PATHOLOGIC CHANGES IN BRAIN CAUSED BY ALPHA PARTICLES 387 



:■•. ._.;:;*'^s^.gu^-^i?H%?f;;S,i'r'-'. • 



Fig. 1. Proton radiation. 6.000 rad surface dose; sacrifice at 10 days. A. A narrow 

 cell-poor band extends across the cerebellar folia. Abo\'e the band the granular layer 

 is rarefied, and some of the granule cells are atrophic. The intrafolial white matter is 

 slightly disrupted and has reduced stainability. The Purkinje cells in the region of the 

 band ha\e disappeared. Bergmann cells show little alteration. Proliferated glia are 

 present in the molecular layer, especially at the le\el of the band. B. In the cerebral 

 cortex a wider ner\e-cell-poor band is to be seen. Glia within the band ha\e increased 

 somewhat in number. Pyknosis of the nerve cells near the cerebral surface represents 

 postmortem artifact. Both stained by \'an Gieson-hcmatoxylin. Both X ~5. 



At the 6.000 rad surface i Fias. 1 and 2 ' a wide nene-cell-poor band was 

 present in the cerebellum and cerebrum, but after 64 days both the band and 

 the cerebellar and cerebral tissue abo\e the band were oreatly shrunken as 

 compared with sections obtained at the 10-day stase. At the 3.000 rad surface 

 dose, after 64 davs i Fia;. 3) the degree of damase was tar less ad\anced. At 



