Interhemispheric asymmetry of the interaction of transcallosal and ascending flows of excitation in the visual cortex of the cat.

Interhemispheric interrelationships under conditions of the combination of transcallosal stimulation and monocular photostimulation with varied time intervals have been studied in acute experiments on 20 curarized cats with topographic recording of evoked potentials (EP) from homotypical areas of the visual cortex of both hemispheres. Interhemispheric asymmetry was established in the amplitude-temporal parameters of the visual and transcallosal EP, as well as of the resulting EP in the entire range of lags between the heteromodal stimuli. The asymmetry of the viral EP was greatest in magnitude, the asymmetry of the transcallosal EP was medium in magnitude, and the minimal magnitude was that of the visual EP with photostimulation the contralateral eye. With the combination of transcallosal and visual stimulation, dynamics were found of the magnitude of the resulting EP which reaches a maximum of the magnitude and has a monohemispheric directivity in conditions of the model experiments which correspond to the most natural conditions of the transcallosal interrelationship of the hemispheres. It is hypothesized that the transcallosal interrelationship is an important factor of the formation of the relative specialization of the cerebral hemispheres.

[Sexual dimorphism of the transcallosal connections in the neocortex of the right cerebral hemisphere in cats]. / O polovom dimorfizme transkallozal'nykh sviazei neokorteksa pravogo polushariia mozga koshek.

Analysis of the amplitude-temporal characteristics and of topographic features of hetero- and homotopic EPs led from projection and associative cortex, was performed in 60 male and 60 female immobilized cats. Homotopic EPs had a greater amplitude and time parameters and were found in a larger area of the projection cortex in female cats as compared with the male ones. The positive component and time parameters of the homotopic EPs were greater in females' associative cortex, whereas the negative component as well as the recording area in the parietal cortex were greater in males. The brain of female cats seems to be organized more bilaterally as compared with the brain in males.

[The possibilities of protection against local radiation injuries in ORL-oncologic patients]. / Vozmozhnosti protektsii mestnykh luchevykh povrezhdenii u LOR-onkologicheskikh bol'nykh.

Quercetin granules and gel were used to provide local protection in 64 ENT-cancer patients given radiotherapy. The highest effect was obtained as a result of a combined (per os and topical) application of quercetin throughout the entire radiotherapy course. The use of quercetin granules to treat acute radiation-induced epithelitis was effective and allowed radiotherapy to be completed.

[Sexual differences in the interhemispheric asymmetry of the transcallosal responses of the associative areas in the cat neocortex]. / Polovye razlichiia mezhpolusharnoi asimmetrii transkallozal'nykh otvetov assotsiativnykh oblastei neokorteksa koshek.

Sex differences of hemisphere asymmetry of homo- and heterotopic transcallosal responses in association cortex of 48 cats (24 male and 24 female) immobilized by tubocurarine have been studied by means of topographic EPs recordings in both hemispheres. In males left hemisphere dominates by the amplitude of homotopic and positive wave of heterotopic EPs and right hemisphere dominates by the amplitude of negative wave of heterotopic sensorimotor cortex EPs. The individual asymmetry of EPs has been observed in sensomotor cortex of females and in parietal cortex of animals of both sex. The interhemispheric asymmetry is expressed distinctly in females than in males. It is concluded that sex dimorphism is present in functional organization of associative system of (callosal and intracortical) connections in cat's neocortex projection and association areas which means its more expressed hemisphere lateralization in males with more expressed interhemispheric asymmetry of functional transcallosal connections in females.

[Interhemispheric asymmetry in the interaction of the transcallosal and ascending flows of excitation in the cat visual cortex]. / Mezhpolusharnaia asimmetriia vzaimodeistviia transkalloznal'nogo i voskhodiashchego potokov vozbuzhdeniia v zritel'noi kore koshki.

Interhemispheric interrelationships in different temporal combinations of transcallosal stimulation and monocular photostimulation, were studied in 20 immobilized cats by means of topographic recordings of homotopic EPs in visual cortex. An interhemispheric asymmetry of the amplitude and time parameters of the EPs was regularly found. The asymmetry of ipsilateral visual EPs was the highest, the asymmetry of transcallosal EP was middle and the asymmetry of visual EP was minimal under the condition of contralateral eye stimulation. The transcallosal interaction is assumed to be an important factor of formation of the specialization in the brain hemispheres.

[Use of contrykal in the prevention of recurrences and metastases of cancer of the upper respiratory tract]. / Primenenie kontrikala dlia profilaktiki retsidivov i metastazov raka verkhnikh dykhatelei putei.

The analysis of data on 96 patients with cancer of the upper respiratory tract showed contrical to improve results of radiotherapy in terms of frequency of recurrence and dissemination. The regimen of administration of contrical is given.

[The interaction of transcallosal and ascending excitation flows in the visual cortex of the cat]. / Vzaimodeistvie transkallozal'nogo i voskhodiashchego potokov vozbuzhdeniia v zritel'noi kore koshki.

The conformity of interhemispheric interaction in visual cortex were studied by means of EPs recordings in 10 immobilized cats under conditions of different time combinations of transcallosal and monocular stimulation of contra- or ipsilateral eyes. Phasic changes of the depression effects under transcallosal conditioning of facilitating effects under conditions of the model interaction similar to natural transcallosal interrelations, occurred in photostimulation of contralateral eye. Whereas the ipsilateral eye stimulation only depressed the time interaction under these conditions. The findings are discussed in terms of morphological, neurophysiological and other research data on transcallosal interhemispheric relations in the cat visual cortex. The 15-25-ms interval between heteromodal stimuli under these research conditions seem to correspond to natural conditions of transcallosal interhemispheric relations which, in binocular vision, are dynamically and topographically organized processes of excitation and inhibition.

[Sex differences in the interhemispheric asymmetry of the transcallosal responses of the visual area in the cat neocortex]. / Polovye razlichiia mezhpolusharnoi asimmetrii transkallozal'nykh otvetov zritel'noi oblasti neokorteksa koshki.

Interhemisphere of homo- and heterotopic transcallosal responses were studied in visual cortex of 12 male and 12 female immobilized cats. The right hemisphere dominated by the amplitude of homo- and heterotopic transcallosal responses in males, whereas in females an individual asymmetry of EPs was observed. The interhemisphere asymmetry was shown to be higher in males than in females. These findings are discussed in terms of sex differences of the morphological asymmetry of visual area and of the interhemisphere asymmetry of visual functions.

Interhemispheric asymmetry of homotopic transcallosal responses of the auditory cortex in the cat.

In acute experiments on 29 d-tubocurarine immobilized cats, with topographical pick-up of potentials from 150-170 symmetrical points of the auditory cortex, the interhemispheric asymmetry of homotopic transcallosal responses were studied. It was established that in the majority of the animals the potentials in the right hemisphere had a greater amplitude and shorter latent periods as compared with the responses of the left hemisphere. A dependence of the properties of the interhemispheric asymmetry on the sex of the animal was noted. In females the asymmetry was characterized by a right hemispheric tendency and by a greater magnitude as compared with males. The maximal magnitude of the asymmetry was detected in the group of pregnant females. The hypothesis is proposed to the effect that the established polarity of transcallosal influenced in the auditory cortex is associated with the dominance of the right hemisphere in the organization of spatial audition.

Functional organization of the callosal connections of the cat auditory cortex.

In acute experiments on immobilized cats, using a method of topographical recording of homotopic and heterotopic transcallosal responses, the functional organization of the callosal connections of the auditory cortex was investigated. It was established that the homotopic potentials of the primary projection field (AI) have the greatest amplitude, minimal temporal parameters, and the maximal stability of these characteristics as compared with the associative fields of the auditory cortex (AII, AIV, Ep). The heterotropic transcallosal responses in field AI appeared during stimulation of the analogous field, while in field Ep, they were recorded both during stimulation of the analogous field, and of fields AI and AII of the opposite hemisphere. It is hypothesized that the structure of the transcallosal connections of the primary projection field s of the auditory cortex is characterizised by homotopy, whereas in the associative auditory fields the role of heterotopic transcallosal interactions increases. It is possible that such a structure of the transcallosal connections assures a significant role for interhemispheric interactins in the mechanisms of spatial audition.

[Patterns in the formation of transcallosal connections in the projection and associative areas of the cat cortex]. / Nekotorye zakonomernosti formirovaniia transkallozal'nykh sviazei proektsionnykh i assotsiativnykh oblastei kory koshki.

In acute experiments on immobilized 2-15-day old and adult cats, regularities of the ontogenetic callosal connexions maturation were studied in projection (somatosensory, auditory visual) and associative (sensorimotor, parietal) areas of the cortex by means of topographic recording of the transcallosal responses in symmetrical points of the opposite hemisphere. The data obtained suggest a heterochrony and different rate of the functional callosal connexions maturation in projection and associative areas of the cortex.

[Structure of the functional transcallosal connections of the projection and association regions of the cat neocortex]. / O strukture funktsional'nykh transkallozal'nykh sviazei proektsionnykh i assotsiativnykh oblastei neokorteksa koshki.

Homotopic responses of cortical projection areas were found to have smaller amplitude-temporal parameters and a greater stability as compared to the associative fields responses. These responses occur in local portions of the projection areas and the space of their recording enhances in the associative fields. Heterotopic responses in the projection fields occur in stimulation of a relatively lesser space of the symmetrical cortex, and the relative space of their recording is also smaller as compared to associative areas. The revealed regularities seem to reflect augmentation of interhemisphere interaction and complication of the structure of transcallosal connections of cortical associative areas. The structure of functional transcallosal connections of the projection areas seem to correspond to the principle of homotopy while the role of heterotopic transcallosal interactions enhances in the associative areas of the cortex.

[Interhemispheric asymmetry of homotopic transcallosal responses of the auditory cortex in the cat]. / Mezhpolusharnaia asimmetriia gomotopicheskikh transkallozal'nykh otvetov slukhovoi kory koshki.

In majority of 29 immobilized cats under study, the potentials in the right hemisphere had a greater amplitude and shorter latencies than in the left hemisphere when comparing 150-170 symmetrical points in the auditory cortex. The interhemispheric asymmetry depended on the sex of the animals: it was more obvious in females. The maximal asymmetry was observed in pregnant females. The described polarity of transcallosal influences in the auditory cortex seems to be associated with the predominant role of the right hemisphere in organization of spatial hearing.

[Functional organization of the callosal connections in the auditory cortex of the cat]. / O funktsional'moi organizatsii kallozal'nykh sviazei slukhovoi kory koshki.

Homotopic transcallosal potentials of the cat auditory cortex primary projection area (AI) had the greatest amplitude, the minimal temporal parameters and the maximal stability of characteristics as compared with the responses of the auditory cortex associative fields AII, AIV, Ep. Heterotopic transcallosal responses in the AI field occurred in stimulation of the field under the same name whereas in the Ep field the responses occurred both in stimulation of the same and the AI and AII fields of the opposite hemisphere. The structure of transcallosal connections of the auditory cortex primary projection field seems to be characterized by homotopy whereas in associative fields the role of heterotopic transcallosal interactions seems to increase. Such a structure of transcallosal connections seems to maintain the important role of interhemispheric interaction in mechanisms of spatial hearing.

[Ontogenesis of the asymmetry of transcallosal responses in the cat parietal cortex]. / Ontogenez asimmetrii transkallozal'nykh otvetov v temennoi kore koshki.

In acute experiments on 2-24 days old immobilized kittens and adult cats, studies have been made on the development of functional interhemispheric asymmetry of homotopical transcallosal responses in the parietal cortex. It was found that the number of animals with evident asymmetry increases with age. Alongside, with respect to such characters as asymmetry coefficient, mean amplitude of components of transcallosal components and the ratio of zones of direct and inverse domination, the increase in functional interhemispheric asymmetry was observed during the second week of postnatal life of kittens, which was accompanied by the inversion of its sign; in adult cats, the decrease in the asymmetry up to its complete absence was found. The data obtained are discussed with respect to peculiarities of the development and functional properties of the associative parietal cortex in cats.

[Local hyperthermia and hyperglycemia in ORL oncology]. / Lokal'naia gipertermiia i giperglikemiia v LOR-onklologii.

Two-year experience of radiotherapy combined with local hyperthermia, hyperglycemia and chemotherapeutic drugs in patients with tumors of the upper respiratory tract showed advantages of this method. The results were compared with those of the control group of patients on radiotherapy only. Three therapeutic schemes were employed. Hyperthermia was performed in 2 temperature regimens. Of chemotherapeutic drugs platidiam, methotrexate, 5-FU and vinblastine were used.

[Features of the homotopical and transcallosal potentials of the somatosensory and parietal cortex in the cat]. / Osobennosti gomotopicheskikh transkallozal'nykh potentsialov somatosensornoi i temennoi kory koshki.

Multiple recording of EPs from analogous areas of cerebral hemispheres was performed with symmetrical relocation of stimulating and recording electrodes. The right hemisphere was shown to prevail by the amplitude of positive component of the somatosensory area EPs whereas an individual asymmetry of this phase of EPs was observed in the parietal cortex. The homotopic transcallosal responses of the somatosensory cortex seem to reflect local processes induced, mainly, by callosal effects whereas the parietal area response seems to be an integrative index of processes stemming from the local convergence of effects spreading over and intracortical projections.

[Comparative characteristics of the interhemispheric asymmetry of transcallosal responses of the projection and association areas of the cortex]. / Sravnitel'naia kharakteristika mezhpolusharnoi asimmetrii transkallozal'nykh otvetov proektsionnykh i assotsiativnykh oblastei kory.

Homo- and heterotopic transcallosal responses from projective and associative cortical areas were studied in 57 immobilized cats. Homotopic potentials revealed a functional interhemisphere asymmetry of their amplitudes. The latters were higher in visual and somatosensory cortex of the right hemisphere, whereas in sensomotor cortex the amplitude of both components of the homotopic EPs was higher in the left hemisphere. Heterotopic transcallosal responses were more symmetrical. The projective and associative areas differed in that the associative cortex revealed a more symmetrical distribution of the heterotopic EPs. The above features of the EPs seem to stem from the asymmetrisizing effect of homotopic callosal pathways and from symmetrisizing effect of intrahemisphere associative projections.

[Asymmetry of the interaction of transcallosal and thalamocortical flows in the sensorimotor cortex]. / Asimmetriia vzaimodeistviia transkallozal'nogo i talamokortikal'nogo potokov v sensomotornoi kore.

The interaction between transcallosal potentials and responses to stimulation of the contralateral sciatic nerve was studied in symmetrical areas of the cat sensorimotor cortex. The interacting responses and the resulting EPs were characterized by a functional interhemisphere asymmetry of an individual form. In transcallosal conditioning with 10-ms interstimuli intervals, the positive components of the EPs prevailed in the left hemisphere. The characteristics of the interhemisphere asymmetry were determined by the animal sex: the spatial--temporal interaction of the flows had different features in different hemispheres, was characterized by unequal markedness of asymmetry of the EP components as well as by opposite character of the asymmetry in animals of different sex. The characteristics of the EP interhemisphere asymmetry seem to be determined by an interaction of dominant foci occurring under these conditions in each of the hemispheres.