Autonomic regulation and vagal tone

Autonomy of autonomic dysfunction in major depression.: Objective: To investigate cardiac autonomic dysfunction in patients with major depressive disorder (MDD). Research in this area has faced several limitations because of the heterogeneity of the disease, the influence of medication, and methodological shortcomings. Methods: Participants were 75 patients suffering from an acute recurrent episode of MDD and 75 matched controls. All participants were assessed at baseline for linear and nonlinear parameters of heart rate variability, QT variability a

Non-invasive vagus nerve stimulation acutely improves spontaneous cardiac baroreflex sensitivity in healthy young men: A randomized placebo-controlled trial.: Background: Despite positive outcomes of transcutaneous vagus nerve stimulation (tVNS) via the auricular branch of the vagus nerve (ABVN), the mechanisms underlying these outcomes remain unclear. Additionally, previous studies have not been controlled the possible placebo effects of tVNS. Objective: To test the hypothesis that tVNS acutely improves spontaneous cardiac baroreflex sensitivity (cBRS) and autonomic modulation, and that these effects are specific to stimulation of ABVN. Methods: Thir

Non-invasive vagus nerve stimulation in healthy humans reduces sympathetic nerve activity.: Background: Vagus nerve stimulation (VNS) is currently used to treat refractory epilepsy and is being investigated as a potential therapy for a range of conditions, including heart failure, tinnitus, obesity and Alzheimer's disease. However, the invasive nature and expense limits the use of VNS in patient populations and hinders the exploration of the mechanisms involved. Objective: We investigated a non-invasive method of VNS through electrical stimulation of the auricular branch of the vagus n

Effects of transcutaneous vagus nerve stimulation in individuals aged 55 years or above: potential benefits of daily stimulation.: Ageing is associated with attenuated autonomic function. Transcutaneous vagal nerve stimulation (tVNS) improved autonomic function in healthy young participants. We therefore investigated the effects of a single session of tVNS (studies 1 and 2) and tVNS administered daily for two weeks (study 3) in volunteers aged ≥ 55 years. tVNS was performed using modified surface electrodes on the tragus and connected to a transcutaneous electrical nerve stimulation (TENS) machine. Study 1: participants (n=

Modulation of vagal tone enhances gastroduodenal motility and reduces somatic pain sensitivity.: Background: The parasympathetic nervous system, whose main neural substrate is the vagus nerve, exerts a fundamental antinociceptive role and influences gastrointestinal sensori-motor function. Our research question was to whether combined electrical and physiological modulation of vagal tone, using transcutaneous electrical vagal nerve stimulation (t-VNS) and deep slow breathing (DSB) respectively, could increase musculoskeletal pain thresholds and enhance gastroduodenal motility in healthy sub

Sex differences in healthy human heart rate variability: A meta-analysis.: The present meta-analysis aimed to quantify current evidence on sex differences in the autonomic control of the heart, indexed by measures of heart rate variability (HRV) in healthy human subjects. An extensive search of the literature yielded 2020 titles and abstracts, of which 172 provided sufficient reporting of sex difference in HRV. Data from 63,612 participants (31,970 females) were available for analysis. Meta-analysis yielded a total of 1154 effect size estimates (k) across 50 different