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Nervous System Activity (nervous + system_activity)
Kinds of Nervous System Activity Selected AbstractsII. INTERACTIONS AMONG MARITAL CONFLICT, SYMPATHETIC, AND PARASYMPATHETIC NERVOUS SYSTEMS ACTIVITY IN THE PREDICTION OF CHILDREN'S EXTERNALIZING PROBLEMSMONOGRAPHS OF THE SOCIETY FOR RESEARCH IN CHILD DEVELOPMENT, Issue 1 2009Article first published online: 18 MAR 200 First page of article [source] Mood states, sympathetic activity, and in vivo ,-adrenergic receptor function in a normal populationDEPRESSION AND ANXIETY, Issue 7 2008Bum-Hee Yu M.D. Ph.D. Abstract The purpose of this study was to examine the relationship between mood states and ,-adrenergic receptor function in a normal population. We also examined if sympathetic nervous system activity is related to mood states or ,-adrenergic receptor function. Sixty-two participants aged 25,50 years were enrolled in this study. Mood states were assessed using the Profile of Mood States (POMS). ,-adrenergic receptor function was determined using the chronotropic 25 dose isoproterenol infusion test. Level of sympathetic nervous system activity was estimated from 24-hr urine norepinephrine excretion. Higher tension-anxiety, depression-dejection, and anger-hostility were related to decreased ,-adrenergic receptor sensitivity (i.e., higher chronotropic 25 dose values), but tension-anxiety was the only remaining independent predictor of ,-adrenergic receptor function after controlling for age, gender, ethnicity, and body mass index (BMI). Urinary norepinephrine excretion was unrelated to either mood states or ,-adrenergic receptor function. These findings replicate previous reports that anxiety is related to decreased (i.e., desensitized) ,-adrenergic receptor sensitivity, even after controlling for age, gender, ethnicity, and body mass index. Depression and Anxiety 0:1,6, 2007. © 2007 Wiley-Liss, Inc. [source] Forearm vasoconstrictor response in uncomplicated type 1 diabetes mellitusEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 10 2006P. J. Van Gurp Abstract Background, According to the ,haemodynamic hypothesis', increased tissue perfusion predisposes to microangiopathy in diabetic patients. We hypothesized that the typical haemodynamic changes underlying the increased tissue perfusion can be explained by a decreased sympathetic nerve activity caused by chronic hyperglycaemia. In this study we investigated sympathetic activity in patients with uncomplicated type 1 diabetes mellitus (DM). Materials and methods, In 15 DM patients (DM duration 6·3 ± 3·8 year; HbA1c 7·9 ± 1·3%) and 16 age- and sex-matched healthy volunteers (Control), sympathetic nervous system activity was measured at rest (baseline) and during sympathoneural stimulation (lower body negative pressure (LBNP)) by means of interstitial and plasma noradrenaline (NA) sampling and power spectral analysis. Muscle sympathetic nerve activity (MSNA) was measured before (baseline) and during a cold pressure test. Forearm blood flow was measured during forearm vascular ,- and ,-adrenergic receptor blockade. Results, At baseline, forearm vascular resistance (FVR), plasma NA concentrations, MSNA and heart rate variability were similar in both groups. LBNP-induced vasoconstriction was significantly attenuated in the DM group compared with the Control group (,FVR: 12 ± 4 vs. 19 ± 3 arbitrary units, P < 0·05). The responses of plasma NA and heart rate variability did not differ. Conclusions,, Baseline FVR and sympathetic nerve activity are normal in patients with uncomplicated type 1 diabetes. However, the forearm vasoconstrictor response to sympathetic stimulation is attenuated, which cannot be attributed to an impaired sympathetic responsiveness. [source] Obesity,hypertension: an ongoing pandemicINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 2 2007E. A. Francischetti Summary Considerable evidence has suggested that excessive weight gain is the most common cause of arterial hypertension. This association has been observed in several populations, in different regions of the world. Obesity,hypertension, a term that underscores the link between these two deleterious conditions, is an important public health challenge, because of its high frequency and concomitant risk of cardiovascular and kidney diseases. The obesity,hypertension pandemic imposes a considerable economic burden on societies, directly reflecting on healthcare system costs. Increased renal sodium reabsorption and blood volume expansion are central features in the development of obesity,hypertension. Overweight is also associated with increased sympathetic activity. Leptin, a protein expressed in and secreted by adipocytes, is the main factor linking obesity, increased sympathetic nervous system activity and hypertension. The renin,angiotensin,aldosterone system has also been causally implicated in obesity,hypertension, because angiotensinogen is expressed in and secreted by adipose tissue. Hypoadiponectinemia, high circulating levels of free fatty acids and increased vascular production of endothelin-1 (ET-1) have been reported as potential mechanisms for obesity,hypertension. Lifestyle changes are effective in obesity,hypertension control, though pharmacological treatment is frequently necessary. Despite the consistency of the mechanistic approach in explaining the causal relation between hypertension and obesity, there is yet no evidence that one class of drug is superior to the others in controlling obesity,hypertension. In this review, we present the current knowledge and research in obesity,hypertension, exploring the epidemiologic evidence of the association, its probable pathophysiological mechanisms and treatment issues. [source] Heart Rate Variability and Sympathetic Skin Response in Male Patients Suffering From Acute Alcohol Withdrawal SyndromeALCOHOLISM, Issue 9 2006Karl-Jürgen Bär Background: Many symptoms of alcohol withdrawal (AW) such as tachycardia or elevated blood pressure might be explained by increased peripheral and central adrenergic activity. In contrast to many neurochemical studies of sympathetic activation during AW, only very few studies investigated autonomic balance using neurophysiological methods. Methods: We investigated heart rate variability (HRV) and sympathetic skin response (SSR) in male patients suffering from mild AW syndrome (n=20, no treatment required) and in patients with moderate to severe AW syndrome (n=20, clomethiazole treatment) in the acute stage. Sympathovagal influence was quantified using measures of time and frequency domain of HRV as well as modern nonlinear parameters (compression entropy). Furthermore, we obtained latencies and amplitudes of SSR to quantify isolated sympathetic influence. Measures were obtained during the climax of withdrawal symptomatology before treatment, 1 day after climax, and shortly before discharge from hospital. Alcohol withdrawal scores were obtained and correlated to autonomic measures. Results: Ambulatory blood pressure and AW scores revealed characteristic withdrawal symptoms in both patient groups. Apart from the nonlinear parameter compression entropy, Hc, measures of HRV revealed no sign of autonomic dysfunction in contrast to the significantly increased heart rates at the time of admission. Latencies and amplitudes of SSR did not indicate any increase of sympathetic activity. A negative correlation was found between Hc and mental withdrawal symptoms. Conclusions: We show here that classical measures for autonomic nervous system activity such as HRV and SSR are not suitable for describing the autonomic changes seen in acute AW, although a major role for the sympathetic nervous system has been proposed. This might be due to multiple dysregulation of metabolites in AWS or to subtle alcohol-induced damage to neuronal structures, issues that should be addressed in future studies. [source] Continuous Vagus Nerve Stimulation Effects on the Gut-Brain Axis in SwineNEUROMODULATION, Issue 1 2007Idoia Díaz-Güemes DVM ABSTRACT Objectives., This study was designed to assess vagus nerve stimulation effects on the food intake pattern in swine and determine the electrical stimulus direction. Material and Methods., Fifteen Large White pigs were randomly divided into three groups, groups A,C. All animals underwent implantation of a vagus nerve stimulator at the gastro-esophogeal junction. In group A, the stimulation was switched off, whereas stimulation was switched on in groups B and C. Food intake and body weight were registered in groups A and B, but not in group C, which was used to measure direction of stimulation in the vagus and effect on heart rate and blood pressure. Variables measured in group C included the bispectral index, blood pressure, and heart rate. A Student's t -test and one-way analysis of variance were used to detect differences between groups. All animals were sacrificed to identify effects of implantation and stimulation on the vagus nerve. Results., With respect to food intake, there was no difference between groups A and B; however, body weight did register a continuous increase. During stimulation, in group C arterial pressures decreased significantly, whereas the heart rate and bispectral index increased. Conclusion., The stimulation protocol applied in this study was insufficient to cause changes in the feeding behavior of swine; however, it did increase central nervous system activity. [source] The peripheral sympathetic nervous system in human obesityOBESITY REVIEWS, Issue 1 2001M. A. van Baak Summary The peripheral sympathetic nervous system is a key factor in the regulation of energy balance in humans. Differences in sympathetic nervous system activity may contribute to variations in 24 h energy expenditure between individuals. ,-Adrenoceptors play a more important role than ,-adrenoceptors in this regulation. The involvement of both ,1-and ,2-adrenoceptor subtypes has been demonstrated, the role of the ,3-adrenoceptor subtype is not yet clear. Normal or increased levels of sympathetic nervous system activity and reduced reactivity appear to be present in established obesity. Furthermore, the sensitivity for ,-adrenoceptor stimulation is impaired in obesity. The blunted reactivity and sensitivity may contribute to the maintenance of the obese state. There are data to suggest that they may also play a role in the aetiology of obesity, because the impairments often remain after weight reduction. Furthermore, a negative correlation between baseline sympathetic nervous system activity and weight gain during follow-up has been found in Pima Indians. Recently, genetic evidence about the involvement of adrenoceptors in obesity has become available. Although the results of association and linkage studies on polymorphisms in the ,2-, ,3- and ,2-adrenoceptor genes are inconsistent, the functional correlates of some of these polymorphisms (changes in agonist-promoted down-regulation, protein expression levels, lipolytic sensitivity, basal metabolic rate, sympathetic nervous system activity) suggest that they may be important in the aetiology of obesity. [source] Modeling multisystem biological risk in young adults: The Coronary Artery Risk Development in Young Adults StudyAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2010Teresa Seeman Although much prior research has focused on identifying the roles of major regulatory systems in health risks, the concept of allostatic load (AL) focuses on the importance of a more multisystems view of health risks. How best to operationalize allostatic load, however, remains the subject of some debate. We sought to test a hypothesized metafactor model of allostatic load composed of a number of biological system factors, and to investigate model invariance across sex and ethnicity. Biological data from 782 men and women, aged 32,47, from the Oakland, CA and Chicago, IL sites of the Coronary Artery Risk Development in Young Adults Study (CARDIA) were collected as part of the Year 15exam in 2000. These include measures of blood pressure, metabolic parameters (glucose, insulin, lipid profiles, and waist circumference), markers of inflammation (interleukin-6, C-reactive protein, and fibrinogen), heart rate variability, sympathetic nervous system activity (12-hr urinary norepinephrine and epinephrine) and hypothalamic-pituitary-adrenal axis activity (diurnal salivary free cortisol). A "metafactor" model of AL as an aggregate measure of six underlying latent biological subfactors was found to fit the data, with the metafactor structure capturing 84% of variance of all pairwise associations among biological subsystems. There was little evidence of model variance across sex and/or ethnicity. These analyses extend work operationalizing AL as a multisystems index of biological dysregulation, providing initial support for a model of AL as a metaconstruct of inter-relationships among multiple biological regulatory systems, that varies little across sex or ethnicity. Am. J. Hum. Biol. 2010. © 2009 Wiley-Liss, Inc. [source] Thermoregulatory sympathetic nervous system activity and diet-induced waist-circumference reduction in obese Japanese womenAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 6 2009Mami Fujibayashi The present study is designed to investigate how and to what extent sympathovagal behavior in a balanced low-calorie diet relates to favorable changes of body mass, waist circumference, and/or metabolic risk factors. The study involved 28 mildly obese women without clinical complications, who underwent an 8-week calorie restriction program using a 1,200-kcal daily diet with an adequate nutrient content; including two regular meals, and one formula meal replacement. All subjects were examined before and after the dietary intervention. We measured anthropometric parameters, blood pressure, and biochemical blood profiles for lipid metabolism. Autonomic nervous system activity was evaluated by heart rate variability power spectral analysis. The dietary intervention induced moderate, but significant reduction of waist circumference (,5.3% ± 0.8%), body fat percentage (,5.8% ± 0.8%), and body mass (,6.6% ± 0.5%). Linear regression analysis showed that ,very low frequency (VLF) power reflecting energy metabolic- and thermoregulatory sympathetic function significantly correlated to ,waist circumference (r = ,0.53, P < 0.01), ,body fat percentage (r = ,0.39, P < 0.05), ,body mass (r = ,0.43, P < 0.05), ,HDL-cholesterol/total cholesterol ratio (HDL-C/TC) (r = 0.62, P < 0.001), and ,nonesterified fatty acids (NEFA) (r = 0.56, P < 0.01). A stepwise multiple regression analysis additionally revealed that ,waist circumference (P = 0.024), ,HDL-C/TC (P = 0.013), and ,NEFA (P = 0.016) were significant and independent factors, which contributing to the variance in ,VLF power (r2 = 0.61). Although causes and consequences of obesity continue to elude researchers, the present study indicates that thermoregulatory sympathetic activity relates to moderate waist-circumference reduction together with favorable changes of blood lipid profiles after short-term dietary modification in mildly obese women. Am. J. Hum. Biol. 2009. © 2009 Wiley-Liss, Inc. [source] Methodological considerations in the use of salivary ,-amylase as a stress marker in field researchAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2008Jason A. DeCaro Salivary ,-amylase recently has been identified as a stress-related biomarker for autonomic nervous system activity. This study addresses sample collection and handling considerations for field researchers. Saliva was collected by unstimulated passive drool from 14 adults and pooled. Incubation of pooled saliva at 22 or 37°C for 21 days did not diminish amylase activity. However, sodium azide added at concentrations ,1.12 mg/ml to pooled saliva artificially inflated activity. After dosing cotton rolls within Salivette saliva collection devices with 0.25 to 1.5 ml of unpooled passive drool saliva from six additional adults, recovery of amylase activity was significantly below 100% at all volumes, with increased variance in recovery when the cotton was incompletely saturated (,1.0 ml). Hence, collection by passive drool instead of cotton-containing devices for amylase determinations is recommended, particularly whenever it is impossible to ensure full, uniform cotton saturation, and azide should be avoided as a preservative. Am. J. Hum. Biol., 2008. © 2008 Wiley-Liss, Inc. [source] Are there ethnic differences in sleep architecture?AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2002Judi Profant The possibility of ethnic differences in sleep architecture was initially examined in conjunction with studies of sleep apnea (study 1). This possibility was then examined in another cohort of patients to determine whether the results might generalize (study 2). Polysomnography was obtained in both cohorts as part of larger protocols investigating sympathetic nervous system activity, blood pressure, and sleep. Sleep monitoring took place in an inpatient clinical research center of a university hospital. Study 1 focused on sleep apnea physiology and involved volunteers with sleep apnea who were otherwise healthy. Study 2 focused on differences in stress reactivity between American Black and White subjects and involved hypertensive and normotensive volunteers who were otherwise healthy. Analyses include 61 participants from study 1 and 35 participants from study 2. Ethnicity in both cohorts was determined by self-report. Participants in both studies were monitored during sleep with traditional polysomnography including electroencephalography (EEG), electromyography (EMG), electrooculography (EOG), and oximetry. In Study 1, Blacks had longer TST (P < 0.01), more REM sleep (P < 0.05), and less WASO (P < 0.05) than Whites. After controling for RDI, Blacks had longer TST and spent a smaller percentage of time in deep sleep (P < 0.05). In study 2, Blacks had longer TST and REM sleep, lower percent deep sleep, and lower percent deep sleep controling for RDI (P < 0.05). In two separate studies, Blacks had longer TST, more minutes of REM, and lower percentage deep sleep. These findings suggest possible ethnic differences in sleep architecture. Am. J. Hum. Biol. 14:321,326, 2002. © 2002 Wiley-Liss, Inc. [source] Alpha power is influenced by performance errorsPSYCHOPHYSIOLOGY, Issue 2 2009Joshua Carp Abstract Error commission evokes changes in event-related potentials, autonomic nervous system activity, and behavior, presumably reflecting the operation of a cognitive control network. Here we test the hypothesis that errors lead to increased cortical arousal, measurable as changes in electroencephalogram (EEG) alpha band power. Participants performed a Stroop task while EEG was recorded. Following correct responses, alpha power increased and then decreased in a quadratic pattern, implying transient mental disengagement during the intertrial interval. This trend was absent following errors, which elicited significantly less alpha power than correct trials. Moreover, post-error alpha power was a better predictor of individual differences in post-error slowing than the error-related negativity (ERN), whereas the ERN was a better predictor of post-error accuracy than alpha power. These findings imply that changes in cortical arousal play a unique role in modulating post-error behavior. [source] Ethnic (Black-White) Contrasts in 24-Hour Heart Rate Variability in Male Adolescents with High and Low Blood Pressure: The Bogalusa Heart StudyANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2000Elaine M. Urbina M.D. Background: Heart rate variability (HRV) has been used to study autonomic effects on the heart. The time-domain measure RMSSD (root mean square of successive differences) represents high frequency (HF) changes in HRV reflecting parasympathetic nervous system activity (PS). The frequency-domain ratio of low to high power (LF/HF) represents sympathetic (SYMP) to PS balance. In adults, increased SYMP tone has been found in hypertensive as compared to normals. The present study was performed to look for differences in HRV by race and between young subjects with high and low levels of diastolic blood pressure (DBP). Methods: Subjects included 34 healthy males age 13,17 years (53% white). Half were selected with K4 DBP < 85th% for height (HT) measured twice, 3,5 years apart. Half had DBP < 15th% for HT. Subjects underwent a physical examination including BP, HT, WT, and ECG prior to Holter monitor application. HRV data was analyzed from 24-hour Holter recordings obtained during normal activity. Results: The RMSSD was lower in whites compared to blacks for day, night, and 24-hour average (P , 0.05) with day-time measurements showing the largest racial difference. This suggests increased PS tone in blacks especially with activity. The LF/HF ratio was higher in whites for all times, reaching significance during the day (all P , 0.05) suggesting SYMP predominance in whites during activity. Subjects with higher levels of DBP had lower RMSSD and higher LF/HF ratio for all times, but these did not reach statistical significance. Conclusions: There is a trend towards SYMP predominance in children with higher DBP. Healthy white adolescents exhibit increased SYMP tone compared to blacks when measured during normal daytime activity. [source] 2357: Autonomic nervous system and endothelial peripheral dysfunction in normal tension glaucoma patientsACTA OPHTHALMOLOGICA, Issue 2010J WIERZBOWSKA Purpose To define parameters of autonomic nervous system activity and peripheral vascular reactive hyperemia in normal tension glaucoma patients. Methods Ambulatory 24-hour electrocardiogram and blood pressure (BP) monitoring by using Lifecard CF and SpaceLab 90207-30 combined with occlusion provocation test were carried out in 54 NTG patients (44 women, mean age 59.7) and 43 matched control subjects (34 women, mean age 57.0). Heart rate variability (HRV) time and frequency domain parameters [low-frequency (LF), high-frequency (HR) and LF/HF ratio], and blood pressure variability (BPV) were calculated and analyzed for both study groups. Postocclusive hyperemia response parameters (TM - time to peak flow, TH ,half-time hyperaemia, TR ,time to rest flow, BZ-biological zero and MAX , maximum hyperemic response) were compared for patients with a nocturnal fall in mean BP (MPB) of less than 10% (non-dippers), of 10-20% (dippers) and of more than 20% (over-dippers) Results NTG patients demonstrated higher LF and LF/HF values for 24-hour period, day-time and night time than control subjects. There was no difference in BPV between study groups (10.4 ± 1.9 vs. 10.5 ± 2.1, p=0.790). In NTG patients, TH was significantly higher (79.0 ± 80.9 s vs. 51.5 ± 35.3 s, p=0.028) and BZ was significantly lower (2.3 ± 1.0 vs. 3.1 ± 2.0, p=0.009) as compared to the control group. There was statistically significant difference between NTG non-dippers, dippers and over,dippers in the BZ parameter (2.3 ± 0.9 vs. 2.7 ± 1.3 vs. 1.4 ± 0.4 p=0.024). Conclusion NTG patients exhibit abnormal ANS system activity and a different systemic hyperemia response as compared with healthy subjects. [source] Rhodiola rosea: A Versatile AdaptogenCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2005Farhath Khanum ABSTRACT Rhodiola rosea (rose root) belonging to the family Crassulaceae is a popular medicinal plant in Russia, Scandinavia, and many other countries. Extracts of the roots of this plant have been found to favorably affect a number of physiological functions including neurotransmitter levels, central nervous system activity, and cardiovascular function. It is being used to stimulate the nervous system, decrease depression, enhance work performance, eliminate fatigue, and prevent high-altitude sickness. Most of these effects have been ascribed to constituents such as salidroside (rhodioloside), rosavins, and p-tyrosol. It has also been found to be a strong antioxidant and anticarcinogen due to the presence of several phenolic compounds. Adaptogens are plant extracts that allow an organism to counteract adverse physical, chemical, and biological stressors by generating nonspecific resistance. Adaptogens are known to increase the availability of energy during the day, reduce stressed feelings, increase endurance, and increase mental alertness. This multipurpose medicinal plant (R. rosea), with adaptogenic properties that increase the body's nonspecific resistance and normalize functions, has been traditionally grown and used in Russia and Mongolia. Due to increasing consumer demands toward natural health products and the growing interests in the secondary metabolites of plants and their application in biotechnology and therapy, much focus has been put on the rose root and its medical properties. The rose root imparts normalizing influences on adverse physical, chemical, and biological disturbances but is otherwise innocuous. In India, the plant has been growing wild in the high altitudes of the Himalayas. The Defence Research and Development Organization in India has taken on the responsibilities of its conservation, as well as the development of multiple management practices and the development of health foods, supplements, and nutraceuticals in India. [source] | |||||||||||||