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Biomedical subjects

S V Minina

Publications and source records attributed to S V Minina.

16 recordsLinked to original sources
PubMed1991

Mechanical influence and cAMP injection evoke the same reaction of neuron ionic channels.

Intracellular cAMP injection and negative pressure in the patch-electrode increase the interburst closed time of the same potassium ionic channels in the snail neuron membrane. Sodium channels which were registered as change of background noise are activated both by cAMP injection and by negative pressure. These results are considered in connection with data about the unusual biochemistry of the neuron reaction to cAMP.

Animals↗
PubMed1989

Quantum molecular computer model of the neuron and a pathway to the union of the sciences.

Cyclic nucleotide injection in neurons shows that cAMP controls a new type of membrane permeability. The neuron response to cAMP has a short delay, unusual bioenergetics and is blocked by drugs binding with the regulatory subunit of protein kinase. These data are interpreted in terms of the hypothesis that the controlling system of the living cell is a molecular (DNA, RNA, protein operators with complementary addresses), holographic (quick changeable lattice--cytoskeleton), quantum (each phonon examines whole lattice), hypersound (with wave length 100-10,000 A that does not destroy molecules) system with an inner point of view (molecular coding of questions and answers about quantum processing). Neither an electron, nor a macroscopic computer has an inner point of view.

Biology↗
PubMed1988

Unusual biochemistry of changes in neuron membrane permeability evoked by cAMP.

Influence of different metabolic poisons on cAMP-evoked neuron membrane permeability is investigated. Drugs preventing cAMP binding with R subunits of protein kinase decrease the cAMP-evoked current, but the inhibitor of the C subunit. H8, has no effect. The cAMP-dependent current is increased by uncouplers and decreased by inhibitors of glycolysis and oxidative phosphorylation. The mechanism of cAMP action on neuron permeability is discussed.

Animals↗
PubMed1985

Neuron generator potentials evoked by intracellular injection of cyclic nucleotides and mechanical distension.

Depolarization of neuron membrane was shown to occur during cAMP injection by means of both iontophoresis and pressure. Distension of the neuron by means of blowing with large volumes of solution without cAMP can produce reversible responses. The time course can be made similar to that of the cAMP effect and the responses can be repeated many times in the same neuron. The effect of cAMP can be differentiated from the mechanical response by injecting small volumes of concentrated solutions. The delay in this depolarization response to cAMP is only 0.1-0.3 s. The calculated time of diffusion from the electrode tip to the membrane is about 10 times greater. The similarity of cAMP and mechanical responses and the short delay of the cAMP effect suggests that a cAMP effect may be mediated by mechanical signals in the cytoskeleton.

Animals↗
PubMedDate not supplied

[Input and output channels of quantum biocomputers].

It is proposed that "Quantum Molecular" computer of a neuron consists of the cell cytoskeleton serving as calculating media and input ionic channel sending a hypersound signal to observe these media. The sound spreads through the media travelling along microtubules and microfilaments and switching between those via molecular bridges which serve as elementary switches. The whole system works like a wave guiding net connecting input ionic channels (which generate different sound signals) and output ionic channels (which are controlled by the processed sound signals). Thus the output of such systems depends on the input (controlled by synaptic activity) and on the construction and state of these calculating media. We think that the sound waves spreading through different calculating media solve different physical problems. The construction of the calculating part of the cytoskeleton, according to the hypothesis, is different in different neurons. It is defined by special protein which is produced by DNA, RNA and protein molecular word processor (during brain development and, may be, education). We comment on how the existence of an extremal computer produces an impact on physics and mathematics exemplified by the optimality principle as substitution of physical relativity principle for a complex problem.

Brain↗
PubMedDate not supplied

[Study of the metabolic synapse. II. Comparison of the effects of cyclic 3',5'-AMP and 3',5'-GMP].

Intracellular microiontoforetic injections of cyclic 3',5'-AMP and cyclic 3',5'-GMP elicit different responses in the same neuron. Drugs were injected by current of 1--10 nA using 3-barrel micropipettes. Unlike cyclic 3',5'-AMP arising the depolarization of the neuron, cyclic 3',5'-GMP usually hyperpolarizes it. An inhibitor of phosphodiesterases, papaverine, increases and prolongates effects of cyclic 3',5'-AMP and cyclic 3',5'-GMP, but in latter case the action of this drug seems to be less.

Animals↗
PubMedDate not supplied

[The effect of various protein kinase inhibitors on the response of snail neurons to the intracellular injection of cAMP].

Drugs preventing cAMP interaction with regulatory subunit of cAMP-dependent protein kinase, tolbutamide and db-cAMP injected into neurons of Helix lucorum decreased the cell response to cAMP, but H-8-a potent inhibitor of this enzyme catalytic subunit did not produce such effect. It is suggested that the neuron electric response to cAMP injection is not caused by protein phosphorylation.

Animals↗
PubMedDate not supplied

[Intraneuronal information processing. An increase in sodium and decrease in potassium permeability after injection of cyclic nucleotide and mechanical stimulation of the neuron].

In voltage clamp experiments the ionic permeability mechanism of the neuron soma evoked by the injection of cyclic nucleotides can be estimated only by studying the reversal potential. The value of this potential allows to conclude that permeability is mainly increased by opening potential independent sodium channels. A delay of ionic current evoked by cyclic nucleotides is tenfold less than the time of cAMP diffusion to the membrane. This leads to a hypothesis about the cyclic nucleotide dependent mechanical opening of sodium channels.

Action Potentials↗
PubMedDate not supplied

[The role of electro-mechanical and reaction-diffusion systems in the intra-neuron processing of information: effect of in-flow of calcium and intracellular calcium on cAMP activity].

Influx of calcium ions cannot control a generatory potential induced by the intraneuronal system because calcium ions enter the cell during impulses. These impulses are the result of problem solving and must not influence directly the generatory potential. Therefore cAMP and not calcium controls the permeability of sodium and potassium channels from the inside of the neuron. However the calcium ions and membrane potential of mitochondria affect the impact of cAMP injections. An increase in the intracellular concentration of free Ca2+ induced by the injection of Ca-EGTA buffer with 5.10(-7) M free Ca2+, electric excitation, uncouplers of oxidative phosphorylation or arsenate leads to an increase of cAMP-dependent depolarization and the inward current. The injection of Ca-EGTA buffer with 10(-5) M free Ca2+ and drop in [Ca2+]in by EGTA as well as generation of impulses after cAMP injection decrease the cAMP effect. As rise in [Ca2+]in activates phosphodiesterase and uncouples oxidative phosphorylation, and vanadate in contrast to arsenate suppresses the cAMP effect, a hypothesis is advanced that activating effect of calcium on cAMP action is associated with neuron deenergization.

Action Potentials↗
PubMedDate not supplied

[A study of the change in conductivity of the neuronal membrane caused by a generator potential using a method of computer modeling].

Injection of cAMP induces in snail neurons generator potential, which is related to an increase of sodium and decrease of potassium permeability of the neuron outer membrane. A model is proposed which takes into account cAMP diffusion inside the neuron from the injection place and interaction of these molecules with the intercellular system controlling permeability of the outer membrane. Resulting impulse generation induces calcium ions current through the outer membrane. The model also considers calcium diffusion toward cAMP and its effect on the rate of the enzyme work destroying cAMP. Agreement between the calculations of ionic current I(t) and the experiment permits determination of the model parameters and calculation of the observed change of time distribution of nerve impulses when calcium input is significant.

Animals↗
PubMedDate not supplied

[Neuron membrane depolarization under the influence of cyclic-3',5'-adenosine monophosphate and its possible role in the neuronal molecular computer (MC)].

The separate fourth intracellular microelectrode was used for controlling the conditions of cyclic nucleotide injection in neurons of Helix pomatia. Ionoforetic increase in intracellular cyclic AMP concentration elicits membrane depolarization in many neurons. Phosphodiesterase inhibitors 3-isobutyl-1-methylxantine and SQ-20009 prolong this depolarization and raise its level. In cell F-1 of helix brain sometimes cAMP induces weak hyperpolarization, but this response turns to usual depolarization after 3-isobutyl-1-methylxantine application. It is suggested that cell molecular computer has an analog input, where diffusion of cAMP, cGMP and Ca++ being a modelling process. Adenylate cyclase and guanylate cyclase and ionic channels of membrane are regulated sources. Phosphodiesterases with Ca2+-binding activator proteins are molecular out flowers and protein kinases--detectors that transform the data about the concentrations of cAMP and cGMP into codes for MCC. Protein kinases control over the activity of proteins directly. The depolarization effect on neuron membrane seems to be associated with protein kinase activation or with direct action of cAMP on phospholipase.

Adenylyl Cyclases↗
PubMedDate not supplied

[Intraneuronal information processing. Delay in the changes in membrane potential after administration of cyclic nucleotides].

Depolarization of the neuron membrane induced by cyclic adenosine monophosphate (cAMP) was shown both by ionophoresis and by injection with pressure. Swelling of the neuron during the injection of various substances with pressure causes membrane depolarization which is similar to that induced by cAMP. When applying pressure the cAMP effect can be distinguished by introducing small volumes of concentrated solutions. Similarity between the effects of cAMP and mechanical stimulation of the neuron suggests that in both cases the effect involves action of the electromechanical system consisting of microskeleton and micromuscles which regulate permeability of molecular channels. The delay of the effect after the moment of cAMP and cGMP introduction is small, which enables a conclusion concerning their direct interaction with the cytoskeleton.

Adenosine Triphosphate↗
PubMedDate not supplied

[The role of the electromechanical and reaction-diffusion system of intraneuronal information processing in brain function].

The experimental data of previous papers are considered as a basis for the hypothesis about intraneuronal system controlled by cyclic nucleotides and changing the membrane permeability upon creating the generatory potential. This system is suggested to be an extremal molecular regulator in which the price of action per single operation approximates the physical limit. The electro-mechanical intraneuronal system is capable of solving multidimensional physical problems by means of molecular "digital" hypersound holo-gram coded by DNA molecular text which is an image of functions of target search.

Animals↗
PubMedDate not supplied

[Effect of oxidative phosphorylation inhibitors and uncoupling agents on cAMP activity].

Uncouplers of oxidative phosphorylation increased the speed of substrate oxidation and ATP hydrolysis and raised cAMP induced neuron membrane current. Different inhibitors decreased it. Both effects support the hypothesis that a signal of intracellular injected cAMP spreads to the neuron membrane as a mechanical signal. This signal propagated to the membrane along microtubules which according to this hypothesis serve as a sound generator with metabolic heat pumping.

Animals↗