WE ARE interested in the effects of asphyxiation on the nervous system and have described changes taking place in the brain after resuscitation of newborn animals.1 More recently, we undertook to determine effects on nerve cells of intermittently subjecting adult animals to reduced pressures of oxygen, reporting results of experiments at a simulated altitude of 23,000 feet (7,700 meters; 307 mm. of mercury).2 It was found that guinea pigs living at the lowered barometric pressure in a chamber, six hours a day and six days a week for periods totaling as much as five hundred hours, exhibited no significant symptoms, nor did the brains show appreciable histopathologic changes with carefully controlled technics. One could not observe any cumulative effect of the day by day exposure. The study demonstrated that greater degrees of anoxia would have to be used to bring about significant structural changes in the nervous system.
A. V. JENSEN, CHAPEL HILL, R. F. BECKER, W. F. WINDLE. CHANGES IN BRAIN STRUCTURE AND MEMORY AFTER INTERMITTENT EXPOSURE TO SIMULATED ALTITUDE OF 30,000 FEET. Arch NeurPsych. 1948;60(3):221–239. doi:10.1001/archneurpsyc.1948.02310030002001