THE EFFECT OF HEAD VERSUS TRUNK X-IRRADIATION ON AVOIDANCE BEHAVIOR IN THE RHESUS MONKEY.
Technical rept. for Jan-Nov 67,
SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX
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The purpose of this study was to establish the effect of large doses of ionizing radiation delivered to the head or trunk alone on learned avoidance behavior in primates Macaca mulatta. Two groups of 8 animals each were exposed to either head or trunk x-irradiation from a high energy source. A total dose of 18,070 rads was given at a dose rate of 280 rads per minute. Irradiation of either the head or trunk alone was found to produce performance decrement however, the character of the decrement differed for the two groups. One-half of the trunk-irradiated animals showed an early reversible decrement after doses of 1,000 to 5,000 rads while the head-irradiated group generally performed well until 10,000 to 16,900 rads had been delivered, at which time a precipitous, irreversible incapacitation occurred which was accompanied by extensive signs of CNS damage. The results suggest the importance of indirect as well as direct effects of radiation on the central nervous system and its function particularly in relation to the period of early, reversible incapacitation after large doses of radiation. Author