ACUTE EFFECTS OF RADIATION ON SPINAL NEURONS 



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0.2 3 01 



02 03 01 



Volts 



Fig. 1. Stimulus strength and amplitude relation. Key: Mono, monosynaptic re- 

 flex; I. M.S., intramedullary spike; NiB^ interneuronal component of cord potential. 



response remained almost constant for more than 1 hour before irradiation. 

 After an initial small dose of irradiation, the monosynaptic reflex began to 

 increase with a considerably steeper slope, while the intramedullaiy spike 

 which is interpreted as revealing the activity of sensory fibers ascending the 

 dorsal column, started to decrease in amplitude. Nib, which is known to 

 represent interneuronal activity, remained constant in ampHtude until the 

 end of the experiment. 



