Effects of Hyperbaric Environments on Neuromuscular Control in Primates.
ARIZONA STATE UNIV TEMPE
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Four monkeys were individually exposed to hyperbaric environments consisting of air, nitrogen-oxygen pO2 200 mm Hg, and argon-oxygen pO2 2001000 mm Hg. Neuromuscular control was assessed via a force discrimination task during the course of simulated dives lasting 7-16 hrs. Performance decrements were related to depth and to gas mixtures. Task failure occurred at 400-500 FSW with argon-oxygen. Air was tolerated at pressures equivalent to 500-700 FSW. Nitrogen-oxygen produced total failures in force discrimination at 600-800 FSW. During compression, performance efficiency was often sustained, although other measures indicated neuromuscular control problems at relatively low pressures. Adaptation to intermediate pressures was exhibited by recovery of effectiveness in performing the force discrimination task. Related measures of cardiac function in waking monkeys revealed stability over all the pressures and gas mixes utilized in the study. The study indicates that the expression of inert gas narcosis relates to pO2 of the breathing gas and that the condition is not clearly related to unusual cardiovascular adjustments. Author
- Stress Physiology