Influence of nembutal on the impulse activity of cells of embryonal nervous tissue transplanted into the rat brain.

The average frequency of the impulse activity of neurons of an allograft of embryonal cortex, in the brain of adult Wistar rats, under nembutal anesthesia was four times lower than in nonanesthetized animals; at the same time the variability of the activity of the cells of the graft, with respect to the frequency and pattern of impulse activity, decreased. As compared with the unanesthetized animals, half as many cells of the graft reacted to tactile stimulation of the contralateral hind extremity; the neuronal reactions to the stimulation of somatic receptors of the ipsilateral side of the body completely disappeared.

[Situational conditioned reflexes in intact and callosotomized dogs when the location of conditioned and unconditioned stimuli is changed]. / Situatsionnye uslovnye refleksy u intaktnykh i kallozotomirovannykh sobak pri izmenenii prostranstvennogo raspolozheniia uslovnykh i bezuslovnykh razdrazhiaelei.

Positive and inhibitory conditioned reflexes were elaborated to signals, presented at the same display. Discrimination between spatially joined signals turned out to be a difficult task for intact and, in particular, for callosectomized dogs, who showed disturbances of the higher nervous activity. The analysis of spatially joined signals is possible for animals, previously trained in experiments with spatial separation of signals. With changed position of conditioned and unconditioned stimuli the callosectomized animals develop an inertness of nervous processes, manifested in a prolonged afteraction of the previously formed activity in an increased number of inadequate reactions, and impairment of differentiations.

[Interaction between the left and right sided systems of secretory conditioned reflexes following section of commissural pathways of the dog brain]. / Vzaimodeistvie levo- i pravostoronnikh sistem sekretornykh uslovnykh refleksov posle pererezki kommissural'nykh putei mozga u sobak

By means of stereotype rhythmic presentation of positive and inhibitory stimuli, systems of unilateral reflexes were elaborated in dogs with symmetrical parts of the tongue brought out by Abuladze method. After section of the corpus callosum as well as of the corpus callosum and the hippocampal and fornix commissures, differentiation of stimuli in the left- and right-side reflexes systems is impeded, and the systemic nervous process is also disturbed. The significance of the interhemispheric interaction has been revealed for the formation of unilateral dominant excitation sites necessary for achievment of a distinct unilateral reaction. The longer retention of unilaterally organized sites of latent excitation after callosotomy testifies to the role of interhemispheric interaction in the timely erasing of traces of unilateral stimuli.

[Electrical activity of the limbic structures of the dog brain during simultaneous stimulation of the cingulate gyrus and hypothalamus]. / Elektricheskaia aktivnost' limbicheskikh struktur mozga sobaki pri odnovremennom razdrazhenii poiasnoi izviliny i gipotalamusa

Simultaneous electrical stimulation of the anterior part of the cingulate gyrus and the anterior-lateral part of the hypothalamus in the dog brought about EEG synchronization in the limbic system structures and increased correlation coefficients between them. The animal's behaviour exhibited positive emotionally reactions (licking, sniffing, wagging the tail), attended with slowing of the heart rate. The indicated changes directly depend on the degree of emotional stress (the changes are more pronounced in hungry than in sated animals). Simultaneous stimulation of the anterior part of the cingulate gyrus and the anterior-lateral part of the hypothalamus apparently activates a system which reduces the level of emotional stress.

[Formation of systems of unilateral conditioned reflexes following section of the rostral portion of the corpus callosum]. / Formirovanie sistem odnostoronnykh uslovnykh refleksov posle pererezki rostral'nogo otdela mozolistogo tela

Unilateral conditioned reflexes and two-link reflex systems with regular rhythmic alternation of positive and inhibitory reflexes were elaborated by Abuladze method in four dogs with a preliminarily dissected rostral part of the callosal body. Whereas the rate of formation of simple unilateral positive reflexes did not differ from that of reflex formation in intact animals, the formation of two-link unilateral systems proved to be disturbed. In spite of considerable stabilization of positive and inhibitory reflexes, ultraparadoxical relations were revealed when the same stimuli were applied in the system which testified to the disturbance of the after-effect dynamics. It has been assumed that rostral parts of the callosal body take part in the fixation of traces as the first component of the memory mechanism.

[The effect of nembutal on the cellular pulse trains of embryonic nerve tissue transplanted into the brain of the rat]. / Vliianie nembutala na impul'satsiiu kletok émbrional'noi nervnoi tkani, transplantirovannoi v mozg krysy.

Under nembutal anaesthesia the mean frequency of single unit discharges recorded from allografts of the rat brain was four times lower than the one measured in unanaesthetized animals. A diminished variability was revealed of firing rates and discharge patterns of the cells within grafts in anaesthetized rat brain. In comparison to unanaesthetized animals the number of graft units reacting to a tactile stimulation of contralateral hindlimb of the operated animals was twice lower. Nembutal anaesthesia provoked a full blockade of reactions to the tactile stimuli applied to the ipsilateral side of the animal body.

[Electroencephalographic correlates of a pathologic inert motor reaction in dogs]. / Elektroéntsefalograficheskie korreliaty patologicheskoi zastoinoi dvigatel'noi reaktsii u sobak

Changes in EEG were examined during setting in of a pathological inert motor reaction in dogs with parts of the tongue brought out and electrodes implanted in the motor cortical area and limbic structures. The reaction was formed when combining stimulation by a salt solution of the part of the tongue with electrical stimulation of the paw. The inert motor reaction is characterized by enhanced synchronization (theta-rhythm) in the hippocampus and increased amplitude of the beta-rhythm in the motor cortical areas. A frequency-amplitude analysis of the summary EEG has shown that the highest correlation was established at the beginning of elaboration of the inert motor reaction only between a small number of limbic structures (the hippocampus, the hypothalamus and the cingulate gyrus), then between all the examined structures of the brain; when the inert reaction became elaborated the number of structures with a high correlation coefficient diminished again and was reduced to the hippocampus, the hypothalamus and the cortical motor area.

[Participation of the hippocampus in regulating a pathologic inactive motor reaction in dogs]. / Uchastie gippokampa v reguliatsii patologicheskoi zastoinoi dvigatel'noi reaktsii u sobak

A local pathological inert motor reaction, involving a forced flexion of the forepaw, was formed after simultaneous stimulation with NaCl solution of a part of the tongue brought out to the cheek and electrical stimulation of the forepaw. The reaction decreased (by 70 to 80%) after electrical stimulation of the dorsal hippocampus (beyond CA3). At the same time the animal's emotional stress diminished, as evidenced by the reduced heart rate and a reduced theta-rhythm in the hippocampus.

[Features of the morphofunctional organization of the embryonal nerve tissue of a transplant into the brain of the adult rat]. / Osobennosti morfofunktsional'noi organizatsii émbrional'noi nervnoi tkani transplantata v mozgu vzroslykh krys.

Foetal CNS tissue was implanted into different sites of mature rat brain. Analysis of morpho--functional organization and unit activity of the grafts was made 2-5 months after the implantation. Correlations among morphological and functional characteristics of the grafts and sites of the implantation are discussed. Morphofunctional peculiarities of the grafts seem to be due to heterogeneous influences of the host brain.

[A neuromorphological analysis of the motor area of the cerebral cortex in rat pups subjected to prenatal exposure to normal and pathological blood serum]. / Neiromorfologicheskii analiz motornoi oblasti kory mozga krysiat, podvergshikhsia prenatal'nomu vozdeistviiu normal'noi i patologicheskoi syvorotki krovi.

Morphological quantitative and qualitative analysis of the pyramidal neurones in the motor cortex of rat puppies after administration of the blood serum from human donors with central motor disorders reveals the dependence of the quality and quantity of neurones from the effect of corresponding blood sera. Pathologic blood serum decreases the number and induces degradation of dendritic organization of the pyramidal neurones. The effect of the blood sera on quantitative and qualitative properties of the pyramidal neurones in rat puppies depends on the age of donor infants with central motor disorders. Blood serum from newborn babies with motor dysfunctions significantly decreases the number of labeled pyramidal neurones and results in degradation of dendritic organization, whereas sera from 11-13-year infants only insignificantly affect these characteristics.