title: Swimming velocity of Paramecium under the conditions of weightlessness.
abstract: During the 6 min-lasting "free-fall conditions" (4 x 10(-6) g) of the parabolic flight of a sounding rocket Paramecium aurelia cells showed an increase of 7.5 % in their mean swimming velocity. A detailed analysis revealed that the kinetic response was transient: after 3 min the velocity decreased to the speed of the former horizontal swimming at 1 g. Control experiments simulating the influence of vibration and hypergravity during launch of the rocket lead to the conclusion that the increase of the velocity during the parabolic flight was exclusively induced by the transition to 0 g. An increased velocity was also observed under the condition of simulated weightlessness on a fast-rotating clinostat microscope.
authors.affiliation: DLR, Institute of Aerospace Medicine, Koln, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Hemmersbach-Krause
authors.forename: W
authors.initials: W
authors.lastname: Briegleb
authors.forename: K
authors.initials: K
authors.lastname: Vogel
authors.forename: D P
authors.initials: DP
authors.lastname: Hader
mesh_terms: D000054:Acceleration; D000818:Animals; D002498:Centrifugation / Q000295:instrumentation; D002923:Cilia; D006112:Gravitation; D018466:Gravity Sensing; D018471:Hypergravity; D007091:Image Processing, Computer-Assisted; D008853:Microscopy / Q000295:instrumentation; D009043:Motor Activity / Q000502:physiology*; D016011:Normal Distribution; D010247:Paramecium / Q000502:physiology*; D012399:Rotation; D013026:Space Flight; D013550:Swimming / Q000502:physiology*; D014732:Vibration; D014893:Weightlessness