1
|
Lozovaya N, Nardou R, Tyzio R, Chiesa M, Pons-Bennaceur A, Eftekhari S, Bui TT, Billon-Grand M, Rasero J, Bonifazi P, Guimond D, Gaiarsa JL, Ferrari DC, Ben-Ari Y. Early alterations in a mouse model of Rett syndrome: the GABA developmental shift is abolished at birth. Sci Rep 2019; 9:9276. [PMID: 31239460 PMCID: PMC6592949 DOI: 10.1038/s41598-019-45635-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/11/2019] [Indexed: 02/06/2023] Open
Abstract
Genetic mutations of the Methyl-CpG-binding protein-2 (MECP2) gene underlie Rett syndrome (RTT). Developmental processes are often considered to be irrelevant in RTT pathogenesis but neuronal activity at birth has not been recorded. We report that the GABA developmental shift at birth is abolished in CA3 pyramidal neurons of Mecp2-/y mice and the glutamatergic/GABAergic postsynaptic currents (PSCs) ratio is increased. Two weeks later, GABA exerts strong excitatory actions, the glutamatergic/GABAergic PSCs ratio is enhanced, hyper-synchronized activity is present and metabotropic long-term depression (LTD) is impacted. One day before delivery, maternal administration of the NKCC1 chloride importer antagonist bumetanide restored these parameters but not respiratory or weight deficits, nor the onset of mortality. Results suggest that birth is a critical period in RTT with important alterations that can be attenuated by bumetanide raising the possibility of early treatment of the disorder.
Collapse
Affiliation(s)
- N Lozovaya
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France
| | - R Nardou
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France
| | - R Tyzio
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France.,Mediterranean Institute of Neurobiology (INMED), Department of Neurobiology, Aix-Marseille University, INSERM U1249, 13273, Marseille, France
| | - M Chiesa
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France.,Mediterranean Institute of Neurobiology (INMED), Department of Neurobiology, Aix-Marseille University, INSERM U1249, 13273, Marseille, France
| | - A Pons-Bennaceur
- Mediterranean Institute of Neurobiology (INMED), Department of Neurobiology, Aix-Marseille University, INSERM U1249, 13273, Marseille, France
| | - S Eftekhari
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France.,Mediterranean Institute of Neurobiology (INMED), Department of Neurobiology, Aix-Marseille University, INSERM U1249, 13273, Marseille, France
| | - T-T Bui
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France.,Mediterranean Institute of Neurobiology (INMED), Department of Neurobiology, Aix-Marseille University, INSERM U1249, 13273, Marseille, France
| | - M Billon-Grand
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France
| | - J Rasero
- Biocruces Health Research Institute, 48903, Barakaldo, Spain
| | - P Bonifazi
- Biocruces Health Research Institute, 48903, Barakaldo, Spain.,IKERBASQUE: The Basque Foundation for Science, 48013, Bilbao, Spain
| | - D Guimond
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France
| | - J-L Gaiarsa
- Mediterranean Institute of Neurobiology (INMED), Department of Neurobiology, Aix-Marseille University, INSERM U1249, 13273, Marseille, France
| | - D C Ferrari
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France
| | - Y Ben-Ari
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Bâtiment Beret-Delaage, Parc scientifique et technologique de Luminy, 13288, Marseille, cedex 09, France.
| |
Collapse
|
2
|
Cloarec R, Riffault B, Dufour A, Rabiei H, Gouty-Colomer LA, Dumon C, Guimond D, Bonifazi P, Eftekhari S, Lozovaya N, Ferrari DC, Ben-Ari Y. Pyramidal neuron growth and increased hippocampal volume during labor and birth in autism. Sci Adv 2019; 5:eaav0394. [PMID: 30746473 PMCID: PMC6357736 DOI: 10.1126/sciadv.aav0394] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
We report that the apical dendrites of CA3 hippocampal pyramidal neurons are increased during labor and birth in the valproate model of autism but not in control animals. Using the iDISCO clearing method, we show that hippocampal, especially CA3 region, and neocortical volumes are increased and that the cerebral volume distribution shifts from normal to lognormal in valproate-treated animals. Maternal administration during labor and birth of the NKCC1 chloride transporter antagonist bumetanide, which reduces [Cl-]i levels and attenuates the severity of autism, abolished the neocortical and hippocampal volume changes and reduced the whole-brain volume in valproate-treated animals. These results suggest that the abolition of the oxytocin-mediated excitatory-to-inhibitory shift of GABA actions during labor and birth contributes to the pathogenesis of autism spectrum disorders by stimulating growth during a vulnerable period.
Collapse
Affiliation(s)
- R. Cloarec
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - B. Riffault
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - A. Dufour
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - H. Rabiei
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - L.-A. Gouty-Colomer
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - C. Dumon
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - D. Guimond
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - P. Bonifazi
- Biocruces Health Research Institute, Barakaldo, Spain & IKERBASQUE: The Basque Foundation for Science, Bilbao, Spain
| | - S. Eftekhari
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - N. Lozovaya
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - D. C. Ferrari
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| | - Y. Ben-Ari
- Neurochlore, Ben-Ari Institute of Neuroarcheology (IBEN), Zone Luminy Biotech Entreprises, 13288 Cedex 09 , Marseille, France
| |
Collapse
|
3
|
Lozovaya N, Gataullina S, Tsintsadze T, Tsintsadze V, Pallesi-Pocachard E, Minlebaev M, Goriounova NA, Buhler E, Watrin F, Shityakov S, Becker AJ, Bordey A, Milh M, Scavarda D, Bulteau C, Dorfmuller G, Delalande O, Represa A, Cardoso C, Dulac O, Ben-Ari Y, Burnashev N. Selective suppression of excessive GluN2C expression rescues early epilepsy in a tuberous sclerosis murine model. Nat Commun 2014; 5:4563. [PMID: 25081057 PMCID: PMC4143949 DOI: 10.1038/ncomms5563] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/30/2014] [Indexed: 01/06/2023] Open
Abstract
Tuberous sclerosis complex (TSC), caused by dominant mutations in either
TSC1 or
TSC2 tumour
suppressor genes is characterized by the presence of brain malformations, the
cortical tubers that are thought to contribute to the generation of
pharmacoresistant epilepsy. Here we report that tuberless heterozygote
Tsc1+/− mice show
functional upregulation of cortical GluN2C-containing N-methyl-D-aspartate receptors (NMDARs) in an
mTOR-dependent manner and exhibit recurrent, unprovoked seizures during early
postnatal life (<P19). Seizures are generated intracortically in the granular
layer of the neocortex. Slow kinetics of aberrant GluN2C-mediated currents in spiny stellate cells promotes
excessive temporal integration of persistent NMDAR-mediated recurrent excitation and
seizure generation. Accordingly, specific GluN2C/D antagonists block seizures in Tsc1+/− mice in vivo
and in vitro. Likewise, GluN2C expression is upregulated in TSC human surgical
resections, and a GluN2C/D
antagonist reduces paroxysmal hyperexcitability. Thus, GluN2C receptor constitutes a promising
molecular target to treat epilepsy in TSC patients. Tuberous sclerosis complex (TSC) is a rare genetic condition
characterized by epileptic seizures that start in infancy. Here, the authors show that
these seizures are modulated by GluN2C-containing NMDA receptors in the cortex of a
mouse model of TSC, and that suppressing their activity attenuates seizures.
Collapse
Affiliation(s)
- N Lozovaya
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France [3] INSERM U1129; University Paris Descartes, CEA, Gif sur Yvette, 149 Rue de Sèvres, 75015 Paris, France [4]
| | - S Gataullina
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France [3] INSERM U1129; University Paris Descartes, CEA, Gif sur Yvette, 149 Rue de Sèvres, 75015 Paris, France [4]
| | - T Tsintsadze
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France [3]
| | - V Tsintsadze
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - E Pallesi-Pocachard
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - M Minlebaev
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France [3] Laboratory of Neurobiology, Kazan Federal University, Kremlevskaya street 18, 420000 Kazan, Russia
| | - N A Goriounova
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - E Buhler
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - F Watrin
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - S Shityakov
- Department of Anaesthesia and Critical Care, University of Würzburg, Josef-Schneider-Street 2, 97080 Würzburg, Germany
| | - A J Becker
- Department of Neuropathology, University of Bonn Medical Center, Sigmund Freud Street 25, D-53105 Bonn, Germany
| | - A Bordey
- Neurosurgery, and Cellular and Molecular Physiology Departments, Yale University School of Medicine, PO Box 208082, New Haven, Connecticut 06520-8082, USA
| | - M Milh
- APHM, Department of Pediatric Neurosurgery and Neurology, CHU Timone, 264 Rue Saint-Pierre, 13385 Marseille Cedex 5, France
| | - D Scavarda
- APHM, Department of Pediatric Neurosurgery and Neurology, CHU Timone, 264 Rue Saint-Pierre, 13385 Marseille Cedex 5, France
| | - C Bulteau
- 1] INSERM U1129; University Paris Descartes, CEA, Gif sur Yvette, 149 Rue de Sèvres, 75015 Paris, France [2] Department of Pediatric Neurosurgery, Foundation Rothschild, 29 Rue Manin, 75019 Paris, France
| | - G Dorfmuller
- 1] INSERM U1129; University Paris Descartes, CEA, Gif sur Yvette, 149 Rue de Sèvres, 75015 Paris, France [2] Department of Pediatric Neurosurgery, Foundation Rothschild, 29 Rue Manin, 75019 Paris, France
| | - O Delalande
- Department of Pediatric Neurosurgery, Foundation Rothschild, 29 Rue Manin, 75019 Paris, France
| | - A Represa
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - C Cardoso
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - O Dulac
- 1] INSERM U1129; University Paris Descartes, CEA, Gif sur Yvette, 149 Rue de Sèvres, 75015 Paris, France [2] Department of Pediatric Neurosurgery, Foundation Rothschild, 29 Rue Manin, 75019 Paris, France [3] APHP, Necker Hospital, 149 Rue de Sèvres, 75015 Paris, France
| | - Y Ben-Ari
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| | - N Burnashev
- 1] INSERM U901, INMED, Parc Scientifique et Technologique de Luminy 163, route de Luminy-BP 13, 13273 Marseille Cedex 09, France [2] UMR901, Aix-Marseille University, 58 Boulevard Charles Livon, 13284 Marseille, France
| |
Collapse
|
4
|
Krishtal O, Lozovaya N, Fedorenko A, Savelyev I, Chizhmakov I. The agonists for nociceptors are ubiquitous, but the modulators are specific: P2X receptors in the sensory neurons are modulated by cannabinoids. Pflugers Arch 2006; 453:353-60. [PMID: 16741755 DOI: 10.1007/s00424-006-0094-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Accepted: 04/18/2006] [Indexed: 10/24/2022]
Abstract
P2X2 and P2X3 receptors expressed in mammalian sensory neurons participate in nociception. Cannabinoid receptors modulate nociceptive processing in various models of pain. They are also expressed in nociceptive sensory neurons. We have examined the effect of cannabinoids on the slow P2X2 and P2X2/3 receptors in the cells isolated from nodosal and dorsal root ganglia of rat. The study was carried out by means of the whole-cell patch clamp and rapid superfusion methods. We have found that both endogenous and synthetic cannabinoids (anandamide, WIN55,212-2, and (R)-(+)-methanandamide) inhibit the slow response to ATP mediated by P2X2 and P2X2/3 receptors in a majority of tested neurons. This inhibition was significant but only partial: anandamide (0.5-1 microM) inhibited the response to 51+/-21% of control. In the remaining minority of tested neurons, the response was transiently facilitated. The effect of cannabinoids appears to be mediated via cannabinoid CB(1) receptors: it was reversibly inhibited by selective CB(1) antagonist, SR141716A (10 microM). Introduction of cyclic AMP (0.5 mM) into the cell potently facilitated the inhibitory effect of cannabinoids: the ATP-activated current was inhibited to 13+/-10% of control. These data indicate that cannabinoids may inhibit nociceptive responses produced by P2X receptors.
Collapse
Affiliation(s)
- O Krishtal
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Bogomoletz Street 4, Kiev, 01024, Ukraine.
| | | | | | | | | |
Collapse
|
5
|
Maximyuk O, Khmyz V, Lozovaya N, Dascal N, Krishtal O. NEUROPHYSIOLOGY+ 2002; 34:182-183. [DOI: 10.1023/a:1020747131908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
6
|
Krishtal O, Lozovaya N, Fisunov A, Tsintsadze T, Pankratov Y, Kopanitsa M, Chatterjee SS. Modulation of ion channels in rat neurons by the constituents of Hypericum perforatum. Pharmacopsychiatry 2001; 34 Suppl 1:S74-82. [PMID: 11518081 DOI: 10.1055/s-2001-15510] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Despite almost forty years of widespread use of antidepressant drugs, their mode of action is still unknown. Hyperforin, a phloroglucinol derivative, is a major pharmacologically and therapeutically active constituent of Hypericum perforatum extract that is widely used as an herbal antidepressant drug. However, the mechanism or mechanisms of action of these naturally abundant, non-toxic extracts remain unclear. Enzymatically isolated patch-clamped rat central and peripheral neurons exposed to rapid changes in the composition of external medium (concentration clamp) were used in our experiments to investigate the modulation of the various voltage- and ligand-gated channels by hyperforin, as well as by other constituents of Hypericum perforatum. At nanomolar concentrations, hyperforin induced significant inhibition of various ion channels. In the case of P-type Ca2+ channels, we established that hyperforin acts via interaction with calmodulin or through calmodulin-activated pathways involving at least one second messenger. The results presented here indicate that multiple mechanisms and extract constituents may be involved in the antidepressant action of Hypericum extracts, and that they could also possess neuroprotective and analgesic effects.
Collapse
Affiliation(s)
- O Krishtal
- Bogomoletz Institute of Physiology, Kiev, Ukraine.
| | | | | | | | | | | | | |
Collapse
|
7
|
Krishtal O, Kirichok Y, Tsintsadze T, Lozovaya N, Loesel W, Arndts D. New channel blocker BIIA388CL blocks delayed rectifier, but not A-type potassium current in central neurons. Neuropharmacology 2001; 40:233-41. [PMID: 11114402 DOI: 10.1016/s0028-3908(00)00150-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A new substance (R,S)-(3,4-dihydro-6,7-dimethoxyisoquinoline-1-yl)-2-cyclohexyl-N-(3,3-diphenylpropyl)-acetamide hydrochloride (BIIA388Cl), which demonstrates neuroprotective properties in animal models, was examined for its action on K(+) currents in acutely isolated rat hippocampal neurons using the patch-clamp/concentration clamp techniques in the whole-cell configuration. The delayed rectifier K(+)-current (I(DR)) was strongly inhibited by externally applied BIIA388Cl, while the transient A-current (I(A)) remained virtually unaffected. Block of I(DR) by the pre-applied BIIA388Cl was revealed as a rapid decay of the current indicating direct interaction of the drug with the open state of the channel. The removal of the block upon repolarization was also rapid (tau=22 ms). The dose-response relationship for the blocking action of BIIA388Cl revealed an IC(50) value of 300 nM for the peak I(DR), whereas the IC(50) value for I(DR) measured 300 ms after the onset of depolarization was 120 nM. The blocking action of BIIA388Cl on I(A) was at least 200 times less potent. These data allow us to conclude that BIIA388Cl is an effective and selective blocker of I(DR). This current is the main pathway for the loss of intracellular potassium by depolarized neurons. Selective obstruction of this pathway could be useful for neuroprotection.
Collapse
Affiliation(s)
- O Krishtal
- Bogomoletz Institute of Physiology, Department of Cellular Membranology, Bogomoletz str., 4, Kyiv, Ukraine, 01024.
| | | | | | | | | | | |
Collapse
|
8
|
Fisunov A, Lozovaya N, Tsintsadze T, Chatterjee S, Nöldner M, Krishtal O. Hyperforin modulates gating of P-type Ca2+ current in cerebellar Purkinje neurons. Pflugers Arch 2000; 440:427-34. [PMID: 10954328 DOI: 10.1007/s004240000306] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Whole-cell, patch-clamp recordings from acutely isolated cerebellar Purkinje neurons demonstrate a two-stage modulation of P-type high-voltage-activated (HVA) Ca2+ current by a constituent of St. John's wort, hyperforin (0.04-0.8 microM). The first stage of modulation was voltage dependent and reversible. It comprised slow-down of the activation kinetics and a shift in the voltage dependence of P-current to more negative voltages. Hyperforin (0.8 microM) shifted the maximum of the current/voltage (I/V) relationship by -8+/-2 mV. The second, voltage-independent stage of modulation was manifested as a slowly developing inhibition of P-current that could not be reversed within the period of study. Neither form of modulation was abolished by intracellular guanosine 5'-O-(2-thiodiphosphate) (GDPPS) or guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS) or by strong depolarising pre-pulses, indicating that modulation via guanine nucleotide-binding proteins (G proteins) is not involved in the observed phenomenon. Calmidazolium (0.5 microM), an antagonist of the intracellular Ca2+-binding protein calmodulin significantly inhibited the hyperforin-induced shift of the IIV curve maximum and the slow-down of the activation kinetics. It did not, however, affect the delayed inhibition of P-current, indicating that the two stages of modulation are mediated by separate mechanisms.
Collapse
Affiliation(s)
- A Fisunov
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | | | | | | | | | | |
Collapse
|
9
|
Abstract
Using an in situ patch clamp in hippocampal CA1 mini-slices, we measured excitatory postsynaptic currents (EPSC) by varying the strength of the stimulus applied to the axons of CA3 neurones. The kinetics of the EPSC was initially independent of the stimulus strength. Post-ischaemic potentiation of the EPSC was observed 60-80 min after brief periods (10 min) of anoxia/aglycaemia. The decay of the EPSC slowed significantly in most of the examined neurones. In 11 of 17 cells the EPSC kinetics became dependent on stimulus strength: a slower decay corresponded to a stronger stimulus. This effect was not abolished by N-methyl-D-aspartate (NMDA) or a non-NMDA receptor blocker (D-2-amino-5-phosphonovaleric acid or 6-cyano-7-nitroquinoxaline-2,3-dione respectively) indicating the polysynaptic nature of the modified EPSC: transient ischaemia led to the long-term recruitment of previously inactive, possibly latent NMDA synapses between CA1 neurones.
Collapse
Affiliation(s)
- T Tsintsadze
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | | | | | | |
Collapse
|
10
|
Klishin A, Tsintsadze T, Lozovaya N, Krishtal O. Latent N-methyl-D-aspartate receptors in the recurrent excitatory pathway between hippocampal CA1 pyramidal neurons: Ca(2+)-dependent activation by blocking A1 adenosine receptors. Proc Natl Acad Sci U S A 1995; 92:12431-5. [PMID: 8618915 PMCID: PMC40371 DOI: 10.1073/pnas.92.26.12431] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
When performed at increased external [Ca2+]/[Mg2+] ratio (2.5 mM/0.5 mM), temporary block of A1 adenosine receptors in hippocampus [by 8-cyclopentyltheophylline (CPT)] leads to a dramatic and irreversible change in the excitatory postsynaptic current (EPSC) evoked by Schaffer collateral/commissural (SCC) stimulation and recorded by in situ patch clamp in CA1 pyramidal neurons. The duration of the EPSC becomes stimulus dependent, increasing with increase in stimulus strength. The later occurring component of the EPSC is carried through N-methyl-D-aspartate (NMDA) receptor-operated channels but disappears under either the NMDA antagonist 2-amino-5-phosphonovaleric acid (APV) or the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). These findings indicate that the late component of the SCC-evoked EPSC is polysynaptic: predominantly non-NMDA receptor-mediated SCC inputs excite CA1 neurons that recurrently excite each other by predominantly NDMA receptor-mediated synapses. These recurrent connections are normally silent but become active after CPT treatment, leading to enhancement of the late component of the EPSC. The activity of these connections is maintained for at least 2 hr after CPT removal. When all functional NMDA receptors are blocked by dizocilpine maleate (MK-801), subsequent application of CPT leads to a partial reappearance of NMDA receptor-mediated EPSCs evoked by SCC stimulation, indicating that latent NMDA receptors are recruited. Altogether, these findings indicate the existence of a powerful system of NMDA receptor-mediated synaptic contacts in SCC input to hippocampal CA1 pyramidal neurons and probably also in reciprocal connections between these neurons, which in the usual preparation are kept latent by activity of A1 receptors.
Collapse
Affiliation(s)
- A Klishin
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | | | | | | |
Collapse
|
11
|
Klishin A, Lozovaya N, Krishtal O. A1 adenosine receptors differentially regulate the N-methyl-D-aspartate and non-N-methyl-D-aspartate receptor-mediated components of hippocampal excitatory postsynaptic current in a Ca2+/Mg(2+)-dependent manner. Neuroscience 1995; 65:947-53. [PMID: 7542373 DOI: 10.1016/0306-4522(94)00518-a] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A1 adenosine receptors efficiently modulate the excitatory synaptic transmission in hippocampus. Here we report that in addition to previously known modulatory action on the synaptic efficacy, A1 adenosine receptors are also capable of regulating the relative contribution of N-methyl-D-aspartate receptor-mediated component of the excitatory postsynaptic current in CA3-CA1 excitatory synapses, in the rat. When applied externally, a selective A1 adenosine receptor antagonist, 8-cyclopentyl-1,3-dimethylxanthine, increases not only the amplitude of excitatory postsynaptic current but also the relative contribution of the N-methyl-D-aspartate receptor-mediated component of postsynaptic current recorded by in situ voltage clamp. This effect develops only at increased external Ca2+ concentration and also depends on the external Ca2+/Mg2+ ratio. The increased ratio of N-methyl-D-aspartate/non-N-methyl-D-aspartate components of excitatory postsynaptic current remains at a new level after the removal of 8-cyclopentyl-1,3-dimethylxanthine, even though the amplitude of excitatory postsynaptic current returns close to control value. These results indicate the existence of a mechanism that preferentially enhances the N-methyl-D-aspartate component of excitatory postsynaptic current when the A1 adenosine receptors are blocked and imprints the newly acquired ratio of corresponding excitatory postsynaptic current components.
Collapse
Affiliation(s)
- A Klishin
- Department of Physico-Chemical Biology of Cellular Membranes, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | | | | |
Collapse
|
12
|
Klishin A, Lozovaya N, Krishtal O. Persistently enhanced ratio of NMDA and non-NMDA components of rat hippocampal EPSC after block of A1 adenosine receptors at increased [Ca2+]o/[Mg2+]o. Neurosci Lett 1994; 179:132-6. [PMID: 7531310 DOI: 10.1016/0304-3940(94)90952-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
NMDA and non-NMDA receptor-mediated components of excitatory post-synaptic current (EPSC) were studied by in situ whole-cell voltage-clamp recordings in the CA1 field of rat hippocampus. We found that the amplitudes ratio of the NMDA to the non-NMDA components can be strongly increased by blocking A1 adenosine receptors. The necessary conditions for this effect are both, increased Ca2+ and lowered Mg2+ in the external medium. The so achieved increase in the NMDA/non-NMDA ratio of EPSC components is irreversible and no longer depends on the activity of A1 adenosine receptors.
Collapse
Affiliation(s)
- A Klishin
- Department of Physico-Chemical Biology of Cellular Membranes, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | | | | |
Collapse
|
13
|
Klishin A, Lozovaya N, Pintor J, Miras-Portugal MT, Krishtal O. Possible functional role of diadenosine polyphosphates: negative feedback for excitation in hippocampus. Neuroscience 1994; 58:235-6. [PMID: 8152536 DOI: 10.1016/0306-4522(94)90030-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Diadenosine polyphosphates (Ap4A and Ap5A) are present in secretory granules of chromaffin cells as well as in the rat brain synaptic terminals. Their contribution to the exocytosis of the total synaptosomal content is considerable, ranging from 7% to 12%. Ap4A and Ap5A are released from synaptosomes in a Ca(2+)-dependent manner. There are indications on the high affinity of diadenosine polyphosphates to P2 receptors, but their action on P1 receptors remains unclear. Here we report that both substances induce a blocking action on excitatory synaptic transmission in the rat hippocampus. This action is elicited via the A1 (subclass of P1) receptors and differs in some respects from the action of adenosine.
Collapse
Affiliation(s)
- A Klishin
- Bogomoletz Institute of Physiology, Kiev, Ukraine
| | | | | | | | | |
Collapse
|