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Xing B, Barbour AJ, Vithayathil J, Li X, Dutko S, Fawcett-Patel J, Lancaster E, Talos DM, Jensen FE. Reversible synaptic adaptations in a subpopulation of murine hippocampal neurons following early-life seizures. J Clin Invest 2024; 134:e175167. [PMID: 38227384 PMCID: PMC10904056 DOI: 10.1172/jci175167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 01/11/2024] [Indexed: 01/17/2024] Open
Abstract
Early-life seizures (ELSs) can cause permanent cognitive deficits and network hyperexcitability, but it is unclear whether ELSs induce persistent changes in specific neuronal populations and whether these changes can be targeted to mitigate network dysfunction. We used the targeted recombination of activated populations (TRAP) approach to genetically label neurons activated by kainate-induced ELSs in immature mice. The ELS-TRAPed neurons were mainly found in hippocampal CA1, remained uniquely susceptible to reactivation by later-life seizures, and displayed sustained enhancement in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated (AMPAR-mediated) excitatory synaptic transmission and inward rectification. ELS-TRAPed neurons, but not non-TRAPed surrounding neurons, exhibited enduring decreases in Gria2 mRNA, responsible for encoding the GluA2 subunit of the AMPARs. This was paralleled by decreased synaptic GluA2 protein expression and heightened phosphorylated GluA2 at Ser880 in dendrites, indicative of GluA2 internalization. Consistent with increased GluA2-lacking AMPARs, ELS-TRAPed neurons showed premature silent synapse depletion, impaired long-term potentiation, and impaired long-term depression. In vivo postseizure treatment with IEM-1460, an inhibitor of GluA2-lacking AMPARs, markedly mitigated ELS-induced changes in TRAPed neurons. These findings show that enduring modifications of AMPARs occur in a subpopulation of ELS-activated neurons, contributing to synaptic dysplasticity and network hyperexcitability, but are reversible with early IEM-1460 intervention.
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2
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Aupy J, Ribot B, Guehl D, Nguyen TH, Burbaud P. Selective striatal fast-spiking interneuron inhibition induces cortical seizure. J Neurosci Res 2024; 102:e25270. [PMID: 38284843 DOI: 10.1002/jnr.25270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 10/09/2023] [Accepted: 10/22/2023] [Indexed: 01/30/2024]
Abstract
Whether striatal fast-spiking interneurons are involved in cortical synchronization remains elusive. We performed acute microinjections of a selective FSI-AMPA receptor antagonist into the sensorimotor striatum of non-human primates to verify whether selective FSI inhibition within the sensorimotor striatum could potentially modify cortical excitability, thereby triggering focal seizures. Experiments were performed on three fascicularis monkeys. During each experimental session, low volumes of IEM-1460 (4-8 μL) were injected slowly at 1 μL/min. Spontaneous behavioral changes were classified according to the Racine scale modified for primates. These induced motor behaviors were correlated with electroencephalographic (EEG and EMG) measures. Power spectrum and time-frequency analysis were performed and compared between each period of interest. Pharmacological selective inhibition of striatal fast-spiking INs induced focal motor seizures. Back averaging confirmed that myoclonic activity was closely linked to cortical spikes-and-waves epileptic activity, with a significant increase in cortical EEG power in all studied frequency bands (p < .0001). Thus, striatal FSIs likely play a role in controlling cortical excitability through the cortico-striato-thalamo-cortical pathway. They may contribute to the pathophysiology of focal motor epilepsies by modulating the threshold at which focal motor seizures are triggered.
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Affiliation(s)
- Jérôme Aupy
- CNRS, IMN, UMR 5293, Université de Bordeaux, Bordeaux, France
- Department of Clinical Neurophysiology, CHU de Bordeaux, Bordeaux, France
| | - Bastien Ribot
- CNRS, IMN, UMR 5293, Université de Bordeaux, Bordeaux, France
| | - Dominique Guehl
- CNRS, IMN, UMR 5293, Université de Bordeaux, Bordeaux, France
- Department of Clinical Neurophysiology, CHU de Bordeaux, Bordeaux, France
| | - Tho-Haï Nguyen
- CNRS, IMN, UMR 5293, Université de Bordeaux, Bordeaux, France
| | - Pierre Burbaud
- CNRS, IMN, UMR 5293, Université de Bordeaux, Bordeaux, France
- Department of Clinical Neurophysiology, CHU de Bordeaux, Bordeaux, France
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3
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Search for Selective Glua1 Ampa Receptor Antagonists in a Series of Dicationic Compounds. Pharm Chem J 2022. [DOI: 10.1007/s11094-022-02635-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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4
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Amakhin DV, Soboleva EB, Chizhov AV, Zaitsev AV. Insertion of Calcium-Permeable AMPA Receptors during Epileptiform Activity In Vitro Modulates Excitability of Principal Neurons in the Rat Entorhinal Cortex. Int J Mol Sci 2021; 22:12174. [PMID: 34830051 PMCID: PMC8621524 DOI: 10.3390/ijms222212174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 12/19/2022] Open
Abstract
Epileptic activity leads to rapid insertion of calcium-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (CP-AMPARs) into the synapses of cortical and hippocampal glutamatergic neurons, which generally do not express them. The physiological significance of this process is not yet fully understood; however, it is usually assumed to be a pathological process that augments epileptic activity. Using whole-cell patch-clamp recordings in rat entorhinal cortex slices, we demonstrate that the timing of epileptiform discharges, induced by 4-aminopyridine and gabazine, is determined by the shunting effect of Ca2+-dependent slow conductance, mediated predominantly by K+-channels. The blockade of CP-AMPARs by IEM-1460 eliminates this extra conductance and consequently increases the rate of discharge generation. The blockade of NMDARs reduced the additional conductance to a lesser extent than the blockade of CP-AMPARs, indicating that CP-AMPARs are a more significant source of intracellular Ca2+. The study's main findings were implemented in a mathematical model, which reproduces the shunting effect of activity-dependent conductance on the generation of discharges. The obtained results suggest that the expression of CP-AMPARs in principal neurons reduces the discharge generation rate and may be considered as a protective mechanism.
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Affiliation(s)
- Dmitry V. Amakhin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
| | - Elena B. Soboleva
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
| | - Anton V. Chizhov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
- Ioffe Institute, Russian Academy of Sciences, Polytekhnicheskaya 26, 194021 Saint Petersburg, Russia
| | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Toreza Prospekt 44, 194223 Saint Petersburg, Russia; (D.V.A.); (E.B.S.); (A.V.C.)
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5
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Zaitsev АV, Amakhin DV, Dyomina AV, Zakharova MV, Ergina JL, Postnikova TY, Diespirov GP, Magazanik LG. Synaptic Dysfunction in Epilepsy. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s002209302103008x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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6
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Alterations in mRNA and Protein Expression of Glutamate Receptor Subunits Following Pentylenetetrazole-induced Acute Seizures in Young Rats. Neuroscience 2021; 468:1-15. [PMID: 34102267 DOI: 10.1016/j.neuroscience.2021.05.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/28/2022]
Abstract
Acute seizures can severely affect brain function and development. However, the underlying pathophysiological mechanisms are still poorly understood. Disturbances of the glutamatergic system are considered one of the critical mechanisms of neurological abnormalities. In the present study, we analyzed changes in the expression of NMDA and AMPA receptor subunits in the different brain regions (dorsal hippocampus, amygdala, and the medial prefrontal, temporal, and entorhinal cortex) using a pentylenetetrazole (PTZ) model of seizures in 3-week-old rats. A distinctive feature of this model is that the administration of PTZ causes severe acute seizures, which are not followed by the development of spontaneous recurrent seizures later on. Subunit expression was analyzed using qRT-PCR and Western blotting during the first week after seizures. The most pronounced alterations of mRNA and protein levels were observed in the dorsal hippocampus. We found decreased expression of the GluA2 mRNA 7 days after seizures (PSE7), as well as reduced GluN2a protein levels on PSE7. Significant alterations in the expression of different receptor subunits in the mRNA but not protein levels were observed in the entorhinal cortex and amygdala. In contrast, in the medial prefrontal and temporal cortex, we found almost no changes in the expression of the studied genes. The identified changes deepen our understanding of post-seizure disturbances in the developing brain and confirm that although various brain structures are involved in seizures, the hippocampus is the most vulnerable.
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7
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Mareš P, Kudová E, Valeš K, Kubová H. Three neurosteroids as well as GABAergic drugs do not convert immediate postictal potentiation to depression in immature rats. Pharmacol Rep 2020; 72:1573-1578. [DOI: 10.1007/s43440-020-00113-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 05/13/2020] [Accepted: 05/20/2020] [Indexed: 10/24/2022]
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8
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Mareš P, Kubová H. Perampanel exhibits anticonvulsant action against pentylentetrazol-induced seizures in immature rats. Epilepsy Res 2020; 169:106523. [PMID: 33296808 DOI: 10.1016/j.eplepsyres.2020.106523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/14/2020] [Accepted: 11/27/2020] [Indexed: 11/25/2022]
Abstract
Perampanel is a new antiepileptic drug with unique mechanism of action - antagonism of AMPA receptors. Its action in immature animals is not yet sufficiently known therefore we started to study anticonvulsant action of perampanel pretreatment (1-20 mg/kg i.p.) against seizures elicited by pentylenetetrazol. Three age groups of rats were examined - 12, 18 and 25 days old. Perampanel selectively suppressed the tonic phase of generalized seizures in the two younger groups and whole tonic-clonic seizures in the 25-day-old group. It exhibited also an anticonvulsant action against minimal clonic seizures present in control 18- and 25-day-old rats. Perampanel is an effective anticonvulsant drug even at very early stages of brain development.
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Affiliation(s)
- Pavel Mareš
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.
| | - Hana Kubová
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
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9
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Culjat M, Huizenga MN, Forcelli PA. Age-dependent anticonvulsant actions of perampanel and brivaracetam in the methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) model of seizures in developing rats. Pharmacol Rep 2020; 73:296-302. [PMID: 33210244 DOI: 10.1007/s43440-020-00189-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 10/09/2020] [Accepted: 10/31/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND The antiseizure drugs commonly used as first- and second-line treatments for neonatal seizures display poor efficacy. Thus, drug mechanisms of action that differ from these typical agents might provide better seizure control. Perampanel, an AMPA-receptor antagonist, and brivaracetam, a SV2A ligand, might fill that role. METHODS We utilized methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) to evoke seizures in rats to assess the efficacy of perampanel and brivaracetam treatment in clinically relevant doses. RESULTS In postnatal day (P)10 rats, neither perampanel nor brivaracetam suppressed seizure activity. By contrast, in P21 rats, both drugs decreased the severity of seizures. This effect was evident at the 20 and 40 mg/kg doses of brivaracetam and at the 0.9 and 2.7 mg/kg doses of perampanel. CONCLUSIONS These data indicate that while the efficacy of these drugs may be limited for neonatal seizures, their efficacy increases over early postnatal development.
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Affiliation(s)
- Marko Culjat
- Department of Neonatal-Perinatal Medicine, MedStar Georgetown University Hospital, 3800 Reservoir Road NW, Washington, DC, 20007, USA.,Pharmacology and Physiology, Georgetown University, New Research Building W209B, Washington, DC, 20057, USA
| | - Megan N Huizenga
- Pharmacology and Physiology, Georgetown University, New Research Building W209B, Washington, DC, 20057, USA
| | - Patrick A Forcelli
- Pharmacology and Physiology, Georgetown University, New Research Building W209B, Washington, DC, 20057, USA. .,Neuroscience, Georgetown University, Washington, DC, USA. .,Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, USA.
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10
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Konen LM, Wright AL, Royle GA, Morris GP, Lau BK, Seow PW, Zinn R, Milham LT, Vaughan CW, Vissel B. A new mouse line with reduced GluA2 Q/R site RNA editing exhibits loss of dendritic spines, hippocampal CA1-neuron loss, learning and memory impairments and NMDA receptor-independent seizure vulnerability. Mol Brain 2020; 13:27. [PMID: 32102661 PMCID: PMC7045468 DOI: 10.1186/s13041-020-0545-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/05/2020] [Indexed: 11/18/2022] Open
Abstract
Calcium (Ca2+)-permeable AMPA receptors may, in certain circumstances, contribute to normal synaptic plasticity or to neurodegeneration. AMPA receptors are Ca2+-permeable if they lack the GluA2 subunit or if GluA2 is unedited at a single nucleic acid, known as the Q/R site. In this study, we examined mice engineered with a point mutation in the intronic editing complementary sequence (ECS) of the GluA2 gene, Gria2. Mice heterozygous for the ECS mutation (named GluA2+/ECS(G)) had a ~ 20% reduction in GluA2 RNA editing at the Q/R site. We conducted an initial phenotypic analysis of these mice, finding altered current-voltage relations (confirming expression of Ca2+-permeable AMPA receptors at the synapse). Anatomically, we observed a loss of hippocampal CA1 neurons, altered dendritic morphology and reductions in CA1 pyramidal cell spine density. Behaviourally, GluA2+/ECS(G) mice exhibited reduced motor coordination, and learning and memory impairments. Notably, the mice also exhibited both NMDA receptor-independent long-term potentiation (LTP) and vulnerability to NMDA receptor-independent seizures. These NMDA receptor-independent seizures were rescued by the Ca2+-permeable AMPA receptor antagonist IEM-1460. In summary, unedited GluA2(Q) may have the potential to drive NMDA receptor-independent processes in brain function and disease. Our study provides an initial characterisation of a new mouse model for studying the role of unedited GluA2(Q) in synaptic and dendritic spine plasticity in disorders where unedited GluA2(Q), synapse loss, neurodegeneration, behavioural impairments and/or seizures are observed, such as ischemia, seizures and epilepsy, Huntington’s disease, amyotrophic lateral sclerosis, astrocytoma, cocaine seeking behaviour and Alzheimer’s disease.
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Affiliation(s)
- Lyndsey M Konen
- Centre for Neuroscience and Regenerative Medicine (CNRM), Faculty of Science, University of Technology Sydney, PO Box 123 Broadway, Sydney, NSW, 2007, Australia.,St Vincent's Centre for Applied Medical Research, Sydney, 2011, Australia
| | - Amanda L Wright
- Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Gordon A Royle
- Middlemore Hospital, Counties Manukau DHB, Otahuhu, Auckland, 1062, New Zealand.,The University of Auckland, Faculty of Medical and Health Sciences, School of Medicine, Grafton, Auckland, 1023, New Zealand
| | - Gary P Morris
- Centre for Neuroscience and Regenerative Medicine (CNRM), Faculty of Science, University of Technology Sydney, PO Box 123 Broadway, Sydney, NSW, 2007, Australia.,St Vincent's Centre for Applied Medical Research, Sydney, 2011, Australia
| | - Benjamin K Lau
- Kolling Institute of Medical Research, Royal North Shore Hospital, The University of Sydney, Sydney, 2065, Australia
| | - Patrick W Seow
- Kolling Institute of Medical Research, Royal North Shore Hospital, The University of Sydney, Sydney, 2065, Australia
| | - Raphael Zinn
- Centre for Neuroscience and Regenerative Medicine (CNRM), Faculty of Science, University of Technology Sydney, PO Box 123 Broadway, Sydney, NSW, 2007, Australia.,St Vincent's Centre for Applied Medical Research, Sydney, 2011, Australia
| | - Luke T Milham
- Centre for Neuroscience and Regenerative Medicine (CNRM), Faculty of Science, University of Technology Sydney, PO Box 123 Broadway, Sydney, NSW, 2007, Australia.,St Vincent's Centre for Applied Medical Research, Sydney, 2011, Australia
| | - Christopher W Vaughan
- Kolling Institute of Medical Research, Royal North Shore Hospital, The University of Sydney, Sydney, 2065, Australia
| | - Bryce Vissel
- Centre for Neuroscience and Regenerative Medicine (CNRM), Faculty of Science, University of Technology Sydney, PO Box 123 Broadway, Sydney, NSW, 2007, Australia. .,St Vincent's Centre for Applied Medical Research, Sydney, 2011, Australia.
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11
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Protection of cochlear synapses from noise-induced excitotoxic trauma by blockade of Ca 2+-permeable AMPA receptors. Proc Natl Acad Sci U S A 2020; 117:3828-3838. [PMID: 32015128 DOI: 10.1073/pnas.1914247117] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Exposure to loud sound damages the postsynaptic terminals of spiral ganglion neurons (SGNs) on cochlear inner hair cells (IHCs), resulting in loss of synapses, a process termed synaptopathy. Glutamatergic neurotransmission via α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)-type receptors is required for synaptopathy, and here we identify a possible involvement of GluA2-lacking Ca2+-permeable AMPA receptors (CP-AMPARs) using IEM-1460, which has been shown to block GluA2-lacking AMPARs. In CBA/CaJ mice, a 2-h exposure to 100-dB sound pressure level octave band (8 to 16 kHz) noise results in no permanent threshold shift but does cause significant synaptopathy and a reduction in auditory brainstem response (ABR) wave-I amplitude. Chronic intracochlear perfusion of IEM-1460 in artificial perilymph (AP) into adult CBA/CaJ mice prevented the decrease in ABR wave-I amplitude and the synaptopathy relative to intracochlear perfusion of AP alone. Interestingly, IEM-1460 itself did not affect the ABR threshold, presumably because GluA2-containing AMPARs can sustain sufficient synaptic transmission to evoke low-threshold responses during blockade of GluA2-lacking AMPARs. On individual postsynaptic densities, we observed GluA2-lacking nanodomains alongside regions with robust GluA2 expression, consistent with the idea that individual synapses have both CP-AMPARs and Ca2+-impermeable AMPARs. SGNs innervating the same IHC differ in their relative vulnerability to noise. We found local heterogeneity among synapses in the relative abundance of GluA2 subunits that may underlie such differences in vulnerability. We propose a role for GluA2-lacking CP-AMPARs in noise-induced cochlear synaptopathy whereby differences among synapses account for differences in excitotoxic susceptibility. These data suggest a means of maintaining normal hearing thresholds while protecting against noise-induced synaptopathy, via selective blockade of CP-AMPARs.
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12
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Adotevi N, Lewczuk E, Sun H, Joshi S, Dabrowska N, Shan S, Williamson J, Kapur J. α-Amino-3-Hydroxy-5-Methyl-4-Isoxazolepropionic Acid Receptor Plasticity Sustains Severe, Fatal Status Epilepticus. Ann Neurol 2019; 87:84-96. [PMID: 31675128 DOI: 10.1002/ana.25635] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/30/2019] [Accepted: 10/30/2019] [Indexed: 01/06/2023]
Abstract
OBJECTIVE Generalized convulsive status epilepticus is associated with high mortality. We tested whether α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor plasticity plays a role in sustaining seizures, seizure generalization, and mortality observed during focal onset status epilepticus. We also determined whether modified AMPA receptors generated during status epilepticus could be targeted with a drug. METHODS Electrically induced status epilepticus was characterized by electroencephalogram and behavior in GluA1 knockout mice and in transgenic mice with selective knockdown of the GluA1 subunit in hippocampal principal neurons. Excitatory and inhibitory synaptic transmission in CA1 neurons was studied using patch clamp electrophysiology. The dose response of N,N,H,-trimethyl-5-([tricyclo(3.3.1.13,7)dec-1-ylmethyl]amino)-1-pentanaminiumbromide hydrobromide (IEM-1460), a calcium-permeable AMPA receptor antagonist, was determined. RESULTS Global removal of the GluA1 subunit did not affect seizure susceptibility; however, it reduced susceptibility to status epilepticus. GluA1 subunit knockout also reduced mortality, severity, and duration of status epilepticus. Absence of the GluA1 subunit prevented enhancement of glutamatergic synaptic transmission associated with status epilepticus; however, γ-aminobutyric acidergic synaptic inhibition was compromised. Selective removal of the GluA1 subunit from hippocampal principal neurons also reduced mortality, severity, and duration of status epilepticus. IEM-1460 rapidly terminated status epilepticus in a dose-dependent manner. INTERPRETATION AMPA receptor plasticity mediated by the GluA1 subunit plays a critical role in sustaining and amplifying seizure activity and contributes to mortality. Calcium-permeable AMPA receptors modified during status epilepticus can be inhibited to terminate status epilepticus. ANN NEUROL 2020;87:84-96.
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Affiliation(s)
- Nadia Adotevi
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Ewa Lewczuk
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Huayu Sun
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Suchitra Joshi
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Natalia Dabrowska
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Sarah Shan
- College of Arts and Sciences, University of Virginia, Charlottesville, VA
| | - John Williamson
- Department of Neurology, University of Virginia, Charlottesville, VA
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Charlottesville, VA.,Department of Neuroscience, University of Virginia, Charlottesville, VA.,UVA Brain Institute, University of Virginia, Charlottesville, VA
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13
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Yennawar M, White RS, Jensen FE. AMPA Receptor Dysregulation and Therapeutic Interventions in a Mouse Model of CDKL5 Deficiency Disorder. J Neurosci 2019; 39:4814-4828. [PMID: 30952813 PMCID: PMC6561688 DOI: 10.1523/jneurosci.2041-18.2019] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 03/13/2019] [Accepted: 03/27/2019] [Indexed: 01/28/2023] Open
Abstract
Pathogenic mutations in cyclin-dependent kinase-like 5 (CDKL5) result in CDKL5 deficiency disorder (CDD), a rare disease marked by early-life seizures, autistic behaviors, and intellectual disability. Although mouse models of CDD exhibit dendritic instability and alterations in synaptic scaffolding proteins, studies of glutamate receptor levels and function are limited. Here we used a novel mouse model of CDD, the Cdkl5R59X knock-in mouse (R59X), to investigate changes in synaptic glutamate receptor subunits and functional consequences. Male mice were used for all experiments to avoid the confounding effects of X-inactivation that would be present in female heterozygous mice. We showed that adult male R59X mice recapitulated the behavioral outcomes observed in other mouse models of CDD, including social deficits and memory and learning impairments, and exhibited decreased latency to seizure upon pentylenetetrazol administration. Furthermore, we observed a specific increase in GluA2-lacking α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)-type glutamate receptors (AMPARs) in the adult R59X hippocampus, which is accompanied electrophysiologically by increased rectification ratio of AMPAR EPSCs and elevated early-phase long term potentiation (LTP). Finally, we showed that acute treatment with the GluA2-lacking AMPAR blocker IEM-1460 decreased AMPAR currents, and rescued social deficits, working memory impairments, and seizure behavior latency in R59X mice.SIGNIFICANCE STATEMENT CDKL5 deficiency disorder (CDD) is a rare disease marked by autistic-like behaviors, intellectual disability, and seizures. While synaptic dysfunction has been observed in mouse models of CDD, there is limited information on how synaptic alterations contribute to behavioral and functional changes in CDD. Here we reveal elevated hippocampal GluA2-lacking AMPAR expression in a novel mouse model of CDD that is accompanied by changes in synaptic AMPAR function and plasticity. We also show, for the first time, that acutely targeting GluA2-lacking AMPAR dysregulation rescues core synaptic and neurobehavioral deficits in CDD.
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MESH Headings
- Adult
- Animals
- Behavior, Animal
- Child, Preschool
- Disease Models, Animal
- Epileptic Syndromes/drug therapy
- Epileptic Syndromes/genetics
- Epileptic Syndromes/psychology
- Excitatory Postsynaptic Potentials/genetics
- Female
- Gene Knock-In Techniques
- Humans
- Learning Disabilities/genetics
- Learning Disabilities/psychology
- Male
- Memory Disorders/genetics
- Memory Disorders/psychology
- Mice
- Mice, Inbred C57BL
- Mice, Neurologic Mutants
- Mutation/genetics
- Protein Serine-Threonine Kinases/deficiency
- Protein Serine-Threonine Kinases/genetics
- Psychomotor Performance
- Receptors, AMPA/deficiency
- Receptors, AMPA/drug effects
- Receptors, AMPA/genetics
- Seizures/chemically induced
- Seizures/physiopathology
- Social Behavior
- Spasms, Infantile/drug therapy
- Spasms, Infantile/genetics
- Spasms, Infantile/psychology
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Affiliation(s)
| | - Rachel S White
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
| | - Frances E Jensen
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19104
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14
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Twomey EC, Yelshanskaya MV, Vassilevski AA, Sobolevsky AI. Mechanisms of Channel Block in Calcium-Permeable AMPA Receptors. Neuron 2018; 99:956-968.e4. [PMID: 30122377 PMCID: PMC6181147 DOI: 10.1016/j.neuron.2018.07.027] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/20/2018] [Accepted: 07/17/2018] [Indexed: 01/14/2023]
Abstract
AMPA receptors mediate fast excitatory neurotransmission and are critical for CNS development and function. Calcium-permeable subsets of AMPA receptors are strongly implicated in acute and chronic neurological disorders. However, despite the clinical importance, the therapeutic landscape for specifically targeting them, and not the calcium-impermeable AMPA receptors, remains largely undeveloped. To address this problem, we used cryo-electron microscopy and electrophysiology to investigate the mechanisms by which small-molecule blockers selectively inhibit ion channel conductance in calcium-permeable AMPA receptors. We determined the structures of calcium-permeable GluA2 AMPA receptor complexes with the auxiliary subunit stargazin bound to channel blockers, including the orb weaver spider toxin AgTx-636, the spider toxin analog NASPM, and the adamantane derivative IEM-1460. Our structures provide insights into the architecture of the blocker binding site and the mechanism of trapping, which are critical for development of small molecules that specifically target calcium-permeable AMPA receptors.
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Affiliation(s)
- Edward C Twomey
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University, New York, NY 10032, USA
| | - Maria V Yelshanskaya
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Alexander A Vassilevski
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; Moscow Institute of Physics and Technology (State University), Dolgoprudny, Moscow Oblast 141700, Russia
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
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15
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Rosenberg EC, Lippman-Bell JJ, Handy M, Soldan SS, Rakhade S, Hilario-Gomez C, Folweiler K, Jacobs L, Jensen FE. Regulation of seizure-induced MeCP2 Ser421 phosphorylation in the developing brain. Neurobiol Dis 2018; 116:120-130. [PMID: 29738885 DOI: 10.1016/j.nbd.2018.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 03/23/2018] [Accepted: 05/03/2018] [Indexed: 12/16/2022] Open
Abstract
Neonatal seizures disrupt normal synaptic maturation and often lead to later-life epilepsy and cognitive deficits. During early life, the brain exhibits heightened synaptic plasticity, in part due to a developmental overabundance of CaV1.2 L-type voltage gated calcium (Ca2+) channels (LT-VGCCs) and Ca2+-permeable AMPARs (CP-AMPARs) lacking GluA2 subunits. We hypothesized that early-life seizures overactivate these channels, in turn dysregulating Ca2+-dependent signaling pathways including that of methyl CPG binding protein 2 (MeCP2), a transcription factor implicated in the autism spectrum disorder (ASD) Rett Syndrome. Here, we show that in vivo hypoxia-induced seizures (HS) in postnatal day (P)10 rats acutely induced phosphorylation of the neuronal-specific target of activity-dependent MeCP2 phosphorylation, S421, as well as its upstream activator CaMKII T286. We next identified mechanisms by which activity-dependent Ca2+ influx induced MeCP2 phosphorylation using in vitro cortical and hippocampal neuronal cultures at embryonic day (E)18 + 10 days in vitro (DIV). In contrast to the prevalent role of NMDARs in the adult brain, we found that both CP-AMPARs and LT-VGCCs mediated MeCP2 S421 and CaMKII T286 phosphorylation induced by kainic acid (KA) or high potassium chloride (KCl) stimulation. Furthermore, in vivo post-seizure treatment with the broad-spectrum AMPAR antagonist NBQX, the CP-AMPAR blocker IEM-1460, or the LT-VGCC antagonist nimodipine blocked seizure-induced MeCP2 phosphorylation. Collectively, these results demonstrate that early-life seizures dysregulate critical activity-dependent developmental signaling pathways, in part via CP-AMPAR and LT-VGCC activation, providing novel age-specific therapeutic targets for convergent pathways underlying epilepsy and ASDs.
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Affiliation(s)
- Evan C Rosenberg
- Boston Children's Hospital, Department of Neurology, Boston, MA 02115, United States; New York University Langone Medical Center, New York, NY 10016, United States
| | - Jocelyn J Lippman-Bell
- Perelman School of Medicine, University of Pennsylvania, Department of Neurology, Philadelphia, PA 19104, United States; Boston Children's Hospital, Department of Neurology, Boston, MA 02115, United States; Philadelphia College of Osteopathic Medicine, Department of Biomedical Sciences, Philadelphia, PA 19131, United States
| | - Marcus Handy
- Perelman School of Medicine, University of Pennsylvania, Department of Neurology, Philadelphia, PA 19104, United States
| | - Samantha S Soldan
- Perelman School of Medicine, University of Pennsylvania, Department of Neurology, Philadelphia, PA 19104, United States
| | - Sanjay Rakhade
- Boston Children's Hospital, Department of Neurology, Boston, MA 02115, United States
| | | | - Kaitlyn Folweiler
- Perelman School of Medicine, University of Pennsylvania, Department of Neurology, Philadelphia, PA 19104, United States
| | - Leah Jacobs
- Perelman School of Medicine, University of Pennsylvania, Department of Neurology, Philadelphia, PA 19104, United States
| | - Frances E Jensen
- Perelman School of Medicine, University of Pennsylvania, Department of Neurology, Philadelphia, PA 19104, United States; Boston Children's Hospital, Department of Neurology, Boston, MA 02115, United States.
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16
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Inhibition of calcium-permeable and calcium-impermeable AMPA receptors by perampanel in rat brain neurons. Neurosci Lett 2016; 633:146-151. [DOI: 10.1016/j.neulet.2016.09.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 09/12/2016] [Accepted: 09/19/2016] [Indexed: 11/22/2022]
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