[Cybernetics--methodological problems].
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Consciousness↗
Biomedical subjects
A I Berg
Publications and source records attributed to A I Berg.
Cortico-hypothalamic interneuronal correlation during learning in cats.
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Action Potentials↗
Organization of network properties of cells in local and distributed neuronal networks of the brain of cats.
The network properties of neurons of the visual and motor cortex and of the lateral nucleus of the hypothalamus were investigated on the basis of identified interneuronal interactions, using the cross-correlation method of analysis, in cats with developed alimentary conditioned instrumental reflexes to light. The varied organization of the network properties of cortical neurons in the organization of local and distributed neuronal networks was demonstrated, namely: the predominance of divergent properties over convergent properties for large cells in local networks and the leveling out of these relationships in distributed networks. The neurons of the lateral nucleus of the hypothalamus had an equal representation of convergent and divergent properties in the organization of local and distributed networks. The network properties of neurons of the cortical and subcortical structures were manifested in the background, following the development of conditioned reflexes, and during extinction. Only the small cells of the visual cortex were functionally dependent and changed the relationship of network properties in local networks during the extinction of conditioned reflexes.
Action Potentials↗
Statistical analysis of the functional connections between the neurons of the visual and motor cortex in different forms of conditioned reflex behavior.
The organization of interneuronal cortical connections was studied in experiments on cats with the development of delayed alimentary instrumental reflexes in response to light. The dynamics of the intra- and interstructural neuronal network at the level of the cortical projection (visual and motor) zones of the cat brain in three forms of behavior was revealed through a cross correlation analysis: the realization of the CR, in the intersignal period with the presence and absence of instrumental movements. The predominance of "informational" or "motivational" neuronal connections was observed depending upon the forms of the behavior.
Animals↗
[Conformational regulation of functional activity of photosynthetic membranes of purple bacteria].
In reaction centres of photosynthetic membranes of R, rubrum the efficiency of redox interactions of the photoreduced primary electron acceptor with secondary acceptors and photooxidized bacteriochlorophyll has a marked and reversible dependence on temperature over the range from -20 degrees to -80 degrees. Similar temperature dependences were observed for correlation times of the rotational diffusion of a spin probe bound to the hydrophobic region of the membrane and of a spin label bound to SH-groups of the protein constituent of the membrane, as well as for characteristics of resonance absorption of the Mössbauer probe (57Fe), embedded in the membrane by biosynthesis. Using the same indicators of intramolecular mobility, a correlation has been observed between photoactivity and structure of the membrane in experiments involving hydratation changes of samples. The data suggest the existence of a close interrelationship between the conformational mobility of the constituents of the photosynthetic membrane and their specific reaction capacity.
Bacteriochlorophylls↗
[The organization of the network characteristics of the cells in local and distributed neuronal networks of the cat brain].
In cats with elaborated alimentary instrumental reflexes to light net characteristics of neurones of visual, motor cortex and the hypothalamus lateral nucleus were studied on the basis of revealed interneuronal interactions by means of cross-correlation method of analysis. Different organization of net properties of the cortical neurones in organization of local and distributed neuronal networks was shown, namely: predominance of the divergent characteristics over the convergent ones for cells in local networks and levelling of these relations in distributed nets. Neurones of the lateral hypothalamus nucleus had equal presentation of divergent and convergent properties in organization of local and distributed networks. Net characteristics of neurones of the cortical and subcortical structures were manifested in the background after the elaboration and the extinction of conditioned reflexes. Only small cells of the visual cortex were functionally dependent and changed correlation of net characteristics in local networks at CR extinction.
Animals↗
[A statistical analysis of the functional connections between the neurons of the visual and motor cortex in different forms of conditioned-reflex behavior].
In experiments on cats with elaboration of delayed alimentary operant reflexes to light organization was studied of interneuronal cortical connections. By means of cross-correlation analysis the dynamics of intra- and interstructural neuronal network was revealed at the level of cortical projections (visual and motor) of cats brain zones at three forms of behaviour: CR realization, in intersignal period with the presence and absence of operant movements. Depending on the forms of behaviour, predominance of "informational" or "motivational" interneuronal connections was observed.
Animals↗
[The choice of reinforcement quality depending on the delay time of the instrumental reaction in cats].
In experiments on seven cats instrumental delayed reflexes with different quality reinforcement were elaborated by method of "active choice", where the time of delay of the motor reaction served as a signal of quality of the reinforcement. Five cats used a strategy with long delay high-quality reinforcement (meat), and two cats preferred short delay and low-quality reinforcement (bread-meat mixture). In special experiments with the change of alimentary motivation (24-hour alimentary deprivation and saturation of animals) it was established that the level of alimentary motivation within the studied limits did not change the strategy of behaviour preferred by the given animal. Individually varying ability to choice of reaction determining more valuable reinforcement it is possible to consider as an experimental analogue of the mechanisms of will. The question is discussed about the role of typological properties of cats in choice of behaviour strategy.
Animals↗
[Conformational mobility and functional activity of photosynthetic reaction centers of Rhodopseudomonas sphaeroides].
In pigment-protein complexes of photosynthetic reaction centres (RC's), extracted from chromatophore membranes of Rps. sphaeroides with sodium dodecylsulphate, functional activity and intramolecular mobility were studied as a function of temperature and hydration by use of the technique of optical absorbance and ESR spectroscopy. Over the studied temperature range from +20 to -120 degrees C and at a relative humidity (P/Ps) from 0.9 to 0.1, there observed a close interrelationship between reversible kinetic changes of direct and backward redox-reactions of the photo-reduced endogeneous acceptor of quinone nature and the effective parameter of the correlation time of the rotational diffusion of the hydrophobic spin probe as well as of spin labels chemically bound to SH- and COOH-groups of amino acid residues of the RC's protein. The findings support the view that the conformational dynamics in the RC controls the effectiveness of the primary processes of stabilization of photochemically separated charges.
Bacterial Chromatophores↗
[Cortico-hypothalamic interneuronal correlation during learning in cats].
Spatial-temporal organization of neuronal activity in the motor cortex and hypothalamus lateral nucleus (inter- and intrastructural neuronal interactions) in cats with elaborated conditioned alimentary instrumental reflexes were studied by means of recording the multineuronal activity of structures under investigation and with the use of cross-correlation method of analysis. An increase was shown of the number of cortico-hypothalamic neurones pairs acting in interconnection after elaboration of conditioned reflexes, and a decrease of their number at extinction due to interaction with temporal delays (up to 30 ms). Local (intrastructural) connections of the motor cortex and lateral hypothalamus had opposite dynamics at extinction of the conditioned reflexes: the number of the first increased and the number of the second decreased. The character of the interconnected activity of neurones pairs of interstructural interaction is discussed.
Animals↗