PRINCIPAL INVESTIGATOR(S ) : Webb Haymaker, Bonne C. Look, and Eugene V. Benton 



EXPERIMENT TITLE/NUMBER : Pocket Mouse Experiment (BIOCORE) , M121 



PROGRAM/MISSION : Apollo 17 



CLASSIFICATION : Animal - Pocket Mouse ( Perognathus longimembris ) 



DISCIPLINE(S) : Radiobiology 



OBJECTIVES : To determine whether a specific portion of the high Z-high energy 

 (HZE) galactic cosmic ray particle spectrum, especially particles with Z no 

 less than 6, can produce microscopically visible injury of brain, eye and 

 other tissues. 



PROTOCOL : Five pocket mice with plastic dosimeters implanted beneath the 

 scalp underwent extensive ground testing for space flight environmental 

 factors. Two cannisters were prepared of five mice each, one flight, one 

 back-up to be used as a control, undergoing the same stresses as the flight 

 mice. Upon return, the mice were sacrificed and fixed with FAM. The animals' 

 heads were fixed and sliced into 1600 sections each, and compared with the 

 heads of the sacrificed control mice (which had had paper dosimeters placed on 

 their heads, and holes drilled to simulate the HZE particle paths that were 

 encountered by the flight mice) . 



EQUIPMENT : Mouse flight cannister, life support system, dosimeters. 



RESULTS : Four of the five flight mice returned alive; two in active and 

 excellent condition; two docile and hunched up. The female was most subdued 

 and uncoordinated on walking. Eighty cosmic ray particles were recorded in 

 the five dosimeters which probably recorded 50$ of the hits through the brain. 

 The body tissues of the four live mice showed no change due to HZE. The 

 olfactory epitheleum was severely damaged in four of the mice, less severely 

 in one. In the flight and back-up mice, there was hemmorhage in the middle 

 ear cavity bilaterally (recovery condition directly related to the amount). 

 There were 13 tiny lesions in the scalps of three flight mice. Five particles 

 were recorded through the eyes. No retinal lesions were found. There were no 

 pathological changes to the brain menninges or calvarium related to flight. 



CONCLUSIONS : Although detailed studies were performed in an effort to answer 

 the question whether HZE cosmic ray particles are injurious to brain and other 

 tissue, it should be noted that the lack of demonstrable lesions does not 

 negate this possibility. Substantially less shielded exposures to cosmic ray 

 particles are needed if the effects (or lack of effects) of the particles on 

 brain tissue and other target structures are to be established. 



PUBLICATIONS : 20, 21, 138, 184, 250, 253, 254, 255, 256, 319, 349, 350, 355, 

 356, 411, 424, 425, 534, 575 



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