[Structurally-functional status of heart of the tuberculosis in teenagers].

The patients divided into two groups: in 12 patients (13-16 years old) including into I group observed decrease of internal size of the left ventricle, in 8 persons (17-18 year old) revealed the elevation of internal size of the cavity of the left ventricle. From the analysis of results of the observations it is seen that, in patients including into 1 group the thickness of the wall of the left ventricle is higher than the internal size of the ventricular cavity. This time, the main aim of hypertrophy is the compensation of the increase of 2R/T thickening the wall of the left ventricle and decrease of the internal size of the ventricular cavity happened. Above mentioned showed the disadaptive character of the remodelization. The analysis of obtained results showed that in patients including into II group the increase of internal size of the left ventricle (EDSV, ESS, EDV, ESV) and the thinness of walls 2R/T bring to considerable decreasing. So, in teenagers during tuberculosis the changings (decrease and increase) of the internal size of the left ventricle resulted with the disturbance of the geometrical mechanisms. The changes in the geometrical structure of the ventricles resulted in disturbance and diastolic dysfunction of haemodinamics.

[Study of visual perception under conditions of extreme light exposures].

Neurophysiological processes of transduction and analysis of information concerning brightness of photostimuli and peculiarities of functioning of visual system under exposure to extra-bright light effects or extreme contrasting of visual objects are studied poorly and present significant interest for unraveling actual mechanisms of visual perception under extreme conditions. Conducting analysis of visual system in maximal broad range both in terms of adequate perception and reflection of light stimulus intensity and adaptive mechanisms to extra-strong illumination regimes is as well very important. The to-date obtained data indicate that under the extreme light effects pathology of the peripheral portion of visual analysator can be induced. The presented review does not pretend to comprise all present information concerning all achievements and results over this problem. Its goal concludes in maximal approaching to understanding the mechanisms of damaging and following recover of visual function under extreme effects of affecting light factors.

[Modern data regarding the cardiovascular system lesions in patients with bronchopulmonary diseases and tuberculosis].

The article presents literature review on modern data regarding cardiovascular system lesions in patients with bronchopulmonary diseases and tuberculosis. To detect these changes is of great importance for an assessment of a functional condition of an organism as a whole.

[The mechanism of interaction between the thalamic posterior lateral nucleus and the sensomotor cortex in rabbits]. / Kharakter vzaimodeistviia zadnego lateral'nogo iadra talamusa i sensomotornoi oblasti kory u krolika.

The thalamic posterior lateral nucleus was shown to exert phasic and tonic effects on the function of sensomotor cortex: the former in the form of pulvinar-cortical responses, and the latter in the form of foci of increased or decreased excitability. The findings suggest an inhibitory tonic effect of the sensomotor cortex on neuronal network of the posterior lateral nucleus.

[The effect of stimulation of the suprachiasmatic and supraoptic nuclei of the anterior hypothalamus on the evoked activity of the visual cortex in rabbits]. / Vliianie stimuliatsii suprakhiazmaticheskogo i supraopticheskogo iader perednego gipotalamusa na vyzvannuiu aktivnost' zritel;noi oblasti kory krolikov.

Stimulation of the hypothalamus' suprachiasmatic (SCH) and supraoptic (SO) nuclei induced short-latency hypothalamo-cortical responses in the visual cortex affecting the light-induced responses. Possible mechanisms of the differential effects of the stimulation upon different phases of the visual EPs, and participation of the RF in these mechanisms, are discussed. There seems to exist an interconnection between the hypothalamic and light stimuli in the visual cortex.

Influence of motivational centers of the hypothalamus on the functioning of the visual area of cerebral cortex.

It has been demonstrated in chronic experiments on awake rabbits that a solitary stimulation of the middle hypothalamus, its ventromedial and lateral nuclei (VMN and LN), exerts a phasic effect on a formation of the primary response of the visual cortex evoked by a test light flash. In the initial period of their action, the hypothalamo-cortical responses (1-43 msec for the VMN and 1-10 msec for the LN) completely inhibit the formation of the response of the visual cortex to the light stimulus, while in the second period (43-130 msec for the VMN and 10-150 msec for the LN, respectively), selectively and highly significantly facilitate the formation of the positive phase of the primary response. In the process the negative component is suppressed, and more significantly and longer with stimulation of the VMN than of the LN (140 and 50 msec, respectively). The data obtained make it possible to hypothesize the existence of a highly organized apparatus of phasic hypothalamic (both from the VMN and the LN) control of the function of the visual cortex which is realized both by means of a facilitatory axosomatic mechanism at the level of the dendrites of the basal neurons of layer IV of the cortex and by means of a suppressant mechanism at the level of the apical dendrites of the surface layers of the cortex.

[The effect of the hypothalamic motivational centers on the function of the cortical visual area of the hemispheres]. / Vliianie motivatsionnykh tsentrov gipotalamusa na funktsiiu zritel'noi oblasti kory bol'shikh polusharii.

Chronic experiments were carried out in waking rabbits. A single stimulation of the middle hypothalamus (the ventromedial, VMN, and the lateral, LN, nuclei) was shown to induce the phasic action on a formation of the primary response (PR) of the visual cortex (VC) to the testing light flash. At the first phase (1-43 ms for the VMN and 1-10 ms for the LN) the hypothalamic-cortical responses completely inhibited the formation of the VC response to the light stimulus. At the second phase (43-130 ms for the VMN and 10-150 ms for the LN) they selectively and rather significantly facilitated the formation of the positive PR component the negative one being suppressed. This suppression was stronger and longer during the stimulation of the VMN, than that of the LN (140 and 50 ms correspondingly). The data obtained suggested the existence of a highly organized apparatus of the phasic (both by the VMN and LN) control of the VC function being realized both by means of facilitatory axo-somatic mechanisms at the level of the basal dendrites of the layer IV cortical neurons, and by means of the inhibitory mechanisms at the level of the apical dendrites of the superficial cortical layers.

[The influence of the anterior hypothalamus on the electrical activity of the retina]. / Issledovanie vliianiia perednego gipotalamusa na élektricheskuiu aktivnost' setchatki.

Single stimuli applied to the suprachiasmatic and supraoptic nuclei of the hypothalamus evoked short-latency hypothalamo-retinal responses which exert influences upon formation of the "a" and "b" waves of the electroretinogram, the changes of the waves being opposite by character. The effects from the suprachiasmatic and supraoptic levels were opposite, too.

Influence of pulse stimulation of the visual cortex on the function of the superior colliculus of the awake rabbit.

It has been demonstrated in awake rabbits that stimulation of the visual cortex by a solitary pulse of electrical current leads to the formation of a short-latency response in the superior colliculus. The formation of this response is suppressed when a light stimulus precedes it. At the same time, a conditioning solitary electrostimulation of the visual cortex induces a short inhibition of the formation of the response to the test light stimulus. This fact suggests that the influences of the visual cortex on the functioning of the superior colliculus may be biphasic in character. When the adrenergic apparatus of the reticular formation is blocked this inhibitory influence bears a more pronounced and prolonged character. The stimulation of the reticular formation, on the other hand, by means of anodic polarization leads to the diametrically opposite effect: the inhibitory character of the influence of the cortex is replaced by a facilitatory one. The inference is drawn that the character and the directionality of the influence of the visual cortex on the functioning of the superior colliculus is determined to a significant degree by the initial functional state of nonspecific brain systems.

[The effect of the impulse stimulation of the posterior hypothalamus on the function of the superior colliculi of the corpora quadrigemina]. / Vliianie impul'snoi stimuliatsii zadnego gipotalamusa na funktsiiu verkhnikh bugrov chetverokholmiia.

Single stimuli applied to the posterior hypothalamus of alert rabbits induced short-latency responses in the superior colliculus. The data obtained suggests existence of phasic mechanisms in hypothalamic control of the superior colliculus' function.

Influence of the posterior hypothalamus on the visual cortex in various states of the reticular formation.

It has been demonstrated in chronic experiments on wakeful rabbits that the stimulation of the posterior hypothalamus by a single electrical stimulus leads to the formation in the visual cortex of a short-latency response which exerts a substantial influence on the formation of the reaction to light stimulation. Depending upon the intervals between the hypothalamic and light stimuli, an initial suppression of the response is observed (1-15 msec), a subsequent selective facilitation of its positive component in the presence of the simultaneous suppression of the negative (20-100 msec), and the complete recovery of the response (200-300 msec). Aminazine and amizil do not alter the directionality of the influence of the stimulation of the posterior hypothalamus on the responses of the visual cortex; however, they do significantly attenuate the degree of expressivity and the dynamics of this influence. Experiments involving local foci in the mesencephalic reticular formation (strychnine, KCl) attest to the inhibitory influence of the latter on the activity of the hypothalamocortical input. The role of the phasic mechanism of hypothalamic control in the realization of the perceptual function of the visual cortex is considered.

[The effect of impulse stimulation of the visual cortex on the function of the superior colliculus in the waking rabbit]. / Vliianie impul'snoi stimuliatsii zritel'noi kory na funktsiiu verkhnego dvukholmiia bodrstvuiushchego krolika.

In alert rabbits, pulse stimulation of the visual cortex interfered with the formation of short latency responses in superior colliculus. The effect of visual cortex upon the superior colliculus function may have a phasic inhibitory character. Blockade of the RF adrenergic apparatus enhances the inhibitory effect, whereas stimulation of the RF by anodal current induces an opposite effect. The character of cortical influence upon the superior colliculus function seems to depend on initial functional state of cerebral unspecific systems.

Role of the posterolateral nucleus of the thalamus in mechanism of information transmission to the visual cortex.

It has been demonstrated in chronic experiments on wakeful rabbits that the posterolateral nucleus of the thalamus exerts tonic and phasic facilitatory influences on the formation of responses of the visual cortex elicited by a light flash. The tonic influences were expressed in an increase in the amplitude parameters of the responses of the visual cortex in conditions of the formation in the posterolateral nucleus of the thalamus of a focus of heightened excitability (anode polarization), and their perceptible diminution with potassium depression in this nucleus. The phasic influences were expressed in the formation in the visual cortex of thalamocortical responses elicited by pulse stimulation of the posterolateral nucleus of the thalamus, which displayed a close interaction with the responses of the cortex elicited by the light flash. This interaction consisted in a noticeable facilitation of the responses of the visual cortex against the background of a conditioning pulse stimulation of the posterolateral nucleus. The facilitatory effect of the phasic influences was more significant than the effect of the tonic influence.

[The influence of the posterior hypothalamus on the visual cortex in different states of the reticular formation]. / Vliianie zadnego gipotalamusa na zritel'nuiu koru pri razlichnom sostoianii retikuliarnoi formatsii.

In alert rabbits, stimulation of posterior hypothalamus induced short-latency responses in the visual cortex and affected the formation of the EPs to light. Depending on the intervals between the stimuli, either initial extinction of the EPs (1-15 msec) or subsequent selective facilitation of its positive component with simultaneous depression of negative (20-100 msec) one, or complete recovery of the response (200-300 msec), were observed. Aminazine and benactizine made the effect of the posterior hypothalamic stimulation on visual EPs to light less obvious and changed its dynamics. Other findings suggested an inhibitory effect of the mesencephalic RF on the activity of hypothalamo-cortical input. A role of phasic mechanism of hypothalamic control in realization of visual cortex's perceptive function, is discussed.

[Control of conduction of afferent impulses across the lateral geniculate body by the side of the superior colliculus in alert rabbits]. / Kontrol' provedeniia afferentnoi impul'satsii cherez naruzhnoe kolenchatoe telo bodrstvuiushchego krolika so storony verkhnikh bugrov chetverokholmiia.

On alert rabbits it was shown that the stimulation of the superior colliculus inhibit visual evoked potential both of the ipsi- and contralateral geniculate body. Besides, the suppression of amplitude of the contralateral geniculate body's evoked potential was more significant than amplitude of the ipsilateral geniculate body's evoked potential. On the basis of the obtained results the authors suppose that superior colliculus is involved in organization of the effect of saccadic suppression of lateral geniculate body's visual responses.

[The role of the posterior lateral thalamic nucleus in the rabbit in the mechanisms of information transmission in the visual cortex]. / Rol' zadnego lateral'nogo iadra talamusa krolika v mekhanizme peredachi informatsii v zritel'nuiu koru.

In chronic alert rabbits, both transient and sustained influence of the nucleus lateralis posterior upon visual cortical responses to the light flashes, were shown. The transient influences were revealed by an increase of the responses amplitude in the nucleus lateralis posterior and by a decrease of the amplitude during the K depression. The sustained influences took part in forming of thalamo-cortical responses in visual cortex. This reciprocity was particularly obvious during pulse stimulation of the nucleus lateralis posterior. The sustained influences were more significant than the transient ones.

[The functional connections of the supraoptic and suprachiasmatic nuclei of the anterior hypothalamus with the superior colliculi]. / Issledovanie funktsional'nykh sviazei supraopticheskogo i suprakhiazmaticheskogo iader perednego gipotalamusa s verkhnimi bugrami chetverokholmiia.

Interrelation of single hypothalamic (supraoptic--SO and suprachiasmatic--SCH nuclei) and light stimuli at the level of superior colliculus (SC) were studied during chronic experiments in waking rabbits. Short-term inhibitory and the subsequent facilitatory effects of the hypothalamic stimuli on SC responses induced by light flashes were established. The foregoing light stimulus caused inhibitory effect on formation of hypothalamo-collicular responses induced by SO and SCH nuclei stimulation. The final result of the anterior hypothalamic effect on SC function is the vector value of the mechanism of interrelation between the hypothalamic inputs in this structure.

[Formation of slow background activity in different parts of the visual analyzer following section of half the tectum mesencephali]. / Formirovanie medlennoi fonovoi aktivnosti razlichnykh otdelov zritel'nogo analizatora pri pererezke poloviny pokryshki srednego mozga.

Significant changes in the formation of electrical activity rhythms have been revealed in the lateral geniculate body, superior colliculus and visual cortex during section of one half of midbrain operculum in cats anesthetized with nembutal. It was determined that all changes in slow activity generation in the lateral geniculate body, superior colliculus are reflected in changes in the formation of electrical activity of the visual cortex. It is suggested that lateral geniculate body and superior colliculus may be involved in the generation of some electrical activity rhythms of the visual cortex.

[Effect of visual cortex stimulation on lipid peroxidation in the rabbit retina]. / Vliianie stimuliatsii zritel'noi kory na perekisnoe okislenie lipidov v setchatke krolika.

Chronic experiments on rabbits have shown that visual cortex stimulation resulted in intensified lipid peroxidation in the retina with the parallel decrease of electroretinogram amplitude parameters. The transsection of the optic nerve resulting in the elimination of retinal corticofugal inputs diminished the accumulation of lipid peroxidation products in the rabbit retina during light adaptation. Preliminary insertion of antioxidants to animals (vitamin E and ionol) prevents the inhibitory effect of the cortex on the function of the retina. The data obtained are discussed in view of possible involvement of lipid peroxidation in the retina into the realization of the regulating influence of the cortex on the function of the retina.