Respiratory Physiology & Neurobiology最新文献

{"title":"Low and sustained doses of erythropoietin prevent preterm infants from intraventricular hemorrhage.","authors":"Diana Andrea Arias Fernández, Héctor Alfonso Romero Diaz, Alan David Figueroa Garnica, Pablo Iturri-Soliz, Christian Arias-Reyes, Edith Mariane Schneider Gasser, Jorge Soliz","doi":"10.1016/j.resp.2024.104363","DOIUrl":"https://doi.org/10.1016/j.resp.2024.104363","url":null,"abstract":"<p><p>In addition to its hematopoietic function, erythropoietin (EPO) has demonstrated neuroprotective properties in preclinical studies, particularly in cases of reduced oxygenation or ischemia in the neonatal brain. While these findings have sparked optimism for its potential clinical application, the efficacy of EPO remains contentious in translational assays. Notably, while repeated administration of low doses of EPO has correlated with a decrease in adverse outcomes, the use of high EPO doses has shown either negligible or potentially detrimental effects on the incidence of brain injury. In this pilot study, we explored the effects of low and sustained doses of EPO (400 IU/kg) on the incidence of intraventricular hemorrhage (IVH) in premature infants. EPO was administered intravenously three times a week until the infants reached 32 weeks corrected gestational age. Our results indicate a significant decrease in the incidence of IVH with EPO treatment. Although, this study does not provide conclusive evidence on EPO's ability to reverse established IVH, these results strongly support the need for larger-scale clinical trials to further assess EPO's therapeutic potential.</p>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142606152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recruitment of the diaphragm and sternocleidomastoid muscle during increasing inspiratory pressure loads in healthy young adults.","authors":"Fang Liu, Alice Y M Jones, Raymond C C Tsang, Timothy T T Yam, William W N Tsang","doi":"10.1016/j.resp.2024.104365","DOIUrl":"10.1016/j.resp.2024.104365","url":null,"abstract":"<p><strong>Background: </strong>Inspiratory muscle training (IMT) is often employed to enhance improvement in inspiratory muscle strength. However, the relationship between inspiratory muscle recruitment patterns and increasing inspiratory load remains unclear. Furthermore, the effect of breathing instructions on diaphragm activity at various inspiratory loads is unknown.</p><p><strong>Objective: </strong>To investigate the recruitment activity of the diaphragm and sternocleidomastoid (SCM) muscle under increased inspiratory pressure loading, with and without diaphragmatic breathing instructions, in healthy young adults.</p><p><strong>Methods: </strong>Participants were invited to breathe, in random order, 6 sets of 10 breaths at inspiratory loads of 30 % to 80 % maximal inspiratory pressure (MIP), in 10 % increments. The measurement process was repeated with a specific focus of diaphragmatic descent during inspiration. During each targeted breath, recordings of surface electromyography of the right SCM muscle and thickness of the right hemi-diaphragm measured by ultrasonography were undertaken concurrently.</p><p><strong>Results: </strong>Sixty-two adults (31 males, age: 23±3 years) participated in the study. Irrespective of breathing instructions, computed diaphragm thickening fraction (DTf) increased with increasing inspiratory load but peaked at 50 % MIP and declined with increasing load to 80 % MIP. SCM recruitment increased with increasing inspiratory load to 80 % MIP. Forced inspiration with diaphragmatic breathing was associated with a higher DTf and lower SCM muscle activity. The above pattern was similar for both male and female participants. Female participants produced higher SCM activity compared with males but only at inspiration loads below 50 % MIP.</p><p><strong>Conclusions: </strong>In a cohort of young healthy adults, magnitude of diaphragmatic effort was greatest at 50 % MIP but declined with increasing inspiratory load to 80 % MIP. Forced inspiration combined with focused diaphragmatic breathing accentuated diaphragm contraction and reduced SCM muscle contribution. Our findings show that diaphragmatic muscle recruitment is non-linear and that the generic clinical prescription of an IMT program may need to be reconfigured.</p>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142569288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemodynamics and vascular oxygenation measured at the forehead during changes in respiration: A SPA-fNIRS study.","authors":"Sabino Guglielmini, Elena Wiggli, Felix Scholkmann, Martin Wolf","doi":"10.1016/j.resp.2024.104364","DOIUrl":"10.1016/j.resp.2024.104364","url":null,"abstract":"<p><strong>Significance: </strong>Cerebral blood flow is influenced by respiration, primarily through changes in the CO₂ concentration of arterial blood.</p><p><strong>Aim: </strong>The objective of this study was to investigate the effect of changes in arterial CO₂ concentration induced by respiratory changes on oxygenation and hemodynamics in the cerebral and extracerebral tissue layers of the forehead.</p><p><strong>Approach: </strong>We used systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) to assess changes in forehead hemodynamics and oxygenation as well as systemic physiology in 20 healthy subjects. All participants performed two respiratory tasks (breath-holding and hyperventilation).</p><p><strong>Results: </strong>In our SPA-fNIRS study we found that changes in breathing affected hemodynamics and oxygenation in both the extracerebral and cerebral tissue layers of the forehead in characteristic ways, depending on the two respiratory tasks.</p><p><strong>Conclusion: </strong>The results show that extracerebrovascular reactivity (ECVR) exists in parallel with the well-known cerebrovascular reactivity (CVR). CVR and ECVR must be considered when performing fNIRS neuroimaging studies involving changes in respiration.</p>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142558619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-day cardiopulmonary exercise testing in long COVID post-exertional malaise diagnosis.","authors":"Chiara Gattoni, Asghar Abbasi, Carrie Ferguson, Charles W Lanks, Thomas W Decato, Harry B Rossiter, Richard Casaburi, William W Stringer","doi":"10.1016/j.resp.2024.104362","DOIUrl":"10.1016/j.resp.2024.104362","url":null,"abstract":"<p><strong>Background: </strong>Long COVID patients present with a myriad of symptoms that can include fatigue, exercise intolerance and post exertional malaise (PEM). Long COVID has been compared to other post viral syndromes, including myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), where a reduction in day 2 cardiopulmonary exercise test (CPET) performance of a two-day CPET protocol is suggested to be a result of PEM. We investigated cardiopulmonary and perceptual responses to a two-day CPET protocol in Long COVID patients.</p><p><strong>Methods: </strong>15 Long COVID patients [n=7 females; mean (SD) age: 53(11) yr; BMI = 32.2(8.5) kg/m²] performed a pulmonary function test and two ramp-incremental CPETs separated by 24 hr. CPET variables included gas exchange threshold (GET), peak oxygen uptake (V̇O_2peak) and peak work rate (WR_peak). Ratings of perceived dyspnoea and leg effort were recorded at peak exercise using the modified 0-10 Borg Scale. PEM (past six months) was assessed using the modified DePaul Symptom Questionnaire (mDSQ). One-sample t-tests were used to test significance of mean difference between days (p<0.05).</p><p><strong>Results: </strong>mDSQ revealed PEM in 80 % of patients. Lung function was normal. Responses to day 1 CPET were consistent with the presence of aerobic deconditioning in 40 % of patients (V̇O_2peak <80 % predicted, in the absence of evidence of cardiovascular and pulmonary limitations). There were no differences between day-1 and day-2 CPET responses (all p>0.05).</p><p><strong>Conclusion: </strong>PEM symptoms in Long COVID patients, in the absence of differences in two-day CPET responses separated by 24 hours, suggests that PEM is not due to impaired recovery of exercise capacity between days.</p>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142569342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A short duration of mechanical ventilation alters redox status in the diaphragm and aggravates inflammation in septic mice","authors":"Pedro Alves Machado-Junior ,&nbsp;Marcelo Santiago Soares Dias ,&nbsp;Ana Beatriz Farias de Souza ,&nbsp;Leonardo Spinelli Estevão Lopes ,&nbsp;Tatiana Prata Menezes ,&nbsp;André Talvani ,&nbsp;Laurent Brochard ,&nbsp;Frank Silva Bezerra","doi":"10.1016/j.resp.2024.104361","DOIUrl":"10.1016/j.resp.2024.104361","url":null,"abstract":"<div><h3>Background</h3><div>Mechanical ventilation (MV) is a life support method used to treat patients with respiratory failure. High tidal volumes during MV can cause ventilator-induced lung injury (VILI), but also affect other organs, such as the diaphragm (Dia) causing ventilator-induced diaphragmatic dysfunction (VIDD). VIDD is often associated with a complicated course on MV. Sepsis can induce inflammation and oxidative stress, contributing to the impairment of the Dia and worsening of the prognosis. This study evaluated the additive or synergistic effects of a short course of mechanical ventilation on Dia in healthy and septic adult mice.</div></div><div><h3>Methods</h3><div>32 adult male C57BL/6 mice were randomly into four groups: Control (CG), non-ventilated animals instilled with saline solution (PBS1x); Lipopolysaccharide (LPS), non-ventilated animals instilled with PBS solution containing lipopolysaccharide; Mechanical Ventilation (MV) for 1 h, ventilated animals instilled with PBS solution; and Mechanical Ventilation and LPS (MV+LPS), ventilated animals instilled with PBS solution containing LPS. At the end of the experimental protocol, the animals were euthanized, then blood and diaphragm tissue samples were collected.</div></div><div><h3>Results</h3><div>Evaluation of leukocyte/blood parameters and diaphragm muscle showed that MV, LPS and the combination of both were able to increase neutrophil count, creatine kinase, inflammatory mediators and oxidative stress in all groups compared to the control. MV and sepsis combined had additive effects on inflammation and lipid peroxidation.</div></div><div><h3>Conclusions</h3><div>A short course of Mechanical ventilation promotes inflammation and oxidative stress and, its combination with sepsis further increases local and systemic inflammation.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142473463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential neuromotor control of the vertical and longitudinal genioglossus muscle fibers: An overlooked tongue retractor","authors":"Ron Oliven ,&nbsp;Arie Oliven ,&nbsp;Mostafa Somri ,&nbsp;Alan R. Schwartz ,&nbsp;Emilia Hardak","doi":"10.1016/j.resp.2024.104354","DOIUrl":"10.1016/j.resp.2024.104354","url":null,"abstract":"<div><h3>Introduction</h3><div>The genioglossus (GG) is known to be the main tongue protrusor, and therefore plays a major role in breathing. However, due to the fan shape of the GG fibers, it could be assumed that contraction of the anterior fibers of the GG do not cause tongue protrusion. In this study, we examined the effect of contraction of the anterior-vertical fibers of the GG (GG_V) on the tongue and their EMG activity during wakefulness and sleep. The findings were compared to those of the longitudinal fibers (GG_L), which, based on their orientation, are responsible for tongue protrusion.</div></div><div><h3>Methods</h3><div>Fine-wire electrode pairs were placed into the GG_V and GG_L in 11 patients with untreated OSA. Movement of the tongue during electrical stimulation at each site was videoed. The same electrodes were used to record EMG from both sites during respiratory stimulation by inspiratory loading and CO₂ rebreathing during wakefulness. During sleep, repetitive flow limitation events were induced with low-level CPAP to augment GG activity.</div></div><div><h3>Results</h3><div>In all participants, electrical stimulation of GG_L and GG_V protruded and retracted the tongue, respectively. Respiratory stimulation increased GG activity, but GG_V reached only 39 % and 23 % of peak GG_L activity during high resistive loading and PCO₂ of 65 mmHg, respectively. Flow limitation during sleep increased GG_L to levels that were considerably higher than awake baseline, but GG_V activity remained tonic or with minimal phasic activity, reaching on average 15 % of GG_L peak activity.</div></div><div><h3>Conclusions</h3><div>Our electrical stimulation findings indicate that GG_V is a tongue retractor and depressor. Tongue stimulation for OSA should avoid this area. The EMG results demonstrate that the anterior part of the GG is controlled very differently from the longitudinal protrusive fibers. The GG_V responses are similar to those previously found in tongue retractors and peri-pharyngeal muscles other than the GG, in which diminished activation during sleep is likely to be involved in the failure of increasing GG_L activity to alleviate flow limitation.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of sildenafil on gas exchange, ventilatory, and sensory responses to exercise in subjects with mild-to-moderate COPD: A randomized cross-over trial","authors":"Ricardo Gass ,&nbsp;Franciele Plachi ,&nbsp;Fernanda O.B. Silva ,&nbsp;Talmir Nolasco ,&nbsp;Mateus Samuel Tonetto ,&nbsp;Leandro S. Goelzer ,&nbsp;Paulo T. Muller ,&nbsp;Marli M. Knorst ,&nbsp;J. Alberto Neder ,&nbsp;Danilo C. Berton","doi":"10.1016/j.resp.2024.104359","DOIUrl":"10.1016/j.resp.2024.104359","url":null,"abstract":"<div><div>Excess exercise ventilation (high ventilation (V̇_E)/carbon dioxide output (V̇CO₂)) contributes significantly to dyspnea and exercise intolerance since the earlier stages of chronic obstructive pulmonary disease (COPD). A selective pulmonary vasodilator (inhaled nitric oxide) has shown to increase exercise tolerance secondary to lower V̇_E/V̇CO₂ and dyspnea in this patient population. We aimed to assess whether a clinically more practical option - oral sildenafil - would be associated with similar beneficial effects. In a randomized, placebo-controlled study, twenty-four patients with mild-to-moderate COPD completed, on different days, two incremental cardiopulmonary exercise tests (CPET) one hour after sildenafil or placebo. Eleven healthy participants performed a CPET in a non-interventional visit for comparative purposes with patients when receiving placebo. Patients (FEV₁= 69.4 ± 13.5 % predicted) showed higher ventilatory demands (V̇_E/V̇CO₂), worse pulmonary gas exchange, and higher dyspnea during exercise compared to controls (FEV₁= 98.3 ±11.6 % predicted). Contrary to our expectations, however, sildenafil (50 mg; N= 15) did not change exertional V̇_E/V̇CO₂, dead space/tidal volume ratio, operating lung volumes, dyspnea, or exercise tolerance compared to placebo (<em>P</em>&gt;0.05). Due to the lack of significant beneficial effects, nine additional patients were trialed with a higher dose (100 mg). Similarly, active intervention was not associated with positive physiological or sensory effects. In conclusion, acute oral sildenafil (50 or 100 mg) failed to improve gas exchange efficiency or excess exercise ventilation in patients with predominantly moderate COPD. The current study does not endorse a therapeutic role for sildenafil to mitigate exertional dyspnea in this specific patient subpopulation.</div><div>Clinical trial registry: <span><span>https://ensaiosclinicos.gov.br/rg/RBR-4qhkf4</span><svg><path></path></svg></span></div><div>Web of Science Researcher ID: O-7665–2019</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142401120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inspiratory muscle training improves autonomic function in myalgic encephalomyelitis/chronic fatigue syndrome and post-acute sequelae of SARS-CoV-2: A pilot study","authors":"Heather Edgell ,&nbsp;Tania J. Pereira ,&nbsp;Kathleen Kerr ,&nbsp;Riina Bray ,&nbsp;Farah Tabassum ,&nbsp;Lauren Sergio ,&nbsp;Smriti Badhwar","doi":"10.1016/j.resp.2024.104360","DOIUrl":"10.1016/j.resp.2024.104360","url":null,"abstract":"<div><div>Post-acute sequelae of SARS-CoV-2 (PASC), or Long COVID, and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are debilitating post-viral conditions with many symptomatic overlaps, including exercise intolerance and autonomic dysfunction. Both conditions are growing in prevalence, and effective safe treatment strategies must be investigated. We hypothesized that inspiratory muscle training (IMT) could be used in PASC and mild to moderate ME/CFS to mitigate symptoms, improve exercise capacity, and improve autonomic function. We recruited healthy controls (n=12; 10 women), people with PASC (n=9; 8 women), and people with mild to moderate ME/CFS (n=12; 10 women) to complete 8 weeks of IMT. This project was registered as a clinical trial (NCT05196529) with clinicaltrials.gov. After completion of IMT, all groups experienced improvements in inspiratory muscle pressure (p&lt;0.001), 6-minute walk distance (p=0.002), resting heart rate (p=0.037), heart rate variability (p&lt;0.05), and symptoms related to sleep (p=0.009). In the ME/CFS group only, after completion of IMT, there were additional improvements with regard to vascular function (p=0.001), secretomotor function (p=0.023), the total weighted score (p=0.005) of the COMPASS 31 autonomic questionnaire, and symptoms related to pain (p=0.016). We found that after 8 weeks of IMT, people with PASC and/or ME/CFS could see some overall improvements in their autonomic function and symptomology.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142392855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The activity of suprahyoid muscles during sevoflurane-induced gasping in mice","authors":"Saki Taiji,&nbsp;Takashi Nishino,&nbsp;Hisayo Jin,&nbsp;Mayumi Hashida,&nbsp;Shiroh Isono","doi":"10.1016/j.resp.2024.104355","DOIUrl":"10.1016/j.resp.2024.104355","url":null,"abstract":"<div><div>Sevoflurane-induced gasping in mice involves an enormous increase in inspiratory effort, mandibular movement, and a marked decrease in respiratory frequency (fR). We examined differences in breathing patterns and electromyogram activity (EMG_SH) of the suprahyoid muscles (SHMs) during eupnea under 3.2 % (1 MAC: minimum alveolar concentration) sevoflurane inhalation and sevoflurane-induced gasping under 6.5 % (2 MAC) sevoflurane inhalation in eight spontaneously breathing, tracheally intubated, adult mice. We found that the phasic EMG_SH is obtained only during inspiration in eupnea and gasping and that integrated EMG_SH increases more, as a percent of baseline (% baseline) than tidal volume (V_T) during gasping (median [interquartile range]; integrated EMG_SH: 720 [425–1965] vs. V_T: 300 [238–373], P &lt; 0.05). We also found that the onset of EMG_SH precedes the start of airflow while maintaining a bell-shaped EMG_SH contour, which characterizes the EMG of upper airway dilator (UAD) muscles during eupnea and gasping. Vigorous respiratory-related mandibular movements were never observed during eupnea but were observed in seven of 8 mice during sevoflurane-induced gasping. Our observations indicate that SHMs act as a preferentially activating UAD muscle, contributing to the development of mandibular respiratory movements.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142381515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Breathing pattern alteration from weanling to old age in male Sprague-Dawley rats","authors":"Mehdi Eslami-Behroozi,&nbsp;Payam Shahsavar,&nbsp;Reyhaneh Vali,&nbsp;Mohammad Reza Raoufy","doi":"10.1016/j.resp.2024.104357","DOIUrl":"10.1016/j.resp.2024.104357","url":null,"abstract":"<div><div>Respiratory patterns were investigated in male Sprague-Dawley rats throughout their lifespan, from weanling (1 month) to old age (24 months), under natural conditions. Both inter-breath interval (IBI) and respiratory volume (RV) were examined. Sample entropy suggested increasing irregularity in IBI but decreasing irregularity in RV until 12 months. According to detrended fluctuation analysis, alpha exponent of the IBI showed a bimodal pattern around the value 0.7. From 1–15 months, the alpha exponent for RV generally decreased to the value 0.5, but it increased again as the animals neared the end of their lifespan. Cross-sample entropy revealed increasing synchronization between IBI and RV until 12 months, then plateauing. Many measures demonstrated a transition around 12 months, potentially reflecting maturation of respiratory control mechanisms. The findings characterize complex dynamics of respiratory patterns across the rat lifespan, providing a normative foundation to identify deviations indicative of dysfunction or disease.</div></div>","PeriodicalId":20961,"journal":{"name":"Respiratory Physiology & Neurobiology","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142372715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}