title: Changes in cerebral oxygenation during parabolic flight.
abstract: Assessing changes in brain activity under extreme conditions like weightlessness is a desirable, but difficult undertaking. Results from previous studies report specific changes in brain activity connected to an increase or decrease in gravity forces. Nevertheless, so far it remains unclear (1) whether this is connected to a redistribution of blood volume during micro- or hypergravity and (2) whether this redistribution might account for neurocognitive alterations. This study aimed to display changes in brain oxygenation caused by altered gravity conditions during parabolic flight. It was hypothesized that an increase in gravity would be accompanied by a decrease in brain oxygenation, whereas microgravity would lead to an increase in brain oxygenation. Oxygenized and deoxygenized haemoglobin were measured using two near infrared spectroscopy (NIRS) probes on the left and right prefrontal cortex throughout ten parabolas in nine subjects. Results show a decrease of 1.44 μmol/l in oxygenized haemoglobin with the onset of hypergravity, followed by a considerable increase during microgravity (up to 5.34 μmol/l). In contrast, deoxygenized haemoglobin was not altered during the first but only during the second hypergravity phase and showed only minor changes during microgravity. Changes in oxygenized and deoxygenized haemoglobin indicate an increase in arterial flow to the brain and a decrease in venous outflow during microgravity.
authors: Institute of Movement and Neurosciences, German Sport University, Cologne, Am Sportpark Müngersdorf 6, 50933 Köln, Germany. schneider@dshs-koeln.de
authors: Stefan
authors: S
authors: Schneider
authors: Vera
authors: V
authors: Abeln
authors: Christopher D
authors: CD
authors: Askew
authors: Tobias
authors: T
authors: Vogt
authors: Uwe
authors: U
authors: Hoffmann
authors: Pierre
authors: P
authors: Denise
authors: Heiko K
authors: HK
authors: Strüder
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006112:Gravitation; D006801:Humans; D008297:Male; D010100:Oxygen / Q000097:blood*; D010108:Oxyhemoglobins / Q000032:analysis; D017397:Prefrontal Cortex / Q000098:blood supply*; D018474:Weightlessness Simulation
chemical_list: D010108:Oxyhemoglobins; D010100:Oxygen