[Evoked potentials: their spatial physiological characteristics and the problem of their functional assessment]. / Vyzvannye otvety: prostranstvenno-fiziologischeskie kharakteristiki i problema ikh funktsional'noi otsenki.

Basic data about physiological evoked responses properties of the brain structures highest level (telencephalon) are presented. Contemporary ideas concerned to mechanisms of these responses are summed up. Data about their distribution in telencephalic structures and morphological basis of the distribution are adduced. The evoked responses especialities of telencephalic structures in awake animals in chronic experiments are revealed. The functional significance of processes that form this bioelectrical reaction is observed. Special attention is paid to earlier (to 100 ms) components. The possibility to use the evoked responses as the functional instruments of investigations of the brain is discussed.

[Single auditory evoked responses of the temporal and associative regions of the cerebral cortex in conscious cats]. / Odinochnye slukhovye vyzvannye otvety visochnoi i assotsiativnoi oblastei kory golovnogo mozga bodrstvuiushchikh koshek.

In awake cats single realizations of acoustic evoked responses (AER) from temporal, parietal and frontal cortex were registered and compared with averaged responses obtained by means of optic superposition of the same realizations. It is shown that the composition of these different realizations considerably varies due to inconstancy of manifestation of each component. The fact that the preceding component falls out does not exclude manifestation of the following one, which proves the functional independence of the mechanisms producing each component. The simultaneous registration of single realizations of AERs of different cortical areas shows that the reactions of frontal and parietal areas are independent of AERs of the temporal cortex.

[Disruptions of instrumental alimentary conditioned reflexes after removal of the frontal and parietal associative cortex in the cat]. / Narusheniia instrumental'nykh pishchevykh uslovnykh refleksov posle udaleniia lobnoi i temennoi assotsiativnoi kory u koshek.

The influence of the extirpation of the frontal and parietal association cortical areas on the elaborated stereotype of instrumental alimentary conditioned reflexes was studied in cats. Errors in reinforcement choice, disturbance of inhibitory conditioned reflexes and appearance of intersignal reactions were observed. The disturbances were more pronounced after the extirpation of the parietal cortex. The data obtained are interpreted as a reflection of the deficit of the inhibitory control of motor program realization formed to a lesser or greater extent after the removal of the frontal as well as parietal areas.

Comparison of electrophysiological characteristics of the retino-collicular and retino-thalamo-cortical parts of the visual system of the monkey Macaca rhesus.

In chronic experiments and in acute experiments with nembutal narcosis, photic-driven evoked potentials (EP's) were studied in the superior colliculi (SC) and in the cerebral visual cortex (VC, Area 17). In chronic experiments it was found that the EP's in SC and VC have similar latency periods (LP's) equal, respectively, to 12 +/- 1 and 12 +/- 2 msec (p less than 0.05); refractory periods during application of paired flashes are 50 and 70 msec for SC and VC, respectively. The critical frequencies for imitation of rhythmic flashes in both visual centers also coincide, reaching 20-25/sec. EP's with short LP's, equal to the LP's of evoked potentials in the VC, were found also in the frontal and motor cortex and the hippocampus. The problem regarding telencephalization of the retino-tectal channel of the visual system is discussed.

[Efferent projections of the caudate nucleus to the cerebral cortex in monkeys]. / Efferentnye proektsii khvostatogo iadra na koru golovnogo mozga obez'ian

The efferent direct connections of the head and tail of the caudate nucleus with the cortex of the ipsilateral hemisphere were studied in adult Macaca mulatta. Degeneration of endings in the frontal, precentral and postcentral convolutions was found ipsilaterally in sections of the brain impregnanted after Wiitanen after destruction of the caudate nucleus. The course of solitary fibres to sites of localization of degenerating endings was followed. as compared with the cat in which caudate-cortical projections had been established earlier, cortical zones with degenerated endings were located more discretely in Macaca mulatta.

[Comparison of the electrophysiologic characteristics of retino-collicular and retino-thalamo-cortical divisions of the visual system of Macaca rhesus monkeys]. / Sopostavlenie élektrofiziologicheskikh kharakteristik retino-kollikuliarnogo i retino-talamo-kortikal'nogo otdelov zritel'noi sistemy u obez'ian Macaca rhesus

In chronic and acute experiments under nembutal anaesthesia, studies have been made on the evoked potentials (EP) elicited by light stimuli in the colliculus superior and in the visual cortex (area 17). It was found that under chronic experiments the EP in the colliculus superior and visual cortex exhibit close (12 +/- 1 and 12 +/- 2 msec. respectively) latent periods; refractory periods determined by paired flashes for both of the parts are equal to 50--70 msec. Critical frequency for EP reproduction of rhythmic flashes in both visual centers is also identical, reaching 20--25/sec. EP with a short latent period equal to that of the EP in the visual cortex were also detected in the frontal and motor cortex, as well as in the hippocamp. The problem of telencephalization of the retinotectal path of the visual system is discussed.