[Interhemispheric asymmetry in unilateral brain damage]. / Mezhpolusharnaia asimmetriia pri odnostoronnem povrezhdenii mozga.

Hemispheric functional changes and interhemispheric interactions were studied by the bioelectrical parameters of asymmetry in the unilateral brain damage. The magnitude of interhemispheric asymmetry was found to depend upon the site of injury, achieving its maximum at the right-sided localization of a pathological process and slightly changing at the left hemispheric tumor site. The application of functional tests was accompanied by profound increases in asymmetry as compared with the baseline. The findings may be an informative predictive tests for the course of an inflammatory process.

[Effects of thymosin and B-activin on lateralization of sensomotor control in rats]. / Vliianie timozina i B-aktivina na lateralizatsiiu sensomotornogo kontrolia u krys.

Characteristics of regulatory effects of B-activin and thymosin (fraction 5) on the activity of right and left hemispheres were studied in rats. The results obtained were estimated basing on the analysis of the following components of food-searching behavior: lateralization of a single conditioned-reflex response; preference of right or left paw; spontaneous rotations. Opposite effects of thymosin and B-activin were found at different stages of the food-searching behavior. Thymosin activated structures of the left hemisphere. A conclusion is made on the possibility of application of these drugs for targeted influencing the balance of intra-hemispheric activity in the brain functional pathology and during the compensatory process.

[Effects of peptide factors from right and left brain hemispheres of rats on amplitude-time characteristics of projective and interhemispheric evoked responses]. / Vliianie peptidnykh faktorov pravogo i levogo polusharii krys na amplitudno-vremennye kharakteristiki proektsionnykh i mezhpolusharnykh vyzvannykh otvetov.

Peptide extracts of the right and left hemispheres were applied to the projective (somatosensory and visual) and temporal associative regions of the left brain hemisphere in cats. In the zones of peptide application, evoked potentials (EP) in response to singular and coupled somatic, visual and transcallosal stimuli were registered. The data obtained showed that right and left peptide extracts had different effects on evoked potentials of the left hemisphere. Thus ipsilateral extract increased the amplitude of projective EP, decreased duration of their cycles and amplitude of transcallosal responses. Contralateral extract, on the contrary, activated interhemispheric inputs to brain cortex, suppressed thalamic inputs and increased multimodal properties of neurons. A differential approach to the problem of specific correction of pathological states of the right and left brain hemispheres is required. Right and left peptide extracts may be used in normalization of interhemispheric activity balance in compensatory-recovering processes.

[Interhemispheric interactions following unilateral injury to the cerebral cortex]. / Mezhpolusharnye vzaimodeistviia v usloviiakh odnostoronnego povrezhdeniia kory golovnogo mozga.

The object of the study was to examine the time-course of interhemispheral relations under unilateral injury to the somatic or optical cortical pathways. Special attention was paid to the characteristics of the function of the associative parietal cortex and areas that are symmetrical to the location of injury. Transcallosal stimulation allows changing the functional condition of the studied zones. This can be considered as a possible factor inducing development of compensatory-rehabilitative processes in the central nervous system.