MODELING VESTIBULAR EFFECTS OF
ARTIFICIAL GRAVITY BY GONDOLA CENTRIFUGATION IN MICE.
E.B. Wagner1,3, M.J.
Theis1, S. Tsikata2,
I.M. Bernal1, A.W. Bryan3,
Aeronautics and Astronautics, 2Department
of Mechanical Engineering, and 3Harvard-MIT
Division of Health Sciences and Technology, Massachusetts Institute of
Technology, Cambridge. 4International
Space University, Strasbourg, France.
use of rotational spaceflight research platforms is planned for the
International Space Station and free-flying biosatellites in coming years.
While long-radius platforms pose inherent practical difficulties, short-radius
platforms cause abnormal vestibular effects in mammals due to inertial forces
in rotating reference frames.
In preparation for the artificial gravity experiment to be flown
aboard the Mars Gravity Biosatellite, we have developed a ground-based gondola
centrifuge for mice to assess these effects in short-radius rotation. In order
to analyze the results from this platform, we have developed a mathematical
model of the physical environment it provides to rodent subjects. The model
accounts for three categories of effects: static ideal effects as
experienced by a stationary body on an ideal centrifuge; static anisotropic
effects as experienced by a stationary body removed from the platform's ideal
dynamic effects due to animal movement within the platform. We assess
the practical implications of the model based on current understanding of
processing and adaptation by the mammalian vestibular system.
Based on the above analysis, we conclude that: (1) the gondola
centrifuge should provide a reasonable indicator of static ideal vestibular
adaptations, but a mechanism for orientation correction will be required to
interpret AG observations; (2) static anisotropic factors should not
substantially affect behavioral results; (3) the platform does not provide
useful information on potentially debilitating dynamic effects. These results
should be considered in planning and assessment of behavioral data for future
short-radius AG studies.
(Supported by the NASA Ames
Fundamental Space Biology Division.)