Effects of Radiation on the Central Nervous 

 System and on Behavior— General Survey* 



Harry F. Harlow 



University of Wisconsin, 

 Madison, Wisconsin 



It has long been known that the adult nervous system, both peripheral 

 and central, is resistant to radiation, and considerable information has been 

 assembled to show that this is tiaie regardless of the criterion taken — ana- 

 tomic, physiologic, or psychologic. 



Lyman et al. (1933) reviewed the German and Russian literature and 

 concluded that in the adult animal, irradiation produces little or no direct 

 effect on the nerve cells or fibers. Subsequently, Warren (1944) concluded 

 that "interruption of the vascular bed, rather than direct injury of the nerve 

 elements, is probably the cause of the rare nervous symptoms following 

 irradiation of the brain or cord," and others have made the same assumption. 

 Desjardins (1931) reported that the neural portions of the eye are not 

 easily damaged by x-rays and that "no evidence of injury to the auditory 

 apparatus of human beings has ever been reported." Snider (1948) reported 

 no changes in the nervous system of mice or chicks given Sr^^ or radium 

 producing a dose below the LD/50/30, even though the animals were 

 tested 1 year after treatment and even though autoradiographs demonstrated 

 that the radioactive material had reached the central nervous system (CNS) . 



Gerstner (1958) presented evidence that showed the x-ray dose that 

 would produce cerebral death in man was in the area of 3,500 r and above. 

 Allen et al. (1960) demonstrated that high doses from a Co''" source, 

 9,000-40,000 r, produce a pattern of severe and progressive dysfunction of 

 the CNS in macaque monkeys, resulting in so-called CNS death, as con- 

 trasted w^ith hematopoietic death or gastrointestinal death. These investi- 

 gators point out that there was also widespread injiny throughout the body 

 which undoubtedly contributed, directly or indirectly, to the short survival 

 time. Allen et al. (1960) cited classical CNS symptomatology in some ani- 



* Wisconsin researches reported were supported in part by the National Institutes 

 of Health and in part by the University of Wisconsin. 



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