Functional similarity of the P-2 form of primary sleep and hypobiosis in the frog Rana temporaria (based on data from luminescent microspectral analysis of the cytoplasm of neurosecretory neurons)

Using luminescent microspectral analysis of preparations stained by acridine orange, studies have been made on the ratio between single- and double-stranded parts in ribosomal RNA from the cytoplasm of neurosecretory neurones of the preoptic nucleus of the frog Rana temporaria. The animals were investigated in active period, during P-2 form of the primary sleep, in hypobiosis, and after injection of the active factor (peptide fraction with a molecular mass 1-10,000 Da) extracted from the small intestine of the ground squirrel Citellus undulatus during winter hibernation. It was shown that unlike actively awake frogs, animals from other experimental series exhibited similar changes, i.e. the decrease in the affinity of acridine orange to single- and double-stranded parts of rRNA and the decrease in the value of alpha which reflects the ratio of single- and double-stranded parts. It was also demonstrated that injection of the active factor from hibernating ground squirrels to frogs results in a condition which is rather similar to a natural resting form (P-2) of the primary sleep in cold-blooded vertebrates.