AUTONOMIC FUNCTION AND PLASMA-CATECHOLAMINES FOLLOWING STRESSFUL SENSORY STIMULI

This experimentation defined a limited role for epinephrine in the aut onomic nervous system function and the nausea that occurred following motion sickness testing. Individual responses to stressful sensory sti muli and nausea, as reflected by rising peripheral levels of epinephri ne, were not significantly diminished upon repeated exposure and adapt ation to the stressor. However, subjects who demonstrated more robust elevations of epinephrine in response to nausea displayed higher resis tances to stressful motion stimuli. Modulation of peripheral catechola minergic function with dexamethasone, or scopolamine plus amphetamine, suggested that altered autonomic nervous system function and nausea f ollowing motion sickness testing were not mediated by peripheral catec holamine receptor stimulation. Marked differences were noted in indivi dual responses to drug and systemic responses of epinephrine and norep inephrine. It is possible that responses in epinephrine to motion sick ness testing may predict resistance to stressful motion, and represent a peripheral manifestation of some as yet unknown central event of et iologic relevance.