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Bukanova JV, Kondratenko RV, Solntseva EI. Positive allosteric modulators of GABA A receptor restore chloride current from blockade by competitive antagonists in a ligand-dependent manner. J Steroid Biochem Mol Biol 2022; 224:106158. [PMID: 35931327 DOI: 10.1016/j.jsbmb.2022.106158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/26/2022] [Accepted: 07/30/2022] [Indexed: 10/31/2022]
Abstract
γ-Aminobutyric acid (GABA) is the main inhibitory neurotransmitter. GABA receptor type A (GABAAR) possesses binding sites for a large group of pharmacological agents which are supposed to interact allosterically with each other. The aim of this work was to study the interaction between the positive allosteric modulators (PAMs) and the competitive antagonists of GABAARs. The GABA-induced chloride current (IGABA) was measured in isolated Purkinje cells of rat cerebellum using the patch-clamp technique. PAMs, neurosteroid allopregnanolone (Allo) and zolpidem (Zolp), a drug that positively modulates the GABAAR through interaction with the benzodiazepine (BDZ) site, doubled the IGABA amplitude in the control solution. Competitive antagonist of GABAARs, bicuculline (Bic, 5 µM) blocked the IGABA by 90%. The addition of 1 μM Allo or 0.5 µM Zolp to the Bic solution caused an unblocking effect, so that the IGABA amplitude increased 10 and 4 times from control value, correspondingly. This unblocking effect developed slowly, as evidenced by a threefold increase in the current rise time. Competitive antagonist of GABAARs, gabazine (GBZ, 0.5 µM) blocked the IGABA by 87%. The addition of 1 μM Allo to the GBZ solution caused an unblocking effect, so that the IGABA amplitude increased 7-fold. However, the addition of 0.5 µM Zolp to the GBZ solution did not cause an unblocking effect. So, Allo appeared to have a stronger unblocking potential than Zolp, and Bic binding site showed a higher sensitivity to the action of unblocking PAMs than GBZ binding site. The results indicate for the first time the existence of an allosteric relationship between the sites binding PAMs and the competitive antagonists of GABAAR.
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Solntseva EI, Bukanova JV, Kondratenko RV, Skrebitsky VG. Copper Ions Reduce the Effect of Protons on Desensitization of Glycine Receptors. Bull Exp Biol Med 2020; 169:791-794. [PMID: 33098514 DOI: 10.1007/s10517-020-04980-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Indexed: 11/28/2022]
Abstract
Chloride current (IGly) evoked by the rapid (600 msec) application of glycine on isolated pyramidal neurons of the rat hippocampus was recorded using the patch clamp technique. We studied the effect of individual or combined application of copper ions (Cu2+) and protons (H+) on IGly. It was found that both Cu2+ (10 μM) and H+ (pH 7.0 and 6.0) applied separately caused a fast and reversible effect on IGly that included two components: a decrease in peak amplitude (Ipeak) and a decrease in the desensitization time constant (τdes). During combined application, the effects on Ipeak were additive, which indicates the independence of the mechanisms of these effects. At the same time, the effect of combined application of Cu2+ and H+ on τdes was not additive and sometimes a slowdown of the total desensitization was observed. The latter result suggests that H+ and Cu2+ can play the role of mutual antagonists when they affect the desensitization of GlyR.
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Bukanova JV, Solntseva EI, Kondratenko RV, Skrebitsky VG. The influence of acidic media on the effect of beta-amyloid peptide on the function of glycine receptor in hippocampal neurons. Neurochem Int 2017; 110:69-74. [PMID: 28919253 DOI: 10.1016/j.neuint.2017.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 09/05/2017] [Accepted: 09/13/2017] [Indexed: 11/25/2022]
Abstract
We have previously shown that application of beta-amyloid peptide 1-42 (Aβ) at picomolar/nanomolar concentrations caused a decrease in the peak amplitude and acceleration of desensitization of the glycine-activated chloride current (IGly) in hippocampal pyramidal neurons (Bukanova et al., 2016). The aim of this work was to study the effect of Aβ on IGly in an acidified medium. The relevance of this work is determined by the fact that the pathogenic effects of Aβ in Alzheimer's disease are usually accompanied by inflammatory processes and acidosis. The IGly was induced by 600 ms application of 100 μM (nearly EC50) or 500 μM (nearly saturating) glycine on isolated rat hippocampal neurons. The solution of glycine was neutral (pH 7.4) or acidic over a pH range of 5.0-7.0. It was found that 600 ms application of protons rapidly, reversibly and in dose-dependent manner decreased the peak amplitude and accelerated the desensitization of IGly. The effect of H+ on IGly desensitization did not depend on glycine concentration and may be considered noncompetitive, while the effect on IGly peak disappeared at saturating glycine concentration and can be regarded as a competitive. These characteristics of the proton effects on IGly coincide with the characteristics of the Aβ effects on IGly. Experiments with joint application of Aβ and H+ showed interdependence of their effects. Addition of Aβ to perfusing solution reduced H+ effects on IGly while long pretreatment of Aβ with acid solution prevented the effects of the peptide on IGly. Our results suggest the existence of common sites for Aβ and H+ on the GlyR and indicate a mutual weakening of the inhibitory action of these molecules on IGly.
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Kapkaeva MR, Popova OV, Kondratenko RV, Rogozin PD, Genrikhs EE, Stelmashook EV, Skrebitsky VG, Khaspekov LG, Isaev NK. Effects of copper on viability and functional properties of hippocampal neurons in vitro. ACTA ACUST UNITED AC 2017; 69:259-264. [PMID: 28189473 DOI: 10.1016/j.etp.2017.01.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 12/17/2016] [Accepted: 01/31/2017] [Indexed: 12/29/2022]
Abstract
Copper (Cu2+) is an essential metal presented in the mammalian brain and released from synaptic vesicles following neuronal depolarization. However, the disturbance of Cu2+ homeostasis results in neurotoxicity. In our study we performed for the first time a combined functional investigation of cultured hippocampal neurons under Cu2+ exposure, its effect on spontaneous spike activity of hippocampal neuronal network cultured on multielectrode array (MEA), and development of long-term potentiation (LTP) in acute hippocampal slices in the presence of Cu2+. Application of 0.2mM CuCl2 for 24h reduced viability of cultured neurons to 40±6%, whereas 0.01mM CuCl2 did not influence significantly on the neuronal survival. However, exposure to the action of 0.01mM Cu2+ resulted in pronounced reduction of network spike activity and abolished LTP induced by high-frequency stimulation of Schaffer's collaterals in CA1 pyramidal neurons of hippocampal slices. Antioxidant Trolox, the hydrosoluble vitamin E analogue, prevented neurotoxic effect and alterations of network activity under Cu2+ exposure, but didn't change the impairment of LTP in Cu2+-exposured hippocampal slices. We hypothesized that spontaneous network neuronal activity probably is one of the potential targets of Cu2+-induced neurotoxicity, in which free radicals can be involved. At the same time, it may be suggested that Cu2+-induced alterations of long-lasting trace processes (like LTP) are not mediated by oxidative damage.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Nickolay K Isaev
- Research Center of Neurology, Moscow, Russia; Moscow State University, A.N. Belozersky Institute of Physico-Chemical Biology, Biological Faculty, Moscow, Russia.
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Bukanova JV, Solntseva EI, Kondratenko RV, Skrebitsky VG. Glycine receptor in hippocampal neurons as a target for action of extracellular cyclic nucleotides. Neurosci Lett 2013; 561:58-63. [PMID: 24373992 DOI: 10.1016/j.neulet.2013.12.037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/10/2013] [Accepted: 12/17/2013] [Indexed: 11/17/2022]
Abstract
Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) are well known intracellular second messengers. At present study, we describe the effects of extracellularly applied cAMP and cGMP on glycine-induced chloride currents (I(Gly)) in isolated rat hippocampal pyramidal neurons. 50 or 500 μM glycine was applied for 600 ms with 1 min intervals. cAMP and cGMP were co-applied with glycine. We found that both cAMP and cGMP rapidly, reversibly and in a dose-dependent manner accelerated the I(Gly) desensitization. The effect was more prominent on I(Gly) induced by 500 μM than by 50 μM glycine. Dose-response curves were constructed in the 0.1-100,000 nM range of cAMP and cGMP concentrations. They demonstrate that threshold concentration of both compounds was about 1 nM and maximal effect was manifested at 100 nM. When cAMP and cGMP were added to the recording pipette, their extracellular application caused the effects similar to those obtained with normal intracellular medium. The effects of cyclic nucleotides remained unchanged in the presence of the antagonist of adenosine receptors in extracellular solution, and the agonist of adenosine receptors did not mimic the effect of cyclic nucleotides. The changes in the decay kinetics were equally pronounced at negative and positive membrane potentials. When co-administered 1 nM cAMP and 1 nM cGMP caused a weaker effect than either of the compounds alone which suggests a negative interaction between binding sites for cAMP and cGMP. This work describes a novel mode of action of cyclic nucleotides, namely, the modulation of GlyRs functions from extracellular side.
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Affiliation(s)
- Julia V Bukanova
- Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
| | - Elena I Solntseva
- Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia.
| | - Rodion V Kondratenko
- Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
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Kapay NA, Popova OV, Isaev NK, Stelmashook EV, Kondratenko RV, Zorov DB, Skrebitsky VG, Skulachev VP. Mitochondria-Targeted Plastoquinone Antioxidant SkQ1 Prevents Amyloid-β-Induced Impairment of Long-Term Potentiation in Rat Hippocampal Slices. J Alzheimers Dis 2013; 36:377-83. [DOI: 10.3233/jad-122428] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Nadezhda A. Kapay
- Department of Brain Research, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
| | - Olga V. Popova
- Department of Brain Research, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
| | - Nikolay K. Isaev
- Department of Brain Research, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute of Mitoengineering, Lomonosov Moscow State University, Moscow, Russia
| | - Elena V. Stelmashook
- Department of Brain Research, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
- Institute of Mitoengineering, Lomonosov Moscow State University, Moscow, Russia
| | - Rodion V. Kondratenko
- Department of Brain Research, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
| | - Dmitry B. Zorov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute of Mitoengineering, Lomonosov Moscow State University, Moscow, Russia
| | - Vladimir G. Skrebitsky
- Department of Brain Research, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia
| | - Vladimir P. Skulachev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Institute of Mitoengineering, Lomonosov Moscow State University, Moscow, Russia
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Skrebitskiĭ VG, Kondratenko RV, Povarov IS, Dereviagin VI. [Peptidergic modulation of the hippocampus synaptic activity]. Ross Fiziol Zh Im I M Sechenova 2011; 97:1169-1178. [PMID: 22390072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Effects of two newly synthesized nootropic and anxiolytic dipeptides: Noopept and Selank on inhibitory synaptic transmission in hippocampal CA1 pyramidal cells were investigated using patch-clamp technique in whole-cell configuration. Bath application of Noopept (1 microM) or Selank (2 microM) significantly increased the frequency of spike-dependent spontaneous m1PSCs, whereas spike-independent mlPSCs remained unchanged. It was suggested that both peptides mediated their effect sue to activation of inhibitory interneurons terminating on CA1 pyramidal cells. Results of current clamp recording of inhibitory interneurons residing in stratum radiatum confirmed this suggestion, at least for Noonent.
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Kondratenko RV, Derevyagin VI, Skrebitsky VG. Novel nootropic dipeptide Noopept increases inhibitory synaptic transmission in CA1 pyramidal cells. Neurosci Lett 2010; 476:70-3. [DOI: 10.1016/j.neulet.2010.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 04/02/2010] [Accepted: 04/05/2010] [Indexed: 10/19/2022]
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Abstract
In experiments on hippocampal slices from young rats subjected to immobilization-cold stress we observed a pronounced increase in the amplitude of long-term potentiation of focal responses in CA1 area. Daily injections of comenic acid during stress exposure normalized parameters of long-term potentiation in the hippocampus.
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Affiliation(s)
- R V Kondratenko
- Research-and-Production Department of Physiologically Active Substances, Kuban State University, Krasnodar, Russia. . Kondratenko R. V
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