[Effect of photostimulation on the wakefulness-sleep cycle in the common frog Rana temporaria].

Effect of daily 30-min photostimulation in the 10 s light: 10 s pause (the total of 5 days) on the time structure of the wakefulness--protosleep cycle (WPC) was studied in the common frog Rana temporaria. Changes were analyzed of EEG wave components in three immobility forms of the type of catalepsy (P-1), catatonia (P-2), and cataplexy (P-3) that form protosleep. The first three photostimulations promoted a gradual increase of the P-1 state to 84.16 +/- 11.6% [the initial value (IV) 22.9 +/- 9.1%] and a decrease of representation of wakefulness to 4.86 +/- 2/1% (IV 13.8 +/- 7.8%), of P-2 to 11.1 +/- 5.3 (IV 53.3 +/- 13.3%), and of P-3 to 2.21 +/- 1.0% (IV 11.1 +/- 5.6%). After 4-5 photostimulations and especially after their complete cessation the percentage of P-1 in the WPC was restored to initial values, whereas the percentage of the frog WPC P-3 considered to be a precursor of the homoiothermal sleep rose to 20 +/- 8.3% after 5 photostimulations and to 38.5 +/- 6.7% the next day. Changes in the frog EEG spectra appeared only after one photostimulation and were characterized by a brief increase of power of alpha-like waves and by inhibition of slow 6-waves. In P-2 the power of the slow delta-waves gradually rose. In P-3 the EEG parameters did not change. In all experimental animals a decrease of the relative thymus and adrenal masses was revealed, which indicates the photostimulation regime used in the work induces stress. The obtained data allow thinking that a certain neurohormonal response to stress has already been formed at the amphibian level and that an important role in this response realization is played by a coordinated interaction of the hypothalamic sleep-regulating system providing protosleep manifestations and of the hypothalamic neurosecretory system triggering the stress-reaction hormonal cascade.

[Neuron reactions of brain structures suppressing motion during development of animal hypnosis in guinea pigs]. / Reaktsii neironov struktur mozga, tormoziashchikh dvizhenie, pri perekhode morskikh svinok v sostoianie zhivotnogo gipnoza.

Multisensory and motor units are suppressed in hypnosis in the guinea pig giganto-cellular reticular nucleus and in the dorsolateral. pons. In contrast, inhibitory intexneuvons neurons and the ponto-medulla neurons are activated in hypnosis. The data obtained suggests a key role of the brain-stem structures in descending unspecific inhibition during hypnosis in animals.

[Neurophysiology and analysis of the phenomenon of catalepsy]. / Neirofiziologiia i analiz fenomena katalepsii.

Neurophysiological mechanisms of the photogenic catalepsy (the "animal hypnosis"), genetic catalepsy, and cataplexy are discussed. The data obtained demonstrates a significance of the brainstem structures suppressing motor activity and the muscle tone in these conditions. Motor disorders associated with the general immobility are discussed from the standpoint of the evolutionary theory.

The brain tryptophan hydroxylase activity in the sleep-like states in frog.

The activity of the rate-limiting enzyme of serotonin biosynthesis, tryptophan hydroxylase, was determined in the brain stem in active awake frogs, and frogs in three sleep-like states: with plastic muscle tone (SLS-1), with rigid muscle tone (SLS-2), and with relaxed muscle tone (SLS-3). Significant decrease in the enzyme activity has been found in frogs in SLS-1 and SLS-2 compared to awake animals. The development in frogs a cataleptic-like immobility after treating the animals with rhythmic lighting was accompanied with a decrease in the brain tryptophan hydroxylase activity. These results provide strong evidence for the involvement of the brain serotonin in frogs in the control of evolutionary ancient sleep-like states, probably by the regulation of muscle tone.

[The regulation of the wakefulness-sleep cycle in normal rats and during sleep pathology]. / Reguliatsiia tsikla bodrstvovanie--son u krys v norme i pri patologii sna.

Studies on the cycle wakefulness-sleep in rats with genetic predisposition to catalepsy revealed that this strain may be also used for investigation of sleep pathology. These animals exhibit abnormal regulation of the cycle which reveals itself in the onset of a "hypnotic" sleep phase. This phase is a result of a special form of sleep regulation and it cannot be classified as slow-wave or paradoxical sleep. In the hypnotic phase, no increase in spatial and temporal synchronization between structures was observed which is typical of the normal delta-sleep (0.704 +/- 0.053). Correlation connections between the visual cortex and subcortical structures remained weak (0.326 +/- 0.076) in spite of the increase in the level of EEG synchronization close to that during slow-wave sleep. It was shown that catalepsy may be due to lack of dopamine.

[The phenomenon of the functional dissolution of the wakefulness-sleep cycle in white rats under the influence of immobilization]. / O iavlenii funktsional'noi dissoliutsii tsikla bodrstvovanie--son u belykh krys pod vliianiem immobilizatsii.

Studies have been made on functional dissolution of the sleep cycle in albino rats due to immobilization of various duration. It was shown that 1-day immobilization increases microactivational representation in the EEG, facilitates rhythmic movements of the lower jaw, affects relative duration of the diurnal and nocturnal sleep, increases sleep fragmentation, and in some of the animals decreases the EEG amplitude. It is suggested that strong stress results in the return of sleep mechanisms to a more ancient level.

[The wakefulness-sleep cycle in rats with a genetic predisposition to catalepsy]. / Tsikl bodrstvovanie--son u krys s geneticheskoi predraspolozhennost'iu k katalepsii.

Neurophysiological studies on wakefulness-sleep cycle have been made in rats selected for hereditary inclination to catalepsy. It was shown that in these animals, the stage of delta-sleep is significantly reduced, whereas the duration of a superficial slow-wave sleep is increased. In a sleeping phase of the cycle, large amount of spindles in the range of alpha- and beta 1-oscillations was observed, especially significant in electrograms of n. caudatum and sensorimotor cortex. This activity is considered as a pathological manifestation of a transient hypnotic phase which includes the increase in immobilization of a cataleptic type.