Regulation Of Breathing Research Articles

IMPLEMENTATION OF YOGA IN EDUCATION AS A STRATEGY FOR ENHANCING STUDENTS EDUCATIONAL ACHIEVEMENTS

Yoga techniques has been practiced from ancient time in india.these techniques has been developed by Indian saints around or before second century BCE.it has been observed and found in literature that many chronic and incurable disease are cured by adopting yogic techniques in our daily life. In present era, yoga is adopted worldwide in different forms and each practitioner defining the yoga in its own form, but the basic aim of yoga is to use it for human mankind. One of the most practiced yogic techniques is breath regulation or controlled breath regulation using closing eyes and concentration of mind on inhaling and exhaling. This technique calm mind and body, which ultimately leads to many mental as well as physical health benefits. This technique doesn’t need any special infrastructure as well as specialized trainer, so it can be easily implemented in class room environment for enhancing the student’s concentration level. By adopting these techniques many studies have found that, it helps the students became more disciplined, energetic and their memory level also enhanced.

Relation between coffee consumption and risk of seizure‐related respiratory dysfunction in patients with drug‐resistant focal epilepsy

Caffeine is an antagonist of the adenosine pathway, which is involved in regulation of breathing. Extracellular concentrations of adenosine are increased in the immediate aftermath of a seizure. Seizure-related overstimulation of adenosine receptors might promote peri-ictal apnea. However, the relation between caffeine consumption and risk of seizure-related respiratory dysfunction in patients with drug-resistant focal epilepsy remains unknown. We performed a cross-sectional analysis of data collected in patients included in the SAVE study in Lyon's epilepsy monitoring unit at the Adult Epilepsy Department of the Lyon University Hospital between February 2016 and October 2018. The video-electroencephalographic recordings of 156 patients with drug-resistant focal epilepsy included in the study were reviewed to identify those with ≥1 focal seizure (FS), valid pulse oximetry (SpO2 ) measurement, and information about usual coffee consumption. This latter was collected at inclusion using a standardized self-questionnaire and further classified into four groups: none, rare (≤3 cups/week), moderate (4 cups/week to 3 cups/day), and high (≥4 cups/day). Peri-ictal hypoxemia (PIH) was defined as SpO2 < 90% for at least 5s occurring during the ictal period, the post-ictal period, or both. Ninety patients fulfilled inclusion criteria, and 323 seizures were analyzed. Both the level of usual coffee consumption (p=.033) and the level of antiepileptic drug withdrawal (p=.004) were independent risk factors for occurrence of PIH. In comparison with FS in patients with no coffee consumption, risk of PIH was four times lower in FS in patients with moderate consumption (odds ratio [OR]=.25, 95% confidence interval [CI]=.07-.91, p=.036) and six times lower in FS in patients with high coffee consumption (OR=.16, 95% CI=.04-.66, p=.011). However, when PIH occurred, its duration was longer in patients with moderate or high consumption than in those with no coffee consumption (p=.042). Coffee consumption may be a protective factor for seizure-related respiratory dysfunction, with a dose-dependent effect.

CO2 sensing by connexin26 and its role in the control of breathing.

Breathing is essential to provide the O2 required for metabolism and to remove its inevitable CO2 by-product. The rate and depth of breathing is controlled to regulate the excretion of CO2 to maintain the pH of arterial blood at physiological values. A widespread consensus is that chemosensory cells in the carotid body and brainstem measure blood and tissue pH and adjust the rate of breathing to ensure its homeostatic regulation. In this review, I shall consider the evidence that underlies this consensus and highlight historical data indicating that direct sensing of CO2 also plays a significant role in the regulation of breathing. I shall then review work from my laboratory that provides a molecular mechanism for the direct detection of CO2 via the gap junction protein connexin26 (Cx26) and demonstrates the contribution of this mechanism to the chemosensory regulation of breathing. As there are many pathological mutations of Cx26 in humans, I shall discuss which of these alter the CO2 sensitivity of Cx26 and the extent to which these mutations could affect human breathing. I finish by discussing the evolution of the CO2 sensitivity of Cx26 and its link to the evolution of amniotes.

Fast breathing facilitates reaction time and movement time of a memory-guided force pulse

Slow controlled breathing can be beneficial for performance of continuous and serial motor tasks. However, how controlled breathing influences discrete motor task performance remains unclear. We sought to determine the impact of paced breathing frequency on measures of movement initiation (reaction time: RT), accuracy (absolute endpoint error: AE; constant error: CE), and variability (trial-to-trial variability: V), in a goal-directed discrete motor task. We hypothesized slow breathing would be accompanied by faster RT, reduced AE and CE, and less V compared to faster breathing rates. Participants (N=47) performed a memory-guided force pulse pinch task targeted at 10% of their maximum voluntary contraction while breathing at metronome-paced slow, normal, and fast frequencies. During each breathing condition, heart rate variability (HRV) as indexed by the standard deviation of 'NN' intervals (SDNN) was measured to ensure objective manipulation check of participants breathing at their set pace. Following each breathing condition, participants provided subjective ratings using the Affect Grid and Visual Analog Scales for arousal, hindrance, and dyspnea. Manipulation check results indicated participants correctly breathed at metronome paces, as indexed by increased HRV for slow breathing and decreased HRV for fast breathing. Results indicated that fast breathing reduced reaction time and movement time, and increased ratings of arousal, hindrance, and dyspnea. In contrast, slow breathing increased reaction time, and levels of hindrance and dyspnea were similar to normal breathing. Breathing frequency did not differentially impact accuracy or variability across conditions. Findings provide evidence that breathing frequency affects fundamental movement parameters, potentially mediated by factors other than arousal.

Hormonal Effects on Respiration and Metabolism of Steroid Hormones

There is a growing public awareness that sex hormones can have an impression on a spread of physiological processes. Yet, despite almost a century of research, we still don't have a transparent picture on the consequences of sex hormones on the regulation of breathing. Extensive information has gathered appearance that estrogen, progesterone and testosterone can impact respiratory capacity in creatures and people. Several disorders of breathing like obstructive apnea (OSA) and sudden sudden infant death syndrome syndrome (SIDS) show clear sex differences in their prevalence, lending weight to the importance of sex hormones in respiratory control.

Yoga-Based Lifestyle Intervention as a Potential Adjuvant in Addressing Anxiety, Fear, Depression, and Perceived Health in Mild-to-Moderate COVID-19 Patients. A Pilot Study

Introduction: Coronavirus infection (COVID-19) has led to a serious public health crisis that has affected both physical and mental health. As we are racing toward a solution for containing the virus, there is a profound need to address the mental health impact of COVID-19 such as anxiety, stress, and depression. The present study evaluates the impact of yoga on mental health issues arising in COVID-19 pandemic. Materials and Methods: Patients who are diagnosed as COVID-19 by polymerase chain reaction and graded as mild-to-moderate COVID-19 as per the ICMR criteria were enrolled for adjuvant yoga and naturopathy-based lifestyle modification, which includes postures, breath regulation, meditation, and eucalyptus essential oil inhalation for 14 days. SpO2 (saturated oxygen) and anxiety, stress, depression, fear, and health were assessed through the depression, anxiety, and stress scale (DASS) at baseline (day 1 of admission) and 7th day, as well as visual analog scale (VAS) at baseline and 7th and 14th day. Results: Statistically significant changes reduction were observed in DASS-21 scores and VAS scores (P &lt; 0.05) but not on SpO2. Slight increase in mean anxiety, depth of fear, sleep disturbance, and health status was observed in VAS between 7th and 14th day, which was statistically nonsignificant. Discussion: Supervised yoga sessions are reported to be of significant impact in alleviating the mental health issues in COVID-19 compared to nonsupervised sessions. Our results suggest the inclusion of yoga therapy into COVID-19 care as an adjuvant considering its impact on mental health. However, future randomized control trials are warranted with more specific end points to ensure enhanced acceptance of yoga in scientific community.

Real-time measurement of adenosine and ATP release in the central nervous system

This brief review recounts how, stimulated by the work of Geoff Burnstock, I developed biosensors that allowed direct real-time measurement of ATP and adenosine during neural function. The initial impetus to create an adenosine biosensor came from trying to understand how ATP and adenosine-modulated motor pattern generation in the frog embryo spinal cord. Early biosensor measurements demonstrated slow accumulation of adenosine during motor activity. Subsequent application of these biosensors characterized real-time release of adenosine in in vitro models of brain ischaemia, and this line of work has recently led to clinical measurements of whole blood purine levels in patients undergoing carotid artery surgery or stroke. In parallel, the wish to understand the role of ATP signalling in the chemosensory regulation of breathing stimulated the development of ATP biosensors. This revealed that release of ATP from the chemosensory areas of the medulla oblongata preceded adaptive changes in breathing, triggered adaptive changes in breathing via activation of P2 receptors, and ultimately led to the discovery of connexin26 as a channel that mediates CO2-gated release of ATP from cells.

Structural basis for pH gating of the two-pore domain K+ channel TASK2.

TASK2 (also known as KCNK5) channels generate pH-gated leak-type K+ currents to control cellular electrical excitability1-3. TASK2 is involved in the regulation of breathing by chemosensory neurons of the retrotrapezoid nucleus in the brainstem4-6 and pH homeostasis by kidney proximal tubule cells7,8. These roles depend on channel activation by intracellular and extracellular alkalization3,8,9, but the mechanistic basis for TASK2 gating by pH is unknown. Here we present cryo-electron microscopy structures of Mus musculus TASK2 in lipid nanodiscs in open and closed conformations. We identify two gates, distinct from previously observed K+ channel gates, controlled by stimuli on either side of the membrane. Intracellular gating involves lysine protonation on inner helices and the formation of a protein seal between the cytoplasm and the channel. Extracellular gating involves arginine protonation on the channel surface and correlated conformational changes that displace the K+-selectivity filter to render it nonconductive. These results explain how internal and external protons control intracellular and selectivity filter gates to modulate TASK2 activity.

Connexin26 mediates CO2-dependent regulation of breathing via glial cells of the medulla oblongata

Breathing is highly sensitive to the PCO2 of arterial blood. Although CO2 is detected via the proxy of pH, CO2 acting directly via Cx26 may also contribute to the regulation of breathing. Here we exploit our knowledge of the structural motif of CO2-binding to Cx26 to devise a dominant negative subunit (Cx26DN) that removes the CO2-sensitivity from endogenously expressed wild type Cx26. Expression of Cx26DN in glial cells of a circumscribed region of the mouse medulla - the caudal parapyramidal area – reduced the adaptive change in tidal volume and minute ventilation by approximately 30% at 6% inspired CO2. As central chemosensors mediate about 70% of the total response to hypercapnia, CO2-sensing via Cx26 in the caudal parapyramidal area contributed about 45% of the centrally-mediated ventilatory response to CO2. Our data unequivocally link the direct sensing of CO2 to the chemosensory control of breathing and demonstrates that CO2-binding to Cx26 is a key transduction step in this fundamental process.

Pregnancy in congenital central hypoventilation syndrome

Congenital central hypoventilation syndrome is a rare genetic disorder of autonomic regulation of breathing resulting from mutations in the paired-like homeobox gene. Individuals with congenital central hypoventilation syndrome demonstrate an absent or diminished physiological response to hypercapnia and hypoxia that is most severe during sleep and depend on mechanical ventilation to maintain normal gas exchange. Increased disease awareness and availability of paired-like homeobox gene testing has improved congenital central hypoventilation syndrome morbidity and mortality, and patients are now living into adulthood. During pregnancy, delivery, and the postpartum period, women with congenital central hypoventilation syndrome are vulnerable to developing respiratory insufficiency. Currently, there is no standardized approach to monitoring ventilatory status and anticipating the need for changes to existing ventilatory support for women with congenital central hypoventilation syndrome during pregnancy, labor, and delivery. This study aimed to characterize current practices for monitoring ventilatory status and managing ventilatory needs in women with congenital central hypoventilation syndrome during pregnancy; identify specific circumstances through which ventilation may be compromised during pregnancy, delivery, and postpartum; evaluate utilization of prenatal congenital central hypoventilation syndrome testing; and report any adverse pregnancy outcomes. We conducted an anonymous cross-sectional survey of women with congenital central hypoventilation syndrome with current or prior pregnancy. The 26-item electronic questionnaire included questions on congenital central hypoventilation syndrome genotype; number and outcome of pregnancies; use of mechanical ventilation; and issues with or adjustments made to ventilation during pregnancy, delivery, and the postpartum period. We received 10 responses. Three patients were not diagnosed with congenital central hypoventilation syndrome until after pregnancy and delivery. The 7 patients with a preexisting congenital central hypoventilation syndrome diagnosis reported information on 10 total pregnancies. At baseline, patients relied on various types of ventilatory support including positive pressure ventilation via tracheostomy, bilevel noninvasive positive pressure ventilation, and diaphragm pacing by phrenic nerve stimulation. Polysomnography for objective assessment of nocturnal ventilation was not consistently utilized. Changes to baseline ventilatory support were required during 3 out of 10 pregnancies. In addition, 2 patients using diaphragm pacing reported discomfort with pacing during the third trimester or after cesarean delivery, prompting discontinuation of diaphragm pacing. In 1 instance, discontinuation of diaphragm pacing and lack of recognition of need for an alternative support method led to respiratory arrest and need for emergent resuscitation. All patients who were offered prenatal congenital central hypoventilation syndrome testing chose to undergo testing. Of note, 9 out of 10 pregnancies were carried successfully to term and 5 infants were diagnosed with congenital central hypoventilation syndrome. Women with congenital central hypoventilation syndrome may experience issues maintaining adequate ventilation during pregnancy, necessitating an adjustment of ventilator settings or use of an alternative type of ventilation. Objective assessment of nocturnal ventilation by means of polysomnography is an important part of congenital central hypoventilation syndrome pregnancy care to optimize maintenance of adequate gas exchange. Patients who rely on diaphragm pacing may experience discomfort with pacing during the later stages of pregnancy and after cesarean delivery. Anticipatory guidance and contingency planning for changing ventilatory needs should be discussed early in pregnancy. Prenatal congenital central hypoventilation syndrome testing should be offered to pregnant patients with congenital central hypoventilation syndrome to inform delivery decisions and prepare for the provision of advanced neonatal care.

Efek Kombinasi Relaksasi Autogenik dan Aromaterapi Lavender Terhadap Kadar Glukosa Darah Pada Pasien DM Tipe 2

Background: Elderly as a group at risk of susceptible to health problems due to physiological decline in the body, one of them is diabetes mellitus type 2. Elderly diabetes mellitus type 2 requires good management both pharmacologically and non pharmacologically. Non-pharmacological management that can control blood glucose levels in the elderly is autogenic relaxation therapy with lavender aromatherapy. Autogenic relaxation is mind body therapy that focuses on heart rate and breath regulation. Aromatherapy lavender is a therapy that uses essential oils that can calm the mind. This scientific work aims to analyze effect of combination therapy of autogenic relaxation and lavender aromatherapy to amount blood sugar in elderly people with diabetes mellitus type 2. Methods: This study used a quasi experimental pre test and post test method without control group. Sampling using a purposive sampling method of 16 respondents. Therapy is done 2 times a day for 15 minutes in each session within 30 days with 10 meetings and blood glucose checks. The analysis test used the paired T-Test. Results: The results of the Paired T-Test statistical test showed a significant decrease in average&#x0D; blood glucose levels of 83.75 mg/dL with a value of p = 0.000. Conclusion: Combination therapy of autogenic relaxation and lavenderaromatherapy are effective for reducing blood glucose levels. Therefore, it is expected that the elderly with diabetes mellitus type 2 can perform autogenic relaxation therapy and lavender aromatherapy routinely so that blood glucose levels can decrease.

Volumetric brain magnetic resonance imaging analysis in children with obstructive sleep apnea

ObjectivesPediatric Obstructive Sleep Apnea (OSA) is associated with neurocognitive deficits. Cerebral structural alterations in the frontal cortex, cerebellum, and hippocampus have been reported in adult OSA patients. These brain areas are important for executive functioning, motor regulation of breathing, and memory function, respectively. Corresponding evidence comparing cerebral structures in pediatric OSA patients is limited. The objective of this study is to investigate MRI differences in cortical thickness and cortical volume in children with and without OSA. Study designProspective, single institutional case-control study. MethodsForty-five children were recruited at a pediatric tertiary care center (27 with OSA; mean age 9.9 ± 1.9 years, and 18 controls; mean age 10.5 ± 1.0 years). The OSA group underwent magnetic resonance imaging (MRI), polysomnography (PSG) and completed the Pediatric Daytime Sleepiness Scale (PDSS) and the Child's Sleep Habits Questionnaire (CSHQ). High-resolution T1-weighted MRI was utilized to examine cortical thickness and gray and white matter volume in children with OSA compared to a healthy group of demographically-comparable children without OSA selected from a pre-existing MRI dataset. ResultsChildren with OSA showed multiple regions of cortical thinning primarily in the left hemisphere. Reduced gray matter (GM) volume was noted in the OSA group in multiple frontal regions of the left hemisphere (superior frontal, rostral medial frontal, and caudal medial frontal regions). Reduced white matter (WM) volume in both the left and right hemisphere was observed in regions of the frontal, parietal, and occipital lobes in children with OSA. ConclusionThis study noted differences in cortical thickness and GM and WM regional brain volumes in children with OSA. These findings are consistent with other pediatric studies, which also report differences between healthy children and those with OSA. We found that the severity of OSA does not correlate with the extent of MRI alterations.

Exhaled breath compositions under varying respiratory rhythms reflects ventilatory variations: translating breathomics towards respiratory medicine

Control of breathing is automatic and its regulation is keen to autonomic functions. Therefore, involuntary and voluntary nervous regulation of breathing affects ventilatory variations, which has profound potential to address expanding challenges in contemporary pulmonology. Nonetheless, the fundamental attributes of the aforementioned phenomena are rarely understood and/or investigated. Implementation of unconventional approach like breathomics may leads to a better comprehension of those complexities in respiratory medicine. We applied breath-resolved spirometry and capnometry, non-invasive hemodynamic monitoring along with continuous trace analysis of exhaled VOCs (volatile organic compounds) by means of real-time mass-spectrometry in 25 young and healthy adult humans to investigate any possible mirroring of instant ventilatory variations by exhaled breath composition, under varying respiratory rhythms. Hemodynamics remained unaffected. Immediate changes in measured breath compositions and corresponding variations occurred when respiratory rhythms were switched between spontaneous (involuntary/unsynchronised) and/or paced (voluntary/synchronised) breathing. Such changes in most abundant, endogenous and bloodborne VOCs were closely related to the minute ventilation and end-tidal CO2 exhalation. Unprecedentedly, while preceded by a paced rhythm, spontaneous rhythms in both independent setups became reproducible with significantly (P-value ≤ 0.005) low intra- and inter-individual variation in measured parameters. We modelled breath-resolved ventilatory variations via alveolar isoprene exhalation, which were independently validated with unequivocal precision. Reproducibility i.e. attained via our method would be reliable for human breath sampling, concerning biomarker research. Thus, we may realize the actual metabolic and pathophysiological expressions beyond the everlasting in vivo physiological noise. Consequently, less pronounced changes are often misinterpreted as disease biomarker in cross-sectional studies. We have also provided novel information beyond conventional spirometry and capnometry. Upon clinical translations, our findings will have immense impact on pulmonology and breathomics as they have revealed a reproducible pattern of ventilatory variations and respiratory homeostasis in endogenous VOC exhalations.

Functional role for preoptic CB1 receptors in breathing and thermal control

The anteroventral preoptic region (AVPO) of the hypothalamus is involved in both temperature and breathing regulation. This area densely express cannabinoid receptors type 1 (CB1) that modulate both excitatory and inhibitory synaptic transmission. However, it is still unknown if the endocannabinoid system located in the AVPO participates in breathing control and thermoregulation. Therefore, we tested the participation of CB1 in the AVPO in the modulation of ventilation and thermal control during normoxia and hypoxia. To this end, body temperature (Tb) of Wistar rats was monitored by datallogers and ventilation (VE) by whole body plethysmography before and after intra-AVPO microinjection of AM-251 (CB1 antagonist, 50 and 100 pmol) followed by 60 min of hypoxia exposure (7% O2). Intra-AVPO microinjection of the higher dose of AM-251 increased VE but did not change Tb under resting conditions. Exposure of rats to 7% of inspired oxygen evoked typical hypoxia-induced anapyrexia and hyperventilation after vehicle microinjection. The higher dose of the cannabinoid antagonist increased the hypoxia-induced hyperventilation, in the same magnitude as observed under normoxic condition, whereas the drop in Tb elicited by hypoxia was attenuated. Therefore, the present results demonstrate that the endocannabinoid system acting on CB1 receptors in the AVPO exerts a tonic inhibitory modulation on breathing but seem not be involved in thermoregulation during resting conditions. In addition, activation of CB1 receptors in the AVPO stimulate thermal response during hypoxia, reducing energetically expensive responses, such as the hypoxic hyperventilation.

A role for neurokinin 1 receptor expressing neurons in the paratrigeminal nucleus in bradykinin-evoked cough in guinea-pigs.

Airway projecting sensory neurons arising from the jugular vagal ganglia terminate centrally in the brainstem paratrigeminal nucleus, synapsing upon neurons expressing the neurokinin 1 receptor. This study aimed to assess the involvement of paratrigeminal neurokinin 1 receptor neurons in the regulation of cough, breathing and airway defensive responses. Lesioning neurokinin 1 receptor expressing paratrigeminal neurons significantly reduced cough evoked by inhaled bradykinin but not inhaled ATP or tracheal mechanical stimulation. The reduction in bradykinin-evoked cough was not accompanied by changes in baseline or evoked respiratory variables (e.g. frequency, volume or timing), animal avoidance behaviours or the laryngeal apnoea reflex. These findings warrant further investigations into targeting the jugular ganglia and paratrigeminal nucleus as a therapy for treating cough in disease. Jugular vagal ganglia sensory neurons innervate the large airways and are thought to mediate cough and associated perceptions of airway irritations to a range of chemical irritants. The central terminals of jugular sensory neurons lie within the brainstem paratrigeminal nucleus, where postsynaptic neurons can be differentiated based on the absence or presence of the neurokinin 1 (NK1) receptor. Therefore, in the present study, we set out to test the hypothesis that NK1 receptor expressing paratrigeminal neurons play a role in cough evoked by inhaled chemical irritants. To test this, we performed selective neurotoxin lesions of NK1 receptor expressing neurons in the paratrigeminal nucleus in guinea-pigs using substance P conjugated to saporin (SSP-SAP). Sham lesion control or SSP-SAP lesion guinea-pigs received nebulised challenges, with the pan-nociceptor stimulant bradykinin or the nodose ganglia specific stimulant adenosine 5'-triphosphate (ATP), in conscious whole-body plethysmography to study cough and associated behaviours. Laryngeal apnoea reflexes and cough evoked by mechanical stimulation of the trachea were additionally investigated in anaesthetised guinea-pigs. SSP-SAP significantly and selectively reduced the number of NK1 receptor expressing neurons in the paratrigeminal nucleus. This was associated with a significant reduction in bradykinin-evoked cough, but not ATP-evoked cough, mechanical cough or laryngeal apnoeic responses. These data provide further evidence for a role of jugular vagal pathways in cough, and additionally suggest an involvement of NK1 receptor expressing neurons in the paratrigeminal nucleus. Therefore, this neural pathway may provide novel therapeutic opportunities to treat conditions of chronic cough.

Mother-Infant Co-Sleeping and Maternally Reported Infant Breathing Distress in the UK Millennium Cohort.

Mother–infant co-sleeping or bed sharing is discouraged by health organisations due to evidence that it is associated with unexplained sudden infant death. On the other hand, there is evidence that it should theoretically be beneficial for infants. One line of this evidence concerns breathing regulation, which at night is influenced by the rocking movement of the mother’s chest as she breathes. Here, the hypothesis that mother–infant co-sleeping will be associated with a lower probability of infant breathing distress is tested in the UK Millennium Cohort Study (n = 18,552 infants). Maternal, infant, family, and socio-economic covariates were included in logistic regression analysis, and in a machine learning algorithm (Random Forest) to make full use of the number of variables available in the birth cohort study data. Results from logistic regression analysis showed that co-sleeping was associated with a reduced risk of breathing difficulties (OR = 0.69, p = 0.027). The Random Forest algorithm placed high importance on socio-economic aspects of infant environment, and indicated that a number of maternal, child, and environmental variables predicted breathing distress. Co-sleeping by itself was not high in the Random Forest variable importance ranking. Together, the results suggest that co-sleeping may be associated with a modest reduction in risk of infant breathing difficulties.

Ld-EEG Effective Brain Connectivity in Patients With Cheyne-Stokes Respiration.

The characterization of brain cortical activity in heart-failure patients affected by Cheyne-Stokes Respiration might provide relevant information about the mechanism underlying this pathology. Central autonomic network is gaining increasing attention for its role in the regulation of breathing and cardiac functions. In this scenario, evaluating changes in cortical connectivity associated with Cheyne-Stokes Respiration may be of interest in the study of specific brain-activity related to such disease. Nonetheless, the inter subject variability, the temporal dynamics of Central-Apnea/Hyperpnea cycles and the limitations of clinical setups lead to different methodological challenges. To this aim, we present a framework for the assessment of cortico-cortical interactions from Electroencephalographic signals acquired using low-density caps and block-design paradigms, arising from endogenous triggers. The framework combines ICA-decomposition, unsupervised clustering, MVAR modelling and a permutation-bootstrap strategy for evaluating significant connectivity differences between conditions. A common network, lateralized towards the left hemisphere, was depicted across 8 patients exhibiting Cheyne-Stokes Respiration patterns during acquisitions. Significant differences in connectivity at the group level were observed based on patients' ventilatory condition. Interactions were significantly higher during hyperpnea periods with respect to central apneas and occurred mainly in the delta band. Opposite-sign differences were observed for higher frequencies (i.e. beta, low-gamma).

Effect of Protective Equipment on Firefighters' External and Internal Workloads During a Simulated Rescue Intervention.

Marcel-Millet, P, Ravier, G, and Groslambert, A. Effect of protective equipment on firefighters' external and internal workloads during a simulated rescue intervention. J Strength Cond Res 36(8): 2291-2297, 2022-Firefighter's protective equipment is one of the main factors increasing psychophysiological demand during rescue intervention. Workload quantification defines the amount of stress placed on an individual. This study aimed to test the relationships and compare different workload methods to discriminate 3 protective equipment conditions based on simulated rescue intervention. The protective equipment was (a) personal protective clothing (PPC); (b) PPC and a self-contained breathing apparatus (SCBA), including a cylinder, a full-face piece, and a breathing regulator; and (c) PPC and only the cylinder of the SCBA (SCBAc). Workload was determined using methods based on heart rate (HR), perceived exertion (sRPE), acceleration, and an indirect method based on postexercise HR variability. Differences between conditions were analyzed with repeated-measures analyses of variance. Relationships between workload methods were determined using Pearson's correlations. Statistical significance was set at p < 0.05. The HR-based and sRPE methods showed higher values in the SCBA and SCBAc conditions than the PPC condition ( p < 0.0001); only the sRPE method had a higher workload for the SCBA condition than the SCBAc condition ( p < 0.0001). Acceleration-based workloads were lower in the SCBA and SCBAc conditions than the PPC condition ( p < 0.0001). The indirect method revealed no difference between the 3 conditions. Significant relationships were observed between the HR-based and sRPE methods ( r = 0.544-0.738). Inverse significant correlations were observed between the HR-based and sRPE methods and the acceleration workload methods ( r = -0.319 to -0.762). Although HR-based and sRPE methods might quantify the workloads, the sRPE method was more sensitive to discriminate between the SCBAc and SCBA conditions.

Регуляция дыхания при электрической стимуляции поясничного отдела спинного мозга у человека

The current research is a continuation of our recent study devoted to the regulation mechanisms of the human respiratory system reaction to transcutaneous electrical stimulation of the spinal cord (tSCS), which causes a locomotor response. With healthy volunteers serving as the subjects in our experiment, we compared the respiratory system reactions to tSCS in the area of T12-L1 vertebrae, which was performed during the voluntary and passive leg movements with equal amplitude and speed parameters, with the reaction under the conditions of external suppression of the locomotor response caused by tSCS, which made it possible to modulate the contribution of the neurogenic mechanism of respiration regulation to the ventilatory reaction. A rehabilitation biomechanical simulator was used for this investigation. Our experiments showed that tSCS with an intensity that induced muscle response under the conditions of external restraint of leg movements causes a decrease in the depth of breathing by 0.10 ± 0.03 l due to an insignificant, but synchronous decrease in the duration and speed of both inspiration and exhalation. Stimulation during voluntary leg movement was accompanied by a significant increase in the minute volume of the ventilation of the lungs by 3.23 ± 1.06 l/min. due to an increase in the depth of breathing by 0.10 ± 0.03 l. The respiratory reaction to tSCS during passive leg movement was weak, but there was a tendency towards an increase in the frequency and a decrease in the depth of breathing with a marked increase in oxygen consumption by 33.10 ± 13.16 ml/min. In case of the passive leg movement, the effects of tSCS and the mechanisms of respiration regulation during muscular activity were almost coherent. The revealed differences in respiratory reactions to tSCS are most likely associated with the imposition of multidirectional effects of stimulation of the lumbar areas of the spinal cord, on the one hand, and a complex of neurogenic and humoral-reflex mechanisms of breathing regulation during physical work, on the other.

Psychological Mediation of Dysfunction and Hyperfunction of Respiratory Regulation.

This research investigates the continuum between the dysfunction and the hyperfunction of breath regulation and presents the psychological mediation that supports or disrupts this regulation. The pilot study compared breathing regulation in patients with hyperventilation syndrome (HVS), free divers, and healthy volunteers. To examine the ability of voluntary respiration regulation, breath holding involving “easy-going” and “struggling” phases was used. Psychological mediation was assessed through (a) respiratory experience interviews, (b) anxiety levels, and (c) psycho-semantic techniques. Free divers have a bigger “positive breathing vocabulary” and can endure the conflict between the physiological need to inhale and the voluntary motivation to hold their breath for longer. The connection between emotions and negative breathing experience in patients with HVS leads to less breathing control.