[Histochemical determination of RNA and protein in the brain during primary sleep in the frog Rana temporaria and during intermediate sleep in the turtle Emys orbicularis]. / Gistokhimicheskoe opredelenie RNK i belka v mozgu vo vremia pervichnogo sna liagushki Rana temporaria i promezhutochnogo sna cherepakhi Emys orbicularis.

It has been shown that resting forms of the primary sleep in the frog and intermediate sleep in the tortoise (P-1, P-2 and P-3) differ from each other with respect to neurochemical characteristics. Cytospectrophotometric studies reveal the increase in the content (per one cell) and concentration of total protein and RNA in cells of the preoptic nuclei of the frog only during one of the resting forms of the primary sleep (P-3), which represents functional homologue of the intermediate sleep of reptiles and sleep of homoiothermic animals. These anabolic changes were not observed during two other resting forms of the primary sleep, this finding being consistent with divergent development of resting forms of the primary sleep in evolution of vertebrates.

[Daily form of rest in the catfish Ictalurus nebulosus and the frog Rana temporaria]. / Osobennosti dnevnoi formy pokoia u karlikovogo somika Ictalurus nebulosus and the frog Rana temporaria

By means of recording the cardiac rhythm, respiration rate and motor activity in unrestrained animals, studies have been made on the dynamics of formation of cataleptic-like immobilization in the teleost I. nebulosus. Rhythmic illumination at a rate 3/min. (10 sec light on - 10 sec light off) in the daytime gradually caused the onset of immobilization in the fish. This immobilization is characterized by the specific heart rate, type of respiration and the degree of plastic tone. Under the same experimental conditions, the formation of photogenic catalepsy in the frog Rana temporaria was confirmed. Typical heart rate, respiration pattern and the degree of plastic tone were determined as well. The role of illumination rhythm in the onset of all conditions which are characteristic for the "awakefulness-rest" cycle is discussed.

[Species characteristics of the diurnal periodicity of rest and activity in Black Sea fish]. / Vidovye osobennosti sutochnoi periodiki dvigatel'noi aktivnosti i pokoia u chernomorskikh ryb

In 6 species of the Black Sea teleosts differing in habitats and other ecological peculiarities, behavioural and electrophysiological experiments revealed 3 types of the diurnal periodism of motor activity and rest. The first type was most evident in the grey mullet Mugil sp., being characterized by the decrease of the level of the activity at night time. In the second type, motor activity was observed at any time; this type of periodism was typical of the dogfish Squalus acanthias and the hunchback Sciaena umbra. In the third type of periodism, the level of the activity remained also unchanged, but in contrast to the second type, it was practically equal to zero. This type was most evident in the scorpionfish Scorpaena porcus. The data obtained indicate that species peculiarities may be found in the diurnal rhythm of the activity and rest. These periods of rest we consider as "presleep" or "protosleep" (the initial stage of the development of sleep) in vertebrates.

[Circadian cycles of wakefulness and rest in Rana temporaria frogs]. / Sutochnye tsikly bodrstvovaniia i pokoia u liagushki Rana temporaria

In the diurnal activity of the frog R. temporaria, rest and awakefulness stages were investigated. Resting stage was differentiated into daily and nocturnal phases. During daily rest, plastic tone in neck muscles was registered. During this phase, the head might be subjected to unnatural position which is maintained for a certain period. The heart rate was minimal, respiration could not be recorded. During nocturnal rest, in contrast to daily one, the animal changed its positon when touched at the head and kept itself in this positon. Cardiac contractions exhibited evident rhythmicity. Sleep episodes were rare and occasional; they were accompanied by eye closing and relaxation of the body.