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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]

Stretching (ST), an exercise modality widely used for flexibility improvement, has been recently proposed as an effective adjunct therapy for declines in cardiovascular health, warranting research into the effects of ST exercise on cardiac autonomic function (CAF). Heart rate (HR) variability (HRV) is a reliable measure of CAF, mainly the sympathetic and parasympathetic modulations of HR. A low HRV has been associated to increased risk of cardiovascular events and mortality. Exercise interventions that enhance HRV are therefore seen as beneficial to cardiovascular health and are sought after. In this review, we discuss the effect of ST both acute and training on HRV. Stretching training seems to be a useful therapeutic intervention to improve CAF in different populations. Although the mechanisms by which ST training improves CAF are not yet well understood; increases in baroreflex sensitivity, relaxation, and nitric oxide bioavailability seem to play an important role. [ABSTRACT FROM AUTHOR]

Purpose: We evaluated the impact of menopause-associated vasomotor symptoms (VMS) on sleep. We also sought to establish the content validity of Patient-Reported Outcomes Measurement Information System (PROMIS) short form Sleep-Related Impairment and Sleep Disturbance measures in postmenopausal women with moderate to severe VMS. Methods: Cross-sectional, in-person, qualitative interviews were conducted in the United States (Texas, Illinois) and European Union (UK, France) with women aged 40–64 years experiencing moderate to severe VMS (≥35/wk). Main outcomes were impact of VMS on sleep based on concept elicitation and content validity of PROMIS Sleep-Related Impairment and Sleep Disturbance short forms via cognitive debriefing. Results: Thirty-two women (US: n = 16; EU: n = 16) participated. A majority (US: 93.8%; EU: 93.8%) said VMS affected sleep; specifically, they had sleep interrupted by sweating or overheating and had difficulty returning to sleep. Sleep disturbance was the most bothersome aspect of VMS (US: 75%; EU: 50%). VMS-associated sleep disturbance affected next-day work productivity, mood, relationships, daily activities, concentration, social activities, and physical health. Participants found both PROMIS sleep measures relevant and easy to answer; the Sleep Disturbance measure was considered the most relevant. Participants had no difficulty remembering their experiences over the 7-day recall period and found the response options to be distinct. Conclusion: VMS associated with menopause significantly interferes with sleep and next-day functioning (e.g., work productivity), supporting assessment of sleep outcomes in studies evaluating treatment of VMS. Women with moderate to severe VMS found that the PROMIS Sleep-Related Impairment and Sleep Disturbance short forms assessed constructs important to understanding sleep in the context of menopause-associated VMS. [ABSTRACT FROM AUTHOR]

Background: Reductions in memory practice effects have gained interest as risk factor for future cognitive decline. Practice effects vary with age and can be moderated by factors such as individual variability in arousal or stress experience acting as an additional cognitive load.Objective: In the current pilot study, we examined whether sympathetic nervous system activation moderates the relationship between age and practice effects.Methods: Thirty cognitively healthy individuals aged 40-70 years performed a mnemonic discrimination task twice. Salivary alpha amylase (sAA) samples were obtained at different time points as a proxy of sympathetic activity. Spearman correlations examined the relation between practice effects and sAA. Subsequently, age by sAA interactions on practice scores were explored with bootstrapped linear regression models. Additionally, participants were divided in learners (exhibiting practice effects) and non-learners based on the difference in mnemonic discrimination performance.Results: Higher age and baseline SNS activity were independently related to lower practice effects. The non-learners showed significantly higher sAA scores at all time points compared to learners. Among the learners, baseline-adjusted lower levels of sAA after encoding were associated with greater practice effects, particularly in middle-aged individuals. No such interaction was observed for non-learners.Conclusion: These results show that higher baseline sympathetic activation is associated with worse practice effects independently of age. Additionally, in a subgroup of middle-aged learners practice effects were observed when sympathetic activity remained low during learning. These findings suggest that elevated sympathetic nervous system activation may be a promising indicator of imminent cognitive decline. [ABSTRACT FROM AUTHOR]

Background: An adaptive neural stress response is essential to adequately cope with a changing environment. It was previously argued that sympathetic/noradrenergic activity during acute stress increases salience network (SN) connectivity and reduces executive control network (ECN) connectivity in healthy controls, with opposing effects in the late aftermath of stress. Altered temporal dynamics of these networks in response to stress are thought to play a role in the development of psychopathology in vulnerable individuals. Methods: We exposed male healthy controls (n = 40, mean age = 33.9) and unaffected siblings of schizophrenia patients (n = 39, mean age = 33.2) to the stress or control condition of the trier social stress test and subsequently investigated resting state functional connectivity of the SN and ECN directly after and 1.5 h after stress. Results: Acute stress resulted in increased functional connectivity within the SN in healthy controls, but not in siblings (group × stress interaction pfwe < 0.05). In the late aftermath of stress, stress reduced functional connectivity within the SN in both groups. Moreover, we found increased functional connectivity between the ECN and the cerebellum in the aftermath of stress in both healthy controls and siblings of schizophrenia patients. Conclusions: The results show profound differences between siblings of schizophrenia patients and controls during acute stress. Siblings lacked the upregulation of neural resources necessary to quickly and adequately cope with a stressor. This points to a reduced dynamic range in the sympathetic response, and may constitute a vulnerability factor for the development of psychopathology in this at-risk group. [ABSTRACT FROM AUTHOR]

Being a cross‐cultural systemic therapist, clinical supervisor, and educator means that culture and language are central to my work. They provide a scaffold to develop deeper understanding, increased trust, and connection between myself and my supervisees, students, and clients and facilitate a process for the latter to connect to their own selves and values. Given the fear and uncertainty generated by the COVID‐19 pandemic, there exists a pervasive activation of the sympathetic nervous system in the community. In this article, I present two case studies as examples of a cross‐cultural/cross‐linguistic approach that facilitates two clients to find a place of comfort and calmness and consequently a balancing activation of the para‐sympathetic nervous system. First is a client who, due to the overwhelming pandemic chaos, suddenly exhibited a host of signs and symptoms of a functional neurological nature, which she experienced as a lack of control and disconnection from her body, her primary language, and herself. Within a trusted therapeutic relationship that draws on the culture and primary language of the therapist, the client regains connection with language and enhances her ability to communicate and connect with her body. Second is an international student who is encouraged to use her culture of origin and primary language to induce calmness, reconnect with herself, and return to the familiar as a 'known' collectively inclusive, comforting, and nurturing environment. [ABSTRACT FROM AUTHOR]

Takotsubo syndrome (TTS) has been a recognized clinical entity for 31 years, since its first description in 1990. TTS is now routinely diagnosed in patients who present with acute chest pain, electrocardiographic changes, troponin elevation, unobstructed coronary arteries, and a typical pattern of circumferential left ventricular wall motion abnormalities that usually involve the apical and midventricular myocardium. Increasing understanding of this intriguing syndrome stems from wider recognition, possible increasing frequency, and a rising number of publications focused on the pathophysiology in clinical and laboratory studies. A comprehensive understanding of TTS pathophysiology and evidence-based treatments are lacking, and specific and effective treatments are urgently required. This paper reviews the pathophysiology of this fascinating syndrome; what is known from both clinical and preclinical studies, including review of the evidence for microvascular dysfunction, myocardial beta-adrenergic signaling, inflammation, and electrophysiology; and where focused research needs to fill gaps in understanding TTS. [ABSTRACT FROM AUTHOR]

Aim: Sympathetic system dysfunction has been described among the theories involved in the pathophysiology of complex regional pain syndrome. Objective measurement of the sympathetic activity of the affected extremity in patients with complex regional pain syndrome has not been compared to normal subjects in the literature. The skin conductance monitor is a non-invasive monitor that can objectively measure sympathetic skin activity of the extremity. In this study, we aimed to compare the differences in sympathetic activity of extremities in subjects with and without complex regional pain syndrome by using a skin conductance monitor. Material and Methods: Sympathetic skin responses were evaluated in 63 subjects, including 25 measurements on the affected extremities in 13 patients with lower extremity complex regional pain syndrome type 1 and 50 measurements in 50 normal subjects in the control group. Among the skin conductance indices, the "peaks per second (0.02)" index was used as the main sympathetic skin response index. Descriptive criteria and the mean values of sympathetic skin response measurements were compared. Results: When sympathetic skin responses were compared with a skin conductance monitor using the "peaks per second (0.02)" index, no statistically significant difference was found between the complex regional pain syndrome and control groups in terms of sympathetic activity in the extremities (p=0.837). Conclusion: In this study, skin sympathetic nerve activity in the affected limb of patients with complex regional pain syndrome was similar to normal subjects. Further studies are required to assess the changes in sympathetic activity in complex regional pain syndrome. [ABSTRACT FROM AUTHOR]

Aims  Cardiac resynchronization therapy (CRT) is a disease-modifying therapy in patients with chronic heart failure (CHF). Current guidelines ascribe CRT eligibility on three parameters only: left ventricular ejection fraction (LVEF), QRS duration, and New York Heart Association (NYHA) functional class. However, one-third of CHF patients does not benefit from CRT. This study evaluated whether 123I- meta -iodobenzylguanidine (123I- m IBG) assessed cardiac sympathetic activity could optimize CRT patient selection. Methods and results  A total of 78 stable CHF subjects (age 66.8 ± 9.6 years, 73% male, LVEF 25.2 ± 6.7%, QRS duration 153 ± 23 ms, NYHA 2.2 ± 0.7) referred for CRT implantation were enrolled. Subjects underwent 123I- m IBG scintigraphy prior to implantation. Early and late heart-to-mediastinum (H/M) ratio and 123I- m IBG washout were calculated. CRT response was defined as either an increase of LVEF to >35%, any improvement in LVEF of >10%, QRS shortening to <150 ms, or improvement in NYHA class of >1 class. In 33 patients LVEF increased to >35%, QRS decreased <150 ms in 36 patients, and NYHA class decreased in 33 patients. Late H/M ratio and hypertension were independent predictors of LVEF improvement to >35% (P  =   0.0014 and P =  0.0149, respectively). In addition, early H/M ratio, LVEF, and absence of diabetes mellitus (DM) were independent predictors for LVEF improvement by >10%. No independent predictors were found for QRS shortening to <150 ms or improvement in NYHA class. Conclusion  Early and late H/M ratio were independent predictors of CRT response when improvement of LVEF was used as measure of response. Therefore, cardiac 123I- m IBG scintigraphy may be used as a tool to optimize selection of subjects that might benefit from CRT. [ABSTRACT FROM AUTHOR]

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Sympathetic innervation of brown adipose tissue (BAT) controls mammalian adaptative thermogenesis. However, the cellular and molecular underpinnings contributing to BAT innervation remain poorly defined. Here, we show that smooth muscle cells (SMCs) support BAT growth, lipid utilization, and thermogenic plasticity. Moreover, we find that BAT SMCs express and control the bioavailability of Cxcl12. SMC deletion of Cxcl12 fosters brown adipocyte lipid accumulation, reduces energy expenditure, and increases susceptibility to diet-induced metabolic dysfunction. Mechanistically, we find that Cxcl12 stimulates CD301 + macrophage recruitment and supports sympathetic neuronal maintenance. Administering recombinant Cxcl12 to obese mice or leptin-deficient (Ob/Ob) mice is sufficient to boost macrophage presence and drive sympathetic innervation to restore BAT morphology and thermogenic responses. Altogether, our data reveal an SMC chemokine-dependent pathway linking immunological infiltration and sympathetic innervation as a rheostat for BAT maintenance and thermogenesis., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Glucagon-like peptide-1 (GLP-1) and its analogs are widely used for diabetes treatment. The paraventricular nucleus (PVN) is crucial for regulating cardiovascular activity. This study aims to determine the roles of GLP-1 and its receptors (GLP-1R) in the PVN in regulating sympathetic outflow and blood pressure. Experiments were carried out in male normotensive rats and spontaneously hypertensive rats (SHR). Renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) were recorded. GLP-1 and GLP-1R expressions were present in the PVN. PVN microinjection of GLP-1R agonist recombinant human GLP-1 (rhGLP-1) or EX-4 increased RSNA and MAP, which were prevented by GLP-1R antagonist exendin 9-39 (EX9-39) or GLP-1R antagonist 1, superoxide scavenger tempol, antioxidant N-acetylcysteine, NADPH oxidase (NOX) inhibitor apocynin, adenylyl cyclase (AC) inhibitor SQ22536 or protein kinase A (PKA) inhibitor H89. PVN microinjection of rhGLP-1 increased superoxide production, NADPH oxidase activity, cAMP level, AC, and PKA activity, which were prevented by SQ22536 or H89. GLP-1 and GLP-1R were upregulated in the PVN of SHR. PVN microinjection of GLP-1 agonist increased RSNA and MAP in both WKY and SHR, but GLP-1 antagonists caused greater effects in reducing RSNA and MAP in SHR than in WKY. The increased superoxide production and NADPH oxidase activity in the PVN of SHR were augmented by GLP-1R agonists but attenuated by GLP-1R antagonists. These results indicate that activation of GLP-1R in the PVN increased sympathetic outflow and blood pressure via cAMP-PKA-mediated NADPH oxidase activation and subsequent superoxide production. GLP-1 and GLP-1R upregulation in the PVN partially contributes to sympathetic overactivity and hypertension., Competing Interests: The authors declare no competing financial interests., (Copyright © 2024 the authors.)

Although more people are engaging in meditation practices that require specialized training, few studies address the issues associated with nervous activity pattern changes brought about by such training. For beginners, it remains unclear how much practice is needed before objective physiological changes can be detected, whether or not they are similar across the novices and what are the optimal strategies to track these changes. To clarify these questions we recruited individuals with no prior meditation experience. The experimental group underwent an eight-week Taoist meditation course administered by a professional, while the control group listened to audiobooks. Both groups participated in audio-guided, 34-min long meditation sessions before and after the 8-week long intervention. Their EEG, photoplethysmogram, respiration, and skin conductance were recorded during the mediation and resting state periods. Compared to the control group, the experimental group exhibited band-specific topically organized changes of the resting state brain activity and heart rate variability associated with sympathetic system activation. Importantly, no significant changes were found during the meditation process prior and post the 8-week training in either of the groups. The absence of notable changes in CNS and ANS activity indicators during meditation sessions, for both the experimental and control groups, casts doubt on the effectiveness of wearable biofeedback devices in meditation practice. This finding redirects focus to the importance of monitoring resting state activity to evaluate progress in beginner meditators. Also, 16 h of training is not enough for forming individual objectively different strategies manifested during the meditation sessions. Our results contributed to the development of tools to objectively monitor the progress in novice meditators and the choice of the relevant monitoring strategies. According to our findings, in order to track early changes brought about by the meditation practice it is preferable to monitor brain activity outside the actual meditation sessions., (© 2024. The Author(s).)

Blood vessels serve as intermediate conduits for the extension of sympathetic axons towards target tissues, while also acting as crucial targets for their homeostatic processes encompassing the regulation of temperature, blood pressure, and oxygen availability. How sympathetic axons innervate not only blood vessels but also a wide array of target tissues is not clear. Here we show that in embryonic skin, after the establishment of co-branching between sensory nerves and blood vessels, sympathetic axons invade the skin alongside these sensory nerves and extend their branches towards these blood vessels covered by vascular smooth muscle cells (VSMCs). Our mosaic labeling technique for sympathetic axons shows that collateral branching predominantly mediates the innervation of VSMC-covered blood vessels by sympathetic axons. The expression of nerve growth factor (NGF), previously known to induce collateral axon branching in culture, can be detected in the vascular smooth muscle cell (VSMC)-covered blood vessels, as well as sensory nerves. Indeed, VSMC-specific Ngf knockout leads to a significant decrease of collateral branching of sympathetic axons innervating VSMC-covered blood vessels. These data suggest that VSMC-derived NGF serves as an inductive signal for collateral branching of sympathetic axons innervating blood vessels in the embryonic skin., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Recent evidence indicates that sex-based differences in cardiovascular disease (CVD) begin early in life, particularly when associated with risk factors such as a sedentary lifestyle. CVD is associated with elevated sympathetic nerve activity (SNA), quantified as increased SNA burst activity in humans. Whether burst characteristics are influenced by sex or sedentary conditions at younger ages is unknown. The purpose of our study is to compare SNA bursts in active and sedentary female and male rats at ages including prepuberty and young adulthood. We hypothesized that burst characteristics and blood pressure are higher under sedentary conditions and lower in female rats compared with males. We analyzed splanchnic SNA (SpSNA) recordings from Inactin-anesthetized male and female rats at 4-, 8-, and 16-wk of age. Physically active and sedentary rats were each housed in separate, environmentally controlled chambers where physically active rats had free access to an in-cage running wheel. Sympathetic bursts were obtained by rectifying and integrating the raw SpSNA signal. Burst frequency, burst height, and burst width were calculated using the Peak Parameters extension in LabChart. Our results showed that sedentary conditions produced a greater burst width in 8- and 16-wk-old rats compared with 4-wk-old rats in both males and females ( P < 0.001 for both). Burst frequency and incidence were both higher in 16-wk-old males compared with 16-wk-old females ( P < 0.001 for both). Our results suggest that there are sedentary lifestyle- and sex-related mechanisms that impact sympathetic regulation of blood pressure at ages that range from prepuberty into young adulthood. NEW & NOTEWORTHY The mechanisms of decreased incidence of cardiovascular disease (CVD) in reproductive-age women compared with age-matched men are unknown. The strong association between elevated sympathetic activity and CVD led us to characterize splanchnic sympathetic bursts in female and male rats. Prepubescent males and females exhibited narrower sympathetic bursts, whereas young adult males had higher resting burst frequency compared with age-matched females. Sex-based regulation of sympathetic activity suggests a need for sex-dependent therapeutic strategies to combat CVD.

During the urine storage phase, tonically contracting urethral musculature would have a higher energy consumption than bladder muscle that develops phasic contractions. However, ischaemic dysfunction is less prevalent in the urethra than in the bladder, suggesting that urethral vasculature has intrinsic properties ensuring an adequate blood supply. Diameter changes in rat or mouse urethral arterioles were measured using a video-tracking system. Intercellular Ca 2+ dynamics in arteriolar smooth muscle (SMCs) and endothelial cells were visualised using NG2- and parvalbumin-GCaMP6 mice, respectively. Fluorescence immunohistochemistry was used to visualise the perivascular innervation. In rat urethral arterioles, sympathetic vasoconstrictions were predominantly suppressed by α,β-methylene ATP (10 μM) but not prazosin (1 μM). Tadalafil (100 nM), a PDE5 inhibitor, diminished the vasoconstrictions in a manner reversed by N-ω-propyl-l-arginine hydrochloride (l-NPA, 1 μM), a neuronal NO synthesis (nNOS) inhibitor. Vesicular acetylcholine transporter immunoreactive perivascular nerve fibres co-expressing nNOS were intertwined with tyrosine hydroxylase immunoreactive sympathetic nerve fibres. In phenylephrine (1 μM) pre-constricted rat or mouse urethral arterioles, nerve-evoked vasodilatations or transient SMC Ca 2+ reductions were largely diminished by l-nitroarginine (l-NA, 10 μM), a broad-spectrum NOS inhibitor, but not by l-NPA. The CGRP receptor antagonist BIBN-4096 (1 μM) shortened the vasodilatory responses, while atropine (1 μM) abolished the l-NA-resistant transient vasodilatory responses. Nerve-evoked endothelial Ca 2+ transients were abolished by atropine plus guanethidine (10 μM), indicating its neurotransmitter origin and absence of non-adrenergic non-cholinergic endothelial NO release. In urethral arterioles, NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions pre- and post-synaptically to restrict arteriolar contractility. KEY POINTS: Despite a higher energy consumption of the urethral musculature than the bladder detrusor muscle, ischaemic dysfunction of the urethra is less prevalent than that of the bladder. In the urethral arterioles, sympathetic vasoconstrictions are predominately mediated by ATP, not noradrenaline. NO released from parasympathetic nerves counteracts sympathetic vasoconstrictions by its pre-synaptic inhibition of sympathetic transmission as well as post-synaptic arteriolar smooth muscle relaxation. Acetylcholine released from parasympathetic nerves contributes to endothelium-dependent, transient vasodilatations, while CGRP released from sensory nerves prolongs NO-mediated vasodilatations. PDE5 inhibitors could be beneficial to maintain and/or improve urethral blood supply and in turn the volume and contractility of urethral musculature., (© 2024 The Authors. The Journal of Physiology © 2024 The Physiological Society.)

The neural crest is an embryonic stem cell population unique to vertebrates 1 whose expansion and diversification are thought to have promoted vertebrate evolution by enabling emergence of new cell types and structures such as jaws and peripheral ganglia 2 . Although jawless vertebrates have sensory ganglia, convention has it that trunk sympathetic chain ganglia arose only in jawed vertebrates 3-8 . Here, by contrast, we report the presence of trunk sympathetic neurons in the sea lamprey, Petromyzon marinus, an extant jawless vertebrate. These neurons arise from sympathoblasts near the dorsal aorta that undergo noradrenergic specification through a transcriptional program homologous to that described in gnathostomes. Lamprey sympathoblasts populate the extracardiac space and extend along the length of the trunk in bilateral streams, expressing the catecholamine biosynthetic pathway enzymes tyrosine hydroxylase and dopamine β-hydroxylase. CM-DiI lineage tracing analysis further confirmed that these cells derive from the trunk neural crest. RNA sequencing of isolated ammocoete trunk sympathoblasts revealed gene profiles characteristic of sympathetic neuron function. Our findings challenge the prevailing dogma that posits that sympathetic ganglia are a gnathostome innovation, instead suggesting that a late-developing rudimentary sympathetic nervous system may have been characteristic of the earliest vertebrates., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

The interplay between cerebral and cardiovascular activity, known as the functional brain-heart interplay (BHI), and its temporal dynamics, have been linked to a plethora of physiological and pathological processes. Various computational models of the brain-heart axis have been proposed to estimate BHI non-invasively by taking advantage of the time resolution offered by electroencephalograph (EEG) signals. However, investigations into the specific intracortical sources responsible for this interplay have been limited, which significantly hampers existing BHI studies. This study proposes an analytical modeling framework for estimating the BHI at the source-brain level. This analysis relies on the low-resolution electromagnetic tomography sources localization from scalp electrophysiological recordings. BHI is then quantified as the functional correlation between the intracortical sources and cardiovascular dynamics. Using this approach, we aimed to evaluate the reliability of BHI estimates derived from source-localized EEG signals as compared with prior findings from neuroimaging methods. The proposed approach is validated using an experimental dataset gathered from 32 healthy individuals who underwent standard sympathovagal elicitation using a cold pressor test. Additional resting state data from 34 healthy individuals has been analysed to assess robustness and reproducibility of the methodology. Experimental results not only confirmed previous findings on activation of brain structures affecting cardiac dynamics (e.g., insula, amygdala, hippocampus, and anterior and mid-cingulate cortices) but also provided insights into the anatomical bases of brain-heart axis. In particular, we show that the bidirectional activity of electrophysiological pathways of functional brain-heart communication increases during cold pressure with respect to resting state, mainly targeting neural oscillations in the δ $$ \delta $$ , β $$ \beta $$ , and γ $$ \gamma $$ bands. The proposed approach offers new perspectives for the investigation of functional BHI that could also shed light on various pathophysiological conditions., (© 2024 The Authors. Human Brain Mapping published by Wiley Periodicals LLC.)

Purpose: We conducted a meta-analysis to determine the effect of hyperoxia on muscle sympathetic nerve activity in healthy individuals and those with cardio-metabolic diseases., Methods: A comprehensive search of electronic databases was performed until August 2022. All study designs (except reviews) were included: population (humans; apparently healthy or with at least one chronic disease); exposures (muscle sympathetic nerve activity during hyperoxia or hyperbaria); comparators (hyperoxia or hyperbaria vs. normoxia); and outcomes (muscle sympathetic nerve activity, heart rate, blood pressure, minute ventilation). Forty-nine studies were ultimately included in the meta-analysis., Results: In healthy individuals, hyperoxia had no effect on sympathetic burst frequency (mean difference [MD] - 1.07 bursts/min; 95% confidence interval [CI] - 2.17, 0.04bursts/min; P = 0.06), burst incidence (MD 0.27 bursts/100 heartbeats [hb]; 95% CI - 2.10, 2.64 bursts/100 hb; P = 0.82), burst amplitude (P = 0.85), or total activity (P = 0.31). In those with chronic diseases, hyperoxia decreased burst frequency (MD - 5.57 bursts/min; 95% CI - 7.48, - 3.67 bursts/min; P < 0.001) and burst incidence (MD - 4.44 bursts/100 hb; 95% CI - 7.94, - 0.94 bursts/100 hb; P = 0.01), but had no effect on burst amplitude (P = 0.36) or total activity (P = 0.90). Our meta-regression analyses identified an inverse relationship between normoxic burst frequency and change in burst frequency with hyperoxia. In both groups, hyperoxia decreased heart rate but had no effect on any measure of blood pressure., Conclusion: Hyperoxia does not change sympathetic activity in healthy humans. Conversely, in those with chronic diseases, hyperoxia decreases sympathetic activity. Regardless of disease status, resting sympathetic burst frequency predicts the degree of change in burst frequency, with larger decreases for those with higher resting activity., (© 2024. Springer-Verlag GmbH Germany.)

Prenatal opioid exposure has been associated with developmental problems, including autonomic nervous system dysregulation. However, little is known about the effects of prenatal opioid exposure on the autonomic nervous system beyond the first days of life, particularly across both the parasympathetic and sympathetic branches, and when accounting for exposure to other substances. The present study examined the effects of prenatal exposure to opioid agonist therapy (OAT, e.g., methadone) and other opioids on infant autonomic nervous system activity at rest and in response to a social stressor (the Still-Face Paradigm) at six months among 86 infants varying in prenatal opioid and other substance exposure. Results indicated that OAT and other opioids have unique effects on the developing autonomic nervous system that may further depend on subtype (i.e., methadone versus buprenorphine) and timing in gestation. Results are discussed in the context of theoretical models of the developing stress response system., (© 2023 The Authors. Psychophysiology published by Wiley Periodicals LLC on behalf of Society for Psychophysiological Research.)

To investigate noxious stimulation-responsive neural circuits that could influence the gut, we recorded from intestinally directed (efferent) nerve filaments dissected from mesenteric nerves close to the small intestine in anesthetized rats. These exhibited baseline multiunit activity that was almost unaffected by vagotomy (VagX) and reduced only slightly by cutting the splanchnic nerves. The activity was halved by hexamethonium (Hex) treatment. When an adjacent gut segment received an intraluminal stimulus 2,4,6-trinitrobenzenesulfonate (TNBS) in 30% ethanol, mesenteric efferent nerve activity increased for more than 1 h. The increased activity was almost unaffected by bilateral vagotomy or splanchnic nerve section, indicating a lack of central nervous involvement, but it was 60% reduced by hexamethonium. Spike sorting discriminated efferent single and predominantly single-unit spike trains that responded to TNBS, were unaffected by splachnectomy but were silenced by hexamethonium. After noxious stimulation of one segment, the adjacent segment showed no evidence of suppression of gut motility or vasoconstriction. We conclude that luminal application of a noxious stimulus to the small intestine activates an entirely peripheral, intestinointestinal reflex pathway. This pathway involves enteric intestinofugal neurons that excite postganglionic sympathetic neurons via a nicotinic synapse. We suggest that the final sympathetic efferent neurons that respond to a tissue damaging stimulus are distinct from vasoconstrictor, secretomotor, and motility inhibiting neurons. NEW & NOTEWORTHY An intraluminal noxious chemical stimulus applied to one segment of small intestine increased mesenteric efferent nerve activity to an adjacent segment. This was identified as a peripheral ganglionic reflex that did not require vagal or spinal connections. Hexamethonium blocked most, but not all, ongoing and reflex mesenteric efferent activity. The prevertebral sympathetic efferent neurons that are activated likely affect inflammatory and immune functions of other gut segments.

Purpose: We evaluated the hypothesis that repetitive gravitoinertial stress would augment the arterial-pressure response to peripheral sympathetic stimulation., Methods: Before and after a 5-weeks G-training regimen conducted in a human-use centrifuge, twenty healthy men performed a hand cold-pressor test, and nine of them also a foot cold-pressor test (4 min; 4 °C water). Arterial pressures and total peripheral resistance were monitored., Results: The cold-induced elevation (P ≤ 0.002) in arterial pressures and total peripheral resistance did not vary between testing periods, either in the hand [mean arterial pressure: Before =  + 16% vs. After =  + 17% and total peripheral resistance: Before =  + 13% vs. After =  + 15%], or in the foot [mean arterial pressure: Before =  + 19% vs. After =  + 21% and total peripheral resistance: Before =  + 16% vs. After =  + 16%] cold-pressor tests (P > 0.05)., Conclusion: Present results demonstrate that 5 weeks of prolonged iterative exposure to hypergravity does not alter the responsiveness of sympathetically mediated circulatory reflexes., (© 2023. The Author(s).)

Microneurographic recordings of muscle sympathetic nerve activity (MSNA) and the succeeding changes in beat-to-beat blood pressure (i.e., sympathetic transduction) provide important insights into the neural control of the circulation in humans. Despite its widespread use, the reliability of this technique remains unknown. Herein, we assessed the intra- and interday test-retest reliability of signal-averaging sympathetic transduction to blood pressure. Data were analyzed from 15 (9 M/6 F) young, healthy participants who completed two baseline recordings of fibular nerve MSNA separated by 60 min (intraday). The interday reliability was obtained in a subset of participants ( n = 13, 9 M/4 F) who completed a follow-up MSNA study. Signal-averaging sympathetic transduction was quantified as peak change in diastolic (DBP) and mean arterial pressure (MAP) following a burst of MSNA. Analyses were also computed considering different MSNA burst sizes (quartiles of normalized MSNA) and burst patterns (singlets, couplets, triplets, and quadruplets+), as well as nonburst responses. Intraclass-correlation coefficients (ICCs) were used as the main reliability measure. Peak changes in MAP [intraday: ICC = 0.76 (0.30-0.92), P = 0.006; interday: ICC = 0.91 (0.63-0.97), P < 0.001] demonstrated very good to excellent reliability. Sympathetic transduction of MSNA burst size displayed moderate to very good reliability, though the reliability of MSNA burst pattern was poor to very good. Nonburst responses revealed poor intraday [ICC = 0.37 (-1.05 to 0.80), P = 0.21], but very good interday [ICC = 0.76 (0.18-0.93), P = 0.01] reliability. Intraday reliability measures were consistently lower than interday reliability. Similar results were obtained using DBP. Collectively, these findings provide evidence that the burst-triggering signal-averaging technique is a reliable measure of sympathetic transduction to blood pressure in young, healthy adults. NEW & NOTEWORTHY We found that signal-averaging sympathetic transduction to blood pressure displayed very good to excellent intra- and interday test-retest reliability in healthy, young adults. Reliability analyses according to muscle sympathetic burst size, burst pattern, and nonburst response were less consistent. Results were similar when using diastolic or mean arterial pressure in the transduction calculation. These findings suggest that the signal-averaging technique can be used with confidence to investigate sympathetic transduction to blood pressure in humans across time.

Brown and white adipose tissue mediate thermogenesis through the thermogenetic centre of the brain, but safe methods for activating thermogensis and knowledge of the associated molecular mechanisms are lacking. We investigated body surface electroacupuncture stimulation (ES) at ST25 (targeted at the abdomen) induction of brown adipose thermogenesis and the neural mechanism of this process. Inguinal white adipose tissue (iWAT) and interscapular brown adipose tissue (iBAT) were collected and the thermogenic protein expression levels were measured to evaluate iBAT thermogenesis capacity. The thermogenic centre activating region and sympathetic outflow were evaluated based on neural electrical activity and c-fos expression levels. iWAT sensory axon plasticity was analysed with whole-mount adipose tissue imaging. ES activated the sympathetic nerves in iBAT and the c-fos-positive cells induced sympathetic outflow activation to the iBAT from the medial preoptic area (MPA), the dorsomedial hypothalamus (DM) and the raphe pallidus nucleus (RPA). iWAT denervation mice exhibited decreased c-fos-positive cells in the DM and RPA, and lower recombinant uncoupling orotein 1 peroxisome proliferator-activated receptor, β3-adrenergic receptor, and tyrosine hydroxylase expression. Remodelling the iWAT sensory axons recovered the signal from the MPA to the RPA and induced iBAT thermogenesis. The sympathetic denervation attenuated sensory nerve density. ES induced sympathetic outflow from the thermogenetic centres to iBAT, which mediated thermogenesis. iWAT sensory axon remodelling induced the MPA-DM-RPA-iBAT thermogenesis pathway., (© 2024 John Wiley & Sons Ltd.)

The purpose of this study was to clarify sex differences in the inhibition of sympathetic vasomotor outflow which is caused by the loading of cardiopulmonary baroreceptors. Ten young males and ten age-matched females participated. The participants underwent a passive leg raising (PLR) test wherein they were positioned supine (baseline, 0º), and their lower limbs were lifted passively at 10º, 20º, 30º, and 40º. Each angle lasted for 3 min. Muscle sympathetic nerve activity (MSNA) was recorded via microneurography of the left radial nerve. Baseline MSNA was lower in females compared to males. MSNA burst frequency was decreased during the PLR in both males (- 6.2 ± 0.4 bursts/min at 40º) and females (- 6.5 ± 0.4 bursts/min at 40º), but no significant difference was detected between the two groups (P = 0.61). These results suggest that sex has minimal influence on the inhibition of sympathetic vasomotor outflow during the loading of cardiopulmonary baroreceptors in young individuals., (© 2024. The Author(s).)

We explored the non-invasive evaluation of the sympathetic nervous system (SNS) by employing two distinct physiological signals: skin sympathetic nerve activity (SKNA), extracted from electrocardiogram (ECG) signals, and electrodermal activity (EDA), a well-studied marker in the context of the SNS assessment. Our investigation focused on cognitive stress and pain; two conditions closely associated with the SNS. We sought to determine if the information and dynamics of EDA could be derived from the novel SKNA signal. To this end, ECG and EDA signals were recorded simultaneously during three experiments aimed at sympathetic stimulation, Valsalva maneuver (VM), Stroop test, and thermal-grill pain test. We calculated the integral area under the rectified SKNA signal (iSKNA) and decomposed the EDA signal to its phasic component (EDA phasic ). An average delay of more than 4.6 s was observed in the onset of EDA phasic bursts compared to their corresponding iSKNA bursts. After shifting the EDA phasic segments by the extent of this delay and smoothing the corresponding iSKNA bursts, our results revealed a strong average correlation coefficient of 0.85±0.14 between the iSKNA and EDA phasic bursts, indicating a noteworthy similarity between the two signals. We also reconstructed the EDA signals with time-varying sympathetic (TVSymp) and modified TVSymp (MTVSymp) methods. Then we extracted the following features from iSKNA, EDA phasic , TVSymp, and MTVSymp signals: peak amplitude, average amplitude (aSKNA), standard deviation (vSKNA), and the cumulative duration during which the signals had higher amplitudes than a specified threshold (HaSKNA). A strong average correlation of 0.89±0.18 was found between vSKNA and subjects' self-rated pain levels during the pain test. Our statistical analysis also included applying Linear Mixed-Effects Models to check if there were significant differences in features across baseline and different levels of SNS stimulation. We then assessed the discriminating power of the features using Area Under the Receiver Operating Characteristic Curve (AUROC) and Fisher's Ratio. Finally, using all the four EDA features, a multi-layer perceptron (MLP) classifier reached the classification accuracies 95.56%, 89.29%, and 67.88% for the VM, Stroop, and thermal-grill pain control and stimulation classes. On the other hand, the highest classification accuracies based on SKNA features were achieved using K-nearest neighbors (KNN) (98.89%), KNN (89.29%), and MLP (95.11%) classifiers for the same experiments. Our comparative analysis showed the feasibility of SKNA as a novel tool for assessing the SNS with accurate classification capability, with a faster onset of amplitude increase in response to SNS activity, compared to EDA., Competing Interests: Declaration of competing interest All authors have nothing to declare., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

In the cold, the absence of the mitochondrial uncoupling protein 1 (UCP1) results in hyper-recruitment of beige fat, but classical brown fat becomes atrophied. Here we examine possible mechanisms underlying this phenomenon. We confirm that in brown fat from UCP1-knockout (UCP1-KO) mice acclimated to the cold, the levels of mitochondrial respiratory chain proteins were diminished; however, in beige fat, the mitochondria seemed to be unaffected. The macrophages that accumulated massively not only in brown fat but also in beige fat of the UCP1-KO mice acclimated to cold did not express tyrosine hydroxylase, the norepinephrine transporter (NET) and monoamine oxidase-A (MAO-A). Consequently, they could not influence the tissues through the synthesis or degradation of norepinephrine. Unexpectedly, in the cold, both brown and beige adipocytes from UCP1-KO mice acquired an ability to express MAO-A. Adipose tissue norepinephrine was exclusively of sympathetic origin, and sympathetic innervation significantly increased in both tissues of UCP1-KO mice. Importantly, the magnitude of sympathetic innervation and the expression levels of genes induced by adrenergic stimulation were much higher in brown fat. Therefore, we conclude that no qualitative differences in innervation or macrophage character could explain the contrasting reactions of brown versus beige adipose tissues to UCP1-ablation. Instead, these contrasting responses may be explained by quantitative differences in sympathetic innervation: the beige adipose depot from the UCP1-KO mice responded to cold acclimation in a canonical manner and displayed enhanced recruitment, while the atrophy of brown fat lacking UCP1 may be seen as a consequence of supraphysiological adrenergic stimulation in this tissue., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The blood pressure-lowering effect of aerobic training is preceded by improving cardiovascular autonomic control. We previously demonstrated that aerobic training conducted in the evening (ET) induces a greater decrease in blood pressure than morning training (MT). To study whether the greater blood pressure decrease after ET occurs through better cardiovascular autonomic regulation, this study aimed to compare MT versus ET on muscle sympathetic nerve activity (MSNA) and baroreflex sensitivity (BRS) in treated patients with hypertension. Elderly patients treated for hypertension were randomly allocated into MT (n = 12, 07.00-10.00 h) or ET (n = 11, 17.00-20.00 h) groups. Both groups trained for 10 weeks, 3 times/week, cycling for 45 min at moderate intensity. Beat-to-beat blood pressure (finger photoplethysmography), heart rate (electrocardiography) and MSNA (microneurography) were assessed at the initial and final phases of the study at baseline and during sequential bolus infusions of sodium nitroprusside and phenylephrine (modified-Oxford technique) to evaluate cardiac and sympathetic BRS. Mean blood pressure decreased significantly after ET but not after MT (-9 ± 11 vs. -1 ± 8 mmHg, P = 0.042). MSNA decreased significantly only after ET with no change after MT (-12 ± 5 vs. -3 ± 7 bursts/100 heart beats, P = 0.013). Sympathetic BRS improved after ET but not after MT (-0.8 ± 0.7 vs. 0.0 ± 0.8 bursts/100 heart beats/mmHg, P = 0.052). Cardiac BRS improved similarly in both groups (ET: +1.7 ± 1.8 vs. MT: +1.4 ± 1.9 ms/mmHg, P phase  ≤ 0.001). In elderly patients treated for hypertension, only ET decreased mean blood pressure and MSNA and improved sympathetic BRS. These findings revealed that the sympathetic nervous system has a key role in ET's superiority to MT in blood pressure-lowering effect. KEY POINTS: Reducing muscle nerve sympathetic activity and increasing sympathetic baroreflex sensitivity plays a key role in promoting the greater blood pressure reduction observed with evening training. These findings indicated that simply changing the timing of exercise training may offer additional benefits beyond antihypertensive medications, such as protection against sympathetic overdrive and loss of baroreflex sensitivity, independent markers of mortality. Our new findings also suggest new avenues of investigation, such as the possibility that evening aerobic training may be beneficial in other clinical conditions with sympathetic overdrive, such as congestive heart failure and hypertrophic cardiomyopathy., (© 2024 The Authors. The Journal of Physiology © 2024 The Physiological Society.)

The 123I-labeled meta-iodobenzylguanidine (MIBG) is an analogue of noradrenaline that can evaluate cardiac sympathetic activity in scintigraphy. Quantitative analysis of 123I-MIBG images has been verified in patients with heart failure and neurodegenerative diseases. However, quantitative results differ due to variations in scintigraphic imaging procedures. Here, we created and assessed the clinical feasibility of a calibration method for 123I-MIBG imaging. The characteristics of scintigraphic imaging systems were determined using an acrylic calibration phantom to generate a multicenter phantom imaging database. Calibration factors corresponding to the scintigraphic imaging procedures were calculated from the database and applied to a clinical study. The results of this study showed that the calibrated analysis eliminated inter-institutional differences among normal individuals. In summary, our standardization methodology for 123I-MIBG scintigraphy could provide the basis for improved diagnostic precision and better outcomes for patients. [ABSTRACT FROM AUTHOR]

Background: Activation of the sympathetic nervous system attenuates inflammation via catecholamines. Recent evidence has shown that electroacupuncture (EA) activates neuronal networks involved in the release of dopamine and norepinephrine that control systemic inflammation. In muscle, catecholamines are related to cyclic adenosine monophosphate (cAMP). This signaling molecule has been implicated in recovery from sustained contractile activity, which may induce muscular pain, such as that which occurs during low back pain (LBP). Objective: Our aim was to evaluate the effects of EA used for the control of LBP on the activation of the sympathetic nervous system in a randomized controlled clinical trial in athletes. Methods: Two groups of athletes with acute or chronic low back pain were studied. EA, sham EA and pharmacological treatment (diclofenac sodium) were evaluated. The outcome measures included a pain score represented by a visual analogue scale (VAS) and serum levels of catecholamines quantified by enzyme-linked immunosorbent assay. In addition, blood was collected into chilled heparin tubes, placed in 96-well cell culture plates and incubated with an equal volume of Roswell Park Memorial Institute (RPMI) medium, with lipopolysaccharide (LPS) alone or with catecholamines. Tumor necrosis factor (TNF)-α levels in the supernatants were analyzed. Results: The results indicated that the initial pain ratings did not differ between the groups analyzed. EA induced epinephrine secretion but not norepinephrine or dopamine secretion. Although EA and pharmacological treatment did not differ in terms of pain relief, in vitro epinephrine and norepinephrine reduced TNF-α production in response to LPS stimuli. Conclusion: EA activates the sympathetic nervous system and induces the release of epinephrine, which could ameliorate inflammation and protect muscular tissue in addition to relieving pain. [ABSTRACT FROM AUTHOR]

Background and Study Aim. Stimulation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis are a crucial mechanism of adaptation to physical exercise, in particular in combat sports. This study assesses changes of the relevant hormonal profiles upon performance in selected combat sports. Material and Methods. Participants (130 men practicing combat sports at a high level) were divided by discipline: karate (K), taekwondo (T), and judo, wrestling, and sumo combined (JWS). Blood concentration of adrenaline, noradrenaline, cortisol, testosterone, and brain-derived neurotrophic factor (BDNF) was determined before and after fighting. Results. Following fighting, the adrenaline concentration was significantly higher in all athletes, most markedly in K (p < 0.001). Baseline cortisol and BDNF levels did not differ among the groups and rose significantly in all the groups after the performance. Baseline testosterone concentration was slightly higher in K than in JSW and rose in all the groups to reach similar levels; the increase in T was significantly higher than in K. Conclusions. Despite substantial differences in the characteristics of the combat sports investigated, including the type of physical effort and the required balance between restraint and aggression, the performance in each of them gives rise to similar hormonal changes with a possible exception of karate showing higher stress hormone levels. [ABSTRACT FROM AUTHOR]

Background/aim: Recently, data from temporal dispersion of myocardial repolarization analysis have gained a capital role in the sudden cardiac death risk stratification. Aim of this study was to evaluate the influence of heart rate, autonomic nervous system, and controlled breathing on different myocardial repolarization markers in healthy subjects. Method: Myocardial repolarization dispersion markers from short‐period (5 minutes) electrocardiogram (ECG) analysis (time and frequency domain) have been obtained in 21 healthy volunteers during the following conditions: free breathing (rest); controlled breathing (resp); the first 5 minutes of postexercise recovery phases (exercisePeak), maximum sympathetic activation; and during the second 5 minutes of postexercise recovery phases (exerciseRecovery), intermediate sympathetic activation. Finally, we analyzed the whole repolarization (QTe), the QT peak (QTp), and T peak ‐ T end intervals (Te). Results: During the exercisePeak, major part of repolarization variables changed in comparison to the rest and resp conditions. Particularly, QTe, QTp, and Te standard deviations (QTeSD, QTpSD, and TeSD); variability indexes (QTeVI and QTpVI), normalized variances (QTeVN, QTpVN, and TeVN); and the ratio between short‐term QTe, QTp, and Te variability RR (STVQTe/RR, STVQTp/RR, and STVTe/RR) increased. During exerciseRecovery, QTpSD (P <.05), QTpVI (P <.05), QTeVN (P <.05), QTpVN (P <.001), TeVN (P <.05), STVQTe/RR (P <.05), STVQTp/RR (P <.001), and STVTe/RR (P <.001) were significantly higher in comparison to the rest. The slope between QTe (0.24 ± 0.06) or QTp (0.17 ± 0.06) and RR were significantly higher than Te (0.07 ± 0.06, P <.001). Conclusion: Heart rate and sympathetic activity, obtained during exercise, seem able to influence the time domain markers of myocardial repolarization dispersion in healthy subjects, whereas they do not alter any spectral components. [ABSTRACT FROM AUTHOR]

Associations between prepregnancy body mass index, gestational weight gain, maternal age, and basal sympathetic nervous system activity (SNA) in normotensive pregnant women have not been explored. Retrospective analysis of microneurography records from 74 normotensive pregnant women during their third trimester indicated that although pregnancy is associated with rapid weight gain, this does not influence SNA. There were also no associations between maternal age and SNA, but more studies are needed to confirm this interpretation. Novelty Neither age nor excessive weight gain appears to influence sympathetic activity during normotensive pregnancy. [ABSTRACT FROM AUTHOR]

Purpose: Early weaning (EW) is a risk factor for obesity development. Brown adipose tissue (BAT) hypofunction is related to obesity onset. Here, we evaluated whether sympathetic nervous system (SNS) activity in BAT and the thermogenic function of BAT are decreased in adulthood in obese rats from two EW models. Methods: At the time of birth, lactating Wistar rats and their pups (three males and three females) were separated into three groups: the control group, in which pups consumed milk throughout lactation; the non-pharmacological EW (NPEW) group, in which suckling was interrupted with a bandage during the last 3 days of lactation; and the pharmacological EW (PEW) group, in which dams were treated with bromocriptine (0.5 mg/twice a day) 3 days before weaning. The offspring were sacrificed on PN180. Results: Adult male rats from both EW models exhibited lower BAT SNS activity. Female rats from the PEW group showed a decrease in BAT SNS activity. The protein levels of UCP1 were lower in the NPEW males, while PGC1α levels were lower in both PEW and NPEW males. Both groups of EW females showed reductions in the levels of β3-AR, TRβ1, and PGC1α. The UCP1 protein level was reduced only in the NPEW females. The EW groups of both sexes had lower AMPK protein levels in BAT. In the hypothalamus, only the PEW females showed an increase in AMPK protein levels. In both groups of EW males, adrenal catecholamine was increased and tyrosine hydroxylase was decreased, while in EW females, adrenal catecholamine was decreased. Conclusions: Early weaning alters the thermogenic capacity of BAT, which partially contributes to obesity in adulthood, and there are sex-related differences in these alterations. [ABSTRACT FROM AUTHOR]

Facial expressions influence both affective and cardiovascular responses to stress. However, previous research focuses primarily on positive expressions and is limited regarding additional facial expressions utilized on a day‐to‐day basis. This study examined an expression that is colloquially called a "Game Face": which refers to a serious, focused or determined facial expression. The current study examined whether Game Face expressions would influence psychophysiological response (e.g., heart rate and skin conductance) and performance. In an investigation of physical performance (Study 1), participants (N = 62) were asked to complete the cold‐pressor task. Study 2 tested cognitive performance utilizing a puzzle task. Participants (N = 62) were divided into two groups and were asked to complete a puzzle. In both studies, one group was asked to make a Game Face, and the other was given no instruction related to facial expression. Results show no significant differences in performance on the physical task. In terms of cognitive performance, results reveal significantly better performance in the Game Face group. Additionally, assessments of skin conductance show that participants, who employed the Game Face during the cognitive task, displayed significant decreases from baseline following the puzzle manipulation. These results are promising regarding performance on a cognitive task and sympathetic nervous system activation, in concert with making a Game Face. [ABSTRACT FROM AUTHOR]

Based on the effects of coffee and caffeine, in particular, a review study is needed to investigate associations between the caffeine consumption and its health-linked effects. Furthermore, effects of coffee on sport performance have not fully been elucidated. Based on the increased popularity of the cold-brew coffee, this study has provided a comprehensive overview of the effects of cold-brew coffee on health and exercise performance. Databases (PubMed, Science Direct and Google Scholar) were searched for articles on human models. Totally, 2805 articles were identified from 2000 to 2020. Keywords included coffee, caffeine, cold brew, exercise, training and sports performance. Studies involving caffeinesuppressing drugs and animal studies and cases with physical limitations were excluded and thus 84 articles were identified. Results showed that consumption of 3 to 4 cups of coffee (300-400 mg/day) was associated with decreased risk factors of cancers, cardiovascular diseases, diabetes and Alzheimer disease. It is noteworthy that caffeine intake in specific groups, particularly in women, needs special consideration. However, health benefits of the cold-brew coffee seem to be greater due to the drink low acidity and high antioxidant activity. In this study, the most important factor included decreases in chlorogenic acid. Moreover, consumption of cold-brew coffee in warm weather prevented hyperthermia. In fact, 3-9 mg/kg of caffeine improved physical performance in resistance and endurance exercises. Caffeine consumption could increase lipid oxidation in aerobic exercises as well as stimulate sympathetic nerves in anaerobic exercises. However, investigation of the acute and chronic effects of consuming coffee in various contexts to achieve integrated results needs further investigations. [ABSTRACT FROM AUTHOR]

Yogic exercises have been known to increase mental and physical control of the body. Earlier practices of yogasan and pranayam have revealed physical and mental well being. Yoga has great therapeutic potential in management of related diseases stress. It improves the psyche of the individual because training causing decrease in psychic stimuli to vasomotor and respiratory centre hence there is less increase in sympathetic activity and less decrease in parasympathetic activity with an optimal blood flow distribution. Greater amount of fat is utilized for providing energy sparing glycogen. [ABSTRACT FROM AUTHOR]

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Introduction: Psycho-behavioral studies have shown that sympathetic skin response (SSR), which is an indicator of sympathetic function, is associated with emotional responses. It has been reported that SSR, which is claimed to be a biological indicator of empathy, has increased in Social Anxiety Disorder (SAD) patients. The aim of this study was to evaluate the relationship between SSR and alexithymia, empathy in patients with SAD. Method: SAD patients and control group were applied Liebowitz Social Anxiety Scale, Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Toronto Alexithymia Scale, Empathy Quotient, Facial Emotion Identification and Discrimination tests (FID, FDSC); during the application FID, SSR were measured. The relationship between alexithymia and empathy levels were investigated. Results: The number of SSR was higher in all visual stimuli of SAD patients (11.13±3.01) compared to the control group (7.4±3.57). More autonomous activity to negative stimuli (SAD: 10.55±2.82, control: 6.36±3.64), sensitivity to positive stimuli (SAD: 0.58±0.69, control: 1.03±0.8) was less than control group. While 41.7% of SAD patients had alexithymic features, 36.1% were diagnosed with depressive disorder. Conclusion: It was thought that depressive and alexithymic features may have contributed to increased sympathetic sensitivity to negative stimuli in SAD patients. Further studies are needed to examine the effects of this situation on the selection and creation of the treatment modalities. [ABSTRACT FROM AUTHOR]

A total of 59 undergraduate students provided self-reports on measures of dispositional mindfulness and perceived stress. Physiological recordings of skin conductance levels were collected during a 15-min resting period. Hierarchical regressions demonstrated a significant association between greater dispositional mindfulness and less perceived stress, as well as lower resting physiological stress (skin conductance levels). These findings replicate previous reports of associations between mindfulness and psychological markers of stress and also present a novel association of dispositional mindfulness and an objective measurement of physiological stress underscoring the potential physiological stress-reducing effects of a mindful disposition. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to prospectively determine the prevalence, duration, and severity of vasomotor symptoms (VMS) during menopause in a Chinese longitudinal cohort.Methods: This longitudinal cohort study recruited 187 participants from an urban Chinese community. The presence, frequency, degree, and duration of VMS were measured and analyzed.Results: A total of 83.4% of participating women experienced hot flashes and 82.9% reported night sweats, with nearly half reporting moderate to severe VMS (more than 3 times per day, or rated 4 or greater on a 1-8 severity scale). The median duration for both hot flashes and night sweats was 4.5 years. In a generalized linear mixed model, presence of VMS was significantly related to menopause stages, serum follicle stimulating hormone concentrations, general distress levels, and baseline body mass index.Discussion and conclusions: The prevalence of VMS in this longitudinal cohort was higher than that of previous Chinese cross-sectional studies and consistent with prior studies in western women. Meanwhile, the duration of symptomatic years in our study was shorter than that of western women. These results indicate that the difference in VMS between western and Chinese women appears to be in terms of the duration of symptoms, not prevalence. [ABSTRACT FROM AUTHOR]

This study investigated the contribution of both physiological and behavioural process data to the comprehension of conflicting digital texts. We measured skin conductance level (SCL) as an index of arousal and the first‐pass and look‐back fixation times as indices of visual behaviour while reading. Forty‐eight seventh graders read four webpages on genetically modified food, and their comprehension of the texts was measured using a short essay. Results showed that the type of webpage did not differentiate the process data. Statistical procedures for the comparison of a series of regression models revealed that SCL and first‐pass fixation time negatively predicted multiple‐text comprehension while also considering the control variables. The more the students were aroused while reading and the longer the processing time during the first encounter with the reading material, the poorer their comprehension of the conflicting texts. However, the interaction of prior knowledge and arousal positively predicted multiple‐text comprehension. A slope analysis revealed that when participants had high prior knowledge and high arousal during reading, their postreading comprehension performance increased. Lay Description: What is already known about this topic Multiple‐text comprehension requires readers to construct both an intertext model and an integrated mental model.The process of reading various texts on the same topic can be traced by physiological and behavioural data.Skin conductance level is an index of physiological arousal.First‐ and second‐pass fixation time are indices of visual behaviour during the immediate and delayed text processing. What this paper adds Physiological arousal per se is negatively associated with the comprehension of various digital texts on the debated topic of genetically modified food.The duration of the first pass is negatively associated with multiple‐text comprehension.The interaction of prior topic knowledge and physiological arousal is positively associated with multiple‐text comprehension.When pre‐existing knowledge is high, multiple‐text comprehension is greater with high arousal. Implications for practice and/or policy Recall of prior knowledge before reading is a beneficial starting point for comprehension processes.Physiological arousal in combination with prior knowledge can reflect interest and enjoyment during reading or less processing effort for comprehension within and across texts.Videos with students' gaze replays can be used to solicit their reflections on the processing behaviour they activated while reading digital texts on the same content, and what processing behaviour is more conducive to successful multiple‐text comprehension. [ABSTRACT FROM AUTHOR]

Ventricular arrhythmias (VA) can range in presentation from asymptomatic to cardiac arrest and sudden cardiac death (SCD). Sustained ventricular tachycardias/ventricular fibrillation (VT/VF) are a common cause of SCD in the setting of myocardial infarction (MI) and heart failure. A particularly arrhythmogenic cardiac syncytia in these conditions can be attributed to both sympathetic activation and parasympathetic dysfunction, while appropriate neuromodulation has the potential to reduce occurrence of VT/VF. In this review, we outline the components of the autonomic nervous system that play an important role in normal cardiac electrophysiology and function. In addition, we discuss changes that occur in the setting of cardiac disease including adverse neural remodeling and neurohormonal activation which significantly contribute to propensity for VT/VF. Finally, we review neuromodulation strategies to mitigate VT/VF which predominantly rely on increasing parasympathetic drive and blockade of sympathetic neurotransmission. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to test our hypothesis that acute hypotension attenuates brachial flow-mediated dilation (FMD) as an index of endothelial function in healthy humans.Methods: Twelve healthy men (21.8 ± 1.6 years, body mass index; 22.2 ± 1.6 kg/m2) participated in this study. Brachial FMD was measured in three trials: standardized FMD protocol (control trial), abrupt decrease in blood pressure (BP) via thigh cuff inflation-deflation (hypotension trial) and decrease in shear rate (SR) via a shortened forearm occlusion time (SR reduction trial). Brachial diameter and blood velocity were measured using Duplex ultrasound.Results: Mean arterial pressure during reactive hyperaemia showed a marked decrease in the hypotension trial (- 23.7 ± 6.0 mmHg), but not in the control and SR reduction trials. SR area under the curve was attenuated in the SR reduction trial (P < 0.001), but not in the control and hypotension trials (P = 0.316). Consequently, FMD was attenuated in the hypotension and SR reduction trials compared with that in the control trial (P = 0.003 and P = 0.043, respectively), and was attenuated to a greater extent in the hypotension trial compared with the SR reduction trial (P = 0.006; control, 6.9 ± 3.5%; hypotension, 3.5 ± 1.7%; SR reduction, 5.0 ± 2.2%). After adjusting FMD using SR, FMD remained attenuated in the hypotension trial (P = 0.014), but not in the SR reduction trial.Conclusion: Our findings indicate that arterial pressure as well as sympathetic nervous system activation could be an important determinant of FMD. Blunted FMD of peripheral arteries may be a rational response to restore BP and/or prevent further reduction of BP following acute hypotension in healthy humans. [ABSTRACT FROM AUTHOR]

Objective: To examine differences in heart rate (HR) responses during international wheelchair rugby competition between athletes with and without a cervical spinal cord injury (SCI) and across standardized sport classifications. Design: Observational study. Setting: The 2015 Parapan American Games wheelchair rugby competition. Participants: Forty-three male athletes (31 ± 8 years) with a cervical SCI (n = 32) or tetraequivalent impairment (non-SCI, n = 11). Main Outcome Measures: Average and peak HR (HRavg and HRpeak, respectively). To characterize HR responses in accordance with an athletes' International Wheelchair Rugby Federation (IWRF) classification, we separated athletes into 3 groups: group I (IWRF classification 0.5-1.5, n = 15); group II (IWRF classification 2.0, n = 15); and group III (IWRF classification 2.5-3.5, n = 13). Results: Athletes with SCI had lower HRavg (111 ± 14 bpm vs 155 ± 13 bpm) and HRpeak (133 ± 12 bpm vs 178 ± 13 bpm) compared with non-SCI (both P < 0.001). Average HR was higher in group III than in I (136 M 25 bpm vs 115 M 20 bpm, P=0.045); however, SCI athletes showed no difference in HRavg or HRpeak between groups. Within group III, SCI athletes had lower HRavg (115 ± 6 bpm vs 160 ± 8 bpm) and HRpeak (135 ± 11 bpm vs 183 ± 11 bpm) than non-SCI athletes (both P < 0.001). Conclusions: This study is the first to demonstrate attenuated HR responses during competition in SCI compared with non-SCI athletes, likely due to injury to spinal autonomic pathways. Among athletes with SCI, IWRF classification was not related to differences in HR. Specific assessment of autonomic function after SCI may be able to predict HR during competition and consideration of autonomic impairments may improve the classification process. [ABSTRACT FROM AUTHOR]