Patricia Ratmanova1, Roxana Semenyuk2, Daniil Popov3, Sergey Kuznetsov3, Irina Zelenkova3,4, Dmitry Napalkov2, Olga Vinogradova3. 1. Department of Higher Nervous Activity, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234, Leninskie Gory 1/12, Moscow, Russia. patricia@neurobiology.ru. 2. Department of Higher Nervous Activity, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234, Leninskie Gory 1/12, Moscow, Russia. 3. Institute of Biomedical Problems of the Russian Academy of Sciences, 123007, Khoroshevskoye Sh., 76A, Moscow, Russia. 4. Russian Olympic Committee Innovation Center, 119991, Luzhnetskaya Embankment 8, Moscow, Russia.
Abstract
PURPOSE: The aim of the study was to investigate the effects of voluntary breath-holding on brain activity and physiological functions. We hypothesised that prolonged apnoea would trigger cerebral hypoxia, resulting in a decrease of brain performance; and the apnoea's effects would be more pronounced in breath-hold divers. METHODS: Trained breath-hold divers and non-divers performed maximal dry breath-holdings. Lung volume, alveolar partial pressures of O2 and CO2, attention and anxiety levels were estimated. Heart rate, blood pressure, arterial blood oxygenation, brain tissue oxygenation, EEG, and DC potential were monitored continuously during breath-holding. RESULTS: There were a few significant changes in electrical brain activity caused by prolonged apnoea. Brain tissue oxygenation index and DC potential were relatively stable up to the end of the apnoea in breath-hold divers and non-divers. We also did not observe any decrease of attention level or speed of processing immediately after breath-holding. Interestingly, trained breath-hold divers had some peculiarities in EEG activity at resting state (before any breath-holding): non-spindled, sharpened alpha rhythm; slowed-down alpha with the frequency nearer to the theta band; and untypical spatial pattern of alpha activity. CONCLUSION: Our findings contradicted the primary hypothesis. Apnoea up to 5 min does not lead to notable cerebral hypoxia or a decrease of brain performance in either breath-hold divers or non-divers. It seems to be the result of the compensatory mechanisms similar to the diving response aimed at centralising blood circulation and reducing peripheral O2 uptake. Adaptive changes during apnoea are much more prominent in trained breath-hold divers.
PURPOSE: The aim of the study was to investigate the effects of voluntary breath-holding on brain activity and physiological functions. We hypothesised that prolonged apnoea would trigger cerebral hypoxia, resulting in a decrease of brain performance; and the apnoea's effects would be more pronounced in breath-hold divers. METHODS: Trained breath-hold divers and non-divers performed maximal dry breath-holdings. Lung volume, alveolar partial pressures of O2 and CO2, attention and anxiety levels were estimated. Heart rate, blood pressure, arterial blood oxygenation, brain tissue oxygenation, EEG, and DC potential were monitored continuously during breath-holding. RESULTS: There were a few significant changes in electrical brain activity caused by prolonged apnoea. Brain tissue oxygenation index and DC potential were relatively stable up to the end of the apnoea in breath-hold divers and non-divers. We also did not observe any decrease of attention level or speed of processing immediately after breath-holding. Interestingly, trained breath-hold divers had some peculiarities in EEG activity at resting state (before any breath-holding): non-spindled, sharpened alpha rhythm; slowed-down alpha with the frequency nearer to the theta band; and untypical spatial pattern of alpha activity. CONCLUSION: Our findings contradicted the primary hypothesis. Apnoea up to 5 min does not lead to notable cerebral hypoxia or a decrease of brain performance in either breath-hold divers or non-divers. It seems to be the result of the compensatory mechanisms similar to the diving response aimed at centralising blood circulation and reducing peripheral O2 uptake. Adaptive changes during apnoea are much more prominent in trained breath-hold divers.
Authors: Jitka Annen; Rajanikant Panda; Olivia Gosseries; Steven Laureys; Charlotte Martial; Andrea Piarulli; Guillaume Nery; Leandro R D Sanz; Juan M Valdivia-Valdivia; Didier Ledoux Journal: Brain Struct Funct Date: 2021-08-22 Impact factor: 3.270