<Outline of Experiment>
Sympathetic nerve activity plays important roles in blood pressure control. Changes in sympathetic nerve activity may be related to orthostatic intolerance often encountered in astronauts. Ground-based experiments have shown that sympathetic nerve activity is strongly suppressed in simulated microgravity. But the neural mechanisms underlying orthostatic intolerance has not been clarified.
In the present study, muscle sympathetic nerve activity is to be measured in astronauts by a tungsten microelectrode inserted percutaneously into the nerve fascicle of autonomic nerves during and after spaceflight to analyze how this activity is changed during adaptation to microgravity and readaptation to terrestrial gravity.

<Expected Outcome>
The present study provides accurate information about autonomic nervous control of cardiovascular functions in humans related to spaceflight. This study will contribute to understanding for the mechanisms and establishing the countermeasures of physiological deconditioning during adaptation to space environment and after returning to the earth.

Sympathetic nerve activity Measurement of sympathetic nerve activity

Medical Experiment System

Last Updated : March 27, 1998