REVIEW OF RESEARCH IN U.S.S.R. 479 



much the same way it analyzes the physical environment. Pavlov advanced 

 such a viewpoint after finding that CRs were possible for introceptive stimuli. 

 Much later work, such as that of Bykov (1957), stressed introceptive stimuli 

 and introceptive reflexes. Presumably, then, the CNS should analyze the 

 complex internal derangements which follow irradiation and adjust the or- 

 ganism to them. This view is tenable for pathology which affects known 

 introceptors, but is somewhat doubtful in matters such as depression of cell 

 mitosis in the gut, testes, or bone marrow, for which no introceptors or 

 central regulatory centers are known. 



It has also been thought by some Soviet research workers that nerves 

 have a direct controlling influence over mitosis, local regeneration, and 

 inflammation. Such mechanisms are usually included under the concept of 

 "trophic nerves," which was developed by Botkin, Speransky, and other 

 older Russian physiologists. This theory is not completely without support 

 in the Western world (Wyburn-Mason, 1950) but a great deal of the evi- 

 dence is contradictory. A recent Soviet report for the U.N. (Mastryukova and 

 Strzhizhovskii, 1960) summarizes considerable research on the matter and 

 concludes that altered levels of epinephrine and adrenal corticoids may be 

 the most iinpK)rtant factor in the mitotic depression known to follow various 

 insults to the nervous system. 



With this background in mind, it is easier to understand Livanov's view- 

 point, though one may not agree with it. In a number of papers Livanov 

 (1960) states that radiation with a few hundred r causes abnormal afferent 

 inflow, reflected in altered cortical and subcortical encephalograms. There 

 follows a complex series of events involving subcortical and cortical inhi- 

 bition, leading to altered spinal and autonomic activity, and then gradual 

 disinhibition occurs at different times. Livanov states that single doses of 

 5-1,000 r commonly cause a stimulatory effect, which may be repeatable, 

 but that after total doses of 200-1,000 r there is a general depression of 

 EEG activity. EEG reactions to radiation have been described by Livanov 

 et al. (1960b) with doses down to 50 r per minute, and such effects are 

 said to be predictable with 10-15 r single exposures. 



Grigoryev published a book (1959) which deals with EEG studies on 

 humans receiving radiation therapy for tumors of the head or other parts of 

 the body. He frequently cites a stimulatory action during the first few 

 sessions, then a depressant effect. The precise origin of the claimed changes 

 of EEG activity remains obscure, but it will be necessary to rule out stimu- 

 lation of the retina, humoral mechanisms, biochemical shifts, and numerous 

 other factors before one can conclude with assurance that the EEG change 

 indicates an alteration in afferent flow which is communicating information 

 about the somatic radiation pathology to the higher nerve centers. 



If significant purposeful, or damaging purposeless, afferent activity oc- 



