[Changes in the sleep-wakefulness cycle in experimental Parkinson's syndrome].

It was demonstrated in rat experiments that in modelling the akinetico-rigid parkinsonian syndrome by injecting kainic acid into the caudate nuclei the phases of wakefulness and light slow-wave sleep decreased while the phase of deep slow-wave sleep increased. In the tremorogenic from of the parkinsonian syndrome induced by reserpine the phases of wakefulness and deep slow-wave sleep decreased in the rats while the phases of light slow-wave and paradoxical sleep increased. In destruction of the substantia nigra with kainic acid the phase of paradoxical sleep reduced.

[Effects of extracts of different parts of the brain of kindled animals on seizure activity of recipient rats].

The peptide-containing fraction was emitted from the hippocampal and ventral mesencephalic region tissue of rats kindled with subconvulsant doses of corazol. Extracts were prepared by the help of hot acetic acid on the stage of generalized clonic-tonic seizure development. The intraventricular injection of VMR-extracts in relatively high dose increased seizure reactions which were induced in intact recipient rats by intraperitoneal corazol injection.

[Effect of the destruction and activation of the caudate nuclei on the convulsive action of corazol kindling].

Chronic experiments on the rats have shown that the pharmacological destruction of caudate nuclei significantly elevates the general brain excitation and induces rapid development of the corazol kindling. The hippocampal destruction exerts an opposite effect. Regression analysis of this processes has shown that mechanism of the general brain excitation and those of epileptogenesis are different on the stage of the developing kindling.

[The role of the substantia nigra in the anticonvulsive and antiaggressive effects of diazepam during pharmacological kindling].

The seizure activity was investigated on the model of pharmacological kindling which was induced by repeated picrotoxin injections in the subthreshold dose, after the tryptic fragment of T5 protein-human diazepam binding inhibitor (DBI) (10 micrograms) injection into a reticular part of substantia nigra. An increase in the seizure reaction and suppression of the antiseizure diazepam action were observed. Intranigral DBI injection induced no change in a threshold of "attacks" in rats which were induced through electric shocks delivered to animals with an electrode floor and no changes in antiaggressive diazepam action were observed under such conditions.

[Development of motor and emotional disorders in rats during daily administration of subliminal doses of picrotoxin].

It was shown in the experiments on rats, that three neuropathological syndromes develop as a result of daily subthreshold picrotoxin injections (1.25 mg/kg). Maximal expression of syndromes was different during various periods of kindling.

[Metabolic characteristics of the myocardium and muscle tissue of the thigh in rats].

Myocardium and skeletal muscle of white rats have a number of specific features in metabolism of carbohydrates. The skeletal muscle is characterized by high intensity of glycolytic processes and glycolytic substrate phosphorylation, that is testified to by the activity of the terminal glycolysis stage enzymes (pyruvate kinase, lactate dehydrogenase, its isoenzyme spectrum) and by the content of lactate and pyruvate metabolites. In contrast to skeletal muscles, the activity of NAD-dependent malate dehydrogenase in the myocardium is significant both in cytoplasm and in mitochondria.

[Effect of delta sleep-inducing peptide, anticonvulsant preparations and nicotinamide on generalized seizure activity].

The influence of delta-sleep inducing peptide (DSIP) upon seizures induced by corazol, bicuculline, picrotoxin, strychnine, thiosemicarbazide were investigated in experiments on F1(CBA X C57 BL/6) mice. It was shown that DSIP increased the latency of first seizure manifestation which were induced by corazol, bicuculline and picrotoxin and also resulted in a suppression of seizure severity of corazol and bicuculline induced seizures. Anticonvulsant action of DSIP was evident under the condition of the mild severity seizures development.

[The effect of delta sleep-inducing peptide on the convulsive activity in corasol kindling].

The influence of intraperitoneal delta-sleep inducing peptide (DSIP) injection (100 micrograms/kg) on the epileptic activity was investigated in the experiments on Wistar rats and (CBA X C57B1/6)F1 mice. The model of chronically developing epileptic activity--the model of pharmacological kindling--was created by daily repeated corasole injections in subconvulsive doses (30 mg/kg). It has been shown that DSIP injection delayed the manifestation of generalized seizures during kindling, led to the suppression of seizure activity and reduced the mortality rate of animals that developed kindled seizures.

[Modelling of the parkinsonian syndrome by the administration of kainic acid into the caudate nucleus].

The experiments on rats have shown that bilateral administration of kainic acid (0.1-0.15 microgram) into the rostral parts of caudate nuclei led to the development of hypokinesia and rigidity.

[Changes in the dehydrogenase and GABA transaminase activity in the cerebral cortex during corazol kindling].

The experiments on (CBA X C57BL/6)F1 mice have shown that regular corazol injections in subliminal doses stimulated seizure susceptibility (pharmacological kindling). Cytophotometric assay of the activity of oxidative metabolism enzymes (glutamate dehydrogenase, malate dehydrogenase, succinate dehydrogenase, alpha-oxoglutarate dehydrogenase, lactate dehydrogenase) and GABA-transaminase in the sensorimotor cortex of kindled mice in post-convulsive period, and 24 hours or 30 days after corazol injections were discontinued, has revealed some specific alterations of the enzymes under study, that suggest the existence of two phases of energy metabolism disturbances. The first phase (24 hours after corazol injections were discontinued) is characterized by intensified succinic acid oxidation, while the second phase (30 days after the last injection) is characterized by anaerobic glycolysis in neuronal and glial cells.

[Effect of destruction of the hippocampus and caudate nucleus on the development of epileptic activity during corazole kindling].

Experiments were carried out on random-bred white rats (250-350 g). Kindling was induced by daily intraperitoneal corazol injections in subthreshold (subconvulsive) doses (30 mg/kg). It has been demonstrated that bilateral hippocampal destruction did not change the seizure threshold, while bilateral caudate nucleus destruction lowered it.

[The hippocampus as the determinant structure generating epileptic activity during korazol kindling].

It has been shown in chronic experiments on rats that two periods of EEG and behavioral alterations may be distinguished during korazol kindling. The bursts of slow waves and spike-wave activity appear on the EEG during the first period as response to subthreshold doses of korazol, which is accompanied behaviorally by standing and myoclonuses. The second period is characterized by the appearance of high-frequency polymorphous generalized seizure discharges on the EEG accompanied by clonicotonic seizures.

[Effect of electric stimulation of the dentate nucleus of the cerebellum on epileptogenic foci in the cerebral cortex].

It has been shown in acute experiments on cats that electrical stimulation (ES, 100-300 Hz) of the dentate nucleus leads to suppression of interictal discharges elicited by application of low concentrated penicillin solution to the neocortex. ES of the nucleus causes activation of discharges in a more powerful focus of seizures. As its activity gradually attenuates the seizure discharges are suppressed during ES.

[Changes in the spectrum of LDH isoenzymes in foci of epileptic activity induced by penicillin in the cerebral cortex of rats].

The correlation between electrophysiological changes and isozymes of LDH of the rat brain cortex was studied in seizure foci induced by application of sodium penicillin. It was discovered that activity of LDH1 was suppressed, and that of LDH5 fraction was elevated in the determinant focus, which indicates the enhanced glucose anaerobic transformation. The spectrum of LDH isozymes did not practically differ from the indicators in control animals in a homotopic region of the contralateral hemisphere prior to creation of the mirror focus.

[Effect of determinant on formation of the complexes of hyperactivity foci in rabbit cerebral cortex].

With the use of weak strychnine solutions foci of enhanced excitability working in independent modes were created in the brain cortex of rabbits during acute experiments. The hyperactive excitability focus induced by concentrated solutions of strychnine played the role of a determinant structure. It enhanced the activity of other foci, united them into a single functional complex and determined the activity pattern of the entire complex.

[Interaction of excitatory foci and their complexes in the cerebral cortex].

Relations between excitation foci and their complexes in the cerebral cortex were studied in acute experiments on cats. Excitatory foci were produced by application of solutions of strychnine, penicillin and acetylcholine with prozerine in different concentrations. Two main types of interrelations were established: the determinant and the dominant ones.

[Effect of stimulation of the paleocerebellar cortex on the multifocal cortical epileptogenic complex].

Effects of paleocortex electrical stimulation on multifocal epileptic complex of the brain cortex alone and in combination with benzodiazepines (diazepam, phenazepam) were investigated in experiments on cats. The animals developed complex reactions which included the increased frequency of seizure potentials during stimulation, their suppression after the cessation of stimulation and the postsuppression rise of frequency (dyssuppression). This points to the dualistic character of cerebellar effects on the brain cortex.

[Effect of electric stimulation of the caudal reticular nucleus of the pons on foci of epileptic activity in the cerebral cortex].

It was shown in experiments on cats that electrostimulation (ES) of the nucleus caudalis reticularis pontis under the destruction of the central grey matter suppressed discharges in a single epileptic focus, created with application of strychnine to the brain cortex and did not suppress the epileptic activity in the complex of foci, formed under the influence of a determinant focus after local application of strychnine to different zones of the neocortex. After increasing the number of foci in the complex the resistance of the latter to suppressive effects of ES of the nucleus caudalis increases too. The complex reduction owing to liquidation of its foci (local application of nembutal) facilitates the suppressive effects of ES of the nucleus caudalis.

[Formation of an epileptic complex in the cerebral cortex and effect of diazepam on it with different levels of cerebral transection].

Effect of diazepam on the activity of the epileptic complex consisting of a number of foci created with strychnine applications to the brain cortex under conditions of intact brain and at different levels of it neuronal isolation was studied in acute and chronic experiments on cats. It was shown that in the preparations of cerveau isolé and cortex isolé a more rapid formation of the epileptic complex under the influence of the determinant focus, and marked generalizaiton of convulsant activity could be observed. Diazepam induced a decrease in the amplitude and frequency of convulsive discharges.

[Effect of nicotinamide on epileptic activity in the cerebral cortex].

The experiments on cats showed that intravenous administration of nicotinamide suppresses the epileptic activity in a solitary epileptic focus as well as in the complex of epileptic foci produced by strychnine application to various cortical zones under the influence of the most powerful focus that plays the role of a determinant. After the intravenous injection of nicotinamide (50-70 mg/kg) the complex was destabilized and broken down. The epileptic activity in the dependent foci of the complex disappeared first in the more remote from the determinant focus and then in the nearer one.

[Formation of determinant structures and functional complexes in the neocortex when the brain is transected at different levels].

A strychnine focus created in the cat neocortex preparations with mediopontine section and encephale isolé, increased activity in other weaker foci, synchronized discharges in them, united them into a functional complex and determined the character of the whole complex activity. Such an hyperactive focus plays an active role of the determinant structure. In cortex isolé and preparations with mesencephalic section of the stem, a more rapid formation of functional complexes occurred under the effect of determinant focus.

Role of hyperactive determinant structures in the creation of functional complexes of seizure activity in the cerebral cortex.

Foci of enhanced excitability, with independent discharge patterns, were created by subconvulsive strychninization in experiments on cats. A focus of more powerful excitation created with the same strychnine played the role of determinant despatch station (DDS). Its importance is that it determines the character of activity of the other foci of excitation, strengthens excitation in them, combines them into a single functional complex, and determines the character of activity of the whole complex.

[Formation of epileptic activity complexes under the effect of the determinant focus in the cortex isolé].

In experiments on cats foci of enhanced excitation working in independent regimes were created in the neuronal-isolated cortex using weak strychnine solutions. Creation of a hyperactive focus by means of application of strychnine concentrated solutions or crystals leads to an increase in the amplitude and discharge frequency in other foci, synchronism in discharges of these foci and their unification into a single functional complex, working in the hyperactive focus regime. The latter, in such a way, presented the determinant structure.