The present study investigated the effects of hypocapnia and hypercapnia on human somatosensory processing by utilizing somatosensory evoked magnetic fields (SEFs) with magnetoencephalography (MEG). Thirteen volunteers participated in two experiments separately to measure respiratory and cardiovascular data and SEFs. Both experiments consisted of a combination of normal and rapid respiratory rhythms and two inspiratory gas conditions (air and a hypercapnic gas); normal breathing with air (NB), rapid breathing with air (RB), normal breathing with the hypercapnic gas (NB+Gas), and rapid breathing with gas (RB+Gas). Partial pressures of end-tidal CO (P) increased during inhaling the hypercapnic gas and decreased during RB, but the RB+Gas condition continued to cause elevated PETCO compared with the baseline. Subsequently, middle cerebral artery blood (MCA) velocity using transcranial Doppler changed as well, while mean MCA velocity increased under the RB+Gas condition. The peak amplitude of the M60 component in SEFs was also significantly larger under with-gas than without-gas conditions, irrespective of the respiratory frequency. These results suggest that there is a close relationship between cerebral blood flow and neural activity of the M60 component in SEFs. This study provides evidence to further understanding on one of the neural mechanisms of hypercapnia.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.neures.2022.11.007 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Does Heart Rate Variability Predict Impairment of Operational Performance in Divers?
Sensors (Basel)
December 2024
Department of Anesthesiology, Duke University, Durham, NC 27708, USA.
We examined data from Naval Sea Systems Command grant project N0463A-12-C-001, "Hypercapnia: cognitive effects and monitoring", with the objective of validating or repudiating heart rate variability (HRV) as a warning sign of cognitive impairment from diving gas narcosis or oxygen toxicity. We compared HRV feature scores to their temporally corresponding cognitive outcomes under normal and narcotizing conditions to identify specific HRV features associated with cognitive changes. N0463A-12-C-001 was conducted between 17 September 2013 and 29 January 2016 and employed NASA's multi-attribute task battery (MATB-II) flight simulator to examine the independent effects of CO, N, and O partial pressure on diver performance at simulated depths up to 61 msw (200 fsw).
View Article and Find Full Text PDFA Multiscale Mathematical Model for Fetal Gas Transport and Regulatory Systems During Second Half of Pregnancy.
Int J Numer Method Biomed Eng
January 2025
Cardiovascular Biomechanics, Biomedical Engineering, Eindhoven University of Technology, The Netherlands.
Fetal asphyxia, a condition resulting from the combined effects of hypoxia and hypercapnia, leads to approximately 900,000 annual deaths worldwide. One cause is umbilical cord compression during labor-induced uterine contractions, disrupting the transport of metabolites to and from the placenta, and resulting in asphyxia. Current fetal well-being assessment relies on monitoring fetal heart rate and uterine contractions as indicators of oxygen delivery to the brain.
View Article and Find Full Text PDFExtreme altitude-induced central sleep apneas lasting more than 100 seconds in a healthy 23-year-old man.
J Sleep Res
December 2024
Center for Investigation and Research in Sleep, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
Central sleep apneas (CSA) can occur de novo at high-altitude in individuals without sleep-disordered breathing at low altitude. These apneas are usually brief, lasting only 5-15 s. This report presents the first documented case of a man experiencing extreme altitude-induced CSA lasting more than 100 s in the absence of any sleep breathing disorder in normoxia.
View Article and Find Full Text PDFFunctional evidence that S-nitroso-L-cysteine may be a candidate carotid body neurotransmitter.
Neuropharmacology
November 2024
Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH, USA.
The primary objective of the present study is to provide further evidence that the endogenous S-nitrosothiol, S-nitroso-L-cysteine (L-CSNO), plays an essential role in signaling the hypoxic ventilatory response (HVR) in rodents. Key findings were that (1) injection of L-CSNO (50 nmol/kg, IV) caused a pronounced increase in frequency of breathing (Freq), tidal volume (TV) and minute ventilation (MV) in naïve C57BL/6 mice, whereas injection of D-CSNO (50 nmol/kg, IV) elicited minimal responses; (2) L-CSNO elicited minor responses in (a) C57BL/6 mice with bilateral carotid sinus nerve transection (CSNX), (b) C57BL/6 mice treated neonatally with capsaicin (CAP) to eliminate small-diameter C-fibers, and (c) C57BL/6 mice receiving continuous infusion of L-CSNO receptor antagonists, S-methyl-L-cysteine and S-ethyl-L-cysteine (L-SMC + L-SEC, both at 5 μmol/kg/min, IV); and (3) injection of S-nitroso-L-glutathione (L-GSNO, 50 nmol/kg, IV) elicited pronounced ventilatory responses that were not inhibited by L-SMC + L-SEC. Subsequent exposure of naïve C57BL/6 mice to a hypoxic gas challenge (HXC; 10% O, 90% N) elicited pronounced increases in Freq, TV and MV that were subject to roll-off.
View Article and Find Full Text PDFFrom Headache to Altered Consciousness: Headache Attributed to Hypoxia and/or Hypercapnia in a Smoker With Undiagnosed Chronic Obstructive Pulmonary Disease.
Cureus
October 2024
Department of Neurosurgery, International University of Health and Welfare Narita Hospital, Narita, JPN.
We present the case of a 57-year-old male with a history of smoking, hypertension, dyslipidemia, and migraines who experienced a one-month history of dyspnea and headaches, followed by sudden-onset altered consciousness. Initial imaging ruled out cerebrovascular and infectious etiologies, and arterial blood gas analysis revealed severe hypercapnia and hypoxemia (partial pressure of arterial carbon dioxide: 117 mmHg, partial pressure of arterial oxygen: 111 mmHg under a 10 L/min oxygen mask). The patient's condition improved with mechanical ventilation, resulting in the resolution of both altered consciousness and headaches.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!