第27回宇宙利用シンポジウム (2011年1月24日-25日, 宇宙航空研究開発機構宇宙科学研究所相模原キャンパス), 相模原市, 神奈川県

The Twenty-seventh Space Utilization Symposium (January 24-25, 2011. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

During extravehicular activity (EVA), astronauts will have mental sweating as well as thermal sweating, which might disturb EVA by high humidity in the gloves or shoes because mental sweating is localized at palms and soles in humans. We have analyzed that mental sweating at soles are exaggerated by hyperactive skin sympathetic nerve activity (SSNA). In the present study, we examined that motor command activates this SSNA during intended movements. Activation of the skin sympathetic nervous system produces activities of the sudomotor and the vasoconstriction preparing for the exercise activities. Two principal theories have been proposed about sympathetic activation that is caused by voluntary muscle contraction. One is that sympathetic activation is induced by somatosensory afferents. The other is the central motor command signal activates to autonomic circuits. The mechanisms how sympathetic outflow is activated preparing for the motor command has not been well elucidated. The aim of this study is to clarify how much contribution is distributed among central motor command, cognitive function and somatic sensation preparing for the voluntary muscle contraction. Sympathetic skin response (SSR) was recorded from the right sole. EMG was recorded from flexor carpi radialis muscle. We recorded SSNA from tibial nerve by microneurography simultaneously with movement related cortical potentials (MRCPs) and P300 to analyze the temporal relationship between cognitive function and SSNA evoked by muscle contraction. We concluded that more contribution of central motor commands rather than cognition and somatic sensation to the skin sympathetic outflow on glabrous skin areas preparing for voluntary muscle contraction. Mental sweating evoked by activating of motor command might disturb EVA with wearing airtight suit.

形態: カラー図版あり

Physical characteristics: Original contains color illustrations

資料番号: AA0065129048