Shades of Gravity: The influence of microgravity on cerebral blood flow and electrocortical activity

Timo Klein, Petra Wollseiffen, Marit L Sanders, Jurgen Claassen, Heather Carnahan, Vera Abeln, Tobias Vogt, Heiko Klaus Strüder, Stefan Schneider

Publication: Chapter in Book/Report/Conference proceedingConference contribution - Published abstract for conference with selection processResearchpeer-review


Introduction: Changes in gravity conditions have previously been reported to be associated with changes in cerebral haemodynamic responses as well as neuronal activity. To better understand the effect of gravity on brain function and the underlying potential link between cerebral blood flow and brain cortical activity we aimed to test the combined responses during parabolic flights.
Methods: Seventeen participants (female: n=8, with a mean age of 37 ± 11 years) were tested under normal gravity (1G) conditions and microgravity (0G) conditions, during 15 bouts of 22 second intervals of weightlessness during a parabolic flight. Middle cerebral artery flow velocity (MCAv) was assessed with transcranial Doppler ultrasound. Two key drivers of MCAv, mean arterial pressure (MAP) and cardiac output (CO) were recorded via finger photoplethysmography. Cortical current density an indicator for brain cortical activity was measured using electroencephalography (EEG). Effects of gravity (1G vs. 0 G) on MCAv, MAP and CO were compared using a t-tests. Changes in cortical current density was determined using repeated measures ANOVA with the within-group factors of “localization” (frontal, parietal, occipital, limbic, hippocampus, MCA, ACA, PCA) and “gravity” (1G, 0G).
Results: Key drivers of MCAv changed during 0G compared to 1G, where MAP (p<0.001) decreased and CO (p<0.001) increased during 0G. However, the averaged MCAv (p=0.28) remained unchanged during the microgravity phase in comparison to the normal gravity condition. Cortical current density decreased globally (p<0.001) during 0G compared to 1G.
Conclusion: Our data replicates earlier experiments reporting a decrease in brain cortical activity in microgravity. This decrease of activity, however, is unlikely to be dependent on haemodynamic changes and may be due to changes in fluid dynamics and membrane viscosity on a cellular level.
Original languageEnglish
Title of host publicationHuman Physiology Workshop : 8th of December 2018
EditorsJörn Rittweger, Tine Becker, Friederike Wütscher, Katrin Stang, Michaela Girgenrath, Christian Rogon
Number of pages1
Place of PublicationKöln
PublisherDeutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
Publication date08.12.2018
Publication statusPublished - 08.12.2018
EventGerman Human Physiology Workshop - DLR :envihab Forum, 51147 Cologne, Germany, Planitzweg, Köln, Germany
Duration: 08.12.201808.12.2018
Conference number: 3 (Link to Abstractbook)


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