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ZEMAN, CURTIS, SCARPELLI, AND KLEINFELD 



Fig. 3. 0.075 mm beam: (from left to right) 540,000 rad, (site of lesion is torn), 

 270,000 rad, and 180,000 rad. 30 hours survival. Cerebellum. Note that the path of 

 the beam is outlined by the dark staining blue indigo granules developed by the ac- 

 tivity of the cathepsin-like enzymes. Frozen section. Holt's technique for esterases, 

 blocking with DFP, counter-stained with Oil Red "O". 



the molecular layer contained only a few spots of activity (Fig. 4) . Much of 

 the latter appeared to be in capillary endothelial cells and astrocytes, but 

 some of the superficial stellate cells also exhibited blue granules in their 

 cytoplasm. 



Owing to the thickness of the sections, it was extremely difficult to prop- 

 erly localize the site of enzyme activity in the Purkinje and granular cell 

 layers. In some instances, however, chance permitted us to make more defi- 

 nite statements. In Fig. 5, one can readily discern the emergence of com- 

 pound granular corpuscles, loaded with blue indigo granules from a capillary 

 wall. Figure 6, on the other hand, shows 2 Purkinje cells, irradiated with 

 540,000 rad, having a deep blue cytoplasm. It can also be noted that their 

 baskets are apparently unaltered. Some of the adjacent granule cells are 

 similarly affected. Figure 7 depicts the granule cell layer of the hippocampus 

 where it was hit by a beam of 180,000 rad. Here, the cytoplasm of many 

 neurons is stained a deep blue. 



