness. There is no consensus on the exact relationship between these two processes and whether they are distinct. So far, no experiment has simultaneously manipulated both. We carried out a full factorial 2 x 2 study of the simultaneous influences of attention and consciousness (as assayed by visibility) on perception, correcting for possible concurrent changes in attention and consciousness. We investigated the duration of afterimages for all four combinations of high versus low attention and visible versus invisible. We show that selective attention and visual consciousness have opposite effects: paying attention to the grating decreases the duration of its afterimage, whereas consciously seeing the grating increases the afterimage duration. These findings provide clear evidence for distinctive influences of selective attention and consciousness on visual perception.

The consciousness state space (CSS – a unifying model for consciousness and self

Directory of Open Access Journals (Sweden)

Aviva eBerkovich-Ohana

2014-04-01

Full Text Available Every experience, those we are aware of and those we are not, is embedded in a subjective timeline, is tinged with emotion, and inevitably evokes a certain sense of self. Here, we present a phenomenological model for consciousness and selfhood which relates time, awareness, and emotion within one framework. The consciousness state space (CSS model is a theoretical one. It relies on a broad range of literature, hence has high explanatory and integrative strength, and helps in visualizing the relationship between different aspects of experience.Briefly, it is suggested that all phenomenological states fall into two categories of consciousness, core and extended (CC and EC, respectively. CC supports minimal selfhood that is short of temporal extension, its scope being the here and now. EC supports narrative selfhood, which involves personal identity and continuity across time, as well as memory, imagination and conceptual thought. The CSS is a phenomenological space, created by three dimensions: time, awareness and emotion. Each of the three dimensions is shown to have a dual phenomenological composition, falling within CC and EC. The neural spaces supporting each of these dimensions, as well as CC and EC, are laid out based on the neuroscientific literature.The CSS dynamics includes two simultaneous trajectories, one in CC and one in EC, typically antagonistic in normal experiences. However, this characteristic behavior is altered in states in which a person experiences an altered sense of self. Two examples are laid out, flow and meditation. The CSS model creates a broad theoretical framework with explanatory and unificatory power. It constructs a detailed map of the consciousness and selfhood phenomenology, which offers constraints for the science of consciousness. We conclude by outlaying several testable predictions raised by the CSS model.

[Recovery of consciousness: process-oriented approach].

Science.gov (United States)

Gusarova, S B

2014-01-01

Traditionally psychological neurorehabilitation of neurosurgical patients is provided subject to availability of clear consciousness and minimal potential to communicate verbally. Cognitive and emotional disorders, problems in social adaptation, neurotic syndromes are normally targets in such cases. We work with patients having survived severe brain damage being in different states of consciousness: vegetative state, minimal state of consciousness, mutism, confusion, posttraumatic Korsaroff syndrom. Psychologist considers recovery of consciousness as the target besides traditional tasks. Construction of communication with patient is central part of such job, where the patient remains unable to contact verbally, yet it is impossible to consider potential aphasia. This is a non-verbal "dialogue" with patient created by psychologist with gradual development and involving other people and objects of environment. Inline with modern neuroscientific achievements demonstrating ability to recognize by patients with severe brain injury (A. Owen, S. Laureys, M. Monti, M. Coleman, A. Soddu, M. Boly and others) we base upon psychological science, on psychotherapeutic approaches containing instruments inevitable to work with patients in altered states of consciousness and creation of non-verbal communication with patient (Jung, Reich, Alexander, Lowen, Keleman, Arnold and Amy Mindell, S. Tomandl, D. Boadella, A. Längle, P. Levin etc). This article will include 15 years of experience to apply Process-oriented approach by A. Mindell to recovery of consciousness of neurosurgical patients based on work with "minimal signals" (micro moves, breath, mimic reactions etc.), principle of feedback, psychosomatic resonance, empathy.

Sleep deprivation increases blood pressure in healthy normotensive elderly and attenuates the blood pressure response to orthostatic challenge.

Science.gov (United States)

Robillard, Rébecca; Lanfranchi, Paola A; Prince, François; Filipini, Daniel; Carrier, Julie

2011-03-01

To determine how aging affects the impact of sleep deprivation on blood pressure at rest and under orthostatic challenge. Subjects underwent a night of sleep and 24.5 h of sleep deprivation in a crossover counterbalanced design. Sleep laboratory. Sixteen healthy normotensive men and women: 8 young adults (mean 24 years [SD 3.1], range 20-28 years) and 8 elderly adults (mean 64.1 years [SD 3.4], range 60-69 years). Sleep deprivation. Brachial cuff arterial blood pressure and heart rate were measured in semi-recumbent and upright positions. These measurements were compared across homeostatic sleep pressure conditions and age groups. Sleep deprivation induced a significant increase in systolic and diastolic blood pressure in elderly but not young adults. Moreover, sleep deprivation attenuated the systolic blood pressure orthostatic response in both age groups. Our results suggest that sleep deprivation alters the regulatory mechanisms of blood pressure and might increase the risk of hypertension in healthy normotensive elderly.

The neural correlates of consciousness: new experimental approaches needed?

Science.gov (United States)

Hohwy, Jakob

2009-06-01

It appears that consciousness science is progressing soundly, in particular in its search for the neural correlates of consciousness. There are two main approaches to this search, one is content-based (focusing on the contrast between conscious perception of, e.g., faces vs. houses), the other is state-based (focusing on overall conscious states, e.g., the contrast between dreamless sleep vs. the awake state). Methodological and conceptual considerations of a number of concrete studies show that both approaches are problematic: the content-based approach seems to set aside crucial aspects of consciousness; and the state-based approach seems over-inclusive in a way that is hard to rectify without losing sight of the crucial conscious-unconscious contrast. Consequently, the search for the neural correlates of consciousness is in need of new experimental paradigms.

The cognitive approach to conscious machines

CERN Document Server

Haikonen, Pentti O

2003-01-01

Could a machine have an immaterial mind? The author argues that true conscious machines can be built, but rejects artificial intelligence and classical neural networks in favour of the emulation of the cognitive processes of the brain-the flow of inner speech, inner imagery and emotions. This results in a non-numeric meaning-processing machine with distributed information representation and system reactions. It is argued that this machine would be conscious; it would be aware of its own existence and its mental content and perceive this as immaterial. Novel views on consciousness and the mind-

Low-dose esmolol: hemodynamic response to endotracheal intubation in normotensive patients

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Suresh Lakshmanappa

2012-06-01

Full Text Available Abstract Purpose: Endotracheal intubation is a frequently utilized and highly invasive component of anesthesia that is often accompanied by potentially harmful hemodynamic pressor responses. The purpose of this study was to investigate the efficiency of a single pre-induction 1 mg/kg bolus injection of esmolol for attenuating these hemodynamic responses to endotracheal intubation in normotensive patients. Material and methods: The study was composed of 100 randomly selected male and female patients between the ages of 18 and 60 that were scheduled for elective surgery and belonged to ASA grade I or II. Two minutes prior to intubation the control group received 10 mL of saline (n=50 and the experimental group received an injection of esmolol 1 mg/kg diluted to 10 mL (n=50. Heart rate (HR, systolic blood pressure (SBP, diastolic blood pressure (DBP, mean arterial pressure (MAP, and rate pressure product (RPP were compared to basal values before receiving medication (T-0, during pre-induction (T-1, induction (T-2, intubation (T-3, and post-intubation at 1 (T-4, 3 (T-6, 5 (T-8, and 10 (T-13 minutes. Results: Esmolol significantly attenuated the hemodynamic responses to endotracheal intubation at the majority of measured points. Attenuation of HR (10.8%, SBP (7.04%, DBP (3.99%, MAP (5%, and RPP (16.9% was observed in the esmolol group when compared to the control group values. Conclusions: A single pre-induction 1 mg/kg bolus injection of esmolol successfully attenuated the hemodynamic pressor response in normotensive patients. A significant attenuation of heart rate, systolic blood pressure, diastolic blood pressure and mean arterial pressure was observed at the majority of measured time points in the esmolol administered group compared to the control group. [J Contemp Med 2012; 2(2.000: 69-76

Entrainment of Spontaneously Hypertensive Rat Fibroblasts by Temperature Cycles

Science.gov (United States)

Sládek, Martin; Sumová, Alena

2013-01-01

The functional state of the circadian system of spontaneously hypertensive rats (SHR) differs in several characteristics from the functional state of normotensive Wistar rats. Some of these changes might be due to the compromised ability of the central pacemaker to entrain the peripheral clocks. Daily body temperature cycles represent one of the important cues responsible for the integrity of the circadian system, because these cycles are driven by the central pacemaker and are able to entrain the peripheral clocks. This study tested the hypothesis that the aberrant peripheral clock entrainment of SHR results from a compromised peripheral clock sensitivity to the daily temperature cycle resetting. Using cultured Wistar rat and SHR fibroblasts transfected with the circadian luminescence reporter Bmal1-dLuc, we demonstrated that two consecutive square-wave temperature cycles with amplitudes of 2.5°C are necessary and sufficient to restart the dampened oscillations and entrain the circadian clocks in both Wistar rat and SHR fibroblasts. We also generated a phase response curve to temperature cycles for fibroblasts of both rat strains. Although some of the data suggested a slight resistance of SHR fibroblasts to temperature entrainment, we concluded that the overall effect it too weak to be responsible for the differences between the SHR and Wistar in vivo circadian phenotype. PMID:24116198

INTERACTION OF EUROPEAN AND RUSSIAN LEGAL CONSCIOUSNESS

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A. Tyrtyshny

2015-01-01

Full Text Available This article provides an overview of certain ideologemes of Western (European and Russian legal consciousness – prominent works of Ivan Ilyin and Duncan Kennedy are taken as examples. The article analyzes the tabula rasa principle and its place in legal consciousness. We use legal scholarship, judicial practice and opinion polls to examine the relationship between legal consciousness and the lack of trust in Russian courts, as well as their inefficiency from the point of view of public opinion. There are a number of shocking cases of torture of innocent people by the Russian police. Why is this so? The answer lies in the legal consciousness of police officers and of judges. This is something that has been inherited from the Soviet period. It is completely different from the Western legal consciousness, one of the key features of which is denial of authority. The critical legal studies branch of American legal realism almost denies the very existence of law, and, perhaps for this reason, American culture is less open to abuses like torture. At the same time, there is no possibility to shift legal consciousness immediately, the tabula rasa principle does not work. The final objective of the article is to provide a perspective on the reform of higher legal education and its relation to legal consciousness and legal anthropology. We propose that a greater part of the university curriculum is devoted to legal anthropology.

Renal, metabolic, and hormonal responses to proteins of different origin in normotensive, nonproteinuric type I diabetic patients.

Science.gov (United States)

Kontessis, P A; Bossinakou, I; Sarika, L; Iliopoulou, E; Papantoniou, A; Trevisan, R; Roussi, D; Stipsanelli, K; Grigorakis, S; Souvatzoglou, A

1995-09-01

Whether the differences in renal function found in vegetarian compared with omnivorous subjects are related to quantity or quality of the protein is unknown. We have studied the renal function of nine normotensive, nonproteinuric type I diabetic patients who were fed in random order for 4 weeks either an animal protein diet (APD) (protein intake 1.1 g . kg-1 . day-1) or a vegetable protein diet VPD (protein intake 0.95 g . kg-1 . day-1). The two diets were isocaloric. In a crossover study, we measured glomerular filtration rate (GFR) (inulin clearance), renal plasma flow (RPF) (p-aminohippurate clearance), plasma amino acids, growth hormone, glucagon, insulin-like growth factor I-(IGF-I), and microalbuminuria. GFR and RPF were lower with the VPD than with the APD (89.9 +/- 4.1 vs. 105.6 +/- 5.1 ml . min-1 . 1.73 m-2, P protein intake in normotensive type I diabetic patients. This could be explained partly by differences in plasma concentrations of amino acids and IGF-I.

Bosman and self-conscious fiction

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N. Meihuizen

1991-05-01

Full Text Available Bosman, in a number of ways, underlines his fascination with his medium. In this article, an attempt is made to indicate some of the ways in which he does this. Particular attention is paid to Bosman’s use of commentary, his own self-conscious reflections on the text before the reader. Using two stories, “Unto Dust”, and “Old Transvaal Story”, I present the ways in which Bosman’s self-consciousness manifests itself in his art. If he is so adept at undermining illusion, what yet entertains us in the most self-conscious of his texts? It is argued that his fascination with his medium is buttressed by his ability to delude us, which displaces our reliance on illusion.

A prospective validation of the Bova score in normotensive patients with acute pulmonary embolism.

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Bova, Carlo; Vanni, Simone; Prandoni, Paolo; Morello, Fulvio; Dentali, Francesco; Bernardi, Enrico; Mumoli, Nicola; Bucherini, Eugenio; Barbar, Sofia; Picariello, Claudio; Enea, Iolanda; Pesavento, Raffaele; Bottino, Fabrizio; Jiménez, David

2018-05-01

The Bova score has shown usefulness in the identification of intermediate-high risk patients with acute pulmonary embolism (PE), but lacks prospective validation. The aim of this study was to prospectively validate the Bova score in different settings from the original derivation cohort. Consecutive, normotensive patients with acute PE recruited at 13 academic or general hospitals were stratified, using their baseline data, into the three Bova risk stages (I-III). The primary outcome was the 30-day composite of PE-related mortality, hemodynamic collapse and non-fatal PE recurrences in the three risk categories. In the study period, 639 patients were enrolled. The primary end point occurred in 45 patients (7.0%; 95% Confidence Intervals, 5.2%-9.3%). Risk stage correlated with the PE-related complication rate (stage I, 2.9%; stage II, 17%; stage III, 27%). Patients classified as stage III by the Bova score had a 6.5-fold increased risk for adverse outcomes (3.1-13.5, p < 0.001) compared with stages I and II combined. Rescue thrombolysis increased from stage I to stage III (0.6%, 12% and 15% respectively). All-cause mortality (5.3%) did not substantially differ among the stages. The Bova score accurately stratifies normotensive patients with acute PE into stages of increasing risk of 30-day PE-related complications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Consciousness in the Universe

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Khalil Chamcham

2013-07-01

Full Text Available So far we can identify at least three concepts within modern cosmology that bring into debate the question of consciousness in the universe: 1 Fine Tuning; 2 The Anthropic Principle and 3 The Multiverse. This does not exclude the question of the role of observer (i.e. consciousness in cosmology as developed within Quantum Physics: we observe the universe through quanta and any breakthrough in understanding the origin and nature of the universe will come only through a quantum theory of gravity […

Converging intracranial markers of conscious access.

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Raphaël Gaillard

2009-03-01

Full Text Available We compared conscious and nonconscious processing of briefly flashed words using a visual masking procedure while recording intracranial electroencephalogram (iEEG in ten patients. Nonconscious processing of masked words was observed in multiple cortical areas, mostly within an early time window (<300 ms, accompanied by induced gamma-band activity, but without coherent long-distance neural activity, suggesting a quickly dissipating feedforward wave. In contrast, conscious processing of unmasked words was characterized by the convergence of four distinct neurophysiological markers: sustained voltage changes, particularly in prefrontal cortex, large increases in spectral power in the gamma band, increases in long-distance phase synchrony in the beta range, and increases in long-range Granger causality. We argue that all of those measures provide distinct windows into the same distributed state of conscious processing. These results have a direct impact on current theoretical discussions concerning the neural correlates of conscious access.

Brain, conscious experience and the observing self

DEFF Research Database (Denmark)

Baars, Bernard J.; Ramsøy, Thomas; Laureys, Steven

2003-01-01

Conscious perception, like the sight of a coffee cup, seems to involve the brain identifying a stimulus. But conscious input activates more brain regions than are needed to identify coffee cups and faces. It spreads beyond sensory cortex to frontoparietal association areas, which do not serve...... as properties of the subject, rather than the object, of experience - the 'observing self' that appears to be needed to maintain the conscious state...

Consciousness and Attention: On sufficiency and necessity

OpenAIRE

Jeroen J A Van Boxtel; Naotsugu Tsuchiya; Naotsugu Tsuchiya; Christof Koch; Christof Koch; Christof Koch

2010-01-01

Recent research has slowly corroded a belief that selective attention and consciousness are so tightly entangled that they cannot be individually examined. In this review, we summarize psychophysical and neurophysiological evidence for a dissociation between top-down attention and consciousness. The evidence includes recent findings that show subjects can attend to perceptually invisible objects. More contentious is the finding that subjects can become conscious of an isolated object, or the...

Adrenergic effects on secretion of amylase from the rat salivary glands

DEFF Research Database (Denmark)

Poulsen, Steen Seier; Nexø, Ebba

1988-01-01

The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly. The res......The present study was undertaken to investigate the effect of adrenergic agents on secretion of amylase from the salivary glands in vivo. Saliva was collected from the distal oesophagus in conscious rats. Adrenaline increased the concentration of amylase in saliva and serum significantly....... The result of infusion of alpha- and beta-adrenergic antagonists as well as noradrenaline and isoproterenol showed that secretion of salivary amylase is predominantly mediated by stimulation of beta-adrenergic receptors, especially of the beta 1-subtype. Investigation of the isoenzyme pattern in saliva......, pancreatic juice and serum demonstrated that the major component in serum is salivary amylase. This study has shown that beta-adrenergic agents stimulate secretion of amylase from the salivary glands in rats. Though the secretion is mainly exocrine small amounts of amylase is found in serum, which seems...

The Role of Consciousness in Human Cognitive Activity

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Victor M. Allakhverdov

2009-01-01

Full Text Available The problem of consciousness is examined in the article. It is argued that all the existing approaches to consciousness do not explain the role consciousness plays in human life. An attempt of revealing and describing the principles of the mind’s work is made. Experimental phenomena observed by the author and his followers, particularly, the tendency of previously non-realized ideas not to be realized subsequently, are reviewed. The discussion of these phenomena allows to formulate a novel view on the nature of consciousness.

Nocturnal blood pressure in normotensive subjects and those with white coat, primary, and secondary hypertension.

OpenAIRE

Middeke, M.; Schrader, J.

1994-01-01

OBJECTIVE--To compare the mean nocturnal blood pressure of patients with various forms of renal and endocrine hypertension with that in patients with primary and white coat hypertension, and normal blood pressure. DESIGN--Ambulatory monitoring of blood pressure over 24 hours in a prospective study. SETTING--Two German centres for outpatients with hypertension and kidney diseases. SUBJECTS--176 normotensive subjects, 490 patients with primary hypertension including mild and severe forms, 42 wi...

Do cortical midline variability and low frequency fluctuations mediate William James' "Stream of Consciousness"? "Neurophenomenal Balance Hypothesis" of "Inner Time Consciousness".

Science.gov (United States)

Northoff, Georg

2014-11-01

William James famously characterized consciousness by 'stream of consciousness' which describes the temporal continuity and flow of the contents of consciousness in our 'inner time consciousness'. More specifically he distinguished between "substantive parts", the contents of consciousness, and "transitive parts", the linkages between different contents. While much research has recently focused on the substantive parts, the neural mechanisms underlying the transitive parts and their characterization by the balance between 'sensible continuity' and 'continuous change' remain unclear. The aim of this paper is to develop so-called neuro-phenomenal hypothesis about specifically the transitive parts and their two phenomenal hallmark features, sensible continuity and continuous change in 'inner time consciousness'. Based on recent findings, I hypothesize that the cortical midline structures and their high degree of variability and strong low frequency fluctuations play an essential role in mediating the phenomenal balance between sensible continuity and continuous change. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparison of the cardiovascular effects of meptazinol and naloxone following haemorrhagic shock in rats and cats.

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Chance, E.; Paciorek, P. M.; Todd, M. H.; Waterfall, J. F.

1985-01-01

The cardiovascular effects of the opioid mixed agonist-antagonist, meptazinol, and the opioid antagonist, naloxone, have been evaluated in conscious rats, anaesthetized rats and anaesthetized cats following the induction of haemorrhagic shock. The mean arterial pressure of conscious rats decreased by 17-29 mmHg following a haemorrhage of 20% of blood volume. Meptazinol (17 mg kg-1, i.m.) administered after haemorrhage evoked a rapid and sustained increase in mean arterial pressure to pre-haemorrhage levels. Naloxone (10 mg kg-1, i.v.) also increased mean arterial pressure to a level significantly higher than post-haemorrhage values. Neither haemorrhage nor subsequent drug treatments evoked significant changes in the heart rates of conscious rats. In anaesthetized rats, 20% haemorrhage evoked decreases in mean arterial pressure, heart rate and cardiac output. Blood flow to the heart, skin, skeletal muscle, kidneys, spleen and liver (arterial) was decreased. Meptazinol and naloxone increased blood pressure and total peripheral resistance, but did not significantly alter heart rate or cardiac output. Hepatic arterial flow decreased further in both drug and vehicle treated groups. In addition meptazinol slightly reduced skeletal muscle flow. In anaesthetized cats 40% haemorrhage decreased mean arterial pressure by 46 +/- 3 mmHg. An intravenous infusion of either meptazinol or naloxone (cumulative 2 mg kg-1, i.v.) partially restored blood pressure. In experimental animal models of haemorrhagic shock, meptazinol has a similar cardiovascular profile to naloxone. The established analgesic activity of meptazinol may confer an advantage in some shock states. PMID:4052729

Magnetic correlates in electromagnetic consciousness.

Science.gov (United States)

Liboff, A R

2016-01-01

We examine the hypothesis that consciousness is a manifestation of the electromagnetic field, finding supportive factors not previously considered. It is not likely that traditional electrophysiological signaling modes can be readily transmitted throughout the brain to properly enable this field because of electric field screening arising from the ubiquitous distribution of high dielectric lipid membranes, a problem that vanishes for low-frequency magnetic fields. Many reports over the last few decades have provided evidence that living tissue is robustly sensitive to ultrasmall (1-100 nT) ELF magnetic fields overlapping the γ-frequency range often associated with awareness. An example taken from animal behavior (coherent bird flocking) lends support to the possibility of a disembodied electromagnetic consciousness. In contrast to quantum consciousness hypotheses, the present approach is open to experimental trial.

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats

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Luis R. Cassinotti

2018-02-01

Full Text Available Overactivity of the sympathetic nervous system and central endothelins (ETs are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA-salt hypertensive rats. Following brain ET receptor type A (ETA blockade by BQ610 (selective antagonist, transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ETA blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein in the right OB of hypertensive animals. However, ETA blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ETA are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

Chronic Blockade of Brain Endothelin Receptor Type-A (ETA) Reduces Blood Pressure and Prevents Catecholaminergic Overactivity in the Right Olfactory Bulb of DOCA-Salt Hypertensive Rats.

Science.gov (United States)

Cassinotti, Luis R; Guil, María J; Schöller, Mercedes I; Navarro, Mónica P; Bianciotti, Liliana G; Vatta, Marcelo S

2018-02-27

Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ET A ) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ET A blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ET A blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ET A are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.

Conscious Experience and Episodic Memory: Hippocampus at the Crossroads

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Ralf-Peter eBehrendt

2013-05-01

Full Text Available If an instance of conscious experience of the seemingly objective world around us could be regarded as a newly formed event memory, much as an instance of mental imagery has the content of a retrieved event memory, and if, therefore, the stream of conscious experience could be seen as evidence for ongoing formation of event memories that are linked into episodic memory sequences, then unitary conscious experience could be defined as a symbolic representation of the pattern of hippocampal neuronal firing that encodes an event memory – a theoretical stance that may shed light into the mind-body and binding problems in consciousness research. Exceedingly detailed symbols that describe patterns of activity rapidly self-organizing, at each cycle of the θ rhythm, in the hippocampus are instances of unitary conscious experience that jointly constitute the stream of consciousness. Integrating object information (derived from the ventral visual stream and orbitofrontal cortex with contextual emotional information (from the anterior insula and spatial environmental information (from the dorsal visual stream, the hippocampus rapidly forms event codes that have the informational content of objects embedded in an emotional and spatiotemporally extending context. Event codes, formed in the CA3-dentate network for the purpose of their memorization, are not only contextualized but also allocentric representations, similarly to conscious experiences of events and objects situated in a seemingly objective and observer-independent framework of phenomenal space and time. Conscious perception is likely to be related to more fleeting and seemingly internal forms of conscious experience, such as autobiographical memory recall, mental imagery, including goal anticipation, and to other forms of externalized conscious experience, namely dreaming and hallucinations; and evidence pointing to an important contribution of the hippocampus to these conscious phenomena will

Conscious experience and episodic memory: hippocampus at the crossroads.

Science.gov (United States)

Behrendt, Ralf-Peter

2013-01-01

If an instance of conscious experience of the seemingly objective world around us could be regarded as a newly formed event memory, much as an instance of mental imagery has the content of a retrieved event memory, and if, therefore, the stream of conscious experience could be seen as evidence for ongoing formation of event memories that are linked into episodic memory sequences, then unitary conscious experience could be defined as a symbolic representation of the pattern of hippocampal neuronal firing that encodes an event memory - a theoretical stance that may shed light into the mind-body and binding problems in consciousness research. Exceedingly detailed symbols that describe patterns of activity rapidly self-organizing, at each cycle of the θ rhythm, in the hippocampus are instances of unitary conscious experience that jointly constitute the stream of consciousness. Integrating object information (derived from the ventral visual stream and orbitofrontal cortex) with contextual emotional information (from the anterior insula) and spatial environmental information (from the dorsal visual stream), the hippocampus rapidly forms event codes that have the informational content of objects embedded in an emotional and spatiotemporally extending context. Event codes, formed in the CA3-dentate network for the purpose of their memorization, are not only contextualized but also allocentric representations, similarly to conscious experiences of events and objects situated in a seemingly objective and observer-independent framework of phenomenal space and time. Conscious perception, creating the spatially and temporally extending world that we perceive around us, is likely to be evolutionarily related to more fleeting and seemingly internal forms of conscious experience, such as autobiographical memory recall, mental imagery, including goal anticipation, and to other forms of externalized conscious experience, namely dreaming and hallucinations; and evidence pointing to

How rich is consciousness? The partial awareness hypothesis.

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Kouider, Sid; de Gardelle, Vincent; Sackur, Jérôme; Dupoux, Emmanuel

2010-07-01

Current theories of consciousness posit a dissociation between 'phenomenal' consciousness (rich) and 'access' consciousness (limited). Here, we argue that the empirical evidence for phenomenal consciousness without access is equivocal, resulting either from a confusion between phenomenal and unconscious contents, or from an impression of phenomenally rich experiences arising from illusory contents. We propose a refined account of access that relies on a hierarchy of representational levels and on the notion of partial awareness, whereby lower and higher levels are accessed independently. Reframing of the issue of dissociable forms of consciousness into dissociable levels of access provides a more parsimonious account of the existing evidence. In addition, the rich phenomenology illusion can be studied and described in terms of testable cognitive mechanisms. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Access is mainly a second-order process: SDT models whether phenomenally (first-order) conscious states are accessed by reflectively (second-order) conscious processes.

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Snodgrass, Michael; Kalaida, Natasha; Winer, E Samuel

2009-06-01

Access can either be first-order or second-order. First order access concerns whether contents achieve representation in phenomenal consciousness at all; second-order access concerns whether phenomenally conscious contents are selected for metacognitive, higher order processing by reflective consciousness. When the optional and flexible nature of second-order access is kept in mind, there remain strong reasons to believe that exclusion failure can indeed isolate phenomenally conscious stimuli that are not so accessed. Irvine's [Irvine, E. (2009). Signal detection theory, the exclusion failure paradigm and weak consciousness-Evidence for the access/phenomenal distinction? Consciousness and Cognition.] partial access argument fails because exclusion failure is indeed due to lack of second-order access, not insufficient phenomenally conscious information. Further, the enable account conforms with both qualitative differences and subjective report, and is simpler than the endow account. Finally, although first-order access may be a distinct and important process, second-order access arguably reflects the core meaning of access generally.

Radiogenic changes in the behavior and physiology of the spontaneously hypertensive rat - Evidence for a dissociation between acute hypotension and incapacitation

International Nuclear Information System (INIS)

Mickley, G.A.; Teitelbaum, H.; Parker, G.A.; Vieras, F.; Dennison, B.A.; Bonney, C.H.

1982-01-01

The Armed Forces Radiobiology Research Institute's linear accelerator was used to expose rats to high-energy electron radiation. The purpose of the study was to investigate both radiogenic blood pressure and performance changes in a strain of rat bred for hypertension (spontaneously hypertensive rat: SHR) in order to determine if high blood pressure might attenuate early transient incapacitation (ETI). Although male SHRs experienced a severe drop in blood pressure, much of the data is inconsistent with the hypothesis that hypotension causes performance decrements. In an additional series of studies, blood volume and serum chemistry data were examined. Male SHRs were significantly higher than normotensive controls on several blood chemistry determinations. Exposure to ionizing radiation tended to enhance these differences. These results could not be explained on the basis of radiogenic blood volume fluctuations

A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience

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Jerath, Ravinder; Crawford, Molly W.; Barnes, Vernon A.

2015-01-01

The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system. PMID:26379573

A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience

Directory of Open Access Journals (Sweden)

Ravinder eJerath

2015-08-01

Full Text Available The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information is filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system.

A unified 3D default space consciousness model combining neurological and physiological processes that underlie conscious experience.

Science.gov (United States)

Jerath, Ravinder; Crawford, Molly W; Barnes, Vernon A

2015-01-01

The Global Workspace Theory and Information Integration Theory are two of the most currently accepted consciousness models; however, these models do not address many aspects of conscious experience. We compare these models to our previously proposed consciousness model in which the thalamus fills-in processed sensory information from corticothalamic feedback loops within a proposed 3D default space, resulting in the recreation of the internal and external worlds within the mind. This 3D default space is composed of all cells of the body, which communicate via gap junctions and electrical potentials to create this unified space. We use 3D illustrations to explain how both visual and non-visual sensory information may be filled-in within this dynamic space, creating a unified seamless conscious experience. This neural sensory memory space is likely generated by baseline neural oscillatory activity from the default mode network, other salient networks, brainstem, and reticular activating system.

A global workspace model for phenomenal and access consciousness.

Science.gov (United States)

Raffone, Antonino; Pantani, Martina

2010-06-01

Both the global workspace theory and Block's distinction between phenomenal and access consciousness, are central in the current debates about consciousness and the neural correlates of consciousness. In this article, a unifying global workspace model for phenomenal and access consciousness is proposed. In the model, recurrent neural interactions take place in distinct yet interacting access and phenomenal brain loops. The effectiveness of feedback signaling onto sensory cortical maps is emphasized for the neural correlates of phenomenal consciousness. Two forms of top-down attention, attention for perception and attention for access, play differential roles for phenomenal and access consciousness. The model is implemented in a neural network form, with the simulation of single and multiple visual object processing, and of the attentional blink. 2010 Elsevier Inc. All rights reserved.

Consciousness: physiological dependence on rapid memory access.

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Hudson, Arthur J

2009-01-01

Consciousness develops from birth during the early months as the senses and other nervous system functions mature sufficiently to receive, process and store information. Among these is the ascending reticular activating (arousal) system in the brain stem that is responsible for wakefulness and was proposed by Penfield and Jasper more than 50 years ago as the "controlling mechanism for states of consciousness". This concept has remained the most advanced physiological interpretation of consciousness although recent developments offer greater insights into its nature. The ascending arousal system is the source of activation of the thalamocortical and cortical mechanisms for sensory input and facilitates the rapid matching of sensory input and the binding of memory during cognitive processing. Nonetheless, it is proposed that memory is the critical element through which our connection with the world exists without which, despite a fully functional arousal system, consciousness as we know it could not exist. Evidence is presented in support of this concept in addition to the physiological difficulties that must be resolved if consciousness is to be understood.

Industrial Application Of Environmentally Conscious Design

DEFF Research Database (Denmark)

McAloone, Timothy Charles

in the design process is key to environmentally conscious design;- the environmental profile of a product is affected the most in the very early stages of the design process, particularly in the pre-specification stage, where tools for environmentally conscious design decision-making are lacking...... when companies have integrated environmental considerations into the design process.In the context of advanced practitioners of environmentally conscious design in the Western European and North American electrical/electronics industry sector, it is shown that:- the timing of environmental decisions...... into their product development processes. This starts with motivation, leading to widening communication and information flows and finally to whole-life thinking....

A framework for consciousness.

Science.gov (United States)

Crick, Francis; Koch, Christof

2003-02-01

Here we summarize our present approach to the problem of consciousness. After an introduction outlining our general strategy, we describe what is meant by the term 'framework' and set it out under ten headings. This framework offers a coherent scheme for explaining the neural correlates of (visual) consciousness in terms of competing cellular assemblies. Most of the ideas we favor have been suggested before, but their combination is original. We also outline some general experimental approaches to the problem and, finally, acknowledge some relevant aspects of the brain that have been left out of the proposed framework.

Reading comprehension and textual consciousness on primary school

Directory of Open Access Journals (Sweden)

Vera Wannmacher Pereira

2014-03-01

Full Text Available The difficulties on reading comprehension in the primary school are evidenced by several official exams applied. Given these statistics and the evidences obtained through academic research and observations on children’s performance during the school life, there is acknowledgment of the situation as a problem that requires further development and finding solutions. The Psycholinguistics is giving its contribution, especially regarding the role of linguistic consciousness on reading learning. Many studies have been conducted specifically focusing on phonological consciousness. Studies on syntactic consciousness are also found, although less than phonological ones. Regarding the role of textual consciousness, few initiatives considers the students of the primary school. This makes the author proposes as the heartland of this communication the textual consciousness with support predominantly on Gombert (1992, aiming to examine the relationship between this level of consciousness and learning to read. Based on recent studies (PEREIRA; SCLIAR-CABRAL, 2012, the author presents in this paper: a the analysis of the context of learning and teaching of reading; b a theoretical exposition about reading learning and textual consciousness; c the pedagogical referrals for education based on the interaction between these two topics; and d the development of reflections on the possibility of the proposed path contribute to the solution of the worrying problem on read learning by the primary schools students.

Using Brain Stimulation to Disentangle Neural Correlates of Conscious Vision

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Tom Alexander de Graaf

2014-09-01

Full Text Available Research into the neural correlates of consciousness (NCCs has blossomed, due to the advent of new and increasingly sophisticated brain research tools. Neuroimaging has uncovered a variety of brain processes that relate to conscious perception, obtained in a range of experimental paradigms. But methods such as fMRI or EEG do not always afford inference on the role these brain processes play in conscious vision. Such empirical neural correlates of consciousness could reflect neural prerequisites, neural consequences, or neural substrates of a conscious experience. Here, we take a closer look at the use of non-invasive brain stimulation (NIBS techniques in this context. We discuss and review how NIBS methodology can enlighten our understanding of brain mechanisms underlying conscious vision by disentangling the empirical neural correlates of consciousness.

Alterations in substance P binding in brain nuclei of spontaneously hypertensive rats

International Nuclear Information System (INIS)

Shigematsu, K.; Niwa, M.; Kurihara, M.; Castren, E.; Saavedra, J.M.

1987-01-01

Substance P binding sites were characterized in brain nuclei of young (4-wk-old) and adult (16-wk-old) spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto (WKY) control rats by quantitative autoradiography. Young SHR presented higher affinity constants (K/sub A/) than young WKY. The changes were restricted to locus coeruleus, the area postrema, the dorsal motor nucleus of the vagus, and to discrete areas located in lobes 9 and 10 of the vermis cerebelli of SHR. There were no differences in the maximal binding capacity (B/sub max/) except in the nucleus ambiguus where the B/sub max/ was lower than WKY. Conversely, the number of substance P binding sites was higher in the locus coeruleus, the nucleus tegmentalis dorsalis, the nucleus ambiguus, the dorsal motor nucleus of the vagus, the hypoglossal nucleus, the inferior olivary nucleus, and lobes 9 and 10 of the vermis cerebelli of adult SHR when compared with adult WKY. The results support the hypothesis of a role for brain substance P in blood pressure regulation and in genetic hypertension in rats

Interaction of mianserin and some hypotensive drugs in Wistar rats.

Science.gov (United States)

Górska, Dorota; Andrzejczak, Dariusz

2004-01-01

Mianserin is thought to exert little effect on the cardiovascular system. In fact its safety in comparison with tricyclic drugs is high. Various experiments gave varying results as for the influence of the drug on arterial blood pressure in people and animals. Therefore, a study was undertaken in Wistar rats to evaluate interactions of mianserin administered intraperitoneally as a single dose, and for 21 days with 3 hypotensive drugs showing different mechanism of action (propranolol, enalapril, prazosine). The systolic, diastolic and mean blood pressure was measured with a LETICA apparatus. The results of the study revealed that administration of mianserin in normotensive rats leads to a short-term decrease in blood pressure and significantly enhanced the hypotensive effect of prazosine. Repeated doses of mianserin lead to a temporary increase in blood pressure after 2 weeks of administration. Single and repeated administration of mianserin did not change the hypotensive effect of propranolol and enalapril. Three-week therapy with mianserin significantly enhanced the hypotensive effect of prazosine.

Noninvasive assessment of cardiomyopathy in normotensive diabetic patients between 20 and 50 years old

International Nuclear Information System (INIS)

Bouchard, A.; Sanz, N.; Botvinick, E.H.; Phillips, N.; Heilbron, D.; Byrd, B.F. III; Karam, J.H.; Schiller, N.B.

1989-01-01

To further the understanding of diabetic heart disease, we tested the hypothesis that an asymptomatic group of normotensive diabetic patients between 20 and 50 years old had a restrictive cardiomyopathy independent of clinically significant coronary artery disease. Quantitative two-dimensional echocardiography and stress myocardial perfusion scintigraphy were performed to detect and characterize the cardiac abnormalities in this study group comprising 88 patients with rigorously classified diabetes and 65 volunteer control subjects. Diabetic patients were shown to have a mildly reduced left ventricular end-diastolic volume index: 50.1 +/- 8.2 and 52.1 +/- 14.7 mL/m2 for patients with type I and type II diabetes, respectively, versus 58.9 +/- 11.7 mL/m2 for control subjects. The left ventricular diastolic filling was also impaired in diabetic patients as reflected by a lower atrial emptying index: 0.73 +/- 0.24 and 0.76 +/- 0.3 for type I and type II diabetics, respectively, compared with 1.14 +/- 0.24 for control subjects. Exercise tolerance was normal in subjects with type I diabetes and slightly reduced in subjects with type II diabetes. Only one patient developed regional ischemia on thallium exercise testing. Using a comprehensive, noninvasive approach, we have shown that asymptomatic normotensive patients with type I or type II diabetes who were between 20 and 50 years old had a restrictive cardiomyopathy characterized by mildly reduced left ventricular end-diastolic volume and altered left ventricular compliance independent of critical coronary artery disease

[The neurodynamic core of consciousness and neural Darwinism].

Science.gov (United States)

Ibáñez, A

In the last decades, the scientific study of consciousness in the scope of the cognitive neurosciences can be considered one of the greatest challenges of contemporary science. The Gerald Edelman theory of consciousness is one of the most promising and controversial perspectives. This theory stands out by its approach to topics usually rejected by other neurophysiologic theories of consciousness, as the case of the neurophysiologic explanation of qualia. The goal of this paper is to review the dynamic core theory of consciousness, presenting the main features of the theory, analyzing the explanation strategies, their empirical extensions, and elaborating some critical considerations about the possibility of the neuroscientific study of qualia. The central and additional theoretical components are analyzed, emphasizing its ontological, restrictive and explanatory assumptions. The properties of conscious phenomena and their cerebral correlates as advanced by the theory are described, and finally its experiments and empirical extensions are examined. The explanatory strategies of the theory are analyzed, based on conceptual isomorphism between the phenomenological properties and the neurophysiological and mathematical measures. Some criticisms could be raised about the limitations of the dynamic core theory, especially regarding its account of the so-called 'hard problem' of consciousness or qualia.

Consciousness and working memory: Current trends and research perspectives.

Science.gov (United States)

Velichkovsky, Boris B

2017-10-01

Working memory has long been thought to be closely related to consciousness. However, recent empirical studies show that unconscious content may be maintained within working memory and that complex cognitive computations may be performed on-line. This promotes research on the exact relationships between consciousness and working memory. Current evidence for working memory being a conscious as well as an unconscious process is reviewed. Consciousness is shown to be considered a subset of working memory by major current theories of working memory. Evidence for unconscious elements in working memory is shown to come from visual masking and attentional blink paradigms, and from the studies of implicit working memory. It is concluded that more research is needed to explicate the relationship between consciousness and working memory. Future research directions regarding the relationship between consciousness and working memory are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Parameters of measuring of european political consciousness

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M. M. Pikula

2015-09-01

Full Text Available In the article the author analyzes the parameters of European political consciousness, i.e. European research field of political consciousness in qualitative and quantitative terms, which may be based on different indicators. The issue of emergence and development of European political consciousness becomes topical because firstly, its formation as the subjective dimension of European integration policy is not a spontaneous process and, secondly, European integration is carried out not only from the top but from the bottom, requiring deliberate interference of the public with the process; the public possesses the formed European political consciousness. Since the latter is a specific mental construct, the author offers to apply the triad «criteria ­ parameters – indicators». The characteristic that makes it possible to evaluate certain processes or phenomena in the system of Europeanness / Europeanism and specifies the quality system of views and opinions, which are realized in European behavior, is considered to be the criterion of European political consciousness. The European political consciousness parameters are seen to include the relevant historical memory, trends of public opinion and awareness regarding the European Union and position of its members in the European integration process, including the assessment of the existence and development of the EU; knowledge and views on the main EU institutions, assessing the importance of the main institutions of the EU and trust in them; a positive vision for the future of the European Union etc. The author considers the performance and objective characteristics and dimensions, including positive correlation of national and European levels of identity (European identity and European behavior to be the indicatiors of European political awareness. On the basis of these indicators the control of the condition and trends of European political consciousness development will be carried out.

Environmentalism and typological characteristics of globalistion consciousness

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Roman M. Kolisnichenko

2016-01-01

Full Text Available Analyzed anthropo-saving and environmental-depth approaches to understanding the essence environmentalism. The definition of environmentalism as global environmental trends that recognizes the intrinsic value of the natural world, all its elements and aims to rescue mankind from global environmental threats by achieving a sustainable balance of planetary ecosystems, the proper state of the environment and harmonious development of man and nature. Developed the typology of globalization consciousness attitude to solving global problems in the relationship between man and nature. The main types globalistion consciousness, as the growth of thrift in relation to nature, located in the following sequence: ecodestructive, anthropocentric, ecoconsumerist, ecotraditional, environmental, sacred-ethical, naturecentric and antropofobiastic. Developing a typology of globalistion consciousness above criteria also highlighted its neutral type. Proved that environmental globalistion consciousness is environmentally oriented system of ideas that reflect solutions to global environmental problems in accordance with the principles environmentalism. This type of consciousness globalistion a high degree of awareness of global environmental problems, persistent desire to implement effective methods of humane solution, the optimal it is due, the need to maximize the spread of population. It is concluded that the formation environmental globalistion consciousness as a prerequisite for saving humanity from self created global environmental threats can be greatly accelerated by the terms of the assistance of governments, the media, educational institutions, political parties, public organizations and other institutions of political socialization.

Music and Consciousness: A Continuing Project

Science.gov (United States)

Clarke, David; Clarke, Eric

2014-01-01

If there is a topic on which the humanities might make a distinctive claim, it is that of consciousness--an essential aspect of human being. And within the humanities, music might make its own claims in relation to both consciousness and being human. To investigate this connection, David Clarke and Eric Clarke brought together a wide variety of…

Glucagon-like peptide-1 acutely affects renal blood flow and urinary flow rate in spontaneously hypertensive rats despite significantly reduced renal expression of GLP-1 receptors.

Science.gov (United States)

Ronn, Jonas; Jensen, Elisa P; Wewer Albrechtsen, Nicolai J; Holst, Jens Juul; Sorensen, Charlotte M

2017-12-01

Glucagon-like peptide-1 (GLP-1) is an incretin hormone increasing postprandial insulin release. GLP-1 also induces diuresis and natriuresis in humans and rodents. The GLP-1 receptor is extensively expressed in the renal vascular tree in normotensive rats where acute GLP-1 treatment leads to increased mean arterial pressure (MAP) and increased renal blood flow (RBF). In hypertensive animal models, GLP-1 has been reported both to increase and decrease MAP. The aim of this study was to examine expression of renal GLP-1 receptors in spontaneously hypertensive rats (SHR) and to assess the effect of acute intrarenal infusion of GLP-1. We hypothesized that GLP-1 would increase diuresis and natriuresis and reduce MAP in SHR. Immunohistochemical staining and in situ hybridization for the GLP-1 receptor were used to localize GLP-1 receptors in the kidney. Sevoflurane-anesthetized normotensive Sprague-Dawley rats and SHR received a 20 min intrarenal infusion of GLP-1 and changes in MAP, RBF, heart rate, dieresis, and natriuresis were measured. The vasodilatory effect of GLP-1 was assessed in isolated interlobar arteries from normo- and hypertensive rats. We found no expression of GLP-1 receptors in the kidney from SHR. However, acute intrarenal infusion of GLP-1 increased MAP, RBF, dieresis, and natriuresis without affecting heart rate in both rat strains. These results suggest that the acute renal effects of GLP-1 in SHR are caused either by extrarenal GLP-1 receptors activating other mechanisms (e.g., insulin) to induce the renal changes observed or possibly by an alternative renal GLP-1 receptor. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Renin angiotensin system and cardiac hypertrophy after sinoaortic denervation in rats

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Aline Cristina Piratello

2010-01-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the role of angiotensin I, II and 1-7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation. METHODS: Ten weeks after sinoaortic denervation, hemodynamic and morphofunctional parameters were analyzed, and the left ventricle was dissected for biochemical analyses. RESULTS: Hypertensive groups (controls and denervated showed an increase on mean blood pressure compared with normotensive ones (controls and denervated. Blood pressure variability was higher in denervated groups than in their respective controls. Left ventricular mass and collagen content were increased in the normotensive denervated and in both spontaneously hypertensive groups compared with Wistar controls. Both hypertensive groups presented a higher concentration of angiotensin II than Wistar controls, whereas angiotensin 1-7 concentration was decreased in the hypertensive denervated group in relation to the Wistar groups. There was no difference in angiotensin I concentration among groups. CONCLUSION: Our results suggest that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1-7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.

Conscious Anxiety, Conscious Repression and Ego-strength as Related to Dream Recall, Content and Vividness

OpenAIRE

Newbold, David

1980-01-01

Subjects' reported dream recall frequency, dream content and vividness or recall were discussed and examined in relation to sex of the subject and MMPI Conscious Anxiety, Conscious Repression and Ego-strength scores. Fifty-three Utah State University students, who volunteered to participate in a study of dreaming behavior, were administered the MMPI and asked to complete a dream log diary. The dream log required a daily recording of total number of dreams recalled, the number of vividly an...

Question of Consciousness: to Quantum Mechanics for the Answers

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Karpenko Ivan A.

2014-09-01

Full Text Available The article presents the possible role of consciousness in quantum-mechanical description of physical reality. The widely spread interpretations of quantum phenomena are considered as indicating the apparent connection between conscious processes (such as observation and the properties of the microcosm. The reasons for discrepancies between the results of observations of the microcosm and macrocosm and the potential association of consciousness with these reasons are closely investigated. The mentioned connection is meant to be interpreted in the sense that the probable requirement for a complete understanding of quantum theory is the adequate description of consciousness within it and that the correct theory of consciousness should include quantum-mechanical theoretical apparatus. In this context, the question about the methods of scientific cognition is discussed, in particular, the problem of the place and the importance of intellectual intuition in science and philosophy of science. The author draws the conclusions about the current state of the “measuring” consciousness. problem in its relationship with

State of consciousness and ERP (event-related potential measures. Diagnostic and prognostic value of electrophysiology for disorders of consciousness

Directory of Open Access Journals (Sweden)

Michela Balconi

2011-11-01

Full Text Available Disorders of consciousness were amply studied in the recent years. At this regards new methodologies and technologies were applied to explore the diagnostic and prognostic criteria that may be applied to the patients. Specifically electrophysiological measures were used to verify the degree of awareness and responsiveness in coma, vegetative states (VS, minimal consciousness state (MC, and locked-in syndrome (LI. Recently, ERPs (event-related potentials were adopted to integrate the classical neuroimaging measures. Between the others, MMN (mismatch negativity and P300 deflections were found to represent a consistent index of the present state of consciousness and to be predictive of successive modifications of this state. Also frequency-based EEG measures, such as brain oscillations, were revealed to be relevant marker of consciousness and awareness, able to predict the future evolution of pathology.

How and to what end may consciousness contribute to action? Attributing properties of consciousness to an embodied, minimally cognitive artificial neural network.

Science.gov (United States)

Cruse, Holk; Schilling, Malte

2013-01-01

An artificial neural network called reaCog is described which is based on a decentralized, reactive and embodied architecture developed to control non-trivial hexapod walking in an unpredictable environment (Walknet) while using insect-like navigation (Navinet). In reaCog, these basic networks are extended in such a way that the complete system, reaCog, adopts the capability of inventing new behaviors and - via internal simulation - of planning ahead. This cognitive expansion enables the reactive system to be enriched with additional procedures. Here, we focus on the question to what extent properties of phenomena to be characterized on a different level of description as for example consciousness can be found in this minimally cognitive system. Adopting a monist view, we argue that the phenomenal aspect of mental phenomena can be neglected when discussing the function of such a system. Under this condition, reaCog is discussed to be equipped with properties as are bottom-up and top-down attention, intentions, volition, and some aspects of Access Consciousness. These properties have not been explicitly implemented but emerge from the cooperation between the elements of the network. The aspects of Access Consciousness found in reaCog concern the above mentioned ability to plan ahead and to invent and guide (new) actions. Furthermore, global accessibility of memory elements, another aspect characterizing Access Consciousness is realized by this network. reaCog allows for both reactive/automatic control and (access-) conscious control of behavior. We discuss examples for interactions between both the reactive domain and the conscious domain. Metacognition or Reflexive Consciousness is not a property of reaCog. Possible expansions are discussed to allow for further properties of Access Consciousness, verbal report on internal states, and for Metacognition. In summary, we argue that already simple networks allow for properties of consciousness if leaving the phenomenal

How and to what end may consciousness contribute to action? Attributing properties of consciousness to an embodied, minimally cognitive artificial neural network

Directory of Open Access Journals (Sweden)

Holk eCruse

2013-06-01

Full Text Available An artificial neural network called reaCog is described which is based on a decentralized, reactive and embodied architecture to control non-trivial hexapod walking in unpredictable environment (Walknet as well as insect-like navigation (Navinet. In reaCog, these basic networks are extended in such a way that the complete system, reaCog, adopts the capability of inventing new behaviors and - via internal simulation - of planning ahead. This cognitive expansion enables the reactive system to be enriched with additional procedures. Here, we focus on the question to what extent properties of phenomena to be characterized on a different level of description as for example consciousness can be found in this minimally cognitive system. Adopting a monist view, we argue that the phenomenal aspect of mental phenomena can be neglected when discussing the function of such a system. Under this condition, reaCog is discussed to be equipped with properties as are bottom-up and top-down attention, intentions, volition and some aspects of Access Consciousness. These properties have not been explicitly implemented but emerge from the cooperation between the elements of the network. The aspects of access consciousness found in reaCog concern the above mentioned ability to plan ahead and to invent and guide (new actions. Furthermore, global accessibility of memory elements, another aspect characterizing Access Consciousness is realized by this network. reaCog allows for both reactive/automatic control and (access- conscious control of behavior. We discuss examples for interactions between both the reactive domain and the conscious domain. Metacognition or Reflexive Consciousness is not a property of reaCog. Possible expansions are discussed to allow for further properties of Access Consciousness, verbal report on internal states, and for Metacognition. In summary, we argue that already simple networks allow for properties of consciousness if leaving the phenomenal

Conscious and nonconscious memory effects are temporally dissociable.

Science.gov (United States)

Slotnick, Scott D; Schacter, Daniel L

2010-03-01

Intentional (explicit) retrieval can reactivate sensory cortex, which is widely assumed to reflect conscious processing. In the present study, we used an explicit visual memory event-related potential paradigm to investigate whether such retrieval related sensory activity could be separated into conscious and nonconscious components. During study, abstract shapes were presented in the left or right visual field. During test, old and new shapes were presented centrally and participants classified each shape as "old-left", "old-right", or "new". Conscious activity was isolated by comparing accurate memory for shape and location (old-hits) with forgotten shapes (old-misses), and nonconscious activity was isolated by comparing old-left-misses with old-right-misses and vice versa. Conscious visual sensory activity had a late temporal onset (after 800 ms) while nonconscious visual sensory activity had an early temporal onset (before 800 ms). These results suggest explicit memory related sensory activity reflects both conscious and nonconscious processes that are temporally dissociable.

Regulation of cerebral circulation in spontaneous hypertension. Abstract. [Intraarterial xanon-133 technique]. Regulacja krazenia mozgowego krwi w genetycznie uwarunkowanym nadcisnieniu tetniczym (streszczenie pracy habilitacyjnej)

Energy Technology Data Exchange (ETDEWEB)

Kozniewska-Kolodziejska, E. (Akademia Medyczna, Warsaw (Poland))

1991-01-01

The study was undertaken in order to determine global cerebral blood flow (intraarterial xenon-133 technique), cerebral oxygen utilization and cerebrovascular resistance and to estimate cerebrocortical microcirculation (Clark-type surface microelectrodes, corrosion casts) during normo- and hypoxemia in normotensive, spontaneously hypertensive stroke-resistant and stroke-prone rats. The reactivity of cerebral circulation to the changes in the arterial partial pressure of carbon dioxide and to calcium channel blockade was also determined. The results of the study suggest that cerebrovascular resistance in spontaneously hypertensive rats under resting conditions depends, to a great extend, upon the increase of the permeability of cerebral blood vessel to calcium ions and upon the ratification of microvascular bed. Cerebral blood flow in spontaneously hypertensive rats is maintained at a normotensive level during normoxia and normocapnia. The reactivity of cerebral circulation to moderate changes of the arterial partial pressure of oxygen and carbon dioxide is well preserved in both strains of hypertensive rats in comparison with normotensive ones, but is diminished during severe hypocapnia. (author).

A Neural Marker of Perceptual Consciousness in Infants

DEFF Research Database (Denmark)

Kouider, Sid; Stahlhut, Carsten; Gelskov, Sofie V.

2013-01-01

Consciousness Arrives Neurophysiological measures in human adults correspond to the transition between very brief, “unnoticeable,” and slightly longer-lived visual stimuli that penetrate deeply enough to leave a conscious imprint that subjects report they can “see.” Kouider et al. (p. 376) have...... performed parallel behavioral and neurophysiological studies in infants to identify a similar neural signal that appears to mark the development of visual consciousness....

Feminist consciousness and assertiveness in Ifeoma Okoye's ...

African Journals Online (AJOL)

Okoye is an African feminist who advocates feminist consciousness as a concept through which women can be enlightened for consciousness-raising, empowerment and assertiveness in her novels, Behind the Clouds and Chimere, while emphasizing education, economic independence and sisterhood as avenues for ...

An integrative view on consciousness and introspection

DEFF Research Database (Denmark)

Overgaard, Morten; Mogensen, Jesper

2017-01-01

The relation between first and higher order mental states is currently unknown. In particular, the relation between conscious experience and introspection is difficult as the same methods are used to investigate them. In order to make progress in the scientific understanding of consciousness...

Rhythmic components in renal autoregulation: Nonlinear modulation phenomena

International Nuclear Information System (INIS)

Pavlov, A.N.; Sosnovtseva, O.V.; Pavlova, O.N.; Mosekilde, E.; Holstein-Rathlou, N.-H.

2009-01-01

Autoregulation of nephron blood flow involves two oscillatory processes: the tubular-flow sensitive tubuloglomerular feedback (TGF) mechanism and the blood-pressure sensitive myogenic mechanism. Both act to regulate the diameter of the afferent arteriole, which carries blood to the nephron. In this paper, we apply wavelet analysis to time series of the proximal tubular pressure obtained from normotensive and hypertensive rats to study how the TGF-mediated oscillations modulate both the frequency and the amplitude of the myogenic oscillations. The tubular pressure oscillations are nearly periodic for normotensive rats, but irregular (or chaotic) for rats with hypertension. Modulation phenomena are clearly observed in both types of rats, but the effect is stronger in those with hypertension.

Disruption of Conscious Access in Schizophrenia.

Science.gov (United States)

Berkovitch, Lucie; Dehaene, Stanislas; Gaillard, Raphaël

2017-11-01

Schizophrenia is a severe and complex psychiatric disorder resulting in delusions, hallucinations, and cognitive impairments. Across a variety of paradigms, an elevated threshold for conscious perception has been repeatedly observed in persons with schizophrenia. Remarkably, even subtle measures of subliminal processing appear to be preserved. We argue here that the dissociation between impaired conscious access and intact unconscious processing may be due to a specific disruption of top-down attentional amplification. This proposal is compatible with the neurophysiological disturbances observed in schizophrenia, including dysconnectivity, abnormal neural oscillations, and glutamatergic and cholinergic dysregulation. Therefore, placing impaired conscious access as a central feature of schizophrenia can help researchers develop a coherent and parsimonious pathophysiological framework of the disease. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is Your Gut Conscious? Is an Extraterrestrial?

Science.gov (United States)

Vos Post, Jonathan

2011-10-01

This paper speculates on questions intending to be taken scientifically rather than metaphysically: "Can the human gut (enteric nervous system) be conscious?"; "Can your immune system think?"; "Could consciousness be coded in DNA?"; "What do we mean when asserting that an Extraterrestrial is Thinking, or is Conscious? We explore through reference to theory, experiment, and computational models by Christof Koch (Caltech), Barbara Wold (Caltech), and Stuart Kauffman (University of Calgary, Tampere University of Technology, Santa Fe Institute). We use a tentative new definition of thinking, designed to be applicable for humans, cetecea, corvids, artificial intelligences, and extraterrestrial intelligences of any substrate (i.e. Life as We Do Not Know It): "Thinking is the occurrence, transformation, and storage in a mind or brain (or simulation thereof) of information-bearing structures (representations) of one kind or another, such as thoughts, concept, percepts, ideas, impressions, notions, rules, schemas, images, phantasms, or subpersonal representations." We use the framework for Consciousness developed by Francis Crick and Christof Koch. We try to describe scientific goals, but discuss Philosophy sufficient to avoid naïve philosophical category errors (thus are careful not to conflate thought, consciousness, and language) Penrose, Hameroff, and Kauffman speculate (differently) that CNS consciousness is a macroscopic quantum phenomenon. Might intestinal, immune system, or genetic regulatory network dynamics exhibit emergent cooperative quantum effects? The speculations are in the context of Evolution by Natural Selection, presumed to operate throughout the Cosmos, and recent work in the foundations of Computational Biology and Quantum Mechanics.

Consciousness as a global property of brain dynamic activity

Science.gov (United States)

Mateos, D. M.; Wennberg, R.; Guevara, R.; Perez Velazquez, J. L.

2017-12-01

We seek general principles of the structure of the cellular collective activity associated with conscious awareness. Can we obtain evidence for features of the optimal brain organization that allows for adequate processing of stimuli and that may guide the emergence of cognition and consciousness? Analyzing brain recordings in conscious and unconscious states, we followed initially the classic approach in physics when it comes to understanding collective behaviours of systems composed of a myriad of units: the assessment of the number of possible configurations (microstates) that the system can adopt, for which we use a global entropic measure associated with the number of connected brain regions. Having found maximal entropy in conscious states, we then inspected the microscopic nature of the configurations of connections using an adequate complexity measure and found higher complexity in states characterized not only by conscious awareness but also by subconscious cognitive processing, such as sleep stages. Our observations indicate that conscious awareness is associated with maximal global (macroscopic) entropy and with the short time scale (microscopic) complexity of the configurations of connected brain networks in pathological unconscious states (seizures and coma), but the microscopic view captures the high complexity in physiological unconscious states (sleep) where there is information processing. As such, our results support the global nature of conscious awareness, as advocated by several theories of cognition. We thus hope that our studies represent preliminary steps to reveal aspects of the structure of cognition that leads to conscious awareness.

Does perceptual learning require consciousness or attention?

NARCIS (Netherlands)

Meuwese, J.D.I.; Post, R.A.G.; Scholte, H.S.; Lamme, V.A.F.

2013-01-01

It has been proposed that visual attention and consciousness are separate [Koch, C., & Tsuchiya, N. Attention and consciousness:Two distinct brain processes. Trends in Cognitive Sciences, 11, 16-22, 2007] and possibly even orthogonal processes [Lamme, V. A. F. Why visual attention and awareness are

The learning organization and the level of consciousness

OpenAIRE

Chiva Gómez, Ricardo

2017-01-01

Purpose – The purpose of this paper is to analyze learning organization by comparing with other types of organizations. This typology is based on the levels of consciousness and relates each type of organization with a level of learning and an organizational structure. Design/methodology/approach – This is a conceptual paper based on the concept of levels of consciousness. Findings – The paper proposes that learning organization requires the highest level of consciousness. O...

Conscious visual memory with minimal attention.

Science.gov (United States)

Pinto, Yair; Vandenbroucke, Annelinde R; Otten, Marte; Sligte, Ilja G; Seth, Anil K; Lamme, Victor A F

2017-02-01

Is conscious visual perception limited to the locations that a person attends? The remarkable phenomenon of change blindness, which shows that people miss nearly all unattended changes in a visual scene, suggests the answer is yes. However, change blindness is found after visual interference (a mask or a new scene), so that subjects have to rely on working memory (WM), which has limited capacity, to detect the change. Before such interference, however, a much larger capacity store, called fragile memory (FM), which is easily overwritten by newly presented visual information, is present. Whether these different stores depend equally on spatial attention is central to the debate on the role of attention in conscious vision. In 2 experiments, we found that minimizing spatial attention almost entirely erases visual WM, as expected. Critically, FM remains largely intact. Moreover, minimally attended FM responses yield accurate metacognition, suggesting that conscious memory persists with limited spatial attention. Together, our findings help resolve the fundamental issue of how attention affects perception: Both visual consciousness and memory can be supported by only minimal attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Cybernetics and consciousness.

Science.gov (United States)

Trabka, J

1999-01-01

This paper is a review of hypotheses of consciousness which arose from application of the theory of information and regulation and the cybernetic theory of mathematical machines in medicine. The author presents these hypotheses on the examples of his own works.

Pharmacological analysis of the cardiac sympatho-inhibitory actions of moxonidine and agmatine in pithed spontaneously hypertensive rats.

Science.gov (United States)

Cobos-Puc, Luis E; Sánchez-López, Araceli; Centurión, David

2016-11-15

This study shows that in spontaneously hypertensive rats (SHR) of 14-weeks-old, the sympathetically-induced, but not noradrenaline-induced tachycardic response are higher than age-matched Wistar normotensive rats. Furthermore, in SHR the sympathetically-induced tachycardic response was: (1) unaffected by moxonidine (3μg/kgmin); (2) partially inhibited by B-HT 933 (30μg/kgmin), both at the lowest doses; and (3) completely inhibited by the highest doses of B-HT 933 (100μg/kgmin), moxonidine (10μg/kgmin) or agmatine (1000 and 3000μg/kgmin) while the noradrenaline-induced tachycardic responses remained unaffected by the above compounds, except by 3000μg/kgmin agmatine. In SHR, 300μg/kg rauwolscine failed to block the sympatho-inhibition to 100μg/kgmin B-HT 933 or 10μg/kgmin moxonidine, but 1000μg/kg rauwolscine abolished, partially antagonized, and did not modify the sympatho-inhibition to the highest doses of B-HT 933, moxonidine, and agmatine, respectively, 3000μg/kg AGN 192403 or 300μg/kg BU224 given alone had no effect in the moxonidine- or agmatine-induced sympatho-inhibition, and the combination rauwolscine plus AGN 192403 but not plus BU224, abolished the sympatho-inhibition to the highest doses of moxonidine and agmatine. In conclusion, the sympathetically-induced tachycardic responses in SHR are inhibited by moxonidine and agmatine. The inhibition of moxonidine is mainly mediated by prejunctional α 2 -adrenoceptors and to a lesser extent by I 1 -imidazoline receptors, while the inhibition of agmatine is mediated by prejunctional α 2 -adrenoceptors and I 1 -imidazoline receptors at the same extent. Notwithstanding, the inhibitory function of α 2 -adrenoceptors seems to be altered in SHR compared with Wistar normotensive rats. Copyright © 2016 Elsevier B.V. All rights reserved.

Chasing the Rainbow: The Non-conscious Nature of Being

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David A. Oakley

2017-11-01

Full Text Available Despite the compelling subjective experience of executive self-control, we argue that “consciousness” contains no top-down control processes and that “consciousness” involves no executive, causal, or controlling relationship with any of the familiar psychological processes conventionally attributed to it. In our view, psychological processing and psychological products are not under the control of consciousness. In particular, we argue that all “contents of consciousness” are generated by and within non-conscious brain systems in the form of a continuous self-referential personal narrative that is not directed or influenced in any way by the “experience of consciousness.” This continuously updated personal narrative arises from selective “internal broadcasting” of outputs from non-conscious executive systems that have access to all forms of cognitive processing, sensory information, and motor control. The personal narrative provides information for storage in autobiographical memory and is underpinned by constructs of self and agency, also created in non-conscious systems. The experience of consciousness is a passive accompaniment to the non-conscious processes of internal broadcasting and the creation of the personal narrative. In this sense, personal awareness is analogous to the rainbow which accompanies physical processes in the atmosphere but exerts no influence over them. Though it is an end-product created by non-conscious executive systems, the personal narrative serves the powerful evolutionary function of enabling individuals to communicate (externally broadcast the contents of internal broadcasting. This in turn allows recipients to generate potentially adaptive strategies, such as predicting the behavior of others and underlies the development of social and cultural structures, that promote species survival. Consequently, it is the capacity to communicate to others the contents of the personal narrative that

The merit of synesthesia for consciousness research

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Tessa Marije Van Leeuwen

2015-12-01

Full Text Available Synesthesia is a phenomenon in which additional perceptual experiences are elicited by sensory stimuli or cognitive concepts. Synesthetes possess a unique type of phenomenal experiences not directly triggered by sensory stimulation. Therefore, for better understanding of consciousness it is relevant to identify the mental and physiological processes that subserve synesthetic experience. In the present work we suggest several reasons why synesthesia has merit for research on consciousness. We first review the research on the dynamic and rapidly growing field of the studies of synesthesia. We particularly draw attention to the role of semantics in synesthesia, which is important for establishing synesthetic associations in the brain. We then propose that the interplay between semantics and sensory input in synesthesia can be helpful for the study of the neural correlates of consciousness, especially when making use of ambiguous stimuli for inducing synesthesia. Finally, synesthesia-related alterations of brain networks and functional connectivity can be of merit for the study of consciousness.

Body mass index predicts aldosterone production in normotensive adults on a high-salt diet.

Science.gov (United States)

Bentley-Lewis, Rhonda; Adler, Gail K; Perlstein, Todd; Seely, Ellen W; Hopkins, Paul N; Williams, Gordon H; Garg, Rajesh

2007-11-01

The mechanisms underlying obesity-mediated cardiovascular disease are not fully understood. Aldosterone and insulin resistance both are associated with obesity and cardiovascular disease. The objectives of this study were to test the hypotheses that aldosterone production is elevated and associated with insulin resistance in overweight adults on a high-sodium diet. Healthy normotensive adults were categorized as lean body mass index (BMI) less than 25 kg/m(2) (n = 63) or overweight BMI 25 kg/m(2) or greater (n = 57). After 7 d of a high-sodium diet, participants fasted overnight and remained supine throughout hemodynamic and laboratory assessments and angiotensin II (AngII) stimulation. The overweight group, compared with the lean group, had higher 24-h urinary aldosterone (9.0 +/- 0.8 vs. 6.6 +/- 0.5 microg per 24 h; P = 0.003) and higher AngII-stimulated serum aldosterone (11.4 +/- 1.0 vs. 9.0 +/- 0.6 ng/dl; P = 0.04). There were no differences in 24-h urinary cortisol or sodium or supine measurements of plasma renin activity, serum aldosterone, or serum potassium. The homeostasis model assessment of insulin resistance was predicted by urinary aldosterone excretion (r = 0.32, P = 0.03) and serum aldosterone response to AngII stimulation (r = 0.28, P = 0.02) independent of age and BMI. Urinary aldosterone excretion and AngII-stimulated aldosterone are increased in overweight, compared with lean, normotensive adults. The correlation of these measures of aldosterone production with insulin resistance suggests a potential role for aldosterone in the pathophysiology of obesity-mediated insulin resistance.

Unitary and Dual Models of Phenomenal Consciousness

Czech Academy of Sciences Publication Activity Database

Marvan, Tomáš; Polák, M.

-, č. 56 (2017), s. 1-12 ISSN 1053-8100 Institutional support: RVO:67985955 Keywords : phenomenal consciousness * David Rosenthal * what it is like * unconscious mind * theories fo consciousness Subject RIV: AA - Philosophy ; Religion OBOR OECD: Philosophy, History and Philosophy of science and technology Impact factor: 2.144, year: 2016

In Situ Representations and Access Consciousness in Neural Blackboard or Workspace Architectures

OpenAIRE

Frank van der Velde

2018-01-01

Phenomenal theories of consciousness assert that consciousness is based on specific neural correlates in the brain, which can be separated from all cognitive functions we can perform. If so, the search for robot consciousness seems to be doomed. By contrast, theories of functional or access consciousness assert that consciousness can be studied only with forms of cognitive access, given by cognitive processes. Consequently, consciousness and cognitive access cannot be fully dissociated. Here,...

Potentiation of Hormonal Responses to Hemorrhage and Fasting, but not Hypoglycemia in Conscious Adrenalectomized Rats

Science.gov (United States)

Darlington, Daniel N.; Keil, Lanny C.; Dallman, Mary F.

1989-01-01

Bilateral adrenalectomy (ADRX) in rats removes the source of two major stress-responsive hormones, corticosterone and epinephrine. To test how ADRX rats with-stand stress, we performed the following experiments in adult male rats provided with indwelling femoral arterial and venous cannulae and either ADRX or sham-adrenalectomized (Sham) 3 days later and given 0.5% NaCl to drink. Five to 6 days after adrenal surgery the rats were studied after either a 15 ml/kg.5 min hemorrhage or after an overnight fast followed by insulin-induced hypoglycemia. In fed unstressed ADRX rats, basal mean arterial blood pressure was slightly decreased; heart rate was increased; blood volume, vasopressin, and oxytocin concentrations were not different from sham values; and renin and norepinephrine were significantly elevated. The recovery of arterial pressure after hemorrhage in the ADRX rats was similar to that in the sham group over a 5-h period; however, the responses of vasopressin and oxytocin were significantly greater, and those of renin and norepinephrine were markedly potentiated in the ADRX group. Heart rate recovered faster in the ADRX group and was elevated, compared to the sham value, for most of the 5-h period. Restitution of blood volume was attenuated in the ADRX group, although the restitution of plasma protein was not different between the groups. A significant difference in the change in plasma osmolality between groups after hemorrhage may account for the attenuated restitution of blood volume. After an overnight fast, which reduced blood volume in both groups of rats, the plasma renin concentration rose still further in ADRX rats; the differences in other measured variables observed between fed ADRX and sham groups remained the same. The insulin-induced 50% decrease in glucose caused minor effects on arterial blood pressure and heart rate and occasioned responses in renin and norepinephrine of similar magnitudes in the two groups. We conclude that in the absence of

IN SEARCH OF SENSES (SOCIAL CONSCIOUSNESS IN WORKS OF G. A. KOTELNIKOV)

OpenAIRE

Oreshkina M. A.

2015-01-01

In the recent past, class-consciousness was considered one of the expression forms of social consciousness and acted as its main form due to close interaction with interests of people. The class-consciousness and the consciousness of classes were two separate matters of consideration. It was supposed that the essence of class-consciousness and of the class-psychology concomitant with it could only be comprehended in consideration of structure of the social consciousness as a whole. The correl...

The thinking ape: the enigma of human consciousness.

Science.gov (United States)

Paulson, Steve; Chalmers, David; Kahneman, Daniel; Santos, Laurie; Schiff, Nicholas

2013-11-01

What is the origin and nature of consciousness? If consciousness is common to humans and animals alike, what are the defining traits of human consciousness? Moderated by Steve Paulson, executive producer and host of To the Best of Our Knowledge, Nobel laureate psychologist Daniel Kahneman, philosopher David Chalmers, expert in primate cognition Laurie Santos, and physician-scientist Nicholas Schiff discuss what it means to be conscious and examine the human capacities displayed in cognitive, aesthetic, and ethical behaviors, with a focus on the place and function of the mind within nature. The following is an edited transcript of the discussion that occurred October 10, 2012, 7:00-8:15 PM, at the New York Academy of Sciences in New York City. © 2013 New York Academy of Sciences.

Obliczeniowe teorie świadomości (Computational theories of consciousness

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Marcin Miłkowski

2010-06-01

Full Text Available In this paper, I review the motivations for having a computational theory of consciousness to see if they turn out to be no longer plausible in the light of recent criticisms. These criticisms focus on the alleged inability of computational theories to deal with qualia, or qualities of experience (or objects of experience in some accounts, and with so-called symbol grounding on the other hand. Yet it seems that computationalism remains the best game in town when one wants to explain and predict the dynamics of information processing of cognitive systems. Conscious information processing does not seem to be explainable better within any other framework; computationalism regarding consciousness can only be discarded by supposing that consciousness is epiphenomenal in information processing.I will argue that recent theories of consciousness that are to deal with the so-called hard problem of consciousness remain in their core computational if they do not subscribe to epiphenomenalism. For example, the quantum theory as proposed by Stuart Hameroff remains openly computational; the same goes for pan(protopsychist speculation of David Chalmers. The qualitative character of information processing that Chalmers takes to explain the existence of subjective experience piggy-backs, so to say, on the very fact that there is information processing that is best explained in a computationalist framework. I also briefly show that other alternative accounts of consciousness (such as direct theories of consciousness that were supposed to oppose computational and functionalist conceptions are not only compatible with them but require them to begin with.In short, to discard credentials of computationalism in consciousness research one would have to show that it`s possible to explain conscious information-processing mechanisms sufficiently in a non-computational way. And this has not been done by any of the critics of computational accounts. This all doesn`t suggest

Affectivity And Time: Towards A Phenomenology Of Embodied Time-Consciousness

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Pokropski Marek

2015-06-01

Full Text Available In the article, I develop some ideas introduced by Edmund Husserl concerning time-consciousness and embodiment. However, I do not discuss the Husserlian account of consciousness of time in its full scope. I focus on the main ideas of the phenomenology of time and the problem of bodily sensations and their role in the constitution of consciousness of time. I argue that time-consciousness is primarily constituted in the dynamic experience of bodily feelings.

Towards environmentally sustainable human behaviour: targeting non-conscious and conscious processes for effective and acceptable policies.

Science.gov (United States)

Marteau, Theresa M

2017-06-13

Meeting climate change targets to limit global warming to 2°C requires rapid and large reductions in demand for products that most contribute to greenhouse gas (GHG) emissions. These include production of bulk materials (e.g. steel and cement), energy supply (e.g. fossil fuels) and animal source foods (particularly ruminants and their products). Effective strategies to meet these targets require transformative changes in supply as well as demand, involving changes in economic, political and legal systems at local, national and international levels, building on evidence from many disciplines. This paper outlines contributions from behavioural science in reducing demand. Grounded in dual-process models of human behaviour (involving non-conscious and conscious processes) this paper considers first why interventions aimed at changing population values towards the environment are usually insufficient or unnecessary for reducing demand although they may be important in increasing public acceptability of policies that could reduce demand. It then outlines two sets of evidence from behavioural science towards effective systems-based strategies, to identify interventions likely to be effective at: (i) reducing demand for products that contribute most to GHG emissions, mainly targeting non-conscious processes and (ii) increasing public acceptability for policy changes to enable these interventions, targeting conscious processes.This article is part of the themed issue 'Material demand reduction'. © 2017 The Authors.

Towards environmentally sustainable human behaviour: targeting non-conscious and conscious processes for effective and acceptable policies

Science.gov (United States)

Marteau, Theresa M.

2017-05-01

Meeting climate change targets to limit global warming to 2°C requires rapid and large reductions in demand for products that most contribute to greenhouse gas (GHG) emissions. These include production of bulk materials (e.g. steel and cement), energy supply (e.g. fossil fuels) and animal source foods (particularly ruminants and their products). Effective strategies to meet these targets require transformative changes in supply as well as demand, involving changes in economic, political and legal systems at local, national and international levels, building on evidence from many disciplines. This paper outlines contributions from behavioural science in reducing demand. Grounded in dual-process models of human behaviour (involving non-conscious and conscious processes) this paper considers first why interventions aimed at changing population values towards the environment are usually insufficient or unnecessary for reducing demand although they may be important in increasing public acceptability of policies that could reduce demand. It then outlines two sets of evidence from behavioural science towards effective systems-based strategies, to identify interventions likely to be effective at: (i) reducing demand for products that contribute most to GHG emissions, mainly targeting non-conscious processes and (ii) increasing public acceptability for policy changes to enable these interventions, targeting conscious processes. This article is part of the themed issue 'Material demand reduction'.

Towards environmentally sustainable human behaviour: targeting non-conscious and conscious processes for effective and acceptable policies

Science.gov (United States)

2017-01-01

Meeting climate change targets to limit global warming to 2°C requires rapid and large reductions in demand for products that most contribute to greenhouse gas (GHG) emissions. These include production of bulk materials (e.g. steel and cement), energy supply (e.g. fossil fuels) and animal source foods (particularly ruminants and their products). Effective strategies to meet these targets require transformative changes in supply as well as demand, involving changes in economic, political and legal systems at local, national and international levels, building on evidence from many disciplines. This paper outlines contributions from behavioural science in reducing demand. Grounded in dual-process models of human behaviour (involving non-conscious and conscious processes) this paper considers first why interventions aimed at changing population values towards the environment are usually insufficient or unnecessary for reducing demand although they may be important in increasing public acceptability of policies that could reduce demand. It then outlines two sets of evidence from behavioural science towards effective systems-based strategies, to identify interventions likely to be effective at: (i) reducing demand for products that contribute most to GHG emissions, mainly targeting non-conscious processes and (ii) increasing public acceptability for policy changes to enable these interventions, targeting conscious processes. This article is part of the themed issue ‘Material demand reduction’. PMID:28461435

Hippocampus is place of interaction between unconscious and conscious memories.

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Marc Alain Züst

Full Text Available Recent evidence suggests that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus-the key structure also recruited for conscious relational (episodic memory. If the hippocampus subserves both conscious and unconscious relational encoding/retrieval, one would expect the hippocampus to be place of unconscious-conscious interactions during memory retrieval. We tested this hypothesis in an fMRI experiment probing the interaction between the unconscious and conscious retrieval of face-associated information. For the establishment of unconscious relational memories, we presented subliminal (masked combinations of unfamiliar faces and written occupations ("actor" or "politician". At test, we presented the former subliminal faces, but now supraliminally, as cues for the reactivation of the unconsciously associated occupations. We hypothesized that unconscious reactivation of the associated occupation-actor or politician-would facilitate or inhibit the subsequent conscious retrieval of a celebrity's occupation, which was also actor or politician. Depending on whether the reactivated unconscious occupation was congruent or incongruent to the celebrity's occupation, we expected either quicker or delayed conscious retrieval process. Conscious retrieval was quicker in the congruent relative to a neutral baseline condition but not delayed in the incongruent condition. fMRI data collected during subliminal face-occupation encoding confirmed previous evidence that the hippocampus was interacting with neocortical storage sites of semantic knowledge to support relational encoding. fMRI data collected at test revealed that the facilitated conscious retrieval was paralleled by deactivations in the hippocampus and neocortical storage sites of semantic knowledge. We assume that the unconscious reactivation has pre-activated overlapping relational representations in the hippocampus reducing the neural effort for conscious

Object of desire self-consciousness theory.

Science.gov (United States)

Bogaert, Anthony F; Brotto, Lori A

2014-01-01

In this article, the authors discuss the construct of object of desire self-consciousness, the perception that one is romantically and sexually desirable in another's eyes. The authors discuss the nature of the construct, variations in its expression, and how it may function as part of a self-schemata or script related to romance and sexuality. The authors suggest that object of desire self-consciousness may be an adaptive, evolved psychological mechanism allowing sexual and romantic tactics suitable to one's mate value. The authors also suggest that it can act as a signal that one has high mate value in the sexual marketplace. The authors then review literature (e.g., on fantasies, on sexual activity preferences, on sexual dysfunctions, on language) suggesting that object of desire self-consciousness plays a particularly important role in heterosexual women's sexual/romantic functioning and desires.

Age and the experience of strong self-conscious emotion.

Science.gov (United States)

Henry, Julie D; von Hippel, William; Nangle, Matthew R; Waters, Michele

2018-04-01

It remains unclear whether there are age-related changes in the experience of strong self-conscious emotion, such as shame, guilt, pride and embarrassment. Because shame and guilt figure prominently in the aetiology of depressive symptoms and other mental health problems, a better understanding of how age affects the strong experience of these two negative self-conscious emotions is of particular importance. Thirty younger, 30 middle-aged and 30 older adults were compared on standardised cognitive assessments, in addition to an interview-based measure that assessed whether there are age differences in the likelihood of strongly experiencing four different types of self-conscious emotion within the past five years (shame, guilt, embarrassment and pride). The three groups did not differ in their likelihood of reporting an event that strongly elicited the positive self-conscious emotion of pride. However, older adults were more likely to report sources of pride that were other (as opposed to self) focused. Older adults were also less likely to report experiencing events that elicited all three negative self-conscious emotions, in particular, shame. Strong negative self-conscious emotion, and in particular shame, appears to be experienced less by older than younger adults.

Statistical parametric maps of 18F-FDG PET and 3-D autoradiography in the rat brain: a cross-validation study

International Nuclear Information System (INIS)

Prieto, Elena; Marti-Climent, Josep M.; Collantes, Maria; Molinet, Francisco; Delgado, Mercedes; Garcia-Garcia, Luis; Pozo, Miguel A.; Juri, Carlos; Fernandez-Valle, Maria E.; Gago, Belen; Obeso, Jose A.; Penuelas, Ivan

2011-01-01

Although specific positron emission tomography (PET) scanners have been developed for small animals, spatial resolution remains one of the most critical technical limitations, particularly in the evaluation of the rodent brain. The purpose of the present study was to examine the reliability of voxel-based statistical analysis (Statistical Parametric Mapping, SPM) applied to 18 F-fluorodeoxyglucose (FDG) PET images of the rat brain, acquired on a small animal PET not specifically designed for rodents. The gold standard for the validation of the PET results was the autoradiography of the same animals acquired under the same physiological conditions, reconstructed as a 3-D volume and analysed using SPM. Eleven rats were studied under two different conditions: conscious or under inhalatory anaesthesia during 18 F-FDG uptake. All animals were studied in vivo under both conditions in a dedicated small animal Philips MOSAIC PET scanner and magnetic resonance images were obtained for subsequent spatial processing. Then, rats were randomly assigned to a conscious or anaesthetized group for postmortem autoradiography, and slices from each animal were aligned and stacked to create a 3-D autoradiographic volume. Finally, differences in 18 F-FDG uptake between conscious and anaesthetized states were assessed from PET and autoradiography data by SPM analysis and results were compared. SPM results of PET and 3-D autoradiography are in good agreement and led to the detection of consistent cortical differences between the conscious and anaesthetized groups, particularly in the bilateral somatosensory cortices. However, SPM analysis of 3-D autoradiography also highlighted differences in the thalamus that were not detected with PET. This study demonstrates that any difference detected with SPM analysis of MOSAIC PET images of rat brain is detected also by the gold standard autoradiographic technique, confirming that this methodology provides reliable results, although partial volume

Perception, Action, and Consciousness

DEFF Research Database (Denmark)

What is the relationship between perception and action, between an organism and its environment, in explaining consciousness? These are issues at the heart of philosophy of mind and the cognitive sciences. This book explores the relationship between perception and action from a variety of interdi......What is the relationship between perception and action, between an organism and its environment, in explaining consciousness? These are issues at the heart of philosophy of mind and the cognitive sciences. This book explores the relationship between perception and action from a variety...... of interdisciplinary perspectives, ranging from theoretical discussion of concepts to findings from recent scientific studies. It incorporates contributions from leading philosophers, psychologists, neuroscientists, and an artificial intelligence theorist. The contributions take a range of positions with respect...

Consciousness, Plasticity, and Connectomics: The Role of Intersubjectivity in Human Cognition

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Micah eAllen

2011-02-01

Full Text Available Consciousness is typically construed as being explainable purely in terms of either private, raw feels or higher-order, reflective representations. In contrast to this false dichotomy, we propose a new view of consciousness as an interactive, plastic phenomenon open to sociocultural influence. We take up our account of consciousness from the observation of radical cortical neuroplasticity in human development. Accordingly, we draw upon recent research on macroscopic neural networks, including the default mode, to illustrate cases in which an individual’s particular connectome is shaped by encultured social practices that depend upon and influence phenomenal and reflective consciousness. On our account, the dynamically interacting connectivity of these networks bring about important individual differences in conscious experience and determine what is present in consciousness. Further, we argue that the organization of the brain into discrete anti-correlated networks supports the phenomenological distinction of prereflective and reflective consciousness, but we emphasize that this finding must be interpreted in light of the dynamic, category-resistant nature of consciousness. Our account motivates philosophical and empirical hypotheses regarding the appropriate time-scale and function of neuroplastic adaptation, the relation of high and low frequency neural activity to consciousness and cognitive plasticity, and the role of ritual social practices in neural development and cognitive function.

Autonomic abnormalities demonstrable in young normotensive subjects who are children of hypertensive parents

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Lopes H.F.

2000-01-01

Full Text Available Although a slightly elevated office blood pressure (BP has been reported in several studies, little is known about the prolonged resting blood pressure, heart rate (HR and baroreflex sensitivity (BRS of prehypertensive subjects with a family history of hypertension. Office blood pressure, prolonged resting (1 h BP and HR were measured in 25 young normotensives with a positive family history of hypertension (FH+ and 25 young normotensives with a negative family history of hypertension (FH-, matched for age, sex, and body mass index. After BP and HR measurements, blood samples were collected for the determination of norepinephrine, plasma renin activity and aldosterone levels, and baroreflex sensitivity was then tested. Casual BP, prolonged resting BP and heart rate were significantly higher in the FH+ group (119.9 ± 11.7/78.5 ± 8.6 mmHg, 137.3 ± 12.3/74.4 ± 7.9 mmHg, 68.5 ± 8.4 bpm compared to the FH- group (112.9 ± 11.4/71.2 ± 8.3 mmHg, 128.0 ± 11.8/66.5 ± 7.4 mmHg, 62.1 ± 6.0 bpm. Plasma norepinephrine level was significantly higher in the FH+ group (220.1 ± 104.5 pg/ml than in the FH- group (169.1 ± 63.3 pg/ml. Baroreflex sensitivity to tachycardia (0.7 ± 0.3 vs 1.0 ± 0.5 bpm/mmHg was depressed in the FH+ group (P<0.05. The FH+ group exhibited higher casual blood pressure, prolonged resting blood pressure, heart rate and plasma norepinephrine levels than the FH- group (P<0.05, suggesting an increased sympathetic tone in these subjects. The reflex tachycardia was depressed in the FH+ group.

Time-varying properties of renal autoregulatory mechanisms

DEFF Research Database (Denmark)

Zou, Rui; Cupples, Will A; Yip, K P

2002-01-01

In order to assess the possible time-varying properties of renal autoregulation, time-frequency and time-scaling methods were applied to renal blood flow under broad-band forced arterial blood pressure fluctuations and single-nephron renal blood flow with spontaneous oscillations obtained from...... normotensive (Sprague-Dawley, Wistar, and Long-Evans) rats, and spontaneously hypertensive rats. Time-frequency analyses of normotensive and hypertensive blood flow data obtained from either the whole kidney or the single-nephron show that indeed both the myogenic and tubuloglomerular feedback (TGF) mechanisms...... have time-varying characteristics. Furthermore, we utilized the Renyi entropy to measure the complexity of blood-flow dynamics in the time-frequency plane in an effort to discern differences between normotensive and hypertensive recordings. We found a clear difference in Renyi entropy between...

Results of Research about Consciousness of Foodstuff Consumers in Hungary

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Ibolya Bravacz

2013-10-01

How self-restrictive and self-conscious are we when purchasing and consuming foodstuff? – with every foodstuff purchase we make decisions about our environment, which indirectly has an effect on the producers, manufacturers and dealers. I will briefly review the foodstuff consumers segments in Hungary, which first have been identified using factor analysis followed by cluster analysis. I have identified the following consumer groups based on health consciousness: Conscious majority, Conscious by commitment, Economist “housewife”, Youthfully eclectic and Passives.

Human Development IX: A Model of the Wholeness of Man, His Consciousness, and Collective Consciousness

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Søren Ventegodt

2006-01-01

Full Text Available In this paper we look at the rational and the emotional interpretation of reality in the human brain and being, and discuss the representation of the brain-mind (ego, the body-mind (Id, and the outer world in the human wholeness (the I or “soul”. Based on this we discuss a number of factors including the coherence between perception, attention and consciousness, and the relation between thought, fantasies, visions and dreams. We discuss and explain concepts as intent, will, morals and ethics. The Jungian concept of the human collective conscious and unconscious is also analyzed. We also hypothesis on the nature of intuition and consider the source of religious experience of man. These phenomena are explained based on the concept of deep quantum chemistry and infinite dancing fractal spirals making up the energetic backbone of the world. In this paper we consider man as a real wholeness and debate the concepts of subjectivity, consciousness and intent that can be deduced from such a perspective.

How neuroscience will change our view on consciousness: discussion paper

NARCIS (Netherlands)

Lamme, V.A.F.

2010-01-01

Is there consciousness in machines? Or in animals? What happens to consciousness when we are asleep, or in vegetative state? These are just a few examples of the many questions about consciousness that are troubling scientists and laypersons alike. Moreover, these questions share a striking feature:

Association Analysis of Arg16Gly Polymorphism of the Beta2-adreneric Receptor Gene in Offspring from Hypertensive and Normotensive Families

Czech Academy of Sciences Publication Activity Database

Jindra, A.; Horký, K.; Peleška, Jan; Jáchymová, M.; Bultas, J.; Umnerová, V.; Heller, S.; Hlubocká, Z.

2002-01-01

Roč. 11, č. 4 (2002), s. 213-217 ISSN 0803-7051 R&D Projects: GA MZd NA5615 Keywords : Arg16Gly polymorphism of the beta2-adrenergic receptor gene * normotensive offspring * essential hypertension Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.344, year: 2002

Interactive communication and political consciousness

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Pikula Mykola Mykolayovych

2015-07-01

Full Text Available The article presents the research of the new communication technologies’ influence on the political consciousness formation. According to the author, today the Internet has become a kind of environment where people spend a lot of time and where the huge flow of information streams, unlimited with national borders and language barriers. This gives the Internet communication a mediating role in the display of the real world in people's minds. Such forms of interactive communication like social networks, blogs, forums and chats have a particularly important role in development of the society political consciousness.

Reading embodied consciousness in "Emma".

Science.gov (United States)

Harbus, Antonina

2011-01-01

The language of Emma (1815) reflects Jane Austen's developing view of embodied consciousness and her particular interest in this novel in the physical manifestations of emotions, such as blushes and nervous responses. The discursive exploration of the inner life in Emma is the product of a cultural context that features emerging brain science and Austen's own conceptualization of the psychophysical nature of emotions. This article analyzes the language of mind and emotion in Emma, to contend that Austen grapples with the implications of the idea of embodied consciousness in a narrative that contrasts mind reading with interpreting the body.

"Conscious Consumption": Ecocapitalism as Ideology

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Maria das Graças e Silva

2012-06-01

Full Text Available The purpose of this article is to raise a set of questions about “conscious consumption.” It is an essay of a bibliographic nature whose central thesis consists in affirming that in a capitalist society conscious consumption cannot be instituted as an affirmation of the principle of socioenvironmental sustainability. The paper presents the ideological nature of this formulation, which associates consumerism and the possibility of overcoming it only to the need for behavioral changes, without explaining its socioeconomic dimensions and its functionality as a mechanism for the reproduction of the destructive logic of capital.

An Heuristic Framework for Non-Conscious Reasoning

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Felipe Lara-Rosano

2017-11-01

Full Text Available Human non-conscious reasoning is one of the most successful procedures evolved for the purposes of solving everyday problems in an efficient way. This is why the field of artificial intelligence should analyze, formalize and emulate the multiple ways of non-conscious reasoning with the purpose of applying them in human problem solving tasks, like medical diagnostics and treatments, educational diagnostics and intervention, organizational and political decision making, artificial intelligence knowledge based systems and neurocomputers, automatic control systems and similar devices for aiding people in the problem-solving process. In this paper, a heuristic framework for those non-conscious ways of reasoning is presented based on neurocognitive representations, heuristics, and fuzzy sets.

Consciousness, accessibility, and the mesh between psychology and neuroscience.

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Block, Ned

2007-12-01

How can we disentangle the neural basis of phenomenal consciousness from the neural machinery of the cognitive access that underlies reports of phenomenal consciousness? We see the problem in stark form if we ask how we can tell whether representations inside a Fodorian module are phenomenally conscious. The methodology would seem straightforward: Find the neural natural kinds that are the basis of phenomenal consciousness in clear cases--when subjects are completely confident and we have no reason to doubt their authority--and look to see whether those neural natural kinds exist within Fodorian modules. But a puzzle arises: Do we include the machinery underlying reportability within the neural natural kinds of the clear cases? If the answer is "Yes," then there can be no phenomenally conscious representations in Fodorian modules. But how can we know if the answer is "Yes"? The suggested methodology requires an answer to the question it was supposed to answer! This target article argues for an abstract solution to the problem and exhibits a source of empirical data that is relevant, data that show that in a certain sense phenomenal consciousness overflows cognitive accessibility. I argue that we can find a neural realizer of this overflow if we assume that the neural basis of phenomenal consciousness does not include the neural basis of cognitive accessibility and that this assumption is justified (other things being equal) by the explanations it allows.

Neural correlates of processing "self-conscious" vs. "basic" emotions.

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Gilead, Michael; Katzir, Maayan; Eyal, Tal; Liberman, Nira

2016-01-29

Self-conscious emotions are prevalent in our daily lives and play an important role in both normal and pathological behavior. Despite their immense significance, the neural substrates that are involved in the processing of such emotions are surprisingly under-studied. In light of this, we conducted an fMRI study in which participants thought of various personal events which elicited feelings of negative and positive self-conscious (i.e., guilt, pride) or basic (i.e., anger, joy) emotions. We performed a conjunction analysis to investigate the neural correlates associated with processing events that are related to self-conscious vs. basic emotions, irrespective of valence. The results show that processing self-conscious emotions resulted in activation within frontal areas associated with self-processing and self-control, namely, the mPFC extending to the dACC, and within the lateral-dorsal prefrontal cortex. Processing basic emotions resulted in activation throughout relatively phylogenetically-ancient regions of the cortex, namely in visual and tactile processing areas and in the insular cortex. Furthermore, self-conscious emotions differentially activated the mPFC such that the negative self-conscious emotion (guilt) was associated with a more dorsal activation, and the positive self-conscious emotion (pride) was associated with a more ventral activation. We discuss how these results shed light on the nature of mental representations and neural systems involved in self-reflective and affective processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Abnormal corticospinal excitability in patients with disorders of consciousness.

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Lapitskaya, Natallia; Gosseries, Olivia; De Pasqua, Victor; Pedersen, Asger Roer; Nielsen, Joergen Feldbaek; de Noordhout, Alain Maertens; Laureys, Steven

2013-07-01

Transcranial magnetic stimulation (TMS) has been frequently used to explore changes in the human motor cortex in different conditions, while the extent of motor cortex reorganization in patients in vegetative state (VS) (now known as unresponsive wakefulness syndrome, UWS) and minimally conscious (MCS) states due to severe brain damage remains largely unknown. It was hypothesized that cortical motor excitability would be decreased and would correlate to the level of consciousness in patients with disorders of consciousness. Corticospinal excitability was assessed in 47 patients (24 VS/UWS and 23 MCS) and 14 healthy controls. The test parameters included maximal peak-to-peak M-wave (Mmax), F-wave persistence, peripheral and central motor conduction times, sensory (SEP) and motor evoked (MEP) potential latencies and amplitudes, resting motor threshold (RMT), stimulus/response curves, and short latency afferent inhibition (SAI). TMS measurements were correlated to the level of consciousness (assessed using the Coma Recovery Scale-Revised). On average, the patient group had lower Mmax, lower MEP and SEP amplitudes, higher RMTs, narrower stimulus/response curves, and reduced SAI compared to the healthy controls (P < 0.05). The SAI alterations were correlated to the level of consciousness (P < 0.05). The findings demonstrated the impairment of the cortical inhibitory circuits in patients with disorders of consciousness. Moreover, the significant relationship was found between cortical inhibition and clinical consciousness dysfunction. Copyright © 2013 Elsevier Inc. All rights reserved.

Cardiovascular and behavioral effects produced by administration of liposome-entrapped GABA into the rat central nervous system.

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Vaz, G C; Bahia, A P C O; de Figueiredo Müller-Ribeiro, F C; Xavier, C H; Patel, K P; Santos, R A S; Moreira, F A; Frézard, F; Fontes, M A P

2015-01-29

Liposomes are nanosystems that allow a sustained release of entrapped substances. Gamma-aminobutyric acid (GABA) is the most prevalent inhibitory neurotransmitter of the central nervous system (CNS). We developed a liposomal formulation of GABA for application in long-term CNS functional studies. Two days after liposome-entrapped GABA was injected intracerebroventricularly (ICV), Wistar rats were submitted to the following evaluations: (1) changes in mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) to ICV injection of bicuculline methiodide (BMI) in anesthetized rats; (2) changes in cardiovascular reactivity to air jet stress in conscious rats; and (3) anxiety-like behavior in conscious rats. GABA and saline-containing pegylated liposomes were prepared with a mean diameter of 200 nm. Rats with implanted cannulas targeted to lateral cerebral ventricle (n = 5-8/group) received either GABA solution (GS), empty liposomes (EL) or GABA-containing liposomes (GL). Following (48 h) central microinjection (2 μL, 0.09 M and 99 g/L) of liposomes, animals were submitted to the different protocols. Animals that received GL demonstrated attenuated response of RSNA to BMI microinjection (GS 48 ± 9, EL 43 ± 9, GL 11 ± 8%; P nervous system. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Effect of exercise training on Ca2+ release units of left ventricular myocytes of spontaneously hypertensive rats.

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Carneiro-Júnior, M A; Quintão-Júnior, J F; Drummond, L R; Lavorato, V N; Drummond, F R; Amadeu, M A; Oliveira, E M; Felix, L B; Cruz, J S; Mill, J G; Natali, A J; Prímola-Gomes, T N

2014-08-29

In cardiomyocytes, calcium (Ca2+) release units comprise clusters of intracellular Ca2+ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca2+ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca2+ sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s) and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ΔF/F0), full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm), total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms), time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms), and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms). These changes were partially reversed in HT rats (frequency of Ca2+ sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ΔF/F0, full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

Effect of exercise training on Ca2+ release units of left ventricular myocytes of spontaneously hypertensive rats

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M.A. Carneiro-Júnior

2014-11-01

Full Text Available In cardiomyocytes, calcium (Ca2+ release units comprise clusters of intracellular Ca2+ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca2+ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age were divided into 4 groups: normotensive (NC and hypertensive control (HC, and normotensive (NT and hypertensive trained (HT animals (7 rats per group. NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2 and FK506 binding protein (FKBP12.6 increased (270% and decreased (88%, respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230% and normalizing FKBP12.6 gene expression (112%. Hypertension also increased the frequency of Ca2+ sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ΔF/F0, full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm, total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms, time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms, and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms. These changes were partially reversed in HT rats (frequency of Ca2+ sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ΔF/F0, full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms. Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes.

Effect of exercise training on Ca2+ release units of left ventricular myocytes of spontaneously hypertensive rats

International Nuclear Information System (INIS)

Carneiro-Júnior, M.A.; Quintão-Júnior, J.F.; Drummond, L.R.; Lavorato, V.N.; Drummond, F.R.; Amadeu, M.A.; Oliveira, E.M.; Felix, L.B.; Cruz, J.S.; Mill, J.G.; Natali, A.J.; Prímola-Gomes, T.N.

2014-01-01

In cardiomyocytes, calcium (Ca 2+ ) release units comprise clusters of intracellular Ca 2+ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca 2+ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca 2+ sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s) and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ΔF/F 0 ), full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm), total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms), time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms), and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms). These changes were partially reversed in HT rats (frequency of Ca 2+ sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ΔF/F 0 , full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of left ventricular myocytes

Acute hypotensive and diuretic activities of Berberis vulgaris root bark aqueous extract in normal rats

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Muhammad Ahmed

2018-03-01

Full Text Available ABSTRACT The aim of this study is to investigate the effectiveness of intravenous administration of Berberis vulgaris root bark aqueous extract (BRBD on the cardiovascular and renal functions of healthy normotensive rats. The different doses of BRBD 1, 10 and 20 mg/kg were administered intravenously (i.v in normal rats. Blood pressure, diuretic activity and serum renal profile were analyzed. Intravenous injection of BRBD at the different doses of 1, 10 and 20 mg/kg showed a dose-dependent reduction in mean arterial blood pressure (P<0.001. At different doses of 1, 10 and 20 mg/kg, the hypotensive effect remained for more than one hour. Single dose administration of BRBD at doses of 10 and 20 mg/kg caused a significant increase in urine output (P<0.001 as compared to the control rats. Serum renal profile test (albumin, Urea, Uric Acid, creatinine and BUN did not show any significant alteration. The authors conclude that the BRBD is a potent hypotensive and possesses diuretic potential

Analysis of Mental Processes Represented in Models of Artificial Consciousness

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Luana Folchini da Costa

2013-12-01

Full Text Available The Artificial Consciousness concept has been used in the engineering area as being an evolution of the Artificial Intelligence. However, consciousness is a complex subject and often used without formalism. As a main contribution, in this work one proposes an analysis of four recent models of artificial consciousness published in the engineering area. The mental processes represented by these models are highlighted and correlations with the theoretical perspective of cognitive psychology are made. Finally, considerations about consciousness in such models are discussed.

Using brain stimulation to disentangle neural correlates of conscious vision.

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de Graaf, Tom A; Sack, Alexander T

2014-01-01

Research into the neural correlates of consciousness (NCCs) has blossomed, due to the advent of new and increasingly sophisticated brain research tools. Neuroimaging has uncovered a variety of brain processes that relate to conscious perception, obtained in a range of experimental paradigms. But methods such as functional magnetic resonance imaging or electroencephalography do not always afford inference on the functional role these brain processes play in conscious vision. Such empirical NCCs could reflect neural prerequisites, neural consequences, or neural substrates of a conscious experience. Here, we take a closer look at the use of non-invasive brain stimulation (NIBS) techniques in this context. We discuss and review how NIBS methodology can enlighten our understanding of brain mechanisms underlying conscious vision by disentangling the empirical NCCs.

Volitional components of consciousness vary across wakefulness, dreaming and lucid dreaming

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Martin eDresler

2014-01-01

Full Text Available Consciousness is a multifaceted concept; its different aspects vary across species, vigilance states or health conditions. While basal aspects of consciousness like perceptions and emotions are present in many states and species, higher-order aspects like reflective or volitional capabilities seem to be most pronounced in awake humans. Here we assess the experience of volition across different states of consciousness: 10 frequent lucid dreamers rated different aspects of volition according to the Volitional Components Questionnaire for phases of normal dreaming, lucid dreaming and wakefulness. Overall, experienced volition was comparable for lucid dreaming and wakefulness, and rated significantly higher for both states compared to non-lucid dreaming. However, three subscales showed specific differences across states of consciousness: planning ability was most pronounced during wakefulness, intention enactment most pronounced during lucid dreaming, and self-determination most pronounced during both wakefulness and lucid dreaming. Our data confirm the multifaceted nature of consciousness: different higher-order aspects of consciousness are differentially expressed across different conscious states.

Volitional components of consciousness vary across wakefulness, dreaming and lucid dreaming.

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Dresler, Martin; Eibl, Leandra; Fischer, Christian F J; Wehrle, Renate; Spoormaker, Victor I; Steiger, Axel; Czisch, Michael; Pawlowski, Marcel

2014-01-01

Consciousness is a multifaceted concept; its different aspects vary across species, vigilance states, or health conditions. While basal aspects of consciousness like perceptions and emotions are present in many states and species, higher-order aspects like reflective or volitional capabilities seem to be most pronounced in awake humans. Here we assess the experience of volition across different states of consciousness: 10 frequent lucid dreamers rated different aspects of volition according to the Volitional Components Questionnaire for phases of normal dreaming, lucid dreaming, and wakefulness. Overall, experienced volition was comparable for lucid dreaming and wakefulness, and rated significantly higher for both states compared to non-lucid dreaming. However, three subscales showed specific differences across states of consciousness: planning ability was most pronounced during wakefulness, intention enactment most pronounced during lucid dreaming, and self-determination most pronounced during both wakefulness and lucid dreaming. Our data confirm the multifaceted nature of consciousness: different higher-order aspects of consciousness are differentially expressed across different conscious states.

Subliminal unconscious conflict alpha power inhibits supraliminal conscious symptom experience.

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Shevrin, Howard; Snodgrass, Michael; Brakel, Linda A W; Kushwaha, Ramesh; Kalaida, Natalia L; Bazan, Ariane

2013-01-01

Our approach is based on a tri-partite method of integrating psychodynamic hypotheses, cognitive subliminal processes, and psychophysiological alpha power measures. We present ten social phobic subjects with three individually selected groups of words representing unconscious conflict, conscious symptom experience, and Osgood Semantic negative valence words used as a control word group. The unconscious conflict and conscious symptom words, presented subliminally and supraliminally, act as primes preceding the conscious symptom and control words presented as supraliminal targets. With alpha power as a marker of inhibitory brain activity, we show that unconscious conflict primes, only when presented subliminally, have a unique inhibitory effect on conscious symptom targets. This effect is absent when the unconscious conflict primes are presented supraliminally, or when the target is the control words. Unconscious conflict prime effects were found to correlate with a measure of repressiveness in a similar previous study (Shevrin et al., 1992, 1996). Conscious symptom primes have no inhibitory effect when presented subliminally. Inhibitory effects with conscious symptom primes are present, but only when the primes are supraliminal, and they did not correlate with repressiveness in a previous study (Shevrin et al., 1992, 1996). We conclude that while the inhibition following supraliminal conscious symptom primes is due to conscious threat bias, the inhibition following subliminal unconscious conflict primes provides a neurological blueprint for dynamic repression: it is only activated subliminally by an individual's unconscious conflict and has an inhibitory effect specific only to the conscious symptom. These novel findings constitute neuroscientific evidence for the psychoanalytic concepts of unconscious conflict and repression, while extending neuroscience theory and methods into the realm of personal, psychological meaning.

Subliminal unconscious conflict alpha power inhibits supraliminal conscious symptom experience

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Howard eShevrin

2013-09-01

Full Text Available Our approach is based on a tri-partite method of integrating psychodynamic hypotheses, cognitive subliminal processes, and psychophysiological alpha power measures. We present ten social phobic subjects with three individually selected groups of words representing unconscious conflict, conscious symptom experience, and Osgood Semantic negative valence words used as a control word group. The unconscious conflict and conscious symptom words, presented subliminally and supraliminally, act as primes preceding the conscious symptom and control words presented as supraliminal targets. With alpha power as a marker of inhibitory brain activity, we show that unconscious conflict primes, only when presented subliminally, have a unique inhibitory effect on conscious symptom targets. This effect is absent when the unconscious conflict primes are presented supraliminally, or when the target is the control words. Unconscious conflict prime effects were found to correlate with a measure of repressiveness in a similar previous study (Shevrin et al., 1992, 1996. Conscious symptom primes have no inhibitory effect when presented subliminally. Inhibitory effects with conscious symptom primes are present, but only when the primes are supraliminal, and they did not correlate with repressiveness in a previous study (Shevrin, et al., 1992, 1996. We conclude that while the inhibition following supraliminal conscious symptom primes is due to conscious threat bias, the inhibition following subliminal unconscious conflict primes provides a neurological blueprint for dynamic repression: it is only activated subliminally by an individual’s unconscious conflict and has an inhibitory effect specific only to the conscious symptom. These novel findings constitute neuroscientific evidence for the psychoanalytic concepts of unconscious conflict and repression, while extending neuroscience theory and methods into the realm of personal, psychological meaning.

Multilocus analyses of renin-angiotensin-aldosterone system gene variants on blood pressure at rest and during behavioral stress in young normotensive subjects

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Ge, Dongliang; Zhu, Haidong; Huang, Ying; Treiber, Frank A.; Harshfield, Gregory A.; Snieder, Harold; Dong, Yanbin

The renin-angiotensin-aldosterone system (RAAS) is a proteolytic cascade that regulates and maintains blood pressure (BP). This study aimed to explore the interactive and integrative effects of multiple RAAS polymorphisms on BP at rest and during behavioral stress in a normotensive population. A

Dreams and the temporality of consciousness.

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MacDuffie, Katherine; Mashour, George A

2010-01-01

Understanding dreams has long been considered fundamental to the development of a theory of consciousness. Evidence from neurobiology and neuroimaging research has paved the way for new theories of dreaming that are empirically supported. In this article we argue that dreaming is a unique state of consciousness that incorporates 3 temporal dimensions: experience of the present, processing of the past, and preparation for the future. The temporal complexity of dreams is made possible in part by the unique neurobiological environment of sleep, in which stimuli are internally generated and many of the restrictions associated with waking thought are absent. Because dream consciousness is not determined by sensory stimuli, a flexible integration of past experiences and the forging of novel connections are possible. We argue that disparate dream theories may not be mutually exclusive but rather relate to different temporal domains of the dream state.

Patterns of gene expression associated with recovery and injury in heat-stressed rats

OpenAIRE

Stallings, Jonathan D; Ippolito, Danielle L; Rakesh, Vineet; Baer, Christine E; Dennis, William E; Helwig, Bryan G; Jackson, David A; Leon, Lisa R; Lewis, John A; Reifman, Jaques

2014-01-01

Background The in vivo gene response associated with hyperthermia is poorly understood. Here, we perform a global, multiorgan characterization of the gene response to heat stress using an in vivo conscious rat model. Results We heated rats until implanted thermal probes indicated a maximal core temperature of 41.8?C (Tc,Max). We then compared transcriptomic profiles of liver, lung, kidney, and heart tissues harvested from groups of experimental animals at Tc,Max, 24 hours, and 48 hours after ...

Construction and Validation of the Self-Conscious Emotions at Work Scale

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Hans Groenvynck

2011-11-01

Full Text Available The present study reports on the construction and validation of a new assessment instrument for self-conscious emotions in the work context, namely the Self-Conscious Emotions at Work Scale (SCEWS. In eight typical self-conscious work scenarios respondents have to indicate their emotional reaction in terms of 20 appraisals, subjective experiences, and action tendencies that are relevant and representative for the domain of self-conscious emotions. In total 512 students and 467 working adults completed the SCEWS and reported the frequency of positive emotions, anger, anxiety and sadness. In both samples a three-factorial structure emerged with a guilt, a shame/humiliation, and an anger in self-conscious situations factor. These three self-conscious emotion factors correlated differentially and in a predicted way with the frequency of emotions. Guilt-proneness was predicted to be psychologically constructive and correlated to the frequency of positive emotions. The proneness to shame/humiliation was expected to relate to internalising psychopathological tendencies, and positively correlated to a frequency of anxiety and sadness. Proneness to anger in self-conscious situations was expected to relate to externalising psychopathological tendencies and correlated with the frequency of anger in general. The present study demonstrates that self-conscious emotions can be validly measured in the work context. The new instrument allows for the systematic study of the role of self-conscious emotions in work and organisational behaviour.

Transcriptional alterations in the left ventricle of three hypertensive rat models.

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Cerutti, Catherine; Kurdi, Mazen; Bricca, Giampiero; Hodroj, Wassim; Paultre, Christian; Randon, Jacques; Gustin, Marie-Paule

2006-11-27

Left ventricular hypertrophy (LVH) is commonly associated with hypertension and represents an independent cardiovascular risk factor. The aim of this study was to test the hypothesis that the cardiac overload related to hypertension is associated to a specific gene expression pattern independently of genetic background. Gene expression levels were obtained with microarrays for 15,866 transcripts from RNA of left ventricles from 12-wk-old rats of three hypertensive models [spontaneously hypertensive rat (SHR), Lyon hypertensive rat (LH), and heterozygous TGR(mRen2)27 rat] and their respective controls. More than 60% of the detected transcripts displayed significant changes between the three groups of normotensive rats, showing large interstrain variability. Expression data were analyzed with respect to hypertension, LVH, and chromosomal distribution. Only four genes had significantly modified expression in the three hypertensive models among which a single gene, coding for sialyltransferase 7A, was consistently overexpressed. Correlation analysis between expression data and left ventricular mass index (LVMI) over all rats identified a larger set of genes whose expression was continuously related with LVMI, including known genes associated with cardiac remodeling. Positioning the detected transcripts along the chromosomes pointed out high-density regions mostly located within blood pressure and cardiac mass quantitative trait loci. Although our study could not detect a unique reprogramming of cardiac cells involving specific genes at early stage of LVH, it allowed the identification of some genes associated with LVH regardless of genetic background. This study thus provides a set of potentially important genes contained within restricted chromosomal regions involved in cardiovascular diseases.

Cardiac remodeling and myocardial dysfunction in obese spontaneously hypertensive rats

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Linz Dominik

2012-09-01

Full Text Available Abstract Background The additive effects of obesity and metabolic syndrome on left ventricular (LV maladaptive remodeling and function in hypertension are not characterized. Methods We compared an obese spontaneously hypertensive rat model (SHR-ob with lean spontaneously hypertensive rats (SHR-lean and normotensive controls (Ctr. LV-function was investigated by cardiac magnetic resonance imaging and invasive LV-pressure measurements. LV-interstitial fibrosis was quantified and protein levels of phospholamban (PLB, Serca2a and glucose transporters (GLUT1 and GLUT4 were determined by immunohistochemistry. Results Systolic blood pressure was similar in SHR-lean and SHR-ob (252 ± 7 vs. 242 ± 7 mmHg, p = 0.398 but was higher when compared to Ctr (155 ± 2 mmHg, p  Conclusion In addition to hypertension alone, metabolic syndrome and obesity adds to the myocardial phenotype by aggravating diastolic dysfunction and a progression towards systolic dysfunction. SHR-ob may be a useful model to develop new interventional and pharmacological treatment strategies for hypertensive heart disease and metabolic disorders.

Edmund Husserl’s Transcendence of the Early Buddhist Theory of Consciousness

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Saman Pushpakumara

2014-03-01

Full Text Available Edmund Husserl, the founding father of western philosophical movement known as phenomenology, formulated a theory of consciousness writing Logical Investigations (1900. The Gautama the Buddha, as far back as the 6th century B.C., had provided an analysis of the conscious phenomena. Many scholars who trace parallels between the Buddhist view of consciousness and Husserl’s phenomenology of the structures of consciousness deal mostly with the similarities between the two, and such a comparison could also be regarded as a worthwhile contribution to the field of comparative philosophy.This paper argues that Husserl's analysis of consciousness, despite its limitations, as elaborated by Derrida, (and also by Heidegger, is more advanced than the Buddha's formulation. Husserl articulated his phenomenology of consciousness as a result of his encounter with Cartesian cogito, (or the Cartesian psychology on the one hand and the positivistic foundation of empirical sciences on the other. Husserl’s notion of phenomenological consciousness was situated within an industrially advanced capitalist society and nurtured by scientific epistemology, despite his criticism of its underlying positivism, which set the basis for his philosophy of internal consciousness. He lived in a controversial era, the rise of National Socialism in Germany, which has to be taken seriously when assessing his philosophy of consciousness.  The Buddha, in contrast, theorized his notion of consciousness within a backward, slow-moving, agricultural and feudal setting .He developed his notion of consciousness as a normative concept as a basis for achieving the spiritual objective he envisaged. While acknowledging the fact that no other philosophy that existed during the Buddha’s time had articulated such a meticulous and in depth analysis of the phenomenology of consciousness, his analysis seems to be less advanced when assessed and compared with the twentieth century phenomenology of

Maintenance of non-consciously presented information engages the prefrontal cortex

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Fredrik eBergström

2014-11-01

Full Text Available Conscious processing is generally seen as required for flexible and willful actions, as well as for tasks that require durable information maintenance. Here we present research that questions the assumption that only consciously perceived information is durable (> 500 ms. Using the attentional blink phenomenon, we rendered otherwise relatively clearly perceived letters non-conscious. In a first experiment we systematically manipulated the delay between stimulus presentation and response, for the purpose of estimating the durability of non-conscious perceptual representations. For items reported not seen, we found that behavioral performance was better than chance across intervals up to 15 seconds. In a second experiment we used fMRI to investigate the neural correlates underlying the maintenance of non-conscious perceptual representations. Critically, the relatively long delay period demonstrated in experiment 1 enabled isolation of the signal change specifically related to the maintenance period, separate from stimulus presentation and response. We found sustained BOLD signal change in the right mid-lateral prefrontal cortex, orbitofrontal cortex, and crus II of the cerebellum during maintenance of non-consciously perceived information. These findings are consistent with the controversial claim that working-memory mechanisms are involved in the short-term maintenance of non-conscious perceptual representations.

Insights on consciousness from taste memory research.

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Gallo, Milagros

2016-01-01

Taste research in rodents supports the relevance of memory in order to determine the content of consciousness by modifying both taste perception and later action. Associated with this issue is the fact that taste and visual modalities share anatomical circuits traditionally related to conscious memory. This challenges the view of taste memory as a type of non-declarative unconscious memory.

No-Report Paradigms: Extracting the True Neural Correlates of Consciousness.

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Tsuchiya, Naotsugu; Wilke, Melanie; Frässle, Stefan; Lamme, Victor A F

2015-12-01

The goal of consciousness research is to reveal the neural basis of phenomenal experience. To study phenomenology, experimenters seem obliged to ask reports from the subjects to ascertain what they experience. However, we argue that the requirement of reports has biased the search for the neural correlates of consciousness over the past decades. More recent studies attempt to dissociate neural activity that gives rise to consciousness from the activity that enables the report; in particular, no-report paradigms have been utilized to study conscious experience in the full absence of any report. We discuss the advantages and disadvantages of report-based and no-report paradigms, and ask how these jointly bring us closer to understanding the true neural basis of consciousness. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

The Effects of Methylphenidate on Goal-Directed Behavior in a Rat Model of ADHD

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Joman Y. Natsheh

2015-11-01

Full Text Available Although attentional and motor alterations in Attention Deficit Hyperactivity Disorder (ADHD have been well characterized, less is known about how this disorder impacts goal-directed behavior. To investigate whether there is a misbalance between goal-directed and habitual behaviors in an animal model of ADHD, we tested adult [P75-P105] Spontaneously Hypertensive Rats (SHR (ADHD rat model and Wistar-Kyoto rats (WKY, the normotensive control strain, on an instrumental conditioning paradigm with two phases: a free-operant training phase in which rats separately acquired two distinct action-outcome contingencies, and a choice test conducted in extinction prior to which one of the food outcomes was devalued through specific satiety. To assess the effects of Methylphenidate, a commonly used ADHD medication, on goal-directed behavior, we injected rats with either Methylphenidate or saline prior to the choice test. Both rat strains acquired an instrumental response, with SHR responding at greater rates over the course of training. During the choice test WKY demonstrated goal-directed behavior, responding more frequently on the lever that delivered, during training, the still-valued outcome. In contrast, SHR showed no goal-directed behavior, responding equally on both levers. However, methylphenidate administration prior to the choice test restored goal-directed behavior in SHR, and disrupted this behavior in WKY rats. This study provides the first experimental evidence for selective impairment in goal-directed behavior in rat models of ADHD, and how methylphenidate acts differently on SHR and WKY animals to restore or impair this behavior, respectively.

A theory of working memory without consciousness or sustained activity

Science.gov (United States)

Trübutschek, Darinka; Marti, Sébastien; Ojeda, Andrés; King, Jean-Rémi; Mi, Yuanyuan; Tsodyks, Misha; Dehaene, Stanislas

2017-01-01

Working memory and conscious perception are thought to share similar brain mechanisms, yet recent reports of non-conscious working memory challenge this view. Combining visual masking with magnetoencephalography, we investigate the reality of non-conscious working memory and dissect its neural mechanisms. In a spatial delayed-response task, participants reported the location of a subjectively unseen target above chance-level after several seconds. Conscious perception and conscious working memory were characterized by similar signatures: a sustained desynchronization in the alpha/beta band over frontal cortex, and a decodable representation of target location in posterior sensors. During non-conscious working memory, such activity vanished. Our findings contradict models that identify working memory with sustained neural firing, but are compatible with recent proposals of ‘activity-silent’ working memory. We present a theoretical framework and simulations showing how slowly decaying synaptic changes allow cell assemblies to go dormant during the delay, yet be retrieved above chance-level after several seconds. DOI: http://dx.doi.org/10.7554/eLife.23871.001 PMID:28718763

Effect of exercise training on Ca{sup 2+} release units of left ventricular myocytes of spontaneously hypertensive rats

Energy Technology Data Exchange (ETDEWEB)

Carneiro-Júnior, M.A. [Universidade Federal do Espírito Santo, Departamento de Ciências Fisiológicas, Vitória, ES (Brazil); Universidade Federal de Viçosa, Laboratório de Biologia do Exercício, Departamento de Educação Física, Viçosa, MG (Brazil); Quintão-Júnior, J.F.; Drummond, L.R.; Lavorato, V.N.; Drummond, F.R. [Universidade Federal de Viçosa, Laboratório de Biologia do Exercício, Departamento de Educação Física, Viçosa, MG (Brazil); Amadeu, M.A.; Oliveira, E.M. [Universidade de São Paulo, Laboratório de Bioquímica e Biologia Molecular do Exercício, Escola de Educação Física e Esportes, São Paulo, SP (Brazil); Felix, L.B. [Universidade Federal de Viçosa, Departamento de Engenharia Elétrica, Viçosa, MG (Brazil); Cruz, J.S. [Universidade Federal de Minas Gerais, Laboratório de Membranas Excitáveis e Biologia Cardiovascular, Departamento de Bioquímica e Imunologia, Belo Horizonte, MG (Brazil); Mill, J.G. [Universidade Federal do Espírito Santo, Departamento de Ciências Fisiológicas, Vitória, ES (Brazil); Natali, A.J.; Prímola-Gomes, T.N. [Universidade Federal de Viçosa, Laboratório de Biologia do Exercício, Departamento de Educação Física, Viçosa, MG (Brazil)

2014-08-29

In cardiomyocytes, calcium (Ca{sup 2+}) release units comprise clusters of intracellular Ca{sup 2+} release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca{sup 2+} sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca{sup 2+} sparks (HC=7.61±0.26 vs NC=4.79±0.19 per 100 µm/s) and decreased its amplitude (HC=0.260±0.08 vs NC=0.324±0.10 ΔF/F{sub 0}), full width at half-maximum amplitude (HC=1.05±0.08 vs NC=1.26±0.01 µm), total duration (HC=11.51±0.12 vs NC=14.97±0.24 ms), time to peak (HC=4.84±0.06 vs NC=6.31±0.14 ms), and time constant of decay (HC=8.68±0.12 vs NC=10.21±0.22 ms). These changes were partially reversed in HT rats (frequency of Ca{sup 2+} sparks=6.26±0.19 µm/s, amplitude=0.282±0.10 ΔF/F{sub 0}, full width at half-maximum amplitude=1.14±0.01 µm, total duration=13.34±0.17 ms, time to peak=5.43±0.08 ms, and time constant of decay=9.43±0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release units of

Creative Consciousness

OpenAIRE

Ashok Natarajan

2013-01-01

Consciousness is creative. That creativity expresses in myriad ways – as moments in time in which decades of progress can be achieved overnight, as organizational innovations of immense power for social accomplishment; as creative social values that further influence the evolution of organizations and society; as the creativity of individuality in the leader, genius, artist and inventor; as social creativity that converts raw human experience into civilization; as cultural creativity that tra...

Effect of atropine or atenolol on cardiovascular responses to novelty stress in freely-moving rats.

Science.gov (United States)

van den Buuse, Maarten

2002-09-01

Cardiac hemodynamic mechanisms involved in cardiovascular responses to stress were studied in conscious, freely-moving female spontaneously hypertensive rats exposed for 15 min to an open-field. When pretreated with saline, the rats displayed a rapid rise in blood pressure, heart rate, aortic dP/dt and locomotor activity. In rats pretreated with 0.5 mg/kg of methylatropine, the tachycardia was slightly, but significantly reduced. In rats pretreated with 1 mg/kg of atenolol, the tachycardis and rise in dP/dt were markedly reduced. These data suggest that the cardiac responses to stress include predominantly cardiac sympathetic activation and a minor component of vagal withdrawal.

Cardiovascular effects of Helichrysum ceres S Moore [Asteraceae] ethanolic leaf extract in some experimental animal paradigms.

Science.gov (United States)

Musabayane, Cephas T; Kamadyaapa, Dave R; Gondwe, Mavuto; Moodley, Kogi; Ojewole, John A O

2008-01-01

The aim of this study was to examine some in vivo and in vitro cardiovascular effects of Helichrysum ceres leaf ethanolic extract (HCE) in experimental animal paradigms. The acute effects of HCE on blood pressure were studied in anaesthetised normotensive male Wistar rats challenged with intravenous hypotonic saline infusion after a 3.5-hour equilibration for four hours of one-hour control, 1.5-hour treatment and 1.5-hour recovery periods. HCE was added to the infusate during the treatment period. Sub-chronic hypotensive effects of HCE were examined in weanling Dahl saltsensitive (DSS) genetically hypertensive rats, which progressively develop hypertension with age, treated with HCE (80 mg/kg) every third consecutive day for seven weeks. Isolated atrial muscle strips, portal veins and descending thoracic aortic rings of healthy normotensive Wistar rats were used to investigate the vascular effects of HCE. Acute HCE administration caused a significant (p < 0.05) fall in blood pressure in the normotensive anaesthetised Wistar rats. DSS hypertensive rats treated with HCE displayed low arterial blood pressure and heart rate values from weeks five to seven. HCE produced concentrationdependent negative inotropic and chronotropic effects on rat isolated electrically driven left, and spontaneously beating right atrial muscle preparations, respectively. HCE also evoked concentration-dependent relaxation responses of endothelium-intact aortic rings and portal veins isolated from healthy normotensive Wistar rats. The vasorelaxant effects of HCE in intact aortic rings were significantly reduced, but not completely abolished by adding endothelial- derived factor (EDRF) inhibitor, L-NAME, suggesting that the vasorelaxant effect of the extract is mediated via EDRF-dependent and independent mechanisms. The results of the study suggest that the hypotensive action of HCE is elicited, in part, directly by decreasing myocardial contractile performance and total peripheral vascular

The Role of Gender Consciousness in Challenging Patriarchy.

Science.gov (United States)

Bierema, Laura L.

2003-01-01

In an action research project, eight women explored their development of gender consciousness, finding that a hidden curriculum taught subordination to the patriarchal system. Connected learning fostered gender consciousness and led to connected action. Action included teaching others about gender issues, making the invisible visible, and adopting…

THE MANIFESTATIONS OF THE POLITICAL CONSCIOUSNESS BETWEEN PHYSICAL EDUCATION TEACHERS

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Guilherme Gil da Silva

2011-02-01

Full Text Available This text address the phenomenon of consciousness of individuals, performing a brief overview of the key elements to understand the process of political consciousness of Physical Education teachers. This is a larger study, which analyzes how is the teachers formation and political engagement, and in the limits of this article, we present the elements for the understanding of expressions of their political consciousness. It seeks to recover the "movement" of consciousness, since it believes that this is not something given and gravel, which can be seen without relating it to their development process, embedded in the history of its formation.

Understanding visual consciousness in autism spectrum disorders.

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Yatziv, Tal; Jacobson, Hilla

2015-01-01

The paper focuses on the question of what the (visual) perceptual differences are between individuals with autism spectrum disorders (ASD) and typically developing (TD) individuals. We argue against the view that autistic subjects have a deficiency in the most basic form of perceptual consciousness-namely, phenomenal consciousness. Instead, we maintain, the perceptual atypicality of individuals with autism is of a more conceptual and cognitive sort-their perceptual experiences share crucial aspects with TD individuals. Our starting point is Ben Shalom's (2005, 2009) three-level processing framework for explaining atypicality in several domains of processing among autistics, which we compare with two other tripartite models of perception-Jackendoff's (1987) and Prinz's (2000, 2005a, 2007) Intermediate Level Hypothesis and Lamme's (2004, 2006, 2010) neural account of consciousness. According to these models, whereas the second level of processing is concerned with viewer-centered visual representations of basic visual properties and incorporates some early forms of integration, the third level is more cognitive and conceptual. We argue that the data suggest that the atypicality in autism is restricted mainly to the third level. More specifically, second-level integration, which is the mark of phenomenal consciousness, is typical, yet third-level integration of perceptual objects and concepts is atypical. Thus, the basic experiences of individuals with autism are likely to be similar to typical subjects' experiences; the main difference lies in the sort of cognitive access the subjects have to their experiences. We conclude by discussing implications of the suggested analysis of experience in autism for conceptions of phenomenal consciousness.

Environmental Consciousness in Daily Activities Measured by Negative Prompts

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Ai Hiramatsu

2015-12-01

Full Text Available The gap between people’s attitude and action as regards environmental issues has been pointed out even while surveys registered an increase in people’s environmental awareness. Among the possible reasons is that people tend to automatically answer “yes”, as most surveys on environmental consciousness use positively-phrased questions or prompts. To remove the “yes-bias” in previous surveys, this present study conducted in Japan a large-scale questionnaire survey on environmental consciousness using negative prompts and free-answered prompts on which behaviors people feel good/bad/uncertain for the environment. This study also investigated peoples’ psychological factors and concrete pro-environmental behaviors (PEBs in daily life. The results of the questionnaire with negative prompts showed that the rate of people’s consciousness to the environment was lower compared with other surveys. Through factor analysis, five psychological factors were extracted as the explanatory factors of environmental attitude. Demographic effects on the consciousness and PEBs were also observed. Comparison of free-answers on concrete daily behaviors among five different environmentally conscious groups showed there were certain phases in the perception of PEBs based on consciousness level. Similar common behaviors were highly ranked as both PEB and doubtful behaviors, indicating that people were worried about actions that involve a trade-off relationship from diversified standpoints.

Decapitation in rats: latency to unconsciousness and the 'wave of death'.

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Clementina M van Rijn

Full Text Available The question whether decapitation is a humane method of euthanasia in awake animals is being debated. To gather arguments in this debate, obsolete rats were decapitated while recording the EEG, both of awake rats and of anesthetized rats. Following decapitation a fast and global loss of power of the EEG was observed; the power in the 13-100 Hz frequency band, expressing cognitive activity, decreased according to an exponential decay function to half the initial value within 4 seconds. Whereas the pre-decapitation EEG of the anesthetized animals showed a burst suppression pattern quite different from the awake animals, the power in the postdecapitation EEG did not differ between the two groups. This might indicate that either the power of the EEG does not correlate well with consciousness or that consciousness is briefly regained in the anesthetized group after decapitation. Remarkably, after 50 seconds (awake group or 80 seconds (anesthetized group following decapitation, a high amplitude slow wave was observed. The EEG before this wave had more power than the signal after the wave. This wave might be due to a simultaneous massive loss of membrane potentials of the neurons. Still functioning ion channels, which keep the membrane potential intact before the wave, might explain the observed power difference. Two conclusions were drawn from this experiment. It is likely that consciousness vanishes within seconds after decapitation, implying that decapitation is a quick and not an inhumane method of euthanasia. It seems that the massive wave which can be recorded approximately one minute after decapitation reflects the ultimate border between life and death. This observation might have implications in the discussions on the appropriate time for organ donation.

Different Signal Enhancement Pathways of Attention and Consciousness Underlie Perception in Humans.

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van Boxtel, Jeroen J A

2017-06-14

It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms. SIGNIFICANCE STATEMENT The relationship between attention and consciousness is still debated. Mapping contrast response functions (CRFs) has allowed (neuro)scientists to gain important insights into the mechanistic underpinnings of visual processing. Here, the influence of both attention and consciousness on these functions were measured and they displayed a strong dissociation. First, attention lowered CRFs, whereas consciousness raised them. Second, attention manifests itself as a response-gain function, whereas consciousness manifests itself as a contrast-gain function. Extensive model comparisons show that these results are best explained in a two-level normalization model in which consciousness affects only the first level, whereas attention affects only the second level

Consciousness, Cognition and the Cognitive Apparatus in the Vedānta Tradition

Science.gov (United States)

Balasubramanian, R.

2011-01-01

A human being is a complex entity consisting of the Self (also known as Consciousness), mind, senses and the body. The Vedānta tradition holds that the mind, the senses and the body are essentially different from the Self or Consciousness. It is through consciousness that we are able to know the things of the world, making use of the medium of the mind and the senses. Furthermore, the mind, though material, is able to reveal things, borrowing the light from consciousness. From the phenomenological point of view, we have to answer the following questions: how does one know the mind/the mental operations/the cogitations of the mind? Does the mind know itself? Is it possible? There is, again, the problem of the intentionality of consciousness. Is consciousness intentional? According to Vedānta, consciousness by its very nature is not intentional, but it becomes intentional through the mind. The mind or the ego is not part of the consciousness; on the contrary, it is transcendent to consciousness. It is difficult to spell out the relation between consciousness and the mind. How does consciousness, which is totally different from the mind, get related to the mind in such a way that it makes the latter capable of comprehending the things of the world? The Vedānta tradition provides the answer to this question in terms of the knower-known relation. Consciousness is pure light, self-luminous by its very nature, that is, although it reveals other objects, it is not revealed by anything else. When Sartre describes it as nothingness, bereft of even ego, it is to show that it is pure light revealing objects outside it. PMID:21694962

Decreases in renal functional reserve and proximal tubular fluid output in conscious oophorectomized rats

DEFF Research Database (Denmark)

Nielsen, Camilla Birch; Flyvbjerg, Allan; Bruun, Jens Meldgaard

2003-01-01

Age-dependent glomerulosclerosis with reduced GFR develops earlier among men than among women. Therefore, whether female sex hormones could prevent the age-dependent decrease in GFR was investigated. The kidney function in oophorectomized rats treated with placebo (OOX group), estrogen (OOX+E(2...... effects were prevented with administration of estrogen. Sham-operated rats demonstrated values for renal functional reserve and fractional lithium excretion that were between those observed for the OOX group and the groups treated with sex hormones....

Loss of Consciousness Induced by a Single Dose Flurbiprofen

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Bulent Yıldız

2012-01-01

Full Text Available Loss of consciousness after the administration of flurbiprofen has not been reported. In this case report, we describe loss of consciousness due to the administration of one oral dosage of flurbiprofen. A 17 year-old girl without a remarkable neurologic and atopic medical history had an loss of consciousness after ingestion of flurbiprofen mg 100 mg tablet. Patient was treated successfully. This report emphasies that this complication may be seen with flurobiprofen and underlying mechanisms and therapeutic approach are discussed.

Stigma Consciousness in the case of Romanian Roma Activists

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Laura SURDU

2013-11-01

Full Text Available Roma people are often stigmatized by the members of the out-groups, the process of stigmatization being enforced through a selection of stereotypically assigned characteristics of the group. In the last two decades, the stigmatization of Roma was contributed by scientists, policy makers and mass media. Stigma is a basis for social exclusion of Roma people and it is transferred from the whole group to the individual level. The negative labelling of the entire Roma group affects identity and stigma consciousness for each individual Roma. This paper addresses ethnic stigma consciousness in a sample of 96 Roma activists, women and men. The results show that stigma consciousness is highly present among Roma participants from the sample, although there are not significant differences between Roma women and Roma men regarding ethnic stigma consciousness.

Effect of exercise training on Ca²⁺ release units of left ventricular myocytes of spontaneously hypertensive rats.

Science.gov (United States)

Carneiro-Júnior, M A; Quintão-Júnior, J F; Drummond, L R; Lavorato, V N; Drummond, F R; Amadeu, M A; Oliveira, E M; Felix, L B; Cruz, J S; Mill, J G; Natali, A J; Prímola-Gomes, T N

2014-11-01

In cardiomyocytes, calcium (Ca²⁺) release units comprise clusters of intracellular Ca²⁺ release channels located on the sarcoplasmic reticulum, and hypertension is well established as a cause of defects in calcium release unit function. Our objective was to determine whether endurance exercise training could attenuate the deleterious effects of hypertension on calcium release unit components and Ca²⁺ sparks in left ventricular myocytes of spontaneously hypertensive rats. Male Wistar and spontaneously hypertensive rats (4 months of age) were divided into 4 groups: normotensive (NC) and hypertensive control (HC), and normotensive (NT) and hypertensive trained (HT) animals (7 rats per group). NC and HC rats were submitted to a low-intensity treadmill running protocol (5 days/week, 1 h/day, 0% grade, and 50-60% of maximal running speed) for 8 weeks. Gene expression of the ryanodine receptor type 2 (RyR2) and FK506 binding protein (FKBP12.6) increased (270%) and decreased (88%), respectively, in HC compared to NC rats. Endurance exercise training reversed these changes by reducing RyR2 (230%) and normalizing FKBP12.6 gene expression (112%). Hypertension also increased the frequency of Ca²⁺ sparks (HC=7.61 ± 0.26 vs NC=4.79 ± 0.19 per 100 µm/s) and decreased its amplitude (HC=0.260 ± 0.08 vs NC=0.324 ± 0.10 ΔF/F0), full width at half-maximum amplitude (HC=1.05 ± 0.08 vs NC=1.26 ± 0.01 µm), total duration (HC=11.51 ± 0.12 vs NC=14.97 ± 0.24 ms), time to peak (HC=4.84 ± 0.06 vs NC=6.31 ± 0.14 ms), and time constant of decay (HC=8.68 ± 0.12 vs NC=10.21 ± 0.22 ms). These changes were partially reversed in HT rats (frequency of Ca²⁺ sparks=6.26 ± 0.19 µm/s, amplitude=0.282 ± 0.10 ΔF/F0, full width at half-maximum amplitude=1.14 ± 0.01 µm, total duration=13.34 ± 0.17 ms, time to peak=5.43 ± 0.08 ms, and time constant of decay=9.43 ± 0.15 ms). Endurance exercise training attenuated the deleterious effects of hypertension on calcium release

On the quantum mechanics of consciousness, with application to anomalous phenomena

International Nuclear Information System (INIS)

Jahn, R.G.; Dunne, B.J.

1986-01-01

Theoretical explication of a growing body of empirical data on consciousness-related anomalous phenomena is unlikely to be achieved in terms of known physical processes. Rather, it will first be necessary to formulate the basic role of consciousness in the definition of reality before such anomalous experience can adequately be represented. This paper takes the position that reality is constituted only in the interaction of consciousness with its environment, and therefore that any scheme of conceptual organization developed to represent that reality must reflect the processes of consciousness as well as those of its environment. In this spirit, the concepts and formalisms of elementary quantum mechanics, as originally proposed to explain anomalous atomic-scale physical phenomena, are appropriated via metaphor to represent the general characteristics of consciousness interacting with any environment. More specifically, if consciousness is represented by a quantum mechanical wave function, and its environment by an appropriate potential profile, Schrodinger wave mechanics defines eigenfunctions and eigenvalues that can be associated with the cognitive and emotional experiences of that consciousness in that environment. To articulate this metaphor it is necessary to associate certain aspects of the formalism, such as the coordinate system, the quantum numbers, and even the metric itself, with various impressionistic descriptors of consciousness, such as its intensity, perspective, approach/avoidance attitude, balance between cognitive and emotional activity, and receptive/assertive disposition

Gender Consciousness among Urban Adolescents in Osun State ...

African Journals Online (AJOL)

This study attempted to find out whether adolescents express their consciousness about the two dimensions of gender (public and private) and to determine the level ofmanifestations of gender consciousness among early and late adolescents. For the purpose of this study, 100(M=56, F=44) were randomly selected from ...

Consumer Ethical Decision Making: Intensity, Self-Consciousness and Neutralization Techniques

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Syed Afzal Moshadi Shah

2017-03-01

Full Text Available The purpose of the study is to examine the effect of moral intensity on self-conscious emotions and neutralization techniques in the context of ethical decision making among consumers. A sample of 388 shopping mall retail consumers was recruited through self-administered survey technique. Descriptive statistics, exploratory factor analysis, correlation was carried out in SPSS whereas the measurement model and structural relationships were estimated using AMOS. Results indicate that moral intensity positively influences consumer’s self-consciousness, neutralization techniques and behavioural intention. Self-consciousness negatively influence consumer’s defence mechanism i.e. neutralization techniques. Neither self-consciousness nor neutralization techniques is found to have an impact on consumers’ behavioural intention. Only self-consciousness is found to complementary mediate the relationship of moral intensity and neutralization. The limitations associated with field survey and crosssectional research design are inevitable. The study offers some relevant practical implications for government, marketing professionals and academia. The study is among the pioneer studies that theoretically links and empirically examines Issue Contingent Model, theory of neutralization and self-consciousness. The study develops and tested an Urdu language version of the questionnaire for retail consumers.

The interpersonal work of dental conscious sedation: A qualitative analysis.

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Woolley, Stephen M; Chadwick, Barbara; Pugsley, Lesley

2017-08-01

Whilst there is a considerable body of literature examining the pharmacology of conscious sedation, the social tasks required to successfully provide conscious sedation have not been reported. This paper discusses data regarding the interpersonal work integral to effective conscious sedation provision, from a larger qualitative study exploring how patients and clinicians engage with secondary care conscious sedation provided within the UK. Semi-structured interviews were conducted with 13 conscious sedation providers and nine patients within UK-based secondary care sedation settings. Digital audio-recordings were transcribed verbatim and subsequently analysed using a constant comparative method within NVivo Data Analysis Software. Four main themes of interpersonal work were reported by participants: displaying care, containing emotions, demonstrating competence and maximizing the effect. This study shows that performing conscious sedation requires more than technical delivery, and involves the projection of attributes in a literal "performance." The importance of managing outward emotional appearance reflects previous dental research. The need to manage outward appearance, and the emotional impact this has, is of relevance to all clinicians. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Central neuropeptide Y receptors are involved in 3rd ventricular ghrelin induced alteration of colonic transit time in conscious fed rats

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Ritter Michael

2005-02-01

Full Text Available Abstract Background Feeding related peptides have been shown to be additionally involved in the central autonomic control of gastrointestinal functions. Recent studies have shown that ghrelin, a stomach-derived orexigenic peptide, is involved in the autonomic regulation of GI function besides feeding behavior. Pharmacological evidence indicates that ghrelin effects on food intake are mediated by neuropeptide Y in the central nervous system. Methods In the present study we examine the role of ghrelin in the central autonomic control of GI motility using intracerobroventricular and IP microinjections in a freely moving conscious rat model. Further the hypothesis that a functional relationship between NPY and ghrelin within the CNS exists was addressed. Results ICV injections of ghrelin (0.03 nmol, 0.3 nmol and 3.0 nmol/5 μl and saline controls decreased the colonic transit time up to 43%. IP injections of ghrelin (0.3 nmol – 3.0 nmol kg-1 BW and saline controls decreased colonic transit time dose related. Central administration of the NPY1 receptor antagonist, BIBP-3226, prior to centrally or peripherally administration of ghrelin antagonized the ghrelin induced stimulation of colonic transit. On the contrary ICV-pretreatment with the NPY2 receptor antagonist, BIIE-0246, failed to modulate the ghrelin induced stimulation of colonic motility. Conclusion The results suggest that ghrelin acts in the central nervous system to modulate gastrointestinal motor function utilizing NPY1 receptor dependent mechanisms.

Temporal neural mechanisms underlying conscious access to different levels of facial stimulus contents.

Science.gov (United States)

Hsu, Shen-Mou; Yang, Yu-Fang

2018-04-01

An important issue facing the empirical study of consciousness concerns how the contents of incoming stimuli gain access to conscious processing. According to classic theories, facial stimuli are processed in a hierarchical manner. However, it remains unclear how the brain determines which level of stimulus content is consciously accessible when facing an incoming facial stimulus. Accordingly, with a magnetoencephalography technique, this study aims to investigate the temporal dynamics of the neural mechanism mediating which level of stimulus content is consciously accessible. Participants were instructed to view masked target faces at threshold so that, according to behavioral responses, their perceptual awareness alternated from consciously accessing facial identity in some trials to being able to consciously access facial configuration features but not facial identity in other trials. Conscious access at these two levels of facial contents were associated with a series of differential neural events. Before target presentation, different patterns of phase angle adjustment were observed between the two types of conscious access. This effect was followed by stronger phase clustering for awareness of facial identity immediately during stimulus presentation. After target onset, conscious access to facial identity, as opposed to facial configural features, was able to elicit more robust late positivity. In conclusion, we suggest that the stages of neural events, ranging from prestimulus to stimulus-related activities, may operate in combination to determine which level of stimulus contents is consciously accessed. Conscious access may thus be better construed as comprising various forms that depend on the level of stimulus contents accessed. NEW & NOTEWORTHY The present study investigates how the brain determines which level of stimulus contents is consciously accessible when facing an incoming facial stimulus. Using magnetoencephalography, we show that prestimulus

Blood pressure responses to dietary sodium: Association with autonomic cardiovascular function in normotensive adults.

Science.gov (United States)

Matthews, Evan L; Brian, Michael S; Edwards, David G; Stocker, Sean D; Wenner, Megan M; Farquhar, William B

2017-12-01

Blood pressure responses to dietary sodium vary widely person-to-person. Salt sensitive rodent models display altered autonomic function, a trait thought to contribute to poor cardiovascular health. Thus, we hypothesized that increased salt sensitivity (SS) in normotensive humans would be associated with increased muscle sympathetic nerve activity (MSNA), decreased high frequency heart rate variability (HF-HRV), and decreased baroreflex sensitivity. Healthy normotensive men and women completed 1week of high (300mmol·day -1 ) and 1week of low (20mmol·day -1 ) dietary sodium (random order) with 24h mean arterial pressure (MAP) assessed on the last day of each diet to assess SS. Participants returned to the lab under habitual sodium conditions for testing. Forty-two participants are presented in this analysis, 19 of which successful MSNA recordings were obtained (n=42: age 39±2yrs., BMI 24.3±0.5kg·(m 2 ) -1 , MAP 83±1mmHg, habitual urine sodium 93±7mmol·24h -1 ; n=19: MSNA burst frequency 20±2 bursts·min -1 ). The variables of interest were linearly regressed over the magnitude of SS. Higher SS was associated with increased MSNA (burst frequency: r=0.469, p=0.041), decreased HF-HRV (r=-0.349, p=0.046), and increased LF/HF-HRV (r=0.363, p=0.034). SS was not associated with sympathetic or cardiac baroreflex sensitivity (p>0.05). Multiple regression analysis accounting for age found that age, not SS, independently predicted HF-HRV (age adjusted no longer significant; p=0.369) and LF/HF-HRV (age adjusted p=0.273). These data suggest that age-related salt sensitivity of blood pressure in response to dietary sodium is associated with altered resting autonomic cardiovascular function. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduction of microalbuminuria by using losartan in normotensive patients with type 2 diabetes mellitus: A randomized controlled trial

International Nuclear Information System (INIS)

Agha, Adnan; Amer, Wasim; Anwar, Eram; Bashir, Kaukab

2009-01-01

Type 2 diabetes mellitus (T2DM) is a worldwide pandemic that may lead to diabetic kidney disease (DKD), a complication which is the single most important and globally prevalent cause of chronic kidney disease. Microalbuminuria has been shown to be an early indicator of DKD and data suggest that angiotensin receptor blockers (ARBs) reduce urinary albumin excretion and retard the progression of renal disease in hypertensive T2DM patients. However, the effects of ARBs on preventing microalbuminuria and ensuing DKD in normotensive patients with T2DM is yet to be fully established. The objective of this study is to assess the anti-microalbuminuric effects of losartan therapy versus placebo in normotensive T2DM patients. This randomized single blinded controlled trial was performed at the Diabetic Clinic, Jinnah Hospital, Lahore over a period of 10 months. A total of 361 normotensive patients with T2DM and microalbuminuria were selected; of them, 171 patients were randomly allocated to the test group and 190 enrolled into the control group. The patients in the test group were started on losartan 50 mg/day for a six month period while those in the control group were put on vitamin B-12 500 mcg/day. The patients as well as the primary attending physicians/lab evaluators were blinded to the study. All study patients were followed up on a monthly basis. Quantitative microalbuminuria was tested at the beginning and at the end of the study. Out of the 171 patients in the test group, 149 (87.1%) had significant reduction of albuminuria by > 30% of their baseline (mean 101.9 +- 21.7 baseline and, 47.5 + - 12.9 post-therapy). The corresponding values for albuminuria in the 190 patients in the control group was mean 104.7 +- 26.3 baseline and post 6-month mean 103.9 +- 22.9, with P< 0.0001. The anti-albuminuric effect of losartan was reversible as seen on re-checking the urinary albumin two months after discontinuation of treatment. Our study shows that losartan was well tolerated

There Is an ‘Unconscious,’ but It May Well Be Conscious

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Bernardo Kastrup

2017-08-01

Full Text Available Depth psychology finds empirical validation today in a variety of observations that suggest the presence of causally effective mental processes outside conscious experience. I submit that this is due to misinterpretation of the observations: the subset of consciousness called “meta-consciousness” in the literature is often mistaken for consciousness proper, thereby artificially creating space for an “unconscious.” The implied hypothesis is that all mental processes may in fact be conscious, the appearance of unconsciousness arising from our dependence on self-reflective introspection for gauging awareness. After re-interpreting the empirical data according to a philosophically rigorous definition of consciousness, I show that two well-known phenomena corroborate this hypothesis: (a experiences that, despite being conscious, aren’t re-represented during introspection; and (b dissociated experiences inaccessible to the executive ego. If consciousness is inherent to all mentation, it may be fundamental in nature, as opposed to a product of particular types of brain function.

Consciousness Indexing and Outcome Prediction with Resting-State EEG in Severe Disorders of Consciousness.

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Stefan, Sabina; Schorr, Barbara; Lopez-Rolon, Alex; Kolassa, Iris-Tatjana; Shock, Jonathan P; Rosenfelder, Martin; Heck, Suzette; Bender, Andreas

2018-04-17

We applied the following methods to resting-state EEG data from patients with disorders of consciousness (DOC) for consciousness indexing and outcome prediction: microstates, entropy (i.e. approximate, permutation), power in alpha and delta frequency bands, and connectivity (i.e. weighted symbolic mutual information, symbolic transfer entropy, complex network analysis). Patients with unresponsive wakefulness syndrome (UWS) and patients in a minimally conscious state (MCS) were classified into these two categories by fitting and testing a generalised linear model. We aimed subsequently to develop an automated system for outcome prediction in severe DOC by selecting an optimal subset of features using sequential floating forward selection (SFFS). The two outcome categories were defined as UWS or dead, and MCS or emerged from MCS. Percentage of time spent in microstate D in the alpha frequency band performed best at distinguishing MCS from UWS patients. The average clustering coefficient obtained from thresholding beta coherence performed best at predicting outcome. The optimal subset of features selected with SFFS consisted of the frequency of microstate A in the 2-20 Hz frequency band, path length obtained from thresholding alpha coherence, and average path length obtained from thresholding alpha coherence. Combining these features seemed to afford high prediction power. Python and MATLAB toolboxes for the above calculations are freely available under the GNU public license for non-commercial use ( https://qeeg.wordpress.com ).

Self-consciousness concept and assessment in self-report measures

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DaSilveira, Amanda; DeSouza, Mariane L.; Gomes, William B.

2015-01-01

This study examines how self-consciousness is defined and assessed using self-report questionnaires (Self-Consciousness Scale (SCS), Self-Reflection and Insight Scale, Self-Absorption Scale, Rumination-Reflection Questionnaire, and Philadelphia Mindfulness Scale). Authors of self-report measures suggest that self-consciousness can be distinguished by its private/public aspects, its adaptive/maladaptive applied characteristics, and present/past experiences. We examined these claims in a study using 602 young adults to whom the aforementioned scales were administered. Data were analyzed as follows: (1) correlation analysis to find simple associations between the measures; (2) factorial analysis using Oblimin rotation of total scores provided from the scales; and (3) factorial analysis considering the 102 items of the scales all together. It aimed to clarify relational patterns found in the correlations between SCSs, and to identify possible latent constructs behind these scales. Results support the adaptive/maladaptive aspects of self-consciousness, as well as distinguish to some extent public aspects from private ones. However, some scales that claimed to be theoretically derived from the concept of Private Self-Consciousness correlated with some of its public self-aspects. Overall, our findings suggest that while self-reflection measures tend to tap into past experiences and judged concepts that were already processed by the participants’ inner speech and thoughts, the Awareness measure derived from Mindfulness Scale seems to be related to a construct associated with present experiences in which one is aware of without any further judgment or logical/rational symbolization. This sub-scale seems to emphasize the role that present experiences have in self-consciousness, and it is argued that such a concept refers to what has been studied by phenomenology and psychology over more than 100 years: the concept of pre-reflective self-conscious. PMID:26191030

Consciousness, Representation, Action : The Importance of Being Goal-Directed

NARCIS (Netherlands)

Pennartz, C.M.A.

2018-01-01

Recent years have witnessed fierce debates on the dependence of consciousness on interactions between a subject and the environment. Reviewing neuroscientific, computational, and clinical evidence, I will address three questions. First, does conscious experience necessarily depend on acute

Blockade of TGF-β 1 Signalling Inhibits Cardiac NADPH Oxidase Overactivity in Hypertensive Rats

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José Luis Miguel-Carrasco

2012-01-01

Full Text Available NADPH oxidases constitute a major source of superoxide anion (⋅O2 - in hypertension. Several studies suggest an important role of NADPH oxidases in different effects mediated by TGF-β 1. In this study we show that chronic administration of P144, a peptide synthesized from type III TGF-β 1 receptor, significantly reduced the cardiac NADPH oxidase expression and activity as well as in the nitrotyrosine levels observed in control spontaneously hypertensive rats (V-SHR to levels similar to control normotensive Wistar Kyoto rats. In addition, P144 was also able to reduce the significant increases in the expression of collagen type I protein and mRNA observed in hearts from V-SHR. In addition, positive correlations between collagen expression, NADPH oxidase activity, and nitrotyrosine levels were found in all animals. Finally, TGF-β 1-stimulated Rat-2 exhibited significant increases in NADPH oxidase activity that was inhibited in the presence of P144. It could be concluded that the blockade of TGF-β 1 with P144 inhibited cardiac NADPH oxidase in SHR, thus adding new data to elucidate the involvement of this enzyme in the profibrotic actions of TGF-β 1.

Brain Endogenous Feedback and Degrees of Consciousness

DEFF Research Database (Denmark)

Carrara-Augustenborg, Claudia; Pereira Jr., Alfredo

2012-01-01

dependent on the previous state of their interaction domain. We also explain complex processes occurring below the threshold of awareness as those that deploy the brain’s computational resources, although without producing resonant states of sufficient magnitude to determine the individual´s overt...... acknowledgment. Finally, our model affords a plausible account of phenomenal and self-consciousness which, by resting at the outskirts of reportable cognitive activity, traditionally compound the 'hard problem' of consciousness....

Characteristics of environmentally conscious production behaviour in agricultural waste management

OpenAIRE

Kormosne-Koch, Krisztina

2008-01-01

When measuring environmentally conscious behaviour and determining its variables, focus often lies only on consumers, but environmental conservation requires not only the consumers’ but also the producers’ input. After defining environmentally conscious behaviour, I utilized the market research method to determine how participating in agri-environmental programs and subsidies affects producers’ environmental consciousness and waste management behaviour. The research result indicates tha...

Global workspace dynamics: Cortical "binding and propagation enables conscious contents.

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Bernard J Baars

2013-05-01

Full Text Available A global workspace is a hub of binding and propagation in a population of loosely coupled signaling elements. Global workspace (GW architectures recruit many distributed, specialized agents to help resolve focal ambiguities. In the brain, conscious experiences may reflect a global workspace function. For animals the natural world is full of fitness-related ambiguities, suggesting a general adaptive pressure for brains to resolve focal ambiguities quickly and accurately. In humans and related species the cortico-thalamic (C-T core is believed to underlie conscious aspects of perception, thinking, learning, feelings of knowing, emotions, imagery, working memory and executive control. The C-T core has many anatomical hubs, but conscious percepts are unitary and internally consistent at any given moment. The repertoire of conscious contents is a large, open set. These points suggest that a brain-based GW capacity cannot be localized in a single anatomical hub. Rather, it should be sought in a dynamic capacity for adaptive binding and propagation of neural signals over multi-hub networks. We refer to this as dynamic global workspace theory (dGW. In this view, conscious contents can arise in any region of the C-T core when multiple signal streams settle on a winner-take-all equilibrium. The resulting bound gestalt may ignite an any-to-many broadcast, lasting ~100-200 ms, and trigger widespread adaptation in established networks. Binding and broadcasting may involve theta/gamma or alpha/gamma phase coupling. Conscious contents (qualia may reflect their sources in cortex. Sensory percepts may bind and broadcast from posterior regions, while non-sensory feelings of knowing (FOKs may be frontotemporal. The small focal capacity of conscious contents may be the biological price to pay for global access. We propose that in the intact brain the hippocampal/rhinal complex may support conscious event organization as well as episodic memory coding.

The Split-Brain Phenomenon Revisited: A Single Conscious Agent with Split Perception.

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Pinto, Yair; de Haan, Edward H F; Lamme, Victor A F

2017-11-01

The split-brain phenomenon is caused by the surgical severing of the corpus callosum, the main route of communication between the cerebral hemispheres. The classical view of this syndrome asserts that conscious unity is abolished. The left hemisphere consciously experiences and functions independently of the right hemisphere. This view is a cornerstone of current consciousness research. In this review, we first discuss the evidence for the classical view. We then propose an alternative, the 'conscious unity, split perception' model. This model asserts that a split brain produces one conscious agent who experiences two parallel, unintegrated streams of information. In addition to changing our view of the split-brain phenomenon, this new model also poses a serious challenge for current dominant theories of consciousness. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Consciousness and the role of valorization. How and why the Self-awareness subjectively administers consciousness

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Ciocan Tudor Cosmin

2017-05-01

Full Text Available It is most likely for anyone to ask himself at least once if it would be possible to live in a dream? Questioning the fabric of “reality” we live in consciously was one of the main doubts man ever had. It is so likely for us to answer positively to it due to so many factors; starting from the many and various facets of reality each individual envision the world, from the enormous differences we all have while perceiving and defining the reality, etc. That is why, at the conscious level, life seems almost like a dream in a dream, always hoping to wake up from the negative, unwanted version of it. That is why my assertion here, based on latest theories on consciousness and AI (artificial intelligence, aim to say that we live in between reality and dream, being “conscious” of ourselves, but not really wanting to be “aware” of what is really going on with us. Living as a human is not a path towards improvement in the way of getting rid of subjectiveness and valorization because these so-called errors make the most of human living.

The Problem of Consciousness.

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Crick, Francis; Koch, Christof

1992-01-01

Discusses approaches to the problem presented in understanding consciousness as a yet undiscovered process of interacting neuron activity. Presents the historical context of research in the area of human awareness and identifies research necessary to scientifically explain how the brain relates to the mind. (MCO)

Avian reflex and electroencephalogram responses in different states of consciousness.

Science.gov (United States)

Sandercock, Dale A; Auckburally, Adam; Flaherty, Derek; Sandilands, Victoria; McKeegan, Dorothy E F

2014-06-22

Defining states of clinical consciousness in animals is important in veterinary anaesthesia and in studies of euthanasia and welfare assessment at slaughter. The aim of this study was to validate readily observable reflex responses in relation to different conscious states, as confirmed by EEG analysis, in two species of birds under laboratory conditions (35-week-old layer hens (n=12) and 11-week-old turkeys (n=10)). We evaluated clinical reflexes and characterised electroencephalograph (EEG) activity (as a measure of brain function) using spectral analyses in four different clinical states of consciousness: conscious (fully awake), semi-conscious (sedated), unconscious-optimal (general anaesthesia), unconscious-sub optimal (deep hypnotic state), as well as assessment immediately following euthanasia. Jaw or neck muscle tone was the most reliable reflex measure distinguishing between conscious and unconscious states. Pupillary reflex was consistently observed until respiratory arrest. Nictitating membrane reflex persisted for a short time (power (PTOT) significantly increased, whereas median (F50) and spectral edge (F95) frequencies significantly decreased. This study demonstrates that EEG analysis can differentiate between clinical states (and loss of brain function at death) in birds and provides a unique integration of reflex responses and EEG activity. Copyright © 2014 Elsevier Inc. All rights reserved.

Divergent neural responses to narrative speech in disorders of consciousness.

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Iotzov, Ivan; Fidali, Brian C; Petroni, Agustin; Conte, Mary M; Schiff, Nicholas D; Parra, Lucas C

2017-11-01

Clinical assessment of auditory attention in patients with disorders of consciousness is often limited by motor impairment. Here, we employ intersubject correlations among electroencephalography responses to naturalistic speech in order to assay auditory attention among patients and healthy controls. Electroencephalographic data were recorded from 20 subjects with disorders of consciousness and 14 healthy controls during of two narrative audio stimuli, presented both forwards and time-reversed. Intersubject correlation of evoked electroencephalography signals were calculated, comparing responses of both groups to those of the healthy control subjects. This analysis was performed blinded and subsequently compared to the diagnostic status of each patient based on the Coma Recovery Scale-Revised. Subjects with disorders of consciousness exhibit significantly lower intersubject correlation than healthy controls during narrative speech. Additionally, while healthy subjects had higher intersubject correlation values in forwards versus backwards presentation, neural responses did not vary significantly with the direction of playback in subjects with disorders of consciousness. Increased intersubject correlation values in the backward speech condition were noted with improving disorder of consciousness diagnosis, both in cross-sectional analysis and in a subset of patients with longitudinal data. Intersubject correlation of neural responses to narrative speech audition differentiates healthy controls from patients and appears to index clinical diagnoses in disorders of consciousness.

Exercise training modulates functional sympatholysis and alpha-adrenergic vasoconstrictor responsiveness in hypertensive and normotensive individuals

DEFF Research Database (Denmark)

Mortensen, Stefan Peter; Nyberg, Michael Permin; Gliemann Hybholt, Lasse

2014-01-01

were measured before and after 8 weeks of aerobic training (3-4 times/week) in 8 hypertensive (47 ± 2 years) and 8 normotensive untrained individuals (46 ± 1 years) during arterial tyramine infusion, arterial ATP infusion and/or one-legged knee extensions. Before training, exercise hypaeremia and leg......Essential hypertension is linked to an increased sympathetic vasoconstrictor activity and reduced tissue perfusion. We investigated the role of exercise training on functional sympatholysis and postjunctional α-adrenergic responsiveness in individuals with essential hypertension. Leg haemodynamics...... vascular conductance (LVC) were lower in the hypertensive individuals (P Training lowered blood pressure in the hypertensive individuals (P

Leg blood pressure measured in orthostatic posture is associated with left ventricular mass in normotensive subjects.

Science.gov (United States)

Gemignani, Tiago; Matos-Souza, José R; Franchini, Kleber G; Nadruz, Wilson

2012-10-01

Changing from a supine to an orthostatic posture is associated with substantial increments in leg blood pressure (BP) levels, which could ultimately influence the hemodynamic burden imposed on the heart. This study investigated the relationship between brachial and leg BP measurements and the left cardiac chamber's structure and assessed the role of body posture changes in this regard. One hundred and thirty normotensive, nondiabetic, nonsmoking, normolipemic subjects were evaluated by a clinical history, anthropometry, the analysis of metabolic parameters, echocardiography, and the measurement of BP in the arm and the calf in both supine and orthostatic positions. Significant correlation coefficients between the leg BP measurements and the cardiac structure were detected, especially between the orthostatic pulse pressure (PP) and the left ventricular (LV) wall thickness (r = 0.38; P < 0.001), the orthostatic PP and the LV mass (r = 0.37; P < 0.001), and the orthostatic systolic BP (SBP) and the left atrial size (r = 0.35; P < 0.001). Stepwise and standard regression analysis adjusted for brachial BP and anthropometric and metabolic variables confirmed that the leg orthostatic PP was independently related to the LV wall thickness and mass. Moreover, the leg orthostatic SBP was associated with the left atrial dimension even after adding the LV mass to the statistical models. Finally, triglyceride levels and body surface area showed significant relationship with leg orthostatic PP and SBP, whereas brachial orthostatic PP and SBP were only associated with age and anthropometric variables. Orthostatic leg BP is independently associated with the cardiac structure in normotensive subjects.

EEG differences between the opioid and adrenergic psyhoneuroendocrine rat types

DEFF Research Database (Denmark)

Cristea, A; Moldovan, M; Munteanu, A M

2000-01-01

(BEA) of the "O" and "A" rat types during restrained wakefulness and anesthesia with Ether and chloral hydrate (CHL). The differentiation of the psyhoneuroendocrine rat types was made using the level of painful sensitivity. 13 hypersensitive "A" and 14 hyposensitive "O" rats were selected from a 91......% (SEF95) and the relative spectral power (RSP) within the Theta (4.5-7.5 Hz), Alpha (7.5-12 Hz) and Beta (12.5-30 Hz) bands. The quantification method used was able to detect statistically significant differences between the two psyhoneuroendocrine rat types during consciousness and light ether...... anesthesia but failed to show any differences during the deep CHL anesthesia. The particularities were shown to be topographically related with the fronto-parietal regions were "O" type showed a higher SEF95 during the awake restrained state. The pain sensitive "A" type showed a significant intrahemispheric...

[An existential-phenomenological approach to consciousness].

Science.gov (United States)

Langle, A

2014-01-01

The human beings are characterized as subjects. Their essence is understood as Person. A treatment which does not consider the subjective and the Person would not correspond their essence. For a feeling and autonomous being, consciousness plays a role but cannot fully correspond the being a person. This has a therapeutic impact on the treatment of unconscious patients and gives the treatment a specific access. Some instructions for the therapeutic application of the phenomenological-existential concept and the phenomenological attitude towards unconscious or brain traumatized patients are given. The role of consciousness for being human is briefly reflected from an existential perspective.

Simulation and Representation of Body, Emotion, and Core Consciousness

NARCIS (Netherlands)

Bosse, T.; Jonker, C.M.; Treur, J.; Henderson-Sellers, B.; Winikoff, M.

2005-01-01

This paper contributes an analysis and formalisation of Damasio's theory on core consciousness. Three important concepts in this theory are 'emotion', 'feeling', and 'feeling a feeling' (or core consciousness). In particular, a simulation model is described of the neural dynamics leading via emotion

On the quantum mechanics of consciousness, with application to anomalous phenomena

Science.gov (United States)

Jahn, Robert G.; Dunne, Brenda J.

1986-08-01

Theoretical explication of a growing body of empirical data on consciousness-related anomalous phenomena is unlikely to be achieved in terms of known physical processes. Rather, it will first be necessary to formulate the basic role of consciousness in the definition of reality before such anomalous experience can adequately be represented. This paper takes the position that reality is constituted only in the interaction of consciousness with its environment, and therefore that any scheme of conceptual organization developed to represent that reality must reflect the processes of consciousness as well as those of its environment. In this spirit, the concepts and formalisms of elementary quantum mechanics, as originally proposed to explain anomalous atomic-scale physical phenomena, are appropriated via metaphor to represent the general characteristics of consciousness interacting with any environment. More specifically, if consciousness is represented by a quantum mechanical wave function, and its environment by an appropriate potential profile, Schrödinger wave mechanics defines eigenfunctions and eigenvalues that can be associated with the cognitive and emotional experiences of that consciousness in that environment. To articulate this metaphor it is necessary to associate certain aspects of the formalism, such as the coordinate system, the quantum numbers, and even the metric itself, with various impressionistic descriptors of consciousness, such as its intensity, perspective, approach/avoidance attitude, balance between cognitive and emotional activity, and receptive/assertive disposition. With these established, a number of the generic features of quantum mechanics, such as the wave/particle duality, and the uncertainty, indistinguishability, and exclusion principles, display metaphoric relevance to familiar individual and collective experiences. Similarly, such traditional quantum theoretic exercises as the central force field and atomic structure, covalent

LEGAL CONSCIOUSNESS OF YOUTH IN CONDITIONS OF VOCATIONAL EDUCATION: PROBLEMS AND SOLUTIONS

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R. R. Kalinina

2014-10-01

Full Text Available Goal: to study peculiarities of legal consciousness among youth in conditions of vocational education in legal and non-legal fields.Methods and practices: empirical (Assessing moral development: dilemmas by L. Kohlberg, Practice of self-analysis diagnostics by A.V. Karpov, Test on legal and civic consciousness by L.A. Yasyukova, “Level of Subjective Control” methodology by E.F. Bazhin et al. and mathematical and statistical methods (descriptive, comparative, and cluster analyses.Result: Peculiarities of contents in legal consciousness and its regulatory function in students of legal and non-legal programs were identified. Three types of students were determined: those with non-formed legal consciousness, with formed legal consciousness and with formal legal consciousness; main directions for psychological and pedagogical work in the university to develop adequate legal consciousness in students of various fields were set.Applicability of results: results of the research can be applied when developing elective courses, extracurricular activities, strategy for character-building work of the university, both in training lawyers and other professionals.

Predictable Internal Brain Dynamics in EEG and Its Relation to Conscious States

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Jaewook eYoo

2014-06-01

Full Text Available Consciousness is a complex and multi-faceted phenomenon defying scientific explanation. Part of the reason why this is the case is due to its subjective nature. In our previous computational experiments, to avoid such a subjective trap, we took a strategy to investigate objective necessary conditions of consciousness. Our basic hypothesis was that predictive internal dynamics serves as such a condition. This is in line with theories of consciousness that treat retention (memory, protention (anticipation, and primary impression as the tripartite temporal structure of consciousness. To test our hypothesis, we analyzed publicly available sleep and awake electroencephalogram (EEG data. Our results show that EEG signals from awake or rapid eye movement (REM sleep states have more predictable dynamics compared to those from slow-wave sleep (SWS. Since awakeness and REM sleep are associated with conscious states and SWS with unconscious or less consciousness states, these results support our hypothesis. The results suggest an intricate relationship among prediction, consciousness, and time, with potential applications to time perception and neurorobotics.

Salt (sodium chloride) content of retail samples of Nigerian white bread: implications for the daily salt intake of normotensive and hypertensive adults.

Science.gov (United States)

Nwanguma, B C; Okorie, C H

2013-10-01

Bread has been identified as a major contributor to the excessive salt (sodium chloride) intake of consumers in many countries, some of which have very high incidences of hypertension and related cardiovascular complications, such as stroke. This has prompted a global rise in interest in the salt content of breads produced and consumed in many other countries. The sodium contents of retail samples of 100 brands of Nigerian white bread were determined by photometry with a view to estimating the relative contribution of bread to the recommended daily sodium intake of both normotensive and hypertensive adults in the country. The salt content of the bread samples varied extensively, ranging from 0.51 g per 100 g (0.51%) to 1.8 g per 100 g (1.8%). The average salt content was 1.36 g per 100 g. Based on an estimated consumption of six slices of bread (about 180 g) per meal of bread, this equates to a daily intake of between 0.99 g and 3.33 g of salt from bread alone. This represents between 19.8% and 66.6% of the recommended daily allowance of 5 g for normotensive adults, and between 24.75% and 83.25% of the recommended daily allowance of 4 g for hypertensive adults. The consumption of some brands of bread by normotensive and hypertensive adults puts them at great risk of exceeding their recommended daily allowance for salt. Thus, there is an urgent need to regulate the amount of salt added to bread. In the interim, compelling bakers to declare the salt content of their products on the packaging could help consumers, especially hypertensive adults, avoid brands with a high salt content. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

Consciousness, Religion and Being. On the Way Towards Nonscientific and Nonanthropological Understanding of Consciousnes

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Ihor Karivets

2016-02-01

Full Text Available In this article the author proposes nonscientific and nonanthropological resolution of “the prob- lem of consciousness” and denies the possibility to explain the nature of consciousness with the help of physics, neuroscience, cognitive science and also analytic philosophy. The author stresses that 1 consciousness transcends Me (selfhood and does not belong to it, 2 consciousness perceives being; being is consciousness. “The problem of consciousness” is not theoretical problem at all. In order to know what consciousness is, it is necessary to work with consciousness. Therefore, we do not theo- rize about consciousness. It is a practical task of a human being. The author argues that meditation, as a kind of practice, is the best way to work with consciousness and enter into it.

The regulatory function of self-conscious emotion: insights from patients with orbitofrontal damage.

Science.gov (United States)

Beer, Jennifer S; Heerey, Erin A; Keltner, Dacher; Scabini, Donatella; Knight, Robert T