Evaluation of the autonomic nervous activity during parabolic flight by pupillary flash response

Abstract

AbstractEvaluating the modulations of the autonomic nervous activity occurring due to gravity changes is an important task in space medicine. In this paper, results of evaluating the autonomic nervous activity in the states of hypergravity (excessive gravity) and hypogravity (very little gravity) during a parabolic flight of an aircraft are reported. A noninvasive pupil monitoring method proposed by the authors has been adopted in evaluating the autonomic nervous activity. This method allows evaluating the sympathetic and parasympathetic nervous activities independently by simple experimental and data processing. In these experiments, only the simple parasympathetic nervous activities are evaluated by experimental protocols, and then the activities of the two nervous systems were simultaneously evaluated after verifying that stable data can be obtained via the experiments. Three males participated in the first experiment and one male in the second experiment. The results of the two experiments suggest that parasympathetic nervous activity is inhibited in one of the three subjects in the state of hypergravity and in all subjects in the state of hypogravity. On the other hand, there are no changes in the state of hypergravity and slight increases in the state of hypogravity in the sympathetic nervous activity. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(11): 56–64, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10054