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Aim: This study assessed the effects of hand‐bathing on sympathetic nervous activity exacerbated by psychological stress. Participants immersed one hand in warm water for 2 min while exposed to noise, and changes in blood flow and skin temperature of the non‐immersed hand were observed. Methods: Twenty‐nine healthy university students aged 20 years or older were randomly assigned to either the hand‐bathing group (n = 14) or the control group (n = 15). After a brief rest in a quiet environment, participants were exposed to noise for 6 min. Those in the hand‐bathing group submerged their left hand in a 40°C thermostatic bath for 2 min, starting 2 min into the noise exposure. The tympanic temperature, blood flow, and skin temperature of the non‐immersed hand were continuously measured, along with blood pressure and subjective evaluations before and after the noise exposure. Results: Both groups experienced a decrease in fingertip skin temperature at the start of the noise exposure, persisting longer in the control group. Conversely, the hand‐bathing group showed increased fingertip skin temperature after 150 s, significantly higher after the noise exposure than the control group (p =.04). Participants in the hand‐bathing group reported significantly increased overall body warmth, thermal comfort, and relaxation during hand‐bathing (p =.007, p =.01, p <.001). Conclusions: The 2‐min hand‐bathing intervention reversed the pronounced vasoconstrictive response induced by noise exposure and elicited heightened sensations of overall body warmth, thermal comfort, and relaxation. Hand‐bathing may mitigate heightened sympathetic nervous activity associated with psychological stress induced by noise exposure. [ABSTRACT FROM AUTHOR]

Frequent extreme cold events in recent years have brought serious threats to outdoor workers and rescuers. Changes in ambient temperature are associated with altered cardiac autonomic function. The study aims to investigate heart rate variability (HRV) and its relationship to other physiological parameters under extreme cold exposures. Twelve males underwent a 30-min preconditioning phase in a neutral environment followed by a 30-min cold exposure (−5, −10, −15, and −20 °C). Time-domain indexes(meanRR, SDNN, RMSSD, and pNN50), frequency domain indexes [Log(HF), Log(LF), and low frequency/high frequency (LF/HF)], parasympathetic nervous system (PNS), and sympathetic nervous system (SNS) were analysed. Results showed all HRV indexes of four cold exposures were significant. The decrease in temperature was accompanied by progressive PNS activation with SNS retraction. SDNN was the most sensitive HRV index and had good linear relationships with blood pressure, pulse, and hand temperature. The results are significant for formulating safety protection strategies for workers in extremely cold environments. Practitioner Summary: This study investigated heart rate variability (HRV) in 12 males during a 30-min cold exposure (−5, −10, −15, and −20 °C). Results showed all HRV indexes of four cold exposures were significant. The decrease in temperature was accompanied by progressive PNS activation with SNS retraction. SDNN was the most sensitive HRV index and had good linear relationships with blood pressure, pulse, and hand temperature. [ABSTRACT FROM AUTHOR]

Background: Diabetic autonomic neuropathy is a common complication of type 2 diabetes mellitus (T2DM), especially in patients with long-term, poorly controlled diabetes. This study investigates the effects of exercise on autonomic nervous system activity in T2DM patients over time. Methods: A literature review using MEDLINE, Embase, Cochrane Library, Scopus, and PubMed identified studies assessed via heart rate variability. Papers were categorized into three groups: immediate effects (within 60 min), short-term effects (2–3 months), and long-term effects (over 4 months). Results: Nine articles with 161 T2DM patients were included in the meta-analysis. RMSSD changes after exercise were −4.3 (p = 0.227), 8.14 (p < 0.001), and 4.17 (p = 0.002) for the immediate, short-term, and long-term groups, respectively. LF/HF ratio changes were 0.21 (p = 0.264), −3.04 (p = 0.102), and −0.05 (p = 0.006) for the respective groups. Meta-regression indicated age, male gender, and exercise duration were associated with increased RMSSD, with coefficients of 2.36 (p = 0.001), 13.76 (p = 0.008), and 1.50 (p = 0.007), respectively. Age positively correlated with the LF/HF ratio, with a coefficient of 0.049 (p = 0.048). Conclusions: Regular exercise (≥3 times per week) for over 2 months increases parasympathetic activity in T2DM patients, while sympathetic activity decreases significantly after 4 months. Further study is needed to validate these findings. [ABSTRACT FROM AUTHOR]

Hypertension is recognised as a leading attributable risk factor for cardiovascular disease and premature mortality. Global initiatives towards the prevention and treatment of arterial hypertension are centred around non-pharmacological lifestyle modification. Exercise recommendations differ between professional and scientific organisations, but are generally unanimous on the primary role of traditional aerobic and dynamic resistance exercise. In recent years, isometric exercise training (IET) has emerged as an effective novel exercise intervention with consistent evidence of reductions in blood pressure (BP) superior to that reported from traditional guideline-recommended exercise modes. Despite a wealth of emerging new data and endorsement by select governing bodies, IET remains underutilised and is not widely prescribed in clinical practice. This expert-informed review critically examines the role of IET as a potential adjuvant tool in the future clinical management of BP. We explore the efficacy, prescription protocols, evidence quality and certainty, acute cardiovascular stimulus, and physiological mechanisms underpinning its anti-hypertensive effects. We end the review with take-home suggestions regarding the direction of future IET research. [ABSTRACT FROM AUTHOR]

Background: Autonomic nervous system (ANS) testing has aided in our ability to evaluate autonomic dysfunction in migraine patients. We reviewed the literature in multiple databases which investigate ANS function in migraine patients and healthy subjects. Methods: This systematic review and meta-analysis examined the respective deep breathing, Valsalva manoeuvre, orthostatic and isometric challenge results, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analyses of Observational Studies in Epidemiology (MOOSE) statements. Results: Seven articles met all inclusion criteria. Fixed-effects meta-analysis showed migraine patients (n = 424), collectively, had lower interictal autonomic test results compared with healthy controls (n = 268). In detail, this was true for the standardized mean difference (g) of deep breathing (g= -0.32; 95% confidence interval (CI) -0.48, -0.16), orthostatic challenge (g= -0.28; 95% CI -0.44, -0.13) and isometric challenge (g= -0.55; 95% CI -0.71, -0.39) and for the difference of means (MD) of the Valsalva ratio (MD = -0.17; 95% CI -0.23, -0.10). Conclusions: Interictal ANS dysfunction can be identified in migraine patients when compared to healthy controls. These findings indicate the importance to evaluate ANS function in migraine patients - especially, as migraine-specific prophylactic therapies (such as anti-calcitonin gene-related peptide (CGRP) antibodies) may affect the function of the ANS. [ABSTRACT FROM AUTHOR]

Objectives: Chronic musculoskeletal pain is associated with decreased parasympathetic and increased sympathetic activity in the autonomic nervous system. The objective of this study was to determine the associations between objective measures of heart rate variability (a measure of autonomic nervous system function), actigraphy (a measure of activity and sleep quality), respiration rates, and subjective patient‐reported outcome measures (PROMs) of central sensitization, kinesiophobia, disability, the effect of pain on sleep, and life quality. Methods: Thirty‐eight study subjects were divided into two subgroups, including low symptoms of central sensitization (n = 18) and high symptoms of central sensitization (n = 20), based on patient‐reported scores on the Central Sensitization Inventory (CSI). Heart rate variability (HRV) and actigraphy measurements were carried out simultaneously in 24 h measurement during wakefulness and sleep. Results: A decrease in HRV during the first 2 h of sleep was stronger in the low CSI subgroup compared to the high CSI subgroup. Otherwise, all other HRV and actigraphy parameters and subjective measures of central sensitization, disability, kinesiophobia, the effect of pain on sleep, and quality of life showed only little associations. Discussion: The high CSI subgroup reported significantly more severe symptoms of disability, kinesiophobia, sleep, and quality of life compared to the low CSI subgroup. However, there were only small and nonsignificant trend in increased sympathetic nervous system activity and poorer sleep quality on the high central sensitization subgroup. Moreover, very little differences in respiratory rates were found between the groups. [ABSTRACT FROM AUTHOR]

Background: Myocardial ischemia–reperfusion can further exacerbate myocardial injury and increase the risk of death. Our previous research found that the paraventricular nucleus (PVN) of the hypothalamus plays a crucial role in the improvement of myocardial ischemia–reperfusion injury (MIRI) by electroacupuncture (EA) pretreatment, but its mechanism of action is still unclear. CRH neurons exhibit periodic concentrated expression in PVN, but further research is needed to determine whether they are involved in the improvement of MIRI by EA pretreatment. Meanwhile, numerous studies have shown that changes in sympathetic nervous system innervation and activity are associated with many heart diseases. This study aims to investigate whether EA pretreatment improves MIRI through sympathetic nervous system mediated by PVNCRH neurons. Methods: Integrated use of fiber-optic recording, chemical genetics and other methods to detect relevant indicators: ECG signals were acquired through Powerlab standard II leads, and LabChart 8 calculated heart rate, ST-segment offset, and heart rate variability (HRV); Left ventricular ejection fraction (LVEF), left ventricular short-axis shortening (LVFS), left ventricular end-systolic internal diameter (LVIDs) and interventricular septal thickness (IVSs) were measured by echocardiography; Myocardial infarct area (IA) and area at risk (AAR) were calculated by Evans-TTC staining. Pathological changes in cardiomyocytes were observed by HE staining; Changes in PVNCRH neuronal activity were recorded by fiber-optic photometry; Sympathetic nerve discharges were recorded for in vivo electrophysiology; NE and TH protein expression was assayed by Western blot. Results: Our data indicated that EA pretreatment can effectively alleviate MIRI. Meanwhile, we found that in the MIRI model, the number and activity of CRH neurons co labeled with c-Fos in the PVN area of the rat brain increased, and the frequency of sympathetic nerve discharge increased. EA pretreatment could reverse this change. In addition, the results of chemical genetics indicated that inhibiting PVNCRH neurons has a similar protective effect on MIRI as EA pretreatment, and the activation of PVNCRH neurons can counteract this protective effect. Conclusion: EA pretreatment can inhibit PVNCRH neurons and improve MIRI by inhibiting sympathetic nerve, which offers fresh perspectives on the application of acupuncture in the management of cardiovascular disease. [ABSTRACT FROM AUTHOR]

Orthodontic forces are strongly associated with pain, the primary complaint among patients wearing orthodontic braces. Compared to other side effects of orthodontic treatment, orthodontic pain is often overlooked, with limited clinical management. Orthodontic forces lead to inflammatory responses in the periodontium, which triggers bone remodeling and eventually induces tooth movement. Mechanical forces and subsequent inflammation in the periodontium activate and sensitize periodontal nociceptors and produce orthodontic pain. Nociceptive afferents expressing transient receptor potential vanilloid subtype 1 (TRPV1) play central roles in transducing nociceptive signals, leading to transcriptional changes in the trigeminal ganglia. Nociceptive molecules, such as TRPV1, transient receptor potential ankyrin subtype 1, acid-sensing ion channel 3, and the P2X3 receptor, are believed to mediate orthodontic pain. Neuropeptides such as calcitonin gene-related peptides and substance P can also regulate orthodontic pain. While periodontal nociceptors transmit nociceptive signals to the brain, they are also known to modulate alveolar bone remodeling in periodontitis. Therefore, periodontal nociceptors and nociceptive molecules may contribute to the modulation of orthodontic tooth movement, which currently remains undetermined. Future studies are needed to better understand the fundamental mechanisms underlying neuroskeletal interactions in orthodontics to improve orthodontic treatment by developing novel methods to reduce pain and accelerate orthodontic tooth movement--thereby achieving "big gains with no pain" in clinical orthodontics. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to examine the effects of binaural beat music (BBM) on sleep quality, heart rate variability, and depression in older people with poor sleep quality in a long‐term care institution. Methods: A single‐blind randomized controlled trial design was employed, and 64 older participants with poor sleep quality were recruited from a long‐term care institution in Taiwan. Participants were randomized into the BBM group or control group and received 14 days of intervention. During the intervention period, participants in the experimental group listened to 20 min of Taiwanese Hokkien oldies embedded with BBM once in the morning and afternoon three times a week. Participants in the control group only listened to Taiwanese Hokkien oldies. Questionnaires and heart rate variability analysis were used to assess participants' sleep quality, heart rate variability, and depressive symptoms. Results: Significant improvements were observed in sleep quality, along with an increase in heart rate variability means of heart rate and normal sinus beats, and a decrease in low‐frequency normalized units and depression severity in the BBM group after the intervention. In the control group, effects on sleep quality were inconsistent, heart rate variability showed significant improvements in some autonomic nervous function regulation, and depression severity was significantly decreased. Furthermore, the BBM group showed a significant improvement in sleep quality and a significant reduction in sympathetic nervous activity compared with the control group. Conclusion: This study demonstrates that 14 days of BBM intervention, a non‐invasive intervention, could improve sleep quality and depression in older people with poor sleep quality in long‐term care institutions. Geriatr Gerontol Int 2024; 24: 297–304. [ABSTRACT FROM AUTHOR]

This research aimed to explore the impact of plank exercise training (PET) on respiratory function, body composition, abdominis performance, and autonomic nervous system (ANS). Sixty‐one young adults participated and were divided into a control group (CG, n = 31) and an exercise group (EG, n = 30), wherein PET was administered 3 days per week for 12 weeks. After the experiment, the body composition of the CG deteriorated, whereas that of the EG improved (p < 0.001). The EG exhibited a reduction of ∼34% in the mean maximum displacement and a rise of ∼20% in the mean contraction time of the abdominis. The sit‐up in the EG demonstrated a significant increase of ∼55%. In the EG, there was a substantial increase in peak expiratory force by ∼24% and forced expiratory volume in 1 s by ∼14%, accompanied by a reduction in resting respiratory rate by ∼ −9%. When compared to the CG, these alterations were significant between the two groups (p = 0.001). In the EG, there was a significant decrease in resting heart rate by ∼2%, accompanied by a decrease in sympathetic nervous activity by ∼ −5% and by an increase in parasympathetic nervous activity by ∼5%. When compared to the CG, these alterations were significant between the two groups (p = 0.001). The findings of this study revealed that implementing PET in young adults, while controlling for dietary intake and physical activity, resulted in noteworthy changes in respiratory capacity. These changes were coupled with improvements in body composition, abdominal functions, and the ANS. Highlights: The plank exercise training (PET) resulted in a decrease in body weight, fat mass, body mass index, and waist‐to‐hip ratio, along with an increase in muscle mass over a 12‐week period.The PET led to a decrease in the maximum displacement and an increase in the contraction time, along with an improvement in abdominal muscle endurance.The peak expiratory flow and forced expiratory volume in 1 s exhibited increases as a result of the PET, accompanied by a notable decrease in resting respiratory rate.The PET led to a reduction in resting heart rate, influenced by a decrease in sympathetic nervous activity and an increase in parasympathetic nervous activity. [ABSTRACT FROM AUTHOR]

(1) Background: Snoring is a cardinal symptom of obstructive sleep apnea (OSA) and has been suggested to potentially increase sympathetic activity. On the other hand, sleep itself usually leads to a decrease in sympathetic activity. Heart rate variability (HRV) analysis is a non-invasive technique used to assess autonomic nervous system function. However, there is limited research on the combined impact of sleep and snoring on sympathetic activity in individuals with OSA, particularly during the first hour of sleep (non-rapid eye movement sleep). The current study aims to investigate the net effect of sleep and snoring on sympathetic activity and explore factors that might contribute to increased sympathetic activity in individuals with OSA during the first hour of sleep. (2) Methods: The participants were referred from the outpatient department for OSA diagnosis and underwent whole-night polysomnography (PSG). Electrocardiogram (EKG) data from the PSG were downloaded for HRV analysis. HRV measurements were conducted in both the time and frequency domain, including the root mean square of successive differences between normal heartbeats (RMSSD) and the ratio of the absolute power of the low-frequency (LF) band (0.04–0.15 Hz) to the absolute power of the high-frequency (HF) band (0.15–0.4 Hz) (LF/HF ratio), respectively. (3) Results: A total of 45 participants (38 men and 7 women) were included in the analysis. The RMSSD gradually increased from 0–5 min to 50–60 min (p = 0.024), while the LF/HF ratio decreased (p < 0.001) during the first hour of sleep (non-rapid eye movement sleep). The LF/HF ratios of the "S" (snoring) episodes were compared with those of the pre-S episodes. An elevated LF/HF ratio during the S episode was associated with the first snoring episode occurring more than 20 min after lying down to sleep (Odds ratio, OR = 10.9, p = 0.004) and with patients diagnosed with severe OSA (OR = 5.01, p = 0.045), as determined by logistic regression. (4) Conclusions: The study observed an increase in the value of RMSSD and a decrease in the value of the LF/HF ratio during the first hour of sleep for patients with OSA. Higher LF/HF ratios were associated with the first occurrence of snoring while lying down for more than 20 min and with patients with severe OSA. [ABSTRACT FROM AUTHOR]

Hemorrhage is a leading cause of preventable battlefield and civilian trauma deaths. Ketamine, fentanyl, and morphine are recommended analgesics for use in the prehospital (i.e., field) setting to reduce pain. However, it is unknown whether any of these analgesics reduce hemorrhagic tolerance in humans. We tested the hypothesis that fentanyl (75 µg) and morphine (5 mg), but not ketamine (20 mg), would reduce tolerance to simulated hemorrhage in conscious humans. Each of the three analgesics was evaluated independently among different cohorts of healthy adults in a randomized, crossover (within drug/placebo comparison), placebo-controlled fashion using doses derived from the Tactical Combat Casualty Care Guidelines for Medical Personnel. One minute after an intravenous infusion of the analgesic or placebo (saline), we employed a pre-syncopal limited progressive lower-body negative pressure (LBNP) protocol to determine hemorrhagic tolerance. Hemorrhagic tolerance was quantified as a cumulative stress index (CSI), which is the sum of products of the LBNP and the duration (e.g., [40 mmHg x 3 min] + [50 mmHg x 3 min] ...). Compared with ketamine (p = 0.002 post hoc result) and fentanyl (p = 0.02 post hoc result), morphine reduced the CSI (ketamine (n = 30): 99 [73–139], fentanyl (n = 28): 95 [68–130], morphine (n = 30): 62 [35–85]; values expressed as a % of the respective placebo trial's CSI; median [IQR]; Kruskal-Wallis test p = 0.002). Morphine-induced reductions in tolerance to central hypovolemia were not well explained by a prediction model including biological sex, body mass, and age (R2=0.05, p = 0.74). These experimental data demonstrate that morphine reduces tolerance to simulated hemorrhage while fentanyl and ketamine do not affect tolerance. Thus, these laboratory-based data, captured via simulated hemorrhage, suggest that morphine should not be used for a hemorrhaging individual in the prehospital setting. [ABSTRACT FROM AUTHOR]

Background: This study tested the hypothesis that training reduces resting sympathetic activity and improves baroreflex control in both hypertensive and normotensive men but reduces blood pressure only in hypertensive men. Methods: Middle‐aged/older un‐medicated stage‐1 hypertensive males (mean age 55 ± 3 years; n = 13) and normotensive controls (mean age 60 ± 5 years; n = 12) participated in 8 weeks of supervised high‐intensity interval spinning training. Before and after training, muscle sympathetic nerve activity (MSNA) and blood pressure were measured at rest and during a sympatho‐excitatory cold pressor test (CPT). Based on the measurements, baroreceptor sensitivity and baroreceptor threshold were calculated. Results: Resting MSNA and baroreceptor sensitivity were similar for the hypertensive and the normotensive groups. Training lowered MSNA (p < 0.05), expressed as burst frequency (burst/min), overall, and to a similar extent, in both groups (17% and 27%, respectively, in hypertensive and normotensive group), whereas blood pressure was only significantly (p < 0.05) lowered (by 4 mmHg in both systolic and diastolic pressure) in the hypertensive group. Training did not (p > 0.05) alter the MSNA or blood pressure response to CPT or increase baroreceptor sensitivity but reduced (p < 0.05) the baroreceptor threshold with a main effect for both groups. Training adherence and intensity were similar in both groups yet absolute maximal oxygen uptake increased by 15% in the normotensive group only. Conclusion: The dissociation between the training induced changes in resting MSNA, lack of change in baroreflex sensitivity and the change in blood pressure, suggests that MSNA is not a main cause of the blood pressure reduction with exercise training in un‐medicated middle‐aged/older men. [ABSTRACT FROM AUTHOR]

The link between childhood harsh parenting and later aggression is well established. However, harsh parenting may occur within the context of nonviolent discipline. Moreover, sympathetic nervous system activity may moderate the effects of harsh parenting on aggression. This study examined whether sympathetic nervous system activity, measured by skin conductance level (SCL), and childhood nonviolent discipline moderate the link between childhood harsh parenting and later aggression among emerging adults. Participants (N = 264, mean age = 19.37, 54% females) reported retrospectively on experiences of childhood harsh parenting and nonviolent discipline as well as current anger, hostility, verbal, and physical aggression. We also measured resting SCL. Regression analyses revealed a significant three-way interaction between childhood harsh parenting, nonviolent discipline, and resting SCL accounting for anger and a significant two-way interaction between childhood harsh parenting and resting SCL accounting for hostility. Results suggested that (1) at high levels of resting SCL and low levels of childhood nonviolent discipline and (2) at low levels of resting SCL and high levels of childhood nonviolent discipline, the link between childhood harsh parenting and anger was stronger. Moreover, the association between childhood harsh parenting and hostility was stronger among participants who exhibited high resting SCL. The findings are consistent with the biological sensitivity to context theory. Our study highlighted the importance to examine the influence of both environmental and biological variables underlying emerging adults' aggression. [ABSTRACT FROM AUTHOR]

Background: Various diagnostic tools are used to assess cutaneous psoriasis, but most of it were subjective. Sympathetic skin response (SSR), skin PH and temperature objectively measure the skin barrier functions that could aid clinicians to evaluate accurately and predict skin disease incidence even before the onset of clinical symptoms. Aim and Objectives: The study's objective was to assess the utility of cutaneous parameters (skin temperature and pH) and SSRs influencing psoriatic patients' diagnosis management and treatment compared to controls. Materials and Methods: A total of 40 healthy participants and 40 psoriasis patients aged 18 to 65 years were recruited for this study. SSR, skin temperature and pH were assessed. The psoriasis disability index (PDI) was recorded from all the patients. Data analysis was carried out using SPSS version 20.0. Results: The results shows significantly increased skin temperature, prolonged SSR latency (bilaterally) and decreased SSR amplitude (bilaterally) among patients affected with psoriasis compared to control subjects. There is a positive correlation between SSR latency with PDI and a negative correlation between SSR amplitude and PDI in psoriasis patients. Conclusion: SSR reveals sympathetic sudomotor dysfunction and increased skin temperature in psoriasis. Furthermore, there is a link between increased SSR latency and PDI, which shows that local nervous system impairment significantly contributes to the inflammatory process in psoriasis. Thus, SSR can be used as a complementary tool for the early identification and assessment of epidermal barrier integrity in psoriasis patients, along with the clinician's standard protocols. [ABSTRACT FROM AUTHOR]

We investigated whether parasympathetic and sympathetic nervous system (SNS) responses to social‐evaluative threat at age 14 were related to the number of substances used between ages 14 and 16 among Mexican‐origin adolescents (N = 243; 70.4% had never used substances by 14). Participants completed the Trier Social Stress Test, while cardiac measures of parasympathetic and SNS activity were measured continuously using respiratory sinus arrhythmia (RSA) and pre‐ejection period (PEP), respectively. Participants reported whether they had ever used alcohol, marijuana, and cigarettes, and had ever vaped nicotine in their lifetime at ages 14 and 16. Multilevel models were used to test associations between RSA and PEP responses at age 14 and substance use at 16. Among youth who had not used substances by 14, dampened RSA and PEP responses, and profiles of greater coinhibition and lower reciprocal SNS activation between RSA and PEP, at age 14 were associated with using substances by 16. Among youth who used by 14, exaggerated PEP responses were associated with using more substances by age 16. Taken together, dampened autonomic responses to social‐evaluative threat predicted initiation of substance use over two years, and difficulties with coordination of physiological responses may confer risk for substance use in adolescence. [ABSTRACT FROM AUTHOR]

Suicide is among the most devastating problems facing clinicians, who currently have limited tools to predict and prevent suicidal behavior. Here we report on real-time, continuous smartphone and sensor data collected before, during, and after a suicide attempt made by a patient during a psychiatric inpatient hospitalization. We observed elevated and persistent sympathetic nervous system arousal and suicidal thinking leading up to the suicide attempt. This case provides the highest resolution data to date on the psychological, psychophysiological, and behavioral markers of imminent suicidal behavior and highlights new directions for prediction and prevention efforts. [ABSTRACT FROM AUTHOR]

Objective: Stress system dysregulation is considered to have an important role in the aetiology of paediatric functional neurological (conversion) disorder. This study examined salivary cortisol and α-amylase awakening responses in children with functional neurological disorder to determine activation patterns of the hypothalamic–pituitary–adrenal axis and sympathetic system. A healthy cortisol awakening response involves a robust increase in cortisol within 30 minutes of awakening. Alpha-amylase awakening response is variable in children. Methods: Cortisol and α-amylase were measured in saliva from 32 patients with functional neurological disorder (26 girls and 6 boys, aged 11.3−16.1 years) and 31 healthy controls (23 girls and 8 boys, aged 8.6–17.7 years). Saliva samples were collected using a Salivette sampling device at two time points – upon awakening and 30 minutes after awakening. Results: Patients with functional neurological disorder showed a decrease in cortisol awakening response (–4 nmol.min/L) and controls showed an increase (107 nmol.min/L), t (55) = –.4.6, p < 0.001. Within the functional neurological disorder group, 57% showed an attenuated cortisol awakening response and 43% showed an obliterated/reversed cortisol awakening response: Cortisol awakening response was negatively correlated with adverse childhood experiences, r (58) = –0.6, p = 0.002, and subjective distress (total Depression Anxiety and Stress Scales score), r (58) = –0.4, p = 0.050. In controls, cortisol awakening response showed no correlation with adverse childhood experiences and a positive correlation with subjective distress, r (56) = 0.4, p = 0.023. Total cortisol remained similar between the functional neurological disorder and control group. No significant differences were observed between the functional neurological disorder and control group in any of the α-amylase analyses. Discussion: The results suggest dysregulation of the hypothalamic–pituitary–adrenal axis in children with functional neurological disorder. Hypothalamic–pituitary–adrenal dysregulation in children with functional neurological disorder may contribute to comorbid symptoms of fatigue, sleep disturbance and subjective loss of well-being because circadian rhythms and energy metabolism are disrupted. Hypothalamic–pituitary–adrenal dysregulation – and changes in glucocorticoid (cortisol) signalling at the molecular level – may also contribute to increased vulnerability for functional neurological disorder symptoms because of epigenetically mediated changes to neural networks implicated in functional neurological disorder. [ABSTRACT FROM AUTHOR]

Affective processing, including induction and regulation of emotion, activates neural networks, induces physiological responses, and generates subjective experience. Dysregulation of these processes can lead to maladaptive behavior and even psychiatric morbidity. Multimodal studies of emotion thus not only help elucidate the nature of emotion, but also contribute to important clinical insights. In the present study, we compared the induction (EI) and effortful regulation (ER) with reappraisal of fear and disgust in healthy subjects using functional near infrared spectroscopy (fNIRS) in conjunction with electrodermal activity (EDA). During EI, there was significant activation in medial prefrontal cortex (PFC) for fear and more widespread activation for disgust, with right lateral PFC significantly more active during disgust compared to fear. ER was equally effective for fear and disgust reducing subjective emotion rating by roughly 45%. Compared to baseline, there was no increased PFC activity for fear during ER, while for disgust lateral PFC was significantly more active. Significant differences between the two negative emotions were also observed in sympathetic nerve activity as reflected in EDA during EI, but not during ER. Lastly, compared to men, women had higher emotion rating for both fear and disgust without corresponding differences in EDA. In conclusion, in the present study we show that emotion induction was associated with differential activation in both PFC and sympathetic nerve activity for fear and disgust. These differences were however less prominent during emotion regulation. We discuss the potential interpretation of our results and their implications regarding our understanding of negative emotion processing. [ABSTRACT FROM AUTHOR]

We investigated pupillary responses to the world's shortest fixed verses, Japanese haiku as aesthetic poetry (AP) and senryu as comic poetry (CP), in comparison with non-poetry control stimuli (NP) comprised of slogans that had the same rhythm patterns. Native Japanese speakers without literary training listened to these stimuli while we recorded their pupil diameters. We found that participants' pupils were significantly dilated for CP compared to NP in an early time window. While AP also evoked larger dilations than NP, the latency for AP-related pupil dilation was relatively long. Thus, lay people experience quick and intense arousal in response to funny and humorous words, while aesthetic properties of words may also elicit intense but slower changes in listeners' arousal levels, presumably because they evoke more implicit and subtle emotional effects. This study is the first to provide evidence that poetic language elicits human pupillary dilation. A better understanding of the cognitive and neural substrates for the sensitive awareness of pleasures expressed via poetic language will provide insights for improving mental and physical health. Hence, pupillometry can act as a useful convenient measurement to delineate the sympathetic activation of emotional contexts via language. [ABSTRACT FROM AUTHOR]

Acute mental fatigue, characterized by a transient decline in cognitive efficiency during or following prolonged cognitive tasks, can be managed through adaptive effort deployment. In response to mental fatigue, individuals can employ two main behavioral patterns: engaging a compensatory effort to limit performance decrements, or disengaging effort, leading to performance deterioration. This study investigated the behavioral pattern used by participants in mental fatigue conditions. Fifty participants underwent a sequential-task protocol with counterbalanced sessions who took place in two separate sessions: a 30-min incongruent Stroop task (fatiguing session) or a 30-min documentary viewing task (control session), followed by a time-to-exhaustion (TTE) handgrip task at 13 % of maximal voluntary contraction. Psychophysiological measures included the preejection period, heart rate variability, blood pressure, and respiration. Behavioral results showed deteriorated TTE handgrip performance after the Stroop task compared to after the documentary viewing task. During the Stroop task participants were more conservative and prioritized accuracy over speed. Self-reported fatigue was greater after the Stroop task. Psychophysiological data revealed a gradual decrease in sympathetic activity over time in both tasks, with the Stroop task showing a more pronounced decrease. Taken together, these findings suggest a disengagement of effort for a large proportion of participants (49 %) that could be partly attributed to a habituation to the demands of the Stroop task. This study illustrates the interplay of behavioral patterns of effort investment in the context of mental fatigue and underscores the role of disengagement as a dominant response to this phenomenon among healthy participants. • A conservative strategy favoring accuracy was adopted during a cognitive task that induced mental fatigue. • Mental fatigue during a cognitive task leads to a decrease in sympathetic activity with increasing time-on task. • Mental fatigue induced by a 30-min effortful cognitive task impairs the performance in a subsequent endurance physical task. [ABSTRACT FROM AUTHOR]

A low-frequency to a high-frequency component ratio (LF/HF) in heart rate variability (HRV) may not accurately reflect sympathetic nervous activity during exercise. Thus, a valid HRV-based index of sympathetic nervous activity is needed. Therefore, the heart rate to LF ratio (Heart rate/LF) was evaluated as sympathetic nervous activity index which is reflected by catecholamine levels during incremental exercise. In this study, 15 healthy adults performed an incremental exercise test using a cycle ergometer. HRV was derived from electrocardiography and HRV components related to the autonomic nervous system were obtained using frequency analysis. Heart rate/LF was calculated using the heart rate and LF component produced by HRV analysis. Catecholamine, blood lactate levels and respiratory gas were also measured throughout the exercise test. While LF/HF did not increase with increasing exercise intensity, Heart rate/LF non-linearly increased during the incremental exercise test, as did noradrenaline and blood lactate. Interestingly, Heart rate/LF values were positively correlated with noradrenaline (ρ = 0.788, p < 0.05) and blood lactate (ρ = 0.802, p < 0.05) levels and carbon dioxide production (ρ = 0.903, p < 0.05) from at rest through the exercise stages. Heart rate/LF reflects sympathetic nervous activity and metabolic responses during incremental cycling exercise and has potential as an HRV index of sympathetic nervous activity during exercise. Trial registration: UMIN Japan identifier: UMIN000039639. [ABSTRACT FROM AUTHOR]

Introduction: Autonomic nervous system functioning is theorised to underpin individual differences in sensory processing, with a small amount of supporting evidence. Despite recognition of the need to measure the balance between sympathetic and parasympathetic activity, most studies have measured only one of these systems. This study investigated whether sensory processing patterns are related to autonomic balance for young adults at rest and in response to a sensory-based stressor. Method: In this cross-sectional laboratory study, 100 young adults completed the adolescent/adult sensory profile. Heart rate variability and pre-ejection period were recorded before, during and after a coldpressor task. Results: Relationships between sensory processing patterns and autonomic balance varied by gender. In males, low sensory thresholds were generally related to a state of reciprocal sympathetic activation. In females, low thresholds were associated with greater autonomic reactivity in response to the coldpressor. Conclusion: This study showed, for the first time in young adults, that sensory processing patterns may be linked to patterns of autonomic balance. Therapists should be aware that young men with low sensory thresholds may be more likely than others to exhibit a resting state of sympathetic hyperarousal and further research should investigate whether this impacts their daily functioning and wellbeing. [ABSTRACT FROM AUTHOR]

The sympathetic and renin-angiotensin systems (RAS) are two critical regulatory systems in the kidney which affect renal hemodynamics and function. These two systems interact with each other so that angiotensin II (Ang II) has the presynaptic effect on the norepinephrine secretion. Another aspect of this interaction is that the sympathetic nervous system affects the function and expression of local RAS receptors, mainly Ang II receptors. Therefore, in many pathological conditions associated with an increased renal sympathetic tone, these receptors' expression changes and renal denervation can normalize these changes and improve the diseases. It seems that the renal sympathectomy can alter Ang II receptors expression and the distribution of RAS receptors in the kidneys, which influence renal functions. [ABSTRACT FROM AUTHOR]

We explore complex dynamic patterns of autonomic physiological linkage (i.e., statistical interdependence of partner's physiology; PL), within the sympathetic and parasympathetic nervous systems (SNS and PNS), as potential correlates of emotional and regulatory dynamics in close relationships. We include electrodermal activity (EDA) as an indicator of SNS activation and respiratory sinus arrhythmia (RSA) as an indicator of regulatory and/or homeostatic processes within the PNS. Measures of EDA and RSA were collected in 10-second increments from 53 heterosexual couples during a mixed-emotion conversation in the laboratory. We used the R statistical package, rties (Butler & Barnard, 2019), to model the dynamics of EDA and RSA with a coupled oscillator model and then categorized couples into qualitatively distinct profiles based on the set of parameters that emerged. We identified two patterns for EDA and three patterns for RSA. We then investigated associations between the PL patterns and self-report measures of relationship and conversation quality and emotional valence using Bayesian multilevel and logistic regression models. Overall, we found robust results indicating that PL profiles were credibly predicted by valence and relationship quality reported prior to the conversations. In contrast, we found very little evidence suggesting that PL patterns predict self-reported conversation quality or valence following the conversation. Together, these results suggest that PL across autonomic subsystems may reflect different processes and therefore have different implications when considering interpersonal dynamics. [ABSTRACT FROM AUTHOR]

It has been suggested that intimate partner violence (IPV) against women perpetrators present emotional dysregulations when dealing with acute stress, which in turn could help to explain their proneness to violence. Emotional regulation can be objectively measured by means of psychophysiological parameters/variables/indicators of autonomic nervous system (ANS) activity, such as cardiorespiratory (heart rate [HR], pre-ejection period [PEP] and respiratory sinus arrythmia [RSA]) and electrodermal (skin conductance levels [SCL]) signals. Therefore, this study aims to assess whether IPV perpetrators (n = 107) present differential psychophysiological and psychological state changes when coping with an acute cognitive laboratory stressor (a set of cognitive tests performed in front of an expert committee) in comparison with nonviolent men (n = 87). Moreover, the study assesses whether psychological state variables foster the psychophysiological response to acute stress. Our results demonstrate that, compared to nonviolent controls, IPV perpetrators showed higher HR and SCL values, shorter PEP, and lower RSA values during recovery from stress. They also presented higher negative affect (i.e., more anger and worse mood) after stress. Thus, high baseline anger explained the increases in emotional arousal when measured as SCL increases. The present study contributes evidence showing that IPV perpetrators and nonviolent men cope differently with stress. These findings might help forensic science to identify characteristics of violent individuals to establish their therapeutic needs. Furthermore, it would be appropriate to combine psychophysiological measurements with self-reports, thus increasing the reliability of the assessment of violent individuals. [ABSTRACT FROM AUTHOR]

Explaining the onset and maintenance of pain can be challenging in many clinical presentations. Allostasis encompasses the mechanisms through which humans adapt to stressors to maintain physiological stability. Due to related neuro-endocrine-immune system effects, allostasis and allostatic load (the cumulative effects on the brain and body that develop through the maintenance of physiological stability) offer the potential to explain the development and maintenance of musculoskeletal pain in certain cases. This paper outlines the concept of allostatic load, highlights the evidence for allostatic load in musculoskeletal pain conditions to date, and discusses mechanisms through which allostatic load influences pain, with particular focus on hypothalamic–pituitary–adrenal axis and sympathetic nervous system function and central, brain-driven governance of these systems. Finally, through case examples, consideration is given as to how allostatic load can be integrated into clinical reasoning and how it can be used to help explain pain to individuals and guide clinical decision-making. Impact Awareness of the concept of allostatic load, and subsequent assessment of physical and psychological stressors potentially contributing to allostatic load, may facilitate a broader understanding of the multidimensional presentations of many people with pain, both acute and persistent. This may facilitate discussion between clinicians and their patients regarding broader influences on their presentations and drive more targeted and inclusive pain management strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Breast cancer is the most common cancer affecting women of all ages worldwide. In spite of the encouraging advances made in early diagnosis, 10% of breast cancer patients are still affected with metastatic breast cancer at the time of diagnosis. The available therapeutic options are predominantly palliative, and thus this unfavourable prognosis is associated with a low survival rate. Intriguingly, stress has been shown to promote the growth of breast tumours and the incidence of metastasis. Herein, we describe the contribution of the sympathetic hyperactivation induced by stress to the progression of breast cancer and its dissemination to distant organs, specifically to the bone, but also to the lung, liver and brain. The putative sympathetic adrenergic signalling mechanisms responsible for this modulation are also summarised. The knowledge gathered highlights the therapeutic potential of targeting sympathetic signalling to tackle cancer progression and metastasis. Breast cancer (BRCA) remains as one the most prevalent cancers diagnosed in industrialised countries. Although the overall survival rate is high, the dissemination of BRCA cells to distant organs correlates with a significantly poor prognosis. This is due to the fact that there are no efficient therapeutic strategies designed to overcome the progression of the metastasis. Over the past decade, critical associations between stress and the prevalence of BRCA metastases were uncovered. Chronic stress and the concomitant sympathetic hyperactivation have been shown to accelerate the progression of the disease and the metastases incidence, specifically to the bone. In this review, we provide a summary of the sympathetic profile on BRCA. Additionally, the current knowledge regarding the sympathetic hyperactivity, and the underlying adrenergic signalling pathways, involved on the development of BRCA metastasis to distant organs (i.e., bone, lung, liver and brain) will be revealed. Since bone is a preferential target site for BRCA metastases, greater emphasis will be given to the contribution of α2- and β-adrenergic signalling in BRCA bone tropism and the occurrence of osteolytic lesions. [ABSTRACT FROM AUTHOR]

Introduction: Postmenopausal women (PMW) display exaggerated increases in blood pressure (BP) during exercise, yet the mechanism(s) involved remain unclear. Moreover, research on the impact of menopausal changes in estradiol on cardiovascular control during exercise are limited. Herein, we tested the hypothesis that sympathetic responses during exercise are augmented in PMWcompared with young women (YW), and estradiol administration attenuates these responses. Methods : Muscle sympathetic nerve activity (MSNA) and mean arterial pressure (MAP) were measured in 13 PMW (58 +/- 1 yr) and 17 YW (22 +/- 1 yr) during 2 min of isometric handgrip. Separately, MSNA and BP responses were measured during isometric handgrip in six PMW (53 +/- 1 yr) before and after 1 month of transdermal estradiol (100 [mu]g[middle dot]d-1). A period of postexercise ischemia (PEI) to isolate muscle metaboreflex activation followed all handgrip bouts. Results : Resting MAP was similar between PMW and YW, whereas MSNA was greater in PMW (23 +/- 3 vs 8 +/- 1 bursts per minute; P < 0.05). During handgrip, the increases in MSNA (PMW [DELTA]16 +/- 2 vs YW [DELTA]6 +/- 1 bursts per minute; P < 0.05) and MAP (PMW [DELTA]18 +/- 2 vs YW [DELTA]12 +/- 2 mm Hg; P < 0.05) were greater in PMW and remained augmented during PEI. Estradiol administration decreased resting MAP but not MSNA in PMW. Moreover, MSNA (PMW (-E2) [DELTA]27 +/- 8 bursts per minute versus PMW (+E2) [DELTA]12 +/- 5 bursts per minute; P < 0.05) and MAP ([DELTA]31 +/- 8 mm Hg vs [DELTA]20 +/- 6 mm Hg; P < 0.05) responses during handgrip were attenuated in PMW after estradiol administration. Likewise, MAP responses during PEI were lower after estradiol. Conclusions : These data suggest that PMW exhibit an exaggerated MSNA and BP response to isometric exercise, due in part to heightened metaboreflex activation. Furthermore, estradiol administration attenuated BP and MSNA responses to exercise in PMW. [ABSTRACT FROM AUTHOR]

Electrodermal activity (EDA)—a measure of electrical skin conductance reflecting (exclusive) sympathetic control of the eccrine sweat gland—holds promise as an indicator of central sympathetic activation. The aim of this study was to determine whether combat and blast exposure modulate the EDA response to acute exercise stress in specialised military men. Fifty‐one men (age M = 36.1, SD = 6.5) participated in this study as part of the Explosive Ordnance Disposal Operational Health Surveillance System. The EDA complex (i.e., tonic + phasic conductance) was continuously measured throughout a maximal effort, graded exercise test. As expected, exercise stress resulted in measurable, stepwise increases in EDA before tapering at higher exercise intensities. Individuals with more substantial combat exposure and those with blast exposure demonstrated blunted EDA patterns in comparison to their low/nonexposed counterparts. This blunted pattern might imply sub‐optimal sympathetic nervous system function in the exposed cohorts and enhances our knowledge of factors influencing resilience in these men. [ABSTRACT FROM AUTHOR]

Stressors and mortality salience share considerable conceptual overlap. Thus, we examined the impact of a standard mortality salience and a standard stress manipulation on the activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis via endocrine measures of stress; a neutral control condition completed the design. The results revealed that stress elicits increased salivary α-amylase and salivary cortisol reactions; however, no endocrine reactions were found in the mortality salience and the control conditions. To the contrary, we did not find any differences regarding positive and negative affect between any conditions. Implications for social and health psychology are being discussed. [ABSTRACT FROM AUTHOR]

The increasing prevalence of obesity has resulted in demands for the development of new effective strategies for obesity treatment. Withaferin A (WA) shows a great potential for prevention of obesity by sensitizing leptin signaling in the hypothalamus. However, the mechanism underlying the weight- and adiposity-reducing effects of WA remains to be elucidated. In this study, we report that WA treatment induced white adipose tissue (WAT) browning, elevated energy expenditure, decreased respiratory exchange ratio, and prevented high-fat diet-induced obesity. The sympathetic chemical denervation dampened the WAT browning and also impeded the reduction of adiposity in WA-treated mice. WA markedly upregulated the levels of Prdm16 and FATP1 (Slc27a1) in the inguinal WAT (iWAT), and this was blocked by sympathetic denervation. Prdm16 or FATP1 knockdown in iWAT abrogated the WAT browning-inducing effects of WA and restored the weight gain and adiposity in WA-treated mice. Together, these findings suggest that WA induces WAT browning through the sympathetic nerve-adipose axis, and the adipocytic Prdm16-FATP1 pathway mediates the promotive effects of WA on white adipose browning. [ABSTRACT FROM AUTHOR]

The study investigated the role of α2-adrenergic receptors of the caudal raphe region in the sympathetic and cardiovascular responses to the acute intermittent hypercapnia (AIHc). Urethane-anesthetized, vagotomized, mechanically ventilated Sprague-Dawley rats (n=38) were exposed to the AIHc protocol (5×3 min, 15 % CO2+50 % O2) in hyperoxic background (50 % O2). α2-adrenergic receptor antagonist-yohimbine was applied intravenously (1 mg/kg, n=9) or microinjected into the caudal raphe region (2 mM, n=12) prior to exposure to AIHc. Control groups of animals received saline intravenously (n=7) or into the caudal raphe region (n=10) prior to exposure to AIHc. Renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) were monitored before exposure to the AIHc protocol (T0), during five hypercapnic episodes (THc1-5) and at 15 min following the end of the last hypercapnic episode (T15). Following intravenous administration of yohimbine, RSNA was significantly greater during THc1-5 and at T15 than in the control group (P<0.05). When yohimbine was microinjected into the caudal raphe region, AIHc elicited greater increases in RSNA during THc1-5 when compared to the controls (THc1: 138.0±4.0 % vs. 123.7±4.8 %, P=0.032; THc2: 137.1±5.0 % vs. 124.1±4.5 %, P=0.071; THc3: 143.1±6.4 % vs. 122.0±4.8 %, P=0.020; THc4: 146.1±6.2 % vs. 120.7±5.7 %, P=0.007 and THc5: 143.2±7.7 % vs. 119.2±7.2 %, P=0.038). During THc1-5, significant decreases in HR from T0 were observed in all groups, while changes in MAP were observed in the group that received yohimbine intravenously. These findings suggest that blockade of the α2-adrenegic receptors in the caudal raphe region might have an important role in sympathetic responses to AIHc. [ABSTRACT FROM AUTHOR]

Diverticular disease pathogenesis is still unknown in depth. Adaptation to a severe social stress possibly generates sustained dominance of the sympathetic over the parasympathetic activity, leading through a prolonged spasm of the sigmoid to the creation of diverticula and the related disease. Based on case series, we suggest an imbalance in autonomic nervous activity as a component of the multisystemic complex pathophysiology of diverticular disease. [ABSTRACT FROM AUTHOR]

Cognitive skills are a set of higher-order thinking processes that allow children to learn successfully. By developing cognitive skills, the brain is connected to Rapidly complete the information processes. The aim of this study was to examine the cognitive process development, decision making and eventually cognitive performance in school-age children evaluated by the galvanic skin conductance response (SCR) method. Peripheral SCR signals during cognitive loading were recorded in children in grades 1 to 3 of a representative school in Southern Thailand. Eriksen flanker and dexterity tests were conducted to evaluate the development of its association with cognitive skill. Regression-based analyses showed reduced reaction time on Eriksen flanker (both congruent trials with regression coefficient = -0.02924, p <0.001 and incongruent trials with regression coefficient = -0.04231, p <0.001) and time spent to achieve dexterity tests (regression coefficient = -0.32206379, p <0.05) from students' grades 1 to 3. In SCR modulation, analysis of variance revealed highest peak SCR magnitudes in students grade 3, compared to students in grade 2 (p <0.001) and grade 1 (p =0.046). On the other hands, numbers of peaks were highest in students grade 1 when they were in the calm stage (p <0.001), and highest in student grade 3 (p =0.002) when they were in the focus mind state. These findings support the association of the psychophysiological index of changes in brain and cognitive development among age related experience to focus attention improving under the task. [ABSTRACT FROM AUTHOR]

Purpose: Larger blood pressure (BP) responses to relative-intensity static exercise in men versus women are thought to involve altered muscle metaboreflex activation, but whether this is because of an intrinsic sex difference in metabolite production or differences in muscle strength and absolute load is unknown. Methods : Continuous BP and heart rate were recorded in 200 healthy young men and women (women: n = 109) during 2 min of static handgrip exercise at 30% of maximal voluntary contraction (MVC), followed by 2 min of postexercise circulatory occlusion (PECO). Muscle sympathetic nerve activity (MSNA) was recorded in a subset of participants (n = 39; women, n = 21), permitting calculation of signal-averaged resting sympathetic transduction (MSNA-diastolic BP). Sex differences were examined with and without statistical adjustment for MVC. Multivariate regression analyses were performed to identify predictors of BP responses. Results : Men had larger systolic BP responses (interactions, P < 0.0001) to static handgrip exercise (24 +/- 10 vs 17 +/- 9 mm Hg [mean +/- SD], P < 0.0001) and PECO (20 +/- 11 vs 16 +/- 9 mm Hg, P < 0.0001). Adjustment for MVC abolished these sex differences in BP (interactions, P > 0.7). In the subset with MSNA, neither burst frequency or incidence responses to static handgrip exercise or PECO differed between men and women (interactions, P > 0.2). Resting sympathetic transduction was also similar (P = 0.8). Multiple linear regression analysis showed that MVC or the change in MSNA, were predictors of BP responses to static handgrip, but only MVC was associated with BP responses during PECO. Conclusions: Sex differences in absolute contraction load contribute to differences in BP responses during muscle metaboreflex isolation using PECO. These data do not support an intrinsic effect of sex as being responsible for exercise BP differences between men and women. [ABSTRACT FROM AUTHOR]

Both anxiety and autism spectrum disorder (ASD) are associated with atypical physiological activity. Few studies have systematically assessed the resting physiological activity in ASD with co-occurring anxiety disorders. We tested 75 participants divided in four groups: youth with ASD, with (ASD + Anxiety = 22, 6F, 12.29 ± 2.83 years old) and without co-occurring anxiety (ASD Alone = 15, 6F, 11.59 ± 2.85 years old) and compared their physiological profile with that of matched typically developing controls (TDC) with (Anxiety Alone = 16, 6F, 11.24 ± 3.36 years old) and without co-occurring anxiety disorders (TDC = 22, 8F, 11.88 ± 2.88 years old). Results indicated reduced sympathetic and parasympathetic activity at rest in ASD as compared to TDC youth. ASD + Anxiety and Anxiety Alone groups showed different sympathetic, but similar parasympathetic activity. These findings suggest that autonomic profile-based approaches may advance research, diagnosis, and treatment of ASD and anxiety. [ABSTRACT FROM AUTHOR]

Objective: This study aims to compare the instantaneous effects of chiropractic upper and middle thoracic manipulations on the autonomic nervous system. Material-Method: The study included 30 healthy volunteers aged 18-45 years. Manipulation was applied to the upper thoracic (T1-4) area (n=15, 8 female, 7 male) and to the middle thoracic (T6-9) area (n=15, 7 female, 8 male). Before the application, heart rate, body temperature and skin conductivity (EDA) measurements were performed using the Empatica E4 wristband device. Thoracic HVLA (high velocity low amplitude) manipulation was performed in the supine position. After the application, the measurement made with the Empatica E4 device was repeated. The mean body temperature and skin conductivity values were calculated for the analysis of the data. Heart rate data were evaluated using Kubios heart rate variability (HRV) standard program. Detailed information about the effects of upper and middle thoracic area manipulation on the autonomic nervous system was obtained according to the analysis results of the data obtained before and after manipulation. Correlation analysis of pre- and post-manipulation data and difference analysis between the two groups were performed based on significance level p<0.05. Results: As a result of the research, no significant changes in parasympathetic nervous system values such as RMSSD, pNN50, PNS Index and sympathetic nervous system values such as Stress Index and SNS Index were observed after upper thoracic manipulation. After middle thoracic manipulation, significant decreases occurred in sympathetic nervous system values such as Stress Index, SNS Index, while significant increases occurred in parasympathetic nervous system values such as RMSSD, pNN50, PNS Index. It was observed that there was no significant change in temperature and EDA. Conclusion: As a result of our measurements and analyzes, it was seen that chiropractic upper and middle thoracic manipulations had different instantaneous effects on the autonomic nervous system. [ABSTRACT FROM AUTHOR]

Objective: To assess the effectiveness of catheter-based renal denervation for reducing blood pressure in patients with resistant hypertension using a 5 F microtube-irrigated ablation catheter. Methods: Sixty patients with resistant hypertension were divided into two groups: a microtube-irrigated ablation catheter group and a general ablation catheter group. We conducted 12-month follow-up of all patients and recorded clinical blood pressure, ambulatory blood pressure, medication use, and biochemistry test results in both groups at the baseline and at the 12-month follow-up. Results: All patients underwent renal denervation. At the 6-month follow-up, ambulatory blood pressure in the microtube-irrigated ablation catheter group was significantly lower than in the general ablation catheter group (systolic blood pressure 142.0 ± 14.4 mmHg vs. 150.8 ± 17.9 mmHg, P = 0.04; diastolic blood pressure 81.2 ± 7.0 mmHg vs. 87.6 ± 8.0 mmHg, P = 0.002). At the 12-month follow-up, the between-group difference in ambulatory blood pressure was not statistically significant. At the 12-month follow-up, the number of antihypertensive drugs and diuretics used in the microtube-irrigated ablation catheter group was less than in the general ablation catheter group (P = 0.043). There was no statistical difference between the two groups in the results of biochemistry tests and echocardiography. Conclusion: The microtube-irrigated ablation catheter is more effective in treating hypertension than the general ablation catheter at the 6-month follow up and thus fewer antihypertensive drugs were used in the microtube-irrigated ablation catheter group than in the general ablation catheter group. [ABSTRACT FROM AUTHOR]

The aim of our study is to investigate the sympathetic output and baroreflex via renal sympathetic nerve activity (RSNA) recording in a model of severe hypertension which exhibits arterial, cardiac, and renal damages, the spontaneously hypertensive rat (SHR) under lowered NO bioavailability. SHR are treated from 18 to 20 weeks of age with a low dose of L-NAME, a NO synthase inhibitor, in drinking water (SHRLN) and compared to SHR and normotensive Wistar Kyoto (WKY) rats. After the two-week treatment, rats are anesthetized for RSNA, mean blood pressure (MBP), and heart rate (HR) recording. MBP is higher in SHR than in WKY and higher in SHRLN than in SHR. Compared to WKY, SHR displays an alteration in the baroreflex with a displacement of the sympathoinhibition curve to highest pressures; this displacement is greater in SHRLN rats. The bradycardic response is reduced in SHRLN compared to both SHR and WKY. In hypertensive rats, SHR and SHRLN, basal RSNA is modified, the maximal amplitude of burst is reduced, but minimal values are increased, indicating an increased basal RSNA with reduced bursting activity. The temporal correlation between RSNA and HR is preserved in SHR but altered in 10 SHRLN out of 10. The RSNA inhibition triggered by the Bezold–Jarisch reflex activation is not modified in hypertensive rats, SHR or SHRLN, in contrast to that triggered by the baroreflex. Histological analysis of the carotid bifurcation does not reveal any abnormality in SHRLN at the level of the carotid sinus. In conclusion, data indicate that the sympathetic outflow is altered in SHRLN with a strong reduction of the baroreflex sympathoinhibition and suggest that its central pathway is not involved. These additional results on SHRLN also confirm the usefulness of this model of severe hypertension with multiple target organ damages. [ABSTRACT FROM AUTHOR]

Purpose: In normotensive patients with obstructive sleep apnea (OSA), the muscle sympathetic nerve activity (MSNA) response to exercise is increased while metaboreflex control of MSNA is decreased. We tested the hypotheses that acute intermittent hypercapnic hypoxia (IHH) in males free from OSA and associated comorbidities would augment the MSNA response to exercise but attenuate the change in MSNA during metaboreflex activation. Methods: Thirteen healthy males (age = 24 ± 4 yr) were exposed to 40 min of IHH. Before and after IHH, the pressor response to exercise was studied during 2 min of isometric handgrip exercise (at 30%maximal voluntary contraction), whereas themetaboreflex was studied during 4min of postexercise circulatory occlusion (PECO).Mean arterial pressure (MAP), heart rate (HR), and fibularMSNA were recorded continuously. MSNA was quantified as burst frequency (BF) and total activity (TA).Mixed effects linear models were used to compare the exercise pressor andmetaboreflex before and after IHH. Results: As expected, IHH led to significant increases in MSNA BF, TA, and MAP at baseline and throughout exercise and PECO. However, during handgrip exercise, the change from baseline inMAP,HR,MSNABF, and TA was similar before and after IHH(All P > 0.31).During PECO, the change from baseline inMSNA BF and TA was similar after IHH, whereas the change from baseline inMAP (Δ14mmHg, 95% CI = 7-19, vs Δ16mmHg, 95% CI = 10-21; P < 0.01) wasmodestly increased. Conclusion: After acute IHH,MSNAresponse to handgrip exercise and metaboreflex activationwere preserved in healthy young males despite overall increases in resting MSNA and MAP. Chronic IHH and comorbidities often associated with OSA may be required to modulate the exercise pressor reflex and metaboreflex. [ABSTRACT FROM AUTHOR]

Background. Changes in the composition and diversity of gut microbiota, which can be altered by autonomic nerve activity, contribute to the development of heart failure (HF). Renal denervation (RDN) can improve cardiac function by reducing sympathetic nerve activity. However, whether the beneficial role of RDN on HF is related to gut microbiota is unknown. Methods. Thirty rats were assigned to a control, HF (with induced transverse aortic constriction (TAC)), RDN (with RDN induced 10 weeks after TAC), Nog (HF rats with Nogo-P4-administered 8 weeks after RDN), and NEP (HF rats with NEP1-40-administered 8 weeks after RDN) group. Then, 16SrRNA amplicon sequencing and analyses of fecal samples were performed. Results. Beta diversity analyses revealed that compared to the HF group, the RDN, Nog, and NEP groups clustered closer to the control group. The Firmicutes/Bacteroidetes ratio was reduced in the HF group (1.59) compared with the control group (3.21) and was significantly decreased compared to the Nog (7.19), RDN (6.20), and NEP (4.42) groups. At the genus level, the HF group showed decreased abundances of Lactobacillus and Alistipes and increased abundances of Bacteroides and Clostridium compared with the control group. The abundances of Lactobacillus and Alistipes were increased, and those of Bacteroides and Clostridium were decreased in the RDN, Nog, and NEP groups compared to the HF group. However, no differences were observed between the three groups that underwent RDN. The microbial function showed the same tendency. Conclusions. RDN reversed the abnormal changes in the gut microbiome in HF rats. Inhibition of reinnervation after RDN did not affect intestinal bacteria. [ABSTRACT FROM AUTHOR]

Background: Neurolytic splanchnic nerve block is used to manage pancreatic cancer pain. However, its impact on survival and quality of life remains controversial. The authors' primary hypothesis was that pain relief would be better with a nerve block. Secondarily, they hypothesized that analgesic use, survival, and quality of life might be affected.Methods: This randomized, double-blind, parallel-armed trial was conducted in five Chinese centers. Eligible patients suffering from moderate to severe pain conditions were randomly assigned to receive splanchnic nerve block with either absolute alcohol (neurolysis) or normal saline (control). The primary outcome was pain relief measured on a visual analogue scale. Opioid consumption, survival, quality of life, and adverse effects were also documented. Analgesics were managed using a protocol common to all centers. Patients were followed up for 8 months or until death.Results: Ninety-six patients (48 for each group) were included in the analysis. Pain relief with neurolysis was greater for the first 3 months (largest at the first month; mean difference, 0.7 [95% CI, 0.3 to 1.0]; adjusted P < 0.001) compared with placebo injection. Opioid consumption with neurolysis was lower for the first 5 months (largest at the first month; mean difference, 95.8 [95% CI, 67.4 to 124.1]; adjusted P < 0.001) compared with placebo injection. There was a significant difference in survival (hazard ratio, 1.56 [95% CI, 1.03 to 2.35]; P = 0.036) between groups. A significant reduction in survival in neurolysis was found for stage IV patients (hazard ratio, 1.94 [95% CI, 1.29 to 2.93]; P = 0.001), but not for stage III patients (hazard ratio, 1.08 [95% CI, 0.59 to 1.97]; P = 0.809). No differences in quality of life were observed.Conclusions: Neurolytic splanchnic nerve block appears to be an effective option for controlling pain and reducing opioid requirements in patients with unresectable pancreatic cancer.Editor’s Perspective: [ABSTRACT FROM AUTHOR]

Background: Transcutaneous electrical acupoint stimulation (TEAS) improves autonomic balance and reduces oxidative stress in subjects with chronic diseases, that decreases the risk of low-grade chronic inflammatory diseases, including cardiovascular diseases. However, these beneficial effects have never been demonstrated in healthy subjects. Objectives: To evaluate the acute effects of TEAS on autonomic balance and oxidative stress of healthy subjects. Methods: A randomized clinical trial was conducted with male healthy subjects (18-30 years old), randomly allocated to control (no intervention; n = 14), placebo (placebo intervention; n = 14) and TEAS group (at PC5 and PC6 acupoints; n = 13). The protocol consisted of accommodation (20 min), intervention (40 min), and recovery (30 min) periods. The acute effects of TEAS on hemodynamics were studied through measurements of heart rate, blood pressure and double product; on the autonomic nervous system by assessing heart rate variability; and on oxidative stress by quantifying reactive oxygen species in saliva samples, collected at the end of each period. Results: TEAS increased heart rate and double-product compared to control and placebo groups (p < 0.01). Moreover, TEAS increased sympathetic and reduced parasympathetic tonus, increasing the sympathovagal balance compared to the control and placebo groups. However, TEAS exerted no effect on oxidative stress in saliva samples. Conclusion: In healthy subjects, TEAS at PC5 and PC6 acupoints acutely improved autonomic balance, increasing sympathetic and reducing parasympathetic tonus, reflecting little improvement on hemodynamic responses. Whether it could be used as a cardioprotective strategy remains uncertain since it exerted no effect on oxidative stress. [ABSTRACT FROM AUTHOR]

The article presents the Heart failure-specific inverse relationship between the muscle sympathetic response to dynamic leg exercise and VO2peak. Topics discussed include Exercise intolerance, a symptom afflicting the majority of patients with heart failure with reduced ejection fraction (HFrEF), has been attributed classically to a range of disturbances; and the purpose of the present work was to test the hypothesis that the percent predicted VO2peak of patients with HFrEF relates.

The article presents the Heart failure-specific inverse relationship between the muscle sympathetic response to dynamic leg exercise and VO2peak. Topics discussed include Exercise intolerance, a symptom afflicting the majority of patients with heart failure with reduced ejection fraction (HFrEF), has been attributed classically to a range of disturbances; and the purpose of the present work was to test the hypothesis that the percent predicted VO2peak of patients with HFrEF relates.

The counterregulatory response to hypoglycemia is an essential survival function. It is controlled by an integrated network of glucose-responsive neurons, which trigger endogenous glucose production to restore normoglycemia. The complexity of this glucoregulatory network is, however, only partly characterized. In a genetic screen of a panel of recombinant inbred mice we previously identified Fgf15, expressed in neurons of the dorsomedial hypothalamus (DMH), as a negative regulator of glucagon secretion. Here, we report on the generation of Fgf15CretdTomato mice and their use to further characterize these neurons. We show that they were glutamatergic and comprised glucose-inhibited and glucose-excited neurons. When activated by chemogenetics, Fgf15 neurons prevented the increase in vagal nerve firing and the secretion of glucagon normally triggered by insulin-induced hypoglycemia. On the other hand, they increased the activity of the sympathetic nerve in the basal state and prevented its silencing by glucose overload. Higher sympathetic tone increased hepatic Creb1 phosphorylation, Pck1 mRNA expression, and hepatic glucose production leading to glucose intolerance. Thus, Fgf15 neurons of the DMH participate in the counterregulatory response to hypoglycemia by a direct adrenergic stimulation of hepatic glucose production while suppressing vagally induced glucagon secretion. This study provides new insights into the complex neuronal network that prevents the development of hypoglycemia. [ABSTRACT FROM AUTHOR]

Purpose: Women who develop gestational hypertension have evidence of elevated muscle sympathetic nerve activity (MSNA) in early pregnancy, which continues to rise after diagnosis. Exercise has been shown to play a preventative role in the development of gestational hypertension and has been shown to reduce resting and reflex MSNA in nonpregnant populations. We sought to investigate whether aerobic exercise affected the sympathetic regulation of blood pressure between the second and third trimesters of pregnancy. Methods: We conducted a randomized controlled trial of structured aerobic exercise (n = 31) compared with no intervention (control, n = 28) beginning at 16–20 wk and continuing until 34–36 wk of gestation (NCT02948439). Women in the exercise group were prescribed aerobic activity at 50%–70% of their heart rate reserve, on 3–4 d·wk−1 for 25–40 min with a 5-min warm-up and 5-min cool-down (i.e., up to 160 min total activity per week). At preintervention and postintervention assessments, data from ~10 min of quiet rest and a 3-min cold pressor test were analyzed to determine sympathetic nervous system activity and reactivity. Results: MSNA was obtained in 51% of assessments. Resting MSNA burst frequency and burst incidence increased across gestation (main effect of gestational age, P = 0.002). Neurovascular transduction was blunted in the control group (P = 0.024) but not in exercisers (P = 0.873) at the postintervention time point. Lastly, MSNA reactivity during the cold pressor test was not affected by gestational age or exercise (P = 0.790, interaction). Conclusions: These data show that exercise attenuates both the rise in MSNA and the blunting of neurovascular transduction. This may partially explain the lower risk of developing gestational hypertension in women who are active during their pregnancies. [ABSTRACT FROM AUTHOR]

Intravascular Laser Irradiation of Blood (ILIB) is a low-level laser technique, that has systemic effects, including activation of the antioxidant system, inhibition of the systemic inflammatory process, increased blood fluidity and hemorrheological property on the red cells. However, the use of ILIB as an ergogenic resource in sports is little studied. To investigate the acute influence of ILIB on muscle power and heart rate variability (HRV), in physically active individuals submitted to a submaximal effort test. The study is a randomized controlled crossover clinical trial. Nine male participants, university students, with a mean age of 24 ± 4.52 years and practitioners of regular physical activity were evaluated. The volunteers participated in the two intervention groups (ILIB and placebo) at different times. First, an evaluation session was carried out, being identified HRV indicators and blood lactate level at rest and in response to the stress test. After seven days, the participants received a session of the experimental protocol, which was drawn. After finishing these sessions, a reassessment was performed, getting data on HRV indicators and blood lactate level at rest and in response to the exercise test. After seven days, the entire data collect was repeated, however, the participants performed the remaining experimental protocol. The results were analyzed using Two-Way ANOVA with repeated measures, complemented with the Bonferroni test. All conclusions were obtained at the 5% significance level. For the physical performance variables, the Fatigue Index showed a significant difference (p<0.05) from the Post-Placebo moment (54.5±13.9) in relation to the Post-ILIB (45.1±9.9). Blood lactate showed a significant difference between moments (initial, post-test and after 15 min) within all groups. For HRV, in the time domain, the indices showed a significant difference (p<0.05) when comparing the moments within the interventions in relation to the initial moment. Furthermore, the RMSSD values were different between Pre-ILIB (3.54±0.44) against Post-ILIB (4.22±0.27); after the Wingate test, the Pre-Placebo (1.00±0.31) differed from the Post-Placebo (1.77±0.74). In the frequency domain, HF and LF/HF showed a significant difference (p<0.05) from Post-ILIB to Pre-ILIB after 15 min. The study showed a possible relationship between the acute influence of the use of ILIB on parasympathetic activity. It did not show improvement in performance in an anaerobic test, but suggested a possible improvement in the ability to withstand high-intensity stimuli. The lack of ILIB studies in sports science, as well as the study's findings, suggest that more research should be done, using different protocols with different stimuli. The ILIB can be useful for coaches and health professionals working with athletes, helping to optimize physical recovery, making it a resource for post-training recovery. [ABSTRACT FROM AUTHOR]

Background: Brown adipose tissue (BAT) is essential to maintain body temperature. Its ability to convert chemical energy in glucose and free fatty acids to heat is conferred by a unique protein, UCP‐1. BAT activity is greatest in children and adolescents, declining through adulthood. Blood glucose concentrations outside the normal nondiabetic range are common in type 1 diabetes and hyperglycaemia leads to insulin resistance in muscle and white adipose tissue, but whether this applies to BAT, is not known. Method: To investigate the effect of type 1 diabetes on BAT activity, we measured the supraclavicular temperature of 20 children with type 1 diabetes and compared them to 20 age‐matched controls, using infrared thermography. Results: The diabetes group had lower stimulated supraclavicular temperatures (diabetes group: 35.03 (34.76–35.30)°C; control group: 35.42 (35.16–35.69)°C; p = 0.037) and a reduced response in relative temperature following cold stimulation, after adjusting for BMI (diabetes group: 0.11 (0.03–0.18)°C; control group: 0.22 (0.15–0.29)°C; p = 0.034). In the diabetes group, there was no association between glycaemic measures and supraclavicular temperatures, but the method of insulin delivery may significantly affect the change in supraclavicular temperature with stimulation (injections: 0.01 (−0.07–0.09)°C; pump: 0.15 (0.04–0.26)°C; p = 0.028). Conclusions: While further work is needed to better understand the glucose‐insulin‐BAT relationship, one possible explanation for the reduced supraclavicular temperature is that exogenous, unlike endogenous, insulin, is not suppressed by the activity of the sympathetic nervous system, preventing lipolysis‐driven activation of BAT. [ABSTRACT FROM AUTHOR]