[Resistance and capacity function of blood vessels of the brain during activation of its cholinergic mechanisms]. / Rezistivnaia i emkostnaia funktsiia sosudov golovnogo mozga v usloviiakh aktivatsii ego kholinergicheskikh mekhanizmov.

Blood from the cat donor was perfused into the haemodynamically isolated cat brain. The changes of the vascular resistance and their capacity during the pharmacological activity of the endogenic cholinergic mechanism on the introduction of phosphacol into the bloodstream were investigated. Research has shown that the reduction of the activity of cholinergics leads to a decrease in pressure in the arteries of the brain and to an increase of the intercellular fluid absorption, caused by the neurogenic cholinergic influences. The possibility of a mediator realisation of the cholinergic influences on the brain vessels is discussed.

Stages of sleep evolution (facts and hypotheses).

The paper contains new data concerning the peculiarities of sleep in poikilotherms (fish, amphibians, reptiles). A conclusion is drawn that sleep and the activation spontaneously arising against its background are the universal phenomena in vertebrates. A supposition is argued about the existence of evolutionary succession between the forms of sleep inherent in lower vertebrates and the quiet and active phases of homoiotherms' sleep.

[Neurophysiologic analysis of activation spontaneously developing in Rana temporaria frogs against a background of primary sleep]. / Neirofiziologicheskii analiz aktivatsii, spontanno voznikaiushchei u liagushki Rana temporaria na fone pervichnogo sna.

The presence of spike-like activity against the background of the primary sleep EEG is described in the frog. Patterns of amplitude--frequency spectra computed for parts of the EEG with this activity differ from those computed for the typical EEG of the primary sleep, but have much in common with the spectra of wakefulness EEG. The point of view suggested by I. Karmanova [8] about functional role of different forms of activation arising against the background of the primary sleep in poikilotherms as possible precursors of paradoxical sleep in homoiotherms is confirmed.

[Electroencephalographic analysis of wakefulness and the primary form of sleep in the frog, Rana temporaria]. / Elektroéntsefalograficheskii analiz bodrstvovaniia i pervichnoi formy sna u liagushki Rana temporaria.

EEG spectral and correlation analyses data were obtained on the forebrain and midbrain during active wakefulness and under sleep-like conditions (primary sleep) in frogs. Autocorrelation analysis indicates that the degree of EEG stability and the content of periodic waves in the EEG during wakefulness and primary sleep are rather low. Cross-correlation connection between the bioelectrical activity in the forebrain primordial hippocamp and midbrain tectum was found to be rather poor. At the background of EEG of primary sleep in the midbrain (and to a lower extent--in the forebrain) spike-like activity was observed which is absent in the wake animals. It is suggested that EEG patterns of primary sleep and wakefulness are essentially different. Possibility of onset of specific electroencephalographic arousal reaction against the background of primary sleep (which differs from that in warm-blooded animals) is noted.