Article
Physiology
James Duffin, David J. Mikulis, Joseph A. Fisher
Summary: Cerebrovascular reactivity can be comprehensively described by a simple mathematical model that takes into account the regulation of intracellular hydrogen ion concentration. Smooth muscle vasoconstriction and vasodilation, along with cerebral blood flow, are assumed to be proportional to the intracellular hydrogen ion concentration. The model's predictions match the observed responses to hypoxia, anemia, hypocapnia, and hypercapnia, suggesting that the underlying theories have merit.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Physiology
Rebecca H. Clough, Jatinder S. Minhas, Victoria J. Haunton, Martha F. Hanby, Thompson G. Robinson, Ronney B. Panerai
Summary: The dynamic response of critical closing pressure (CrCP) and resistance-area product (RAP) in the cerebral circulation was investigated during paced hyperventilation (PHPV). Contrary to hypercapnia, hypocapnia showed an initial depression of cerebral autoregulation, followed by improvements controlled by changes in RAP.
JOURNAL OF APPLIED PHYSIOLOGY
(2022)
Article
Medicine, General & Internal
Stefan Sandru, Dan Buzescu, Carmen Denise Mihaela Zahiu, Ana Spataru, Anca Maria Panaitescu, Sebastian Isac, Cosmin Ion Balan, Ana-Maria Zagrean, Bogdan Pavel
Summary: This study used near-infrared spectroscopy (NIRS) to monitor changes in cerebral oxygen saturation during hyperventilation and found that a decrease in end-tidal CO2 (ETCO2) greater than 26% can predict changes in oxygen saturation. An increase in respiratory rate alone cannot accurately predict the occurrence of a cerebral vasoconstrictor response induced by hyperventilation.
MEDICINA-LITHUANIA
(2022)
Article
Critical Care Medicine
Ursula Kahl, Yuanyuan Yu, Axel Nierhaus, Daniel Frings, Barbara Sensen, Anne Daubmann, Stefan Kluge, Marlene Fischer
Summary: Early hypercapnia is common in ARDS patients, however, moderate hypercapnia during the acute phase does not have adverse effects on cerebrovascular autoregulation, while hypocapnia may compromise cerebral blood flow regulation.
ANNALS OF INTENSIVE CARE
(2021)
Article
Critical Care Medicine
Daniel Agustin Godoy, Maximiliano Rovegno, Christos Lazaridis, Rafael Badenes
Summary: This article discusses the impact of carbon dioxide on cerebral blood flow and other physiological parameters of the body, emphasizing the importance of maintaining normal carbon dioxide partial pressure in acute brain injury, as well as the risks of hypercapnia and hypocapnia. It suggests avoiding excessive hypo- and hypercapnia during treatment.
JOURNAL OF CRITICAL CARE
(2021)
Article
Geriatrics & Gerontology
Belinda Yew, Jung Yun Jang, Shubir Dutt, Yanrong Li, Isabel J. Sible, Aimee Gaubert, Jean K. Ho, Anna E. Blanken, Anisa Marshall, Xingfeng Shao, Danny J. J. Wang, Daniel A. Nation
Summary: This study compared cerebrovascular reactivity (CVR) in cognitively unimpaired older adults and younger adults. The results showed that older adults had lower levels of global CVR under both hypercapnia and hypocapnia compared to younger adults. Region-of-interest analyses revealed attenuated CVR to hypocapnia in select frontal and temporal regions, and lower CVR to hypercapnia in all cortical, limbic, and subcortical regions examined in older adults compared to younger adults. The findings suggest age-related deficits in CVR, especially in vasodilatory responses, even in cognitively unimpaired older adults.
NEUROBIOLOGY OF AGING
(2022)
Article
Physiology
Akira Katagiri, Yasuhiko Kitadai, Akira Miura, Yoshiyuki Fukuba, Naoto Fujii, Takeshi Nishiyasu, Bun Tsuji
Summary: This study found that sodium bicarbonate ingestion can alleviate heat-induced hyperventilation, reduce PaCO2, and increase cerebral blood flow velocity during prolonged exercise in the heat, while also decreasing perceived exertion levels.
JOURNAL OF APPLIED PHYSIOLOGY
(2021)
Article
Neurosciences
Travis D. Gibbons, Jerome A. Dempsey, Kate N. Thomas, Holly A. Campbell, Tiarna A. M. Stothers, Luke C. Wilson, Philip N. Ainslie, James D. Cotter
Summary: Humans experience hyperventilation under heat and cold strain. The carotid body, which regulates ventilation, plays a crucial role in thermally mediated hyperventilation. The study found that carotid body activity and sensitivity increase in a dose-dependent manner with heating, while cold stress only saturates the effect of carotid body activity. This suggests that carotid body likely contributes to heat-induced hyperventilation.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Multidisciplinary Sciences
Zhensen Chen, Anders Gould, Duygu Baylam Geleri, Niranjan Balu, Li Chen, Baocheng Chu, Kristi Pimentel, Gador Canton, Thomas S. Hatsukami, Chun Yuan
Summary: The study aimed to explore the associations between intracranial vascular features extracted from NCE-MRA images and global cognition. The results showed that artery length and number of branches were positively associated with cognitive scores. These findings suggest that intracranial vascular features may serve as useful markers of cerebrovascular health and provide additional information in individuals with cognitive impairment.
SCIENTIFIC REPORTS
(2022)
Article
Multidisciplinary Sciences
Michael G. Hutchison, Alex P. Di Battista, David W. Lawrence, Kyla Pyndiura, Danielle Corallo, Doug Richards
Summary: This study aimed to examine the effect of a readily accessible, structured aerobic exercise intervention on the recovery process of sport-related concussion patients. The results showed that the structured aerobic exercise protocol led to faster attainment of asymptomatic status and medical clearance compared to usual care exercise prescription. Additionally, the symptom severity was lower in the structured aerobic exercise group throughout the trial.
Article
Physiology
Rebecca H. Clough, Jatinder S. Minhas, Victoria J. Haunton, Martha F. Hanby, Thompson G. Robinson, Ronney B. Panerai
Summary: The study investigated the changes in cerebral blood flow during paced hyperventilation (PHPV) using parameters such as critical closing pressure (CrCP) and resistance area product (RAP). It was found that PHPV caused changes in CBFV, end-tidal CO2, and heart rate, mainly explained by the RAP parameter. The time-varying responses for CBFV and RAP during PHPV showed considerable nonstationarity compared to normal conditions.
JOURNAL OF APPLIED PHYSIOLOGY
(2021)
Article
Neurosciences
Khushali Parikh, Brooke R. Shepley, Michael M. Tymko, Jamie G. Hijmans, Ryan L. Hoiland, Christopher A. Desouza, Mypinder S. Sekhon, Philip N. Ainslie, Anthony R. Bain
Summary: Passive hyperthermia can cause cerebral hypoperfusion, while mild alkalosis may help attenuate cerebral inflammation. This study examines the exchange of extracellular microvesicles in hyperthermia with respiratory alkalosis and suggests a potential beneficial role of alkalosis in heat stress.
JOURNAL OF PHYSIOLOGY-LONDON
(2023)
Article
Biophysics
Jonathan Ince, Alex S. Mankoo, Meeriam Kadicheeni, David Swienton, Ronney B. Panerai, Thompson G. Robinson, Jatinder S. Minhas
Summary: This exploratory analysis examined the differences in hypocapnic responses between healthy controls and patients with ICH, and found significant differences in factors associated with cerebrovascular tone and resistance. Reduced autoregulation index was observed bilaterally in ICH patients compared to healthy controls, suggesting underlying cerebral autoregulation changes in ICH.
PHYSIOLOGICAL MEASUREMENT
(2021)
Article
Optics
Changyoon Yi, Jaewoo Jung, Jeongmyo Im, Kyung Chul Lee, Euiheon Chung, Seung Ah Lee
Summary: We propose a single-shot wide-field imaging method called rolling shutter speckle imaging (RSSI), which utilizes the short time intervals between each row of a rolling shutter CMOS image sensor to map the local temporal intensity decorrelations of dynamic speckle fields. The method generates elongated speckle patterns on the image sensor and quantifies temporal decorrelations from row-by-row intensity correlations (RICs) within a single image. Experimental results show that RSSI can map flow rate distributions in cerebral blood vessels with the correction of static scattering, making it a powerful and cost-effective imaging tool for in vivo quantitative blood flow measurements.
Article
Multidisciplinary Sciences
Jesus J. Bosque, Gabriel F. Calvo, Victor M. Perez-Garcia, Maria Cruz Navarro
Summary: Research suggests that tumors in well-perfused organs like the brain may only reach therapeutic temperatures if their vasculature is highly disrupted, with characteristic times of return to normal temperature levels much shorter than those required for adjuvant radiotherapy. Mechanistic coupling of perfusion and temperature may not explain significant oxygenation boost in brain tumors immediately after hyperthermia.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Physiology
Davide Filingeri, Hui Zhang, Edward A. Arens
JOURNAL OF APPLIED PHYSIOLOGY
(2018)
Letter
Physiology
Bun Tsuji, Davide Filingeri, Yasushi Honda, Tsubasa Eguchi, Naoto Fujii, Narihiko Kondo, Takeshi Nishiyasu
JOURNAL OF APPLIED PHYSIOLOGY
(2018)
Article
Sport Sciences
Georgia K. Chaseling, Davide Filingeri, Michael Barnett, Phu Hoang, Scott L. Davis, Ollie Jay
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
(2018)
Article
Physiology
Tomomi Fujimoto, Bun Tsuji, Yosuke Sasaki, Kohei Dobashi, Yasuo Sengoku, Naoto Fujii, Takeshi Nishiyasu
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
(2019)
Article
Neurosciences
Alessandro Valenza, Antonino Bianco, Davide Filingeri
JOURNAL OF PHYSIOLOGY-LONDON
(2019)
Article
Biology
Charlotte Merrick, Davide Filingeri
JOURNAL OF THERMAL BIOLOGY
(2019)
Article
Physiology
Oliver Typolt, Davide Filingeri
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
(2020)
Article
Physiology
Alessandro Valenza, Harry Charlier, Antonino Bianco, Davide Filingeri
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
(2020)
Article
Physiology
Georgia K. Chaseling, Davide Filingeri, Dustin Allen, Michael Barnett, Steve Vucic, Scott L. Davis, Ollie Jay
Summary: The study aimed to determine whether multiple sclerosis (MS) alters thermoregulatory capacity during exercise in the heat. The results showed that heat intolerance in MS is not attributable to thermoregulatory impairments, as even at high temperatures, the ability to regulate body temperature remains unaffected.
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY
(2021)
Article
Physiology
Akira Katagiri, Yasuhiko Kitadai, Akira Miura, Yoshiyuki Fukuba, Naoto Fujii, Takeshi Nishiyasu, Bun Tsuji
Summary: This study found that sodium bicarbonate ingestion can alleviate heat-induced hyperventilation, reduce PaCO2, and increase cerebral blood flow velocity during prolonged exercise in the heat, while also decreasing perceived exertion levels.
JOURNAL OF APPLIED PHYSIOLOGY
(2021)
Article
Physiology
Davide Filingeri, Helena Cowley, Charlotte Merrick, Victoria L. Filingeri
PHYSIOLOGICAL REPORTS
(2020)
Article
Physiology
Bun Tsuji, Yuta Hoshi, Yasushi Honda, Naoto Fujii, Yosuke Sasaki, Stephen S. Cheung, Narihiko Kondo, Takeshi Nishiyasu
PHYSIOLOGICAL REPORTS
(2019)