The Experts below are selected from a list of 24 Experts worldwide ranked by ideXlab platform
S. A. Kozyrev - One of the best experts on this subject based on the ideXlab platform.
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Effect of Protein Synthesis Inhibitors on Neuronal Mechanisms of Sensitization in Helix Snail
Neurophysiology, 1994Co-Authors: V. P. Nikitin, S. A. KozyrevAbstract:A sensitizing treatment with 5–10% quinine solution causes short-term (lasting 50–70 min) and long-term (lasting several hours) changes in the activity of the command neurons for defensive behavior (LPl1 and PPl1) in the SnailHelix lucorum. The short-term effects are characterized by a depolarizing shift in membrane potential, increased excitability, and an initial increase in the content of bound calcium (Ca-c) in the neurons. The long-term effects appear as facilitation of synaptic components of neuronal responses to sensory stimuli without any changes in excitability and in membrane potential, and also as a repeated increase of Ca-c content. Treatment with anisomycin or cycloheximide during sensitization acquirement prevents development of long-term sensitization.
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Learning-related long-term synaptic facilitation in Snails: Possible mechanisms of long-term memory formation
Neurophysiology, 1993Co-Authors: V. P. Nikitin, S. A. KozyrevAbstract:The long-term changes in the electrical activity of command neurons related to sensitization and elaboration of associative defensive behavioral habit (food rejection) were studied in Helix Snail. The long-term effects consisted of facilitation of synaptic components in neuronal responses to the test stimulations. Variations were found in the dynamics of long-term synaptic facilitation of responses to the applied chemical and tactile stimuli in the course of sensitization, as well as dependence of the degree of long-term facilitation of responses to the test stimulation at the site of its application with respect to the site of the sensitizing stimulation (“site-specific” sensitization). After conditioning, the synaptic response of command neurons to the conditioning stimulation appeared approximately 30 min later than did the long-term sensitization in these cells. The minimum duration of long-term synaptic facilitation of responses to the test stimulation varied from 1 h (for tactile stimulation) to 3 h (for chemical stimulation). The maximum duration of effects exceeded 4 h. It is suggested that the observed features of the synaptic plasticity in command neurons during learning are based on the selective regulation of synaptic inputs by specific protein regulators, whose lifespan does not exceed 1 h to 3 h.
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Sensitization inHelix Snail: Morphofunctional correlates in command neurons of withdrawal behavior
Neurophysiology, 1993Co-Authors: V. D. Goncharuk, S. A. Kozyrev, V. P. NikitinAbstract:Electrophysiological effects have been studied in command neurons of withdrawal behavior in Helix Snail. In parallel, correlated changes in the content of bound calcium (Ca-b), as well as changes in DNA condensation, were investigated using a chlortetracycline fluorescent probe and the fluorescent dye bisbenzimide, respectively. Short-term electrophysiological changes (depolarization of the membrane and elevation of its excitability) in sensitized Snails have been found to be accompanied by an increase in the Ca-b level in the cell nucleus and by partial DNA decondensation. Long-term effects were characterized by more pronounced synaptic components of the responses — slow EPSPs evoked by sensory stimuli, as well as by further DNA decondensation and considerable elevation of the Ca-b content in the nucleus and cytoplasm. The results obtained in in vitro conditions have shown that Ca-binding nonhistone proteins of chromatin are components of the cell nucleus whose content may be measured by chlortetracycline fluorescence.
V. P. Nikitin - One of the best experts on this subject based on the ideXlab platform.
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Effect of Protein Synthesis Inhibitors on Neuronal Mechanisms of Sensitization in Helix Snail
Neurophysiology, 1994Co-Authors: V. P. Nikitin, S. A. KozyrevAbstract:A sensitizing treatment with 5–10% quinine solution causes short-term (lasting 50–70 min) and long-term (lasting several hours) changes in the activity of the command neurons for defensive behavior (LPl1 and PPl1) in the SnailHelix lucorum. The short-term effects are characterized by a depolarizing shift in membrane potential, increased excitability, and an initial increase in the content of bound calcium (Ca-c) in the neurons. The long-term effects appear as facilitation of synaptic components of neuronal responses to sensory stimuli without any changes in excitability and in membrane potential, and also as a repeated increase of Ca-c content. Treatment with anisomycin or cycloheximide during sensitization acquirement prevents development of long-term sensitization.
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Learning-related long-term synaptic facilitation in Snails: Possible mechanisms of long-term memory formation
Neurophysiology, 1993Co-Authors: V. P. Nikitin, S. A. KozyrevAbstract:The long-term changes in the electrical activity of command neurons related to sensitization and elaboration of associative defensive behavioral habit (food rejection) were studied in Helix Snail. The long-term effects consisted of facilitation of synaptic components in neuronal responses to the test stimulations. Variations were found in the dynamics of long-term synaptic facilitation of responses to the applied chemical and tactile stimuli in the course of sensitization, as well as dependence of the degree of long-term facilitation of responses to the test stimulation at the site of its application with respect to the site of the sensitizing stimulation (“site-specific” sensitization). After conditioning, the synaptic response of command neurons to the conditioning stimulation appeared approximately 30 min later than did the long-term sensitization in these cells. The minimum duration of long-term synaptic facilitation of responses to the test stimulation varied from 1 h (for tactile stimulation) to 3 h (for chemical stimulation). The maximum duration of effects exceeded 4 h. It is suggested that the observed features of the synaptic plasticity in command neurons during learning are based on the selective regulation of synaptic inputs by specific protein regulators, whose lifespan does not exceed 1 h to 3 h.
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Sensitization inHelix Snail: Morphofunctional correlates in command neurons of withdrawal behavior
Neurophysiology, 1993Co-Authors: V. D. Goncharuk, S. A. Kozyrev, V. P. NikitinAbstract:Electrophysiological effects have been studied in command neurons of withdrawal behavior in Helix Snail. In parallel, correlated changes in the content of bound calcium (Ca-b), as well as changes in DNA condensation, were investigated using a chlortetracycline fluorescent probe and the fluorescent dye bisbenzimide, respectively. Short-term electrophysiological changes (depolarization of the membrane and elevation of its excitability) in sensitized Snails have been found to be accompanied by an increase in the Ca-b level in the cell nucleus and by partial DNA decondensation. Long-term effects were characterized by more pronounced synaptic components of the responses — slow EPSPs evoked by sensory stimuli, as well as by further DNA decondensation and considerable elevation of the Ca-b content in the nucleus and cytoplasm. The results obtained in in vitro conditions have shown that Ca-binding nonhistone proteins of chromatin are components of the cell nucleus whose content may be measured by chlortetracycline fluorescence.
Catherine E. Morris - One of the best experts on this subject based on the ideXlab platform.
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Channels activated by stretch in neurons of a Helix Snail.
Canadian journal of physiology and pharmacology, 1992Co-Authors: Elaine Bédard, Catherine E. MorrisAbstract:Single-channel recordings from central neurons of the Helix Snail, Cepaea nemoralis, revealed two types of channels that could be activated by stretch (i.e., by the membrane deformation produced wh...
E. É. Saftenku - One of the best experts on this subject based on the ideXlab platform.
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Simulation of mechanisms responsible for initiation and modulation of bursting activity in RPa1 neuron of theHelix Snail
Neurophysiology, 1995Co-Authors: E. É. SaftenkuAbstract:A mathematical model of bursting activity in the RPa1 neuron of the Helix Snail has been developed. The model allowed us to describe the processes of initiation and augmentation of the bursting activity related to transient secretion of a modulatory factor. Based on the analysis of computer simulations of various mechanisms underlying the effect of a modulating factor on the ionic membrane conductances in the bursting neuron, we suggested that modulating factor evokes a transition of non-voltage-dependent sodium channels and hyperpolarization-activated outward current channels to an active state and influences the gating of voltage-dependent sodium channels.
Elaine Bédard - One of the best experts on this subject based on the ideXlab platform.
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Channels activated by stretch in neurons of a Helix Snail.
Canadian journal of physiology and pharmacology, 1992Co-Authors: Elaine Bédard, Catherine E. MorrisAbstract:Single-channel recordings from central neurons of the Helix Snail, Cepaea nemoralis, revealed two types of channels that could be activated by stretch (i.e., by the membrane deformation produced wh...