Behavioral Changes in Rats at Ground Level Following Gestation and Growth in 100% Oxygen at Reduced Pressures

摘要

After removal from a hypobaric normoxic environment (an altitude chamber containing 97% O2 at a total pressure of 210 torr or 210 mm. Hg, absolute), exploratory activity of rats conceived, born, and raised in such an environment was measured from photographic light tracings made during the animals' movements. Within 15 minutes after the first encounter with room air at ground level, experimental animals displayed more exploratory activity than ground-level controls. No differences were measured 4 hours later, but a reduced amount of exploratory behavior occurred after 1 day's exposure to room air at ground level. The extra amount of work necessary to ventilate the lungs owing to increased turbulence in the more dense air at ground level is believed to result in initial excitement and hyperactivity, followed by a reduction in movement as tiring occurs. Adaptation to room air at ambient pressures has apparently not been completed within 22 hours following a previous growth to maturity in a hypobaric normoxic environment. (Author)