280 G. M. FRANK AND A. D. SNEZHKO 



The condition for the rise of this rhj^thm is a good start of the develop- 

 ment of the whole cell population. Then the clearly manifested, some- 

 times extraordinarily demonstrative and very regular, oscillating 

 character of the free oxygen level is revealed. Some minutes after 

 irradiation a quite smooth line is seen instead of the dentate one regis- 

 tered prior to exposure. In other cases, under similar treatment the 

 character of the rhythmical process is conspicuously changed. Regular 

 waves of a change in free oxygen concentration are replaced by an 

 irregular broken line. 



The slow rhythm of the rate of oxygen utilization is by no means an 

 exception. Two other types of periodic phenomena which were found 

 recently in our laboratory are worth mentioning. 



The first is the slow component of bioelectric activity, from the work 

 of Dr. Aladjalova. It turns out that, apart from electric processes of 

 impulse character, with the fi^equency of several times per second and 

 a steep augmentation of the difference of potentials, a very slow rhythm 

 can be revealed in many objects. This was called by Dr. Aladjalova, 

 (1956), the "infra-slow" component of the change of potential in direct 

 curi'ent. 



The regularity of such a rhythm is clearly revealed, for example, in 

 various recordings from the tissue of the central nervous system. This 

 form of electric activity is also most closely I'elated to functional state. 



Consideration of this question in detail exceeds by far the prol)lems 

 concerned in our conference; therefore, I shall give but one example. 



Under defined conditions a depression of infra-slow oscillations of the 

 potential in the brain cortex after irradiation of the ral)])it head, say, 

 with 1,000 r can be clearly shown. A not very regular rhythm of the 

 order of 8 to 10 oscillations per minute becomes smoothed 5 min after 

 irradiation. Twenty-four hours after in-adiation this rhythm is restored 

 and even acquires a gi'eater amplitude and regularity. 



From its appearance only — and for the time being we can only speak 

 of this — the very character of the process, its depression and in some 

 cases even a stimulation of rhythmical activity some time after irradi- 

 ation very much resemble all that has been said with respect to the 

 periodic character of the processes of oxygen utilization. 



We have failed thus far to establish the complete synchronism of 

 both processes u])on their simultaneous registration. They run simul- 

 taneously and with comparable frequencies while being determined by 

 different physico-chemical mechanisms. 



The possibility of observing periodical mechanical motility in cells 

 and tissues not specialized for the function of motility seems to us to 

 be of no lesser importance. This mechanical motility can be revealed 



