[Audiogenic epilepsy: a morphofunctional analysis].

The rats of K-M line with high level of convulsive readiness to sound stimuli were tested. It was established that systemic application of epileptogenic stimulus evoked the decrease of level of convulsive readiness. The phenomena of habituation and normalization of animal behavior were revealed.

[The dependence of spatial-motor asymmetry on the nature of the reinforcement].

Spatial-motor asymmetry (SMA) of rats goal-directed running was studied in condition of numerous alternative choices in complex T-maze. In condition of free choices SMA in trained rats depended on reinforcement biological significance, volume and disposition scheme. In condition of non-free choices a change was possible of asymmetry of sequence of goal-directed motor acts adequate to situation, i.

[The habituation of KM-strain rats to the action of an epileptogenic stimulus].

A decrease in the level of epileptic susceptibility to a strong sound which induces the epileptiform seizures has been studied in KM-strain of rats. Reflectory control of seizure activity, i.e.

[A morphofunctional analysis of the participation of the cerebral cortex in the habituation of Krushinskiĭ-Molodkina strain rats to an epileptogenic stimulus].

Systematic action of epileptogenic stimulus (sound) leads to gradual lowering of the level of convulsive readiness (LCR) in rats of KM (Krushinski'i-Molodkina) line to the formation of the habituation, to blocking of convulsive seizures. It is shown that at single action of sound, functional switching-off of the cerebral cortex causes LCR lowering but does not prevent the development of the epileptiform seizure. Alongside with it, in conditions of repeated sound action, functional decortication considerably retards LCR lowering.

[The volume of reinforcement and the structure of rat behavior in a radial labyrinth].

In rats choice reaction was elaborated in 12 passages radial labyrinth with different volumes of food only in six of twelve passages. Then the conditions were modified: the first group of rats in the beginning of the experiment was placed to another labyrinth sector, and in the second group the food volume was changed in passages. In new situations in animals of both groups the reaction efficiency temporarily decreased, simultaneously the correction of behaviour structure took place.

[Behavioral tactics of rats receiving unequally distributed reinforcement in a radial maze].

Rats behaviour was studied in 12-arms radial maze with food reinforcement of different volumes presented only in 6 passages. Dynamics of changes is shown in the process of learning both in the preference of the passages with greater volume of reinforcement and in the number of errors, characterizing the working and referent memories. In the trained rats, their behaviour is determined by at least two behavioural tactics: visiting more remote passages and choice in the beginning of the test of more reinforced passages.

[Changes in the level of seizure readiness of KM strain rats undergoing systematic stimulation by light and sound].

A possibility of reflex change in the rats seizure activity level of KM line in which an intensive sound causes epileptiform seizures has been studied. Interrupted light stimulation (non-specific for the given form of seizures) does not cause any seizures. It has been found however that the initial presentations of light stimulation favour the increase of seizure activity level in rats.

[Spatial-motor asymmetry in rat behavior].

The experiments were carried out on rats in three different mazes: U-shape, complicated linear and 12-beam radial. Series of tests differed by succession of rats learning in the mazes and the character of reinforcement. Most of the rats manifested a spatial-motor asymmetry (SMA) in all used situations.

[Behavioral tactics among rats in a radial maze].

The experiments were carried out on rats of Wistar (W) and Krushinsky-Molodkina (KM) lines, differing in the level of task performance in conditions of multiple choice of food sources in a 12ray radial symmetrical maze. It is shown that in the radial maze, the rats of both lines use a number of behavioural tactics. To determine the influence of changes of environmental spatial characteristics while preserving the main experimental strategy--never revisit the places of reinforcement,--on the peculiarities of tactics manifestations maze modifications were elaborated.

[Effect of systematic exposure to sound on the level of seizure susceptibility of KM rats].

The effects of systematic sound exposition on seizure readiness were investigated in KM rats. Numerous sound expositions (90 dB) first led to the development of epileptiform seizures whereupon to a decrease in seizure readiness. The latter reduced as well after systematic long-term sound action which did not provoke seizure activity.

[Training of rats of the Wistar and Krushinskii-Molodkinaia lines in a radial maze].

The experiments were conducted on rats of Wistar (W) and Krushinsky--Molodkina (KM) (with audiogenic epilepsy) lines in 12-rays radial-symmetrical labyrinth. The trained rats of W line made less erroneous (repeated) visits to the labyrinth corridors than the rats of KM line. The corridors repeatedly visited by the rats of W line were more frequently situated near the unvisited corridors.

[Asymmetry of movement direction as a tactic in the feeding behavior of rats].

The sign and degree of spatial-motor asymmetry in rats were studied in conditions both of spontaneous or signalled choice in an U-maze and spontaneous multiple choice in a radial labyrinth. It was shown that during investigation of a new environment, motor asymmetry in rats was feebly expressed in all conditions of experiments, irrespective of the labyrinth scheme and experimental procedures. In the process of training, adequate behaviour was formed and in some conditions a distinctly expressed spatial asymmetry appeared, while in other cases it was absent.

[Effect of gamma-aminobutyric acid on audiogenic seizures and conditioned reflexes in the rat].

The influence of GABA injection (intraperiotoneal) on the sensitivity to sound and behaviour was studied on KM line rats, in which a strong sound produces epileptiform seizures, and on sound-resistant Wistar line rats. It was shown that in the KM line rats the previously elaborated motor alimentary conditioned reflex was impaired for several hours after the seizures. The two first GABA injections to the rats of both lines reduce the number of adequate reactions to a signal stimulus.

[Functional differentiation of different portions of the the rat neocortex].

The effect of uni- and bilateral ablation of rostral and caudal parts of neocortex on conditioned avoidance reflex was studied on naive and pretrained albino rats. Maximal impairment of the reflex was seen after bilateral ablation of the caudal region of neocortex, minimal one--after unilateral neocortex ablation. The rats without rostral cortex showed medium impairment.

[The effect of total extirpation of the neocortex on reflex activity in rats].

Using motor-feeding methods, studies have been made of the effect of complete extirpation of the neocortex on formation of new or recovery of pre-formed differentiation of localization of sources of light of identical intensity. It was shown that decortication results in significant and mostly irreversible disturbances of unconditioned reflex activity. In decorticated rats, only the simplest forms of conditioned motor reaction were noted which exhibit dominant features.