[Substantiation of possibility of use GABA-receptor's chloride channel blockers for modelling of the temporal epilepsy].

In work the review of some clinik-morphological and pharmacological researches devoted to a temporal epilepsy and its experimental models is resulted. On the basis of the analysis of existing problems in working out antiepileptic drugs and in studying of mechanisms epilepsy necessity of development of new chronic experimental models of a temporal epilepsy is proved. The basic criteria of experimental model of a temporal epilepsy are generalised. It is shown that parametres of acute toxicity and the remote consequences of an intoxication convulsive agents from group GABA-receptor's chloride channel blockers correspond to the basic criteria a post-epistatus of model of a temporal epilepsy. The conclusion is presented on use possibility GABA-receptor's chloride channel blockers in quality agents for modelling of a temporal epilepsy.

[Ultrastructure of optic nerve fibers in rabbits after intravitreal infusion of perfluoroorganic compounds].

Ultrastructure of optic nerve myelinated fibers after intravitreal infusion of perfluorooctylbromide (PFOB) and perfluorodecaline (PFD) for 30 days was studied in rabbits (n = 14). After inraocular administration of PFOB, the ultrastructural changes of optic nerve fibers were mainly reactive in nature. Mitochondrial swelling and partial destruction of cristae were detected in the axons. After PFD infusion, the changes were observed that were not only reactive, but highly degenerative, including destruction of organelles and myelin sheath and axon cytoskeleton disintegration. Thus, the changes associated with PFOB were less pronounced than those found after PFD application. Therefore, PFOB is more promising for the use as an ophthalmologic implant.

[Structural basis for the regulation of the neuronal sensitivity]. / Strukturnye osnovy reguliatsii chuvstvitel'nosti neironov.

Using light and electron microscopy structural bases for intracellular, extracellular and integrative regulation of synaptic efficiency and neuron sensitivity were established in rat sensomotor cortex. Intracellular regulation is realized basically through modulation of postsynaptic components of the synapse, while extracellular one is provided by synaptic endings of "recurrent" axons on GABA-ergic relay and interneurons. Integrative regulation is realized by means of concentration of similar axonal terminals in restricted cortical area and arrangement of "neuromediatory" pool.

[Audiogenic epilepsy: a morphofunctional analysis]. / Audiogennaia épilepsiia: morfofunktsional'nyi analiz.

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 intraperitoneal injection of inhibitory transmitter--GABA and taurine (separately or in mixture) blocked the convulsive seizures. The functional influence by KCl-induced spreading depression in the cerebral cortex bilaterally impairs the inhibitory processes, but not the changes the form of epileptiform seizure. In neurophysiological experiments using microelectrophoresis technique it was shown that taurine as inhibitory agent is more effective when applied to dendritic layers II-III; GABA is more effective if it is applied on soma of cortical pyramidal cells. Using the electron microscopic methods, the following changes were observed during the clonic seizure: axo-dendritic and axo-spine synapses in rat auditory cortex were activated. After the habituation to the epileptogenic stimulus, some features evidencing the decrease of activity were observed in ultrastructure of synapses in layers II-III. In 2 days after that the majority of ultrastructural shifts were normalized. Role of calcium ions in generation of epileptic seizures and their depression as main factor of antiepileptic mechanisms is discussed.

[The identification of synapses in the cerebral cortex]. / Identifikatsiia sinapsov kory polusharii bol'shogo mozga.

The correlation between structure and function of synapses is discussed. Identification of 4 types of synapses has been made based on the authors' own evidence provided for the rat sensomotor cortex with the light and electron microscopy: 1--asymmetrical (excitatory, glutamate- or aspartatergic); 2--symmetrical (inhibitory, GABAergic); 3--symmetrical (disinhibitory, GABAergic); 4--symmetrical or asymmetrical (modulatory, monoaminergic). The ultrastructure of some synaptic categories may be equalized with their function. It makes possible to identify not only excitatory and inhibitory synapses, as considered before, but also disinhibitory and modulatory ones.

[A morphofunctional analysis of the participation of the cerebral cortex in the habituation of Krushinskii-Molodkina strain rats to an epileptogenic stimulus]. / Morfofunktsional'nyi analiz uchastiia kory golovnogo mozga v privykanii krys linii Krushinskogo--Molodkinoi k épileptogennomu stimulu.

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. After cessation of the cortical depression, during which the rats were given systematic sound exposition, sharp LCR lowering takes place. If the habituation has been already formed, then the subsequent switching-off of the cortex does not lead to LCR growth. Ultrastructural characteristics of asymmetric axo-dendritic and axo-spine synapses in the auditory cerebral cortex of KM line rats in the moment of convulsive seizure testifies to their active functioning, while against the background of short-term habituation to epileptogenic stimulus signs of lowering of the efficiency of synaptic transmission are revealed in these synapses. The obtained results allow to suggest that in the rats of KM line the neocortex takes part in antiepileptic defensive reactions, in LCR regulation in connection with formation of the habituation to systematic action of epileptogenic stimulus.

[Structural bases of the plasticity of the nervous system]. / Strukturnye osnovy plastichnosti nervnoi sistemy.

The present state of morphological study of variability in the nervous elements under conditions of adaptive change under the influence of afferent effects, age changes during different periods of ontogenesis, under conditions of de- and regeneration of synapses have been considered. A question on correlation between structure and the function of synapses during the change has been analysed. The tasks of subsequent study of this problem have been outlined.

[Structural organization of preganglionic sympathetic neurons]. / Strukturnaia organizatsiia preganglionarnykh simpaticheskikh neironov.

Distribution of marked preganglionic neurons over spinal nuclei and segments was studied in cats with the aid of microinjections of the horse-radish peroxidase into the cranial cervical ganglion. The major part of these neurons were revealed in the main part of the intermediolateral nucleus. A somewhat lesser number of the cells were found in the funicular part of the nucleus. In the T1 segment they constituted about 90% of cells containing the peroxidase. Other neurons were localized in the paraependymal and intercalative nuclei. In longitudinal sections of the spinal cord, the preganglionic sympathetic neurons projecting their axons into the cranial cervical ganglion, form a rostro-caudal chain made of small ensembles of cells.

[Ultrastructure of the synapses of the initial axonal segment of the pyramidal neuron]. / Ul'trastruktura sinapsov na nachal'nom segmente aksona piramidnogo neirona.

Ultrastructure of the proximal part of the axon in the neurons, identified according to a number of morphological signs as pyramidal, has been studied in the layer III of the cat cerebral hemisphere sensomotor cortex. In sections, tangential to the cortical surface, in the initial axonal segment, a submembranous osmophilic layer and fasciculi of microtubules are revealed. On the initial segment spines are found, they contain cysterns resembling by their structure the spine system of the dendritic spines. Axonal terminals revealed along the axonal distribution are in contact both with the axonal trunk and with the spines. Regarding the initial segment, they are presynaptic, contain oval synaptic vesicles and form symmetric axo-axonal synapses only. In transversal sections axonal terminals are detected, arranging on the surface of the initial segment mostly as single ones, in longitudinal sections they are seen as clusters. Analysing the author's data and those from the literature, a conclusion is made that in intact animals the synaptic contacts at the initial segment of the axon are the only form of axo-axonal synapses in the neocortex.

[Structural characteristics of the mediodorsal nucleus of the cat thalamus]. / Strukturnaia kharakteristika mediodorsal'nogo iadra talamusa koshki.

By means of the light and electron microscopy, construction and architectonics of neurons in the cat thalamus medio-dorsal nucleus are described. Differences in the neuronal body dimentions, their form, number of deferent dendrites and character of axonal branching made it possible to define 3 types of neurons. Applying the method based on retrograde axonal transport of exogenous horse-radish peroxidase, it was demonstrated that neurons of type II, contrary to the existing opinion, send their axons into the prefrontal cortex and, hence, are associative-projective. Ultrastructural difference of axonal terminals, differences in the form and size of synaptic vesicles made it possible to reveal 5 types of presynapses.

[Experience with the use of horseradish peroxidase for light and electron microscope studies of interneuronal connections]. / Opyt ispol'zovaniia peroksidazy khrena klia izucheniia mezhneironnykh sviazei v svetovoi i élektronnoi mikroskopii

By the method based on a retrograde axonal transport of exogenous horseradish peroxidase (HRP), the origins of afferentation of the motor cortex of adult cats, kittens and albino rats were studied. HRP-positive neurons were found by light and electron microscopy in the somatosensory cortex (C1) of the ipsilateral hemisphere and in the portions of the cortex of the contralateral hemisphere which were symmetrical to the site of injection of HRP. The disposition of neurons, marked by HRP, in the Vth layer of the motor cortex suggest that these neurons may send their axons into the bundles of comissural fibres going to the motor cortex of the opposite hemisphere. This method considerably expands possibilities of revealing the origins of afferentation of the investigated portion of the nervous system and allows more complete and reliable investigation of interneuronal connections.