Biomedical subjects

B A Konnikov

Publications and source records attributed to B A Konnikov.

9 recordsLinked to original sources

PubMed1979

[Pathogenetic factors in experimental photogenic epilepsy].

Male albino rats were used in chronic experiments. The photogenic epilepsy syndrome was induced by local tetanus toxin injection into the lateral geniculate blody (LGB) which caused the formation of a pathologically enhanced excitation. The primary symptoms of photogenic epilepsy resulted from the pathologically enhanced specific sensory excitation in the LGB, and correlated with a significant increase of the evoked potential amplitude in the corresponding visual cortex field. The following progress of the neuropathological syndrome was connected with generalized disturbances of the rhythmic electrical activity of the brain, characterizing the state of increased epileptic sensibility. The experimental results demonstrate an important role of specific and nonspecific factors in the pathogenesis of experimental photogenic epilepsy.

Animals↗

PubMed1979

[Neuropathologic effects developing after administration of tetanus toxin to several rat brain structures].

Neuropathological syndromes following local tetanus toxin (TT) injection into different rat brain structures were studied. As demonstrated, there arose specific neuropathological signs dissimilar to those developing with different TT localization, i.e. as a rule the action of TT in the given brain parts was local. Experiments carried out confirmed the theory of the generator mechanisms of the neuropathological syndromes according to which specific manifestations of the corresponding syndrome were due to the localization of a generator of pathologically-enhanced excitation in definite brain structures.

Amygdala↗

PubMed1979

[Effect of diazepam on the epileptic activity of rats with experimental photogenic epilepsy].

Chronic experiments were conducted on rats. A study was made of the effect of diazepam (in a dose of 4 mg/kg of body weight) on the specific and nonspecific mechanisms of experimentally-induced photogenic epilepsy developing as a result of tetanus toxin injection into the lateral geniculate body (LGB) and formation in this nucleus of a pathologically enhanced excitation generator (PEEG). Diazepam in the mentioned dose had a relatively weak effect on the extent of pathological enhancement of the sensory visual signal in the LGB under conditions of PEEG formation aided detection of focal interictal discharges in this nucleus, and completely inhibited generalized epileptic activity in experimental animals in the course of one hour.

Animals↗

PubMed1979

[Problem of focal pathology in "genuine" epilepsy].

Chronic experiments on rats permitted one to obtain an experimental model of photogenic epilepsy. This was accomplished by creating in the external geniculate body (EGB) a generator of pathologically intensified excitation (GPIE) with the aid of tetanus toxin (TT). According to some clinical and electrographic characteristics this form of epilepsy may be alloted to the type of primarily generalized or "genuine" epilepsy. The existance of focal pathology in the respective EGB was detected only by special electrophysiological and pharmacological methods. The studied model demonstrates a necessity of using special methods of detecting brain focal pathology (GPIE) in order to determine the focus of neuron hyperactivity in those cases where the clinical picture is characterized by signs of the so-called genuine epilepsy. Experimental photogenic epilepsy attained by creating GPIE in the EGB with the aid of TT, is proposed as a model for studying the mechanism of epileptogenesis and testing the efficacy of anticonvulsive drugs.

Animals↗

PubMed1978

[Analysis of the neuronal activity of the lateral geniculate body in cats].

Activity of the lateral geniculate body neurons was studied in immobilized cats. Four parameters of impulse activity of every neuron were determined by computer analysis: T1, minimal, T2, average interspike intervals of the spontaneous activity, T3, latent period, and T4, duration of the first cluster of poststimulation activity. Classification of neuronal groups was made according to these parameters. This classification was used as a basis for the construction of a scheme of neuronal interaction in the lateral geniculate body.

Animals↗

PubMed1978

[Alteration of the functional organization of the lateral geniculate body after injection of tetanus toxin into it].

Changes in neuronal activity of the lateral geniculate body were studied in cat under conditions of the formation of a generator of pathologically enhanced excitation after local injection of tetanus toxin into this nucleus. To evaluate the changes, an analysis of interdischarge intervals histograms of spontaneous activity and poststimulation histograms were performed. A conclusion was made that as a result of the tetanus toxin injection the inhibitory mechanisms of many relay neurons became destructed, producing substantial changes in their discharge patterns.

Animals↗

PubMed1978

[Change in the evoked potentials in the visual centers of the rat brain following administration of tetanus toxin to the lateral geniculate body].

Changes in visual evoked potentials were studied under conditions of tetanus-toxin injection into the lateral geniculate body in rats. The main abnormality of the evoked potentials in the geniculate body was the function of a new phase of the primary response. At the same time a strong increase in the amplitude of the first negative component of the evoked response in the ipsilateral cortical visual field was observed. The results show the formation of disturbances in the relay function of the lateral geniculate body during the formation of a generator of pathologically enhanced excitation in this nucleus.

Animals↗

PubMed1976

[Photogenic epilepsy with localization of the generator of excitation in the lateral geniculate body (the phenomenon of a determining dispatch station)].

The photogenic seizure syndrome was produced in experiments on rats and cats by injection of purified tetanus toxin into the lateral geniculate body (LGB). The seizures followed light stimulus or arose spontaneously. At the intervals between the attacks every light stimulus provoked a specific photojerk. Disturbance of the inhibitory mechanisms by tetanus toxin proved to result in a rise in the LGB of a generator of pathologically enhanced excitation underlying the hyperactive determinative dispatch station causing the described photogenic epilepsy.

Animals↗

PubMed1976

[Experimental vestibulopathy produced as a result of formation of a generator of pathologically enhanced excitation in the vestibular nuclei (phenomenon of a determinative dispatch station)].

A possibility of formation of a generator of pathologically enhanced excitation in the system of the vestibular nuclei of the medulla oblongata by disturbance of their inhibitory processes (resulting in development of contralateral rotatory motions in animals) was shown. Experiments with electrical stimulation of the lateral vestibular nucleus and its coagulation showed the system of the vestibular neurons organizing the synchronous message by the vestibulo-spinal pathways to underlie the generator of the pathologically enhanced excitation. It was concluded that the generator of the pathologically enhanced excitation formed in the lateral vestibular nucleus as a result of disturbed inhibition underlied the hyperactive determinative dispatch station causing the syndrome of vestibulopathy

Animals↗