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Ali I, Silva J, Casillas-Espinosa PM, Braine E, Yamakawa GR, Hudson MR, Brady RD, Major B, Thergarajan P, Haskali MB, Wright DK, Jupp B, Vivash L, Shultz SR, Mychasiuk R, Kwan P, Jones NC, Fukushima K, Sachdev P, Cheng JY, O'Brien TJ. E2730, an uncompetitive γ-aminobutyric acid transporter-1 inhibitor, suppresses epileptic seizures in a rat model of chronic mesial temporal lobe epilepsy. Epilepsia 2023; 64:2806-2817. [PMID: 37539645 DOI: 10.1111/epi.17735] [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: 03/21/2023] [Revised: 08/01/2023] [Accepted: 08/01/2023] [Indexed: 08/05/2023]
Abstract
OBJECTIVE More than one third of mesial temporal lobe epilepsy (MTLE) patients are resistant to current antiseizure medications (ASMs), and half experience mild-to-moderate adverse effects of ASMs. There is therefore a strong need to develop and test novel ASMs. The objective of this work is to evaluate the pharmacokinetics and neurological toxicity of E2730, a novel uncompetitive inhibitor of γ-aminobutyric acid transporter-1, and to test its seizure suppression effects in a rat model of chronic MTLE. METHODS We first examined plasma levels and adverse neurological effects of E2730 in healthy Wistar rats. Adult male rats were implanted with osmotic pumps delivering either 10, 20, or 100 mg/kg/day of E2730 subcutaneously for 1 week. Blood sampling and behavioral assessments were performed at several timepoints. We next examined whether E2730 suppressed seizures in rats with chronic MTLE. These rats were exposed to kainic acid-induced status epilepticus, and 9 weeks later, when chronic epilepsy was established, were assigned to receive one of the three doses of E2730 or vehicle for 1 week in a randomized crossover design. Continuous video-electroencephalographic monitoring was acquired during the treatment period to evaluate epileptic seizures. RESULTS Plasma levels following continuous infusion of E2730 showed a clear dose-related increase in concentration. The drug was well tolerated at all doses, and any sedation or neuromotor impairment was mild and transient, resolving within 48 h of treatment initiation. Remarkably, E2730 treatment in chronically epileptic rats led to seizure suppression in a dose-dependent manner, with 65% of rats becoming seizure-free at the highest dose tested. Mean seizure class did not differ between the treatment groups. SIGNIFICANCE This study shows that continuous subcutaneous infusion of E2730 over 7 days results in a marked, dose-dependent suppression of spontaneous recurrent seizures, with minimal adverse neurological effects, in a rat model of chronic MTLE. E2730 shows strong promise as an effective new ASM to be translated into clinical trials.
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Affiliation(s)
- Idrish Ali
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Juliana Silva
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Pablo M Casillas-Espinosa
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Emma Braine
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Glenn R Yamakawa
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Matthew R Hudson
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Rhys D Brady
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Brendan Major
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | | | - Mohammad B Haskali
- Radiopharmaceutical Research Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - David K Wright
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Bianca Jupp
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Lucy Vivash
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Sandy R Shultz
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Patrick Kwan
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
| | - Nigel C Jones
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | - Terence J O'Brien
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia
- University of Melbourne, Parkville, Victoria, Australia
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Arias HR, Pierce SR, Germann AL, Xu SQ, Ortells MO, Sakamoto S, Manetti D, Romanelli MN, Hamachi I, Akk G. Chemical, Pharmacological, and Structural Characterization of Novel Acrylamide-Derived Modulators of the GABA A Receptor. Mol Pharmacol 2023; 104:115-131. [PMID: 37316350 PMCID: PMC10441626 DOI: 10.1124/molpharm.123.000692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/22/2023] [Accepted: 06/01/2023] [Indexed: 06/16/2023] Open
Abstract
Acrylamide-derived compounds have been previously shown to act as modulators of members of the Cys-loop transmitter-gated ion channel family, including the mammalian GABAA receptor. Here we have synthesized and functionally characterized the GABAergic effects of a series of novel compounds (termed "DM compounds") derived from the previously characterized GABAA and the nicotinic α7 receptor modulator (E)-3-furan-2-yl-N-p-tolyl-acrylamide (PAM-2). Fluorescence imaging studies indicated that the DM compounds increase apparent affinity to the transmitter by up to 80-fold in the ternary αβγ GABAA receptor. Using electrophysiology, we show that the DM compounds, and the structurally related (E)-3-furan-2-yl-N-phenylacrylamide (PAM-4), have concurrent potentiating and inhibitory effects that can be isolated and observed under appropriate recording conditions. The potentiating efficacies of the DM compounds are similar to those of neurosteroids and benzodiazepines (ΔG ∼ -1.5 kcal/mol). Molecular docking, functionally confirmed by site-directed mutagenesis experiments, indicate that receptor potentiation is mediated by interactions with the classic anesthetic binding sites located in the transmembrane domain of the intersubunit interfaces. Inhibition by the DM compounds and PAM-4 was abolished in the receptor containing the α1(V256S) mutation, suggestive of similarities in the mechanism of action with that of inhibitory neurosteroids. Functional competition and mutagenesis experiments, however, indicate that the sites mediating inhibition by the DM compounds and PAM-4 differ from those mediating the action of the inhibitory steroid pregnenolone sulfate. SIGNIFICANCE STATEMENT: We have synthesized and characterized the actions of novel acrylamide-derived compounds on the mammalian GABAA receptor. We show that the compounds have concurrent potentiating effects mediated by the classic anesthetic binding sites, and inhibitory actions that bear mechanistic resemblance to but do not share binding sites with, the inhibitory steroid pregnenolone sulfate.
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Affiliation(s)
- Hugo R Arias
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Spencer R Pierce
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Allison L Germann
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Sophia Q Xu
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Marcelo O Ortells
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Seiji Sakamoto
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Dina Manetti
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Maria Novella Romanelli
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Itaru Hamachi
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
| | - Gustav Akk
- Department of Pharmacology and Physiology, Oklahoma State University College of Osteopathic Medicine, Tahlequah, Oklahoma (H.R.A.); Department of Anesthesiology, Washington University School of Medicine, St. Louis, Missouri (S.R.P., A.L.G., S.Q.X., G.A.); Facultad de Medicina, Universidad de Morón, Morón, and CONICET, Argentina (M.O.O.); Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan (S.S., I.H.); Department of Neurosciences, Psychology, Drug Research and Child Health Section of Pharmaceutical and Nutraceutical Sciences, University of Florence, Florence, Italy (D.M., M.N.R.); The Taylor Family Institute for Innovative Psychiatric Research, Washington University School of Medicine, St. Louis, Missouri (G.A.)
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Sleep and wake cycles dynamically modulate hippocampal inhibitory synaptic plasticity. PLoS Biol 2022; 20:e3001812. [PMID: 36318572 PMCID: PMC9624398 DOI: 10.1371/journal.pbio.3001812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/30/2022] [Indexed: 01/01/2023] Open
Abstract
Sleep is an essential process that consolidates memories by modulating synapses through poorly understood mechanisms. Here, we report that GABAergic synapses in hippocampal CA1 pyramidal neurons undergo daily rhythmic alterations. Specifically, wake inhibits phasic inhibition, whereas it promotes tonic inhibition compared to sleep. We further utilize a model of chemically induced inhibitory long-term potentiation (iLTP) to examine inhibitory plasticity. Intriguingly, while CA1 pyramidal neurons in both wake and sleep mice undergo iLTP, wake mice have a much higher magnitude. We also employ optogenetics and observe that inhibitory inputs from parvalbumin-, but not somatostatin-, expressing interneurons contribute to dynamic iLTP during sleep and wake. Finally, we demonstrate that synaptic insertion of α5-GABAA receptors underlies the wake-specific enhancement of iLTP at parvalbumin-synapses, which is independent of time of the day. These data reveal a previously unappreciated daily oscillation of inhibitory LTP in hippocampal neurons and uncover a dynamic contribution of inhibitory synapses in memory mechanisms across sleep and wake.
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Wu K, Shepard RD, Castellano D, Han W, Tian Q, Dong L, Lu W. Shisa7 phosphorylation regulates GABAergic transmission and neurodevelopmental behaviors. Neuropsychopharmacology 2022; 47:2160-2170. [PMID: 35534528 PMCID: PMC9556544 DOI: 10.1038/s41386-022-01334-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/27/2022] [Accepted: 04/19/2022] [Indexed: 11/09/2022]
Abstract
GABA-A receptors (GABAARs) are crucial for development and function of the brain. Altered GABAergic transmission is hypothesized to be involved in neurodevelopmental disorders. Recently, we identified Shisa7 as a GABAAR auxiliary subunit that modulates GABAAR trafficking and GABAergic transmission. However, the underlying molecular mechanisms remain elusive. Here we generated a knock-in (KI) mouse line that is phospho-deficient at a phosphorylation site in Shisa7 (S405) and combined with electrophysiology, imaging and behavioral assays to illustrate the role of this site in GABAergic transmission and plasticity as well as behaviors. We found that expression of phospho-deficient mutants diminished α2-GABAAR trafficking in heterologous cells. Additionally, α1/α2/α5-GABAAR surface expression and GABAergic inhibition were decreased in hippocampal neurons in KI mice. Moreover, chemically induced inhibitory long-term potentiation was abolished in KI mice. Lastly, KI mice exhibited hyperactivity, increased grooming and impaired sleep homeostasis. Collectively, our study reveals a phosphorylation site critical for Shisa7-dependent GABAARs trafficking which contributes to behavioral endophenotypes displayed in neurodevelopmental disorders.
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Affiliation(s)
- Kunwei Wu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ryan David Shepard
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - David Castellano
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Wenyan Han
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Qingjun Tian
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
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Glutamate and GABA A receptor crosstalk mediates homeostatic regulation of neuronal excitation in the mammalian brain. Signal Transduct Target Ther 2022; 7:340. [PMID: 36184627 PMCID: PMC9527238 DOI: 10.1038/s41392-022-01148-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 05/29/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
Maintaining a proper balance between the glutamate receptor-mediated neuronal excitation and the A type of GABA receptor (GABAAR) mediated inhibition is essential for brain functioning; and its imbalance contributes to the pathogenesis of many brain disorders including neurodegenerative diseases and mental illnesses. Here we identify a novel glutamate-GABAAR interaction mediated by a direct glutamate binding of the GABAAR. In HEK293 cells overexpressing recombinant GABAARs, glutamate and its analog ligands, while producing no current on their own, potentiate GABA-evoked currents. This potentiation is mediated by a direct binding at a novel glutamate binding pocket located at the α+/β− subunit interface of the GABAAR. Moreover, the potentiation does not require the presence of a γ subunit, and in fact, the presence of γ subunit significantly reduces the potency of the glutamate potentiation. In addition, the glutamate-mediated allosteric potentiation occurs on native GABAARs in rat neurons maintained in culture, as evidenced by the potentiation of GABAAR-mediated inhibitory postsynaptic currents and tonic currents. Most importantly, we found that genetic impairment of this glutamate potentiation in knock-in mice resulted in phenotypes of increased neuronal excitability, including decreased thresholds to noxious stimuli and increased seizure susceptibility. These results demonstrate a novel cross-talk between excitatory transmitter glutamate and inhibitory GABAAR. Such a rapid and short feedback loop between the two principal excitatory and inhibitory neurotransmission systems may play a critical homeostatic role in fine-tuning the excitation-inhibition balance (E/I balance), thereby maintaining neuronal excitability in the mammalian brain under both physiological and pathological conditions.
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Tipton AE, Russek SJ. Regulation of Inhibitory Signaling at the Receptor and Cellular Level; Advances in Our Understanding of GABAergic Neurotransmission and the Mechanisms by Which It Is Disrupted in Epilepsy. Front Synaptic Neurosci 2022; 14:914374. [PMID: 35874848 PMCID: PMC9302637 DOI: 10.3389/fnsyn.2022.914374] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/17/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory signaling in the brain organizes the neural circuits that orchestrate how living creatures interact with the world around them and how they build representations of objects and ideas. Without tight control at multiple points of cellular engagement, the brain’s inhibitory systems would run down and the ability to extract meaningful information from excitatory events would be lost leaving behind a system vulnerable to seizures and to cognitive decline. In this review, we will cover many of the salient features that have emerged regarding the dynamic regulation of inhibitory signaling seen through the lens of cell biology with an emphasis on the major building blocks, the ligand-gated ion channel receptors that are the first transduction point when the neurotransmitter GABA is released into the synapse. Epilepsy association will be used to indicate importance of key proteins and their pathways to brain function and to introduce novel areas for therapeutic intervention.
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Affiliation(s)
- Allison E. Tipton
- Graduate Program for Neuroscience, Boston University, Boston, MA, United States
- Biomolecular Pharmacology Program, Boston University School of Medicine, Boston, MA, United States
- Boston University MD/PhD Training Program, Boston, MA, United States
| | - Shelley J. Russek
- Biomolecular Pharmacology Program, Boston University School of Medicine, Boston, MA, United States
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, United States
- Center for Systems Neuroscience, Boston University, Boston, MA, United States
- Boston University MD/PhD Training Program, Boston, MA, United States
- *Correspondence: Shelley J. Russek,
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Zachlod D, Bludau S, Cichon S, Palomero-Gallagher N, Amunts K. Combined analysis of cytoarchitectonic, molecular and transcriptomic patterns reveal differences in brain organization across human functional brain systems. Neuroimage 2022; 257:119286. [PMID: 35597401 DOI: 10.1016/j.neuroimage.2022.119286] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/22/2022] [Accepted: 05/05/2022] [Indexed: 01/14/2023] Open
Abstract
Brain areas show specific cellular, molecular, and gene expression patterns that are linked to function, but their precise relationships are largely unknown. To unravel these structure-function relationships, a combined analysis of 53 neurotransmitter receptor genes, receptor densities of six transmitter systems and cytoarchitectonic data of the auditory, somatosensory, visual, motor systems was conducted. Besides covariation of areal gene expression with receptor density, the study reveals specific gene expression patterns in functional systems, which are most prominent for the inhibitory GABAA and excitatory glutamatergic NMDA receptors. Furthermore, gene expression-receptor relationships changed in a systematic manner according to information flow from primary to higher associative areas. The findings shed new light on the relationship of anatomical, functional, and molecular and transcriptomic principles of cortical segregation towards a more comprehensive understanding of human brain organization.
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Affiliation(s)
- Daniel Zachlod
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany.
| | - Sebastian Bludau
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Sven Cichon
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; Department of Biomedicine, University of Basel, Basel, Switzerland; Institute of Medical Genetics and Pathology, University Hospital Basel, Basel, Switzerland
| | - Nicola Palomero-Gallagher
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; C. & O. Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany; Department of Psychiatry, Psychotherapy, and Psychosomatics, Medical Faculty, RWTH Aachen, and JARA - Translational Brain Medicine, Aachen, Germany
| | - Katrin Amunts
- Institute of Neurosciences and Medicine (INM-1), Research Centre Jülich, Jülich, Germany; C. & O. Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
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Wu K, Castellano D, Tian Q, Lu W. Distinct regulation of tonic GABAergic inhibition by NMDA receptor subtypes. Cell Rep 2021; 37:109960. [PMID: 34758303 PMCID: PMC8630577 DOI: 10.1016/j.celrep.2021.109960] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 09/03/2021] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
Tonic inhibition mediated by extrasynaptic GABAARs regulates various brain functions. However, the mechanisms that regulate tonic inhibition remain largely unclear. Here, we report distinct actions of GluN2A- and GluN2B-NMDA receptors (NMDARs) on tonic inhibition in hippocampal neurons under basal and high activity conditions. Specifically, overexpression of GluN2B, but not GluN2A, reduces α5-GABAAR surface expression and tonic currents. Additionally, knockout of GluN2A and GluN2B decreases and increases tonic currents, respectively. Mechanistically, GluN2A-NMDARs inhibit and GluN2B-NMDARs promote α5-GABAAR internalization, resulting in increased and decreased surface α5-GABAAR expression, respectively. Furthermore, GluN2A-NMDARs, but not GluN2B-NMDARs, are required for homeostatic potentiation of tonic inhibition induced by prolonged increase of neuronal activity. Last, tonic inhibition decreases during acute seizures, whereas it increases 24 h later, involving GluN2-NMDAR-dependent signaling. Collectively, these data reveal an NMDAR subunit-specific regulation of tonic inhibition in physiological and pathological conditions and provide mechanistic insight into activity-dependent modulation of tonic inhibition.
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Affiliation(s)
- Kunwei Wu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - David Castellano
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Qingjun Tian
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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Hong GP, Kim MH, Kim HJ. Sex-related Differences in Glial Fibrillary Acidic Protein-positive GABA Regulate Neuropathology Following Pilocarpine-induced Status Epilepticus. Neuroscience 2021; 472:157-166. [PMID: 34400247 DOI: 10.1016/j.neuroscience.2021.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 07/28/2021] [Accepted: 08/03/2021] [Indexed: 12/31/2022]
Abstract
Status epilepticus (SE) is a life-threatening neurological disorder that causes neuronal death and glial activation. Studies have explained the clinical side effects and lack of effectiveness of neurological disorder treatments based on sex-related differences in brain structure and function. However, the sex-specific outcomes of seizure disorders and the underlying mechanisms remain unknown. We compared SE-induced behavioral and pathophysiological changes in male and female mice. The time taken to reach stage 6 seizure following pilocarpine injection was shorter in male mice than in female mice, and the prevalence of SE was higher in male mice than in female mice. Fluoro-Jade B staining revealed more extensive SE-induced hippocampal neuronal death in male mice than in female mice. Glial cells were more activated in male mice than in female mice. In contrast, astrocyte-derived γ-aminobutyric acid (GABA)-immunostaining was less expressed in male mice than in female mice. Moreover, the mRNA levels of inflammatory cytokines released from activated glial cells were higher in male mice than in female mice. Notably, the mRNA level of astrocytic γ-aminobutyric acid transporter (GAT-3) involved in extracellular GABA uptake was lower in female mice than in male mice, while the mRNA levels of glutamate/aspartate transporter (GLAST (EAAT1)) and glutamate transporter (GLT-1 (EAAT2)) involved in extracellular glutamate uptake were higher in female mice. Our findings suggest that male mice are more vulnerable to SE than female mice, resulting in more extensive neuronal cell death and glial activation in male mice, partly due to increased GAT-3 expression that subsequently leads to reduced glial fibrillary acidic protein (GFAP)-positive GABA content assessed with anti-GABA antibodies.
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Affiliation(s)
- Geum Pyo Hong
- Department of Physiology, College of Medicine, Dankook University, Cheonan, Republic of Korea; Department of Medical Laser, Graduate School, Dankook University, Cheonan, Republic of Korea
| | - Mi-Hye Kim
- Department of Physiology, College of Medicine, Dankook University, Cheonan, Republic of Korea; Department of Medical Laser, Graduate School, Dankook University, Cheonan, Republic of Korea
| | - Hee Jung Kim
- Department of Physiology, College of Medicine, Dankook University, Cheonan, Republic of Korea.
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10
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Neocortex- and hippocampus-specific deletion of Gabrg2 causes temperature-dependent seizures in mice. Cell Death Dis 2021; 12:553. [PMID: 34050134 PMCID: PMC8163876 DOI: 10.1038/s41419-021-03846-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/17/2021] [Indexed: 02/04/2023]
Abstract
Mutations in the GABRG2 gene encoding the γ-aminobutyric acid (GABA) A receptor gamma 2 subunit are associated with genetic epilepsy with febrile seizures plus, febrile seizures plus, febrile seizures, and other symptoms of epilepsy. However, the mechanisms underlying Gabrg2-mediated febrile seizures are poorly understood. Here, we used the Cre/loxP system to generate conditional knockout (CKO) mice with deficient Gabrg2 in the hippocampus and neocortex. Heterozygous CKO mice (Gabrg2fl/wtCre+) exhibited temperature-dependent myoclonic jerks, generalised tonic-clonic seizures, increased anxiety-like symptoms, and a predisposition to induce seizures. Cortical electroencephalography showed the hyperexcitability in response to temperature elevation in Gabrg2fl/wtCre+ mice, but not in wild-type mice. Gabrg2fl/wtCre+ mice exhibited spontaneous seizures and susceptibility to temperature-induced seizures. Loss of neurons were observed in cortical layers V-VI and hippocampus of Gabrg2fl/wtCre+ mice. Furthermore, the latency of temperature- or pentylenetetrazol-induced seizures were significantly decreased in Gabrg2fl/wtCre+ mice compared with wild-type mice. In summary, Gabrg2fl/wtCre+ mice with Gabrg2 deletion in the neocortex and hippocampus reproduce many features of febrile seizures and therefore provide a novel model to further understand this syndrome at the cellular and molecular level.
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11
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Rudolph S, Guo C, Pashkovski SL, Osorno T, Gillis WF, Krauss JM, Nyitrai H, Flaquer I, El-Rifai M, Datta SR, Regehr WG. Cerebellum-Specific Deletion of the GABA A Receptor δ Subunit Leads to Sex-Specific Disruption of Behavior. Cell Rep 2021; 33:108338. [PMID: 33147470 PMCID: PMC7700496 DOI: 10.1016/j.celrep.2020.108338] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 08/04/2020] [Accepted: 10/08/2020] [Indexed: 12/19/2022] Open
Abstract
Granule cells (GCs) of the cerebellar input layer express high-affinity δ GABAA subunit-containing GABAA receptors (δGABAARs) that respond to ambient GABA levels and context-dependent neuromodulators like steroids. We find that GC-specific deletion of δGABAA (cerebellar [cb] δ knockout [KO]) decreases tonic inhibition, makes GCs hyperexcitable, and in turn, leads to differential activation of cb output regions as well as many cortical and subcortical brain areas involved in cognition, anxiety-like behaviors, and the stress response. Cb δ KO mice display deficits in many behaviors, but motor function is normal. Strikingly, δGABAA deletion alters maternal behavior as well as spontaneous, stress-related, and social behaviors specifically in females. Our findings establish that δGABAARs enable the cerebellum to control diverse behaviors not previously associated with the cerebellum in a sex-dependent manner. These insights may contribute to a better understanding of the mechanisms that underlie behavioral abnormalities in psychiatric and neurodevelopmental disorders that display a gender bias. Rudolph et al. show that deletion of the neuromodulator and hormone-sensitive δGABAA receptor subunit from cerebellar granule cells results in anxiety-like behaviors and female-specific deficits in social behavior and maternal care. δGABAA deletion is associated with hyperexcitability of the cerebellar input layer and altered activation of many stress-related brain regions.
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Affiliation(s)
- Stephanie Rudolph
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Chong Guo
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Stan L Pashkovski
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Tomas Osorno
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Winthrop F Gillis
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Jeremy M Krauss
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Hajnalka Nyitrai
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Isabella Flaquer
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Mahmoud El-Rifai
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Wade G Regehr
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA.
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12
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Wang X, Hu Y, Liu W, Ma Y, Chen X, Xue T, Cui D. Molecular Basis of GABA Hypofunction in Adolescent Schizophrenia-Like Animals. Neural Plast 2021; 2021:9983438. [PMID: 33936193 PMCID: PMC8062182 DOI: 10.1155/2021/9983438] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/22/2021] [Accepted: 03/30/2021] [Indexed: 01/11/2023] Open
Abstract
Schizophrenia is a neurodevelopmental disorder that NMDA receptor (NMDAR) hypofunction appears centrally involved. Schizophrenia typically emerges in adolescence or early adulthood. Electrophysiological and several neurochemical changes have linked the GABA deficits to abnormal behaviors induced by NMDAR hypofunction. However, few studies have systematically investigated the molecular basis of GABA deficits, especially during adolescence. To address this issue, we transiently administrated MK-801 to mice on PND 10, which exhibited schizophrenia-relevant deficits in adolescence. Slice recording showed reduced GABA transmission and PVI+ hypofunction, indicating GABAergic hypofunction. Cortical proteomic evaluation combined with analysis of single cell data from the Allen Brain showed that various metabolic processes were enriched in top ranks and differentially altered in excitatory neurons, GABAergic interneurons, and glial cells. Notably, the GABA-related amino acid metabolic process was disturbed in both astrocytes and interneurons, in which we found a downregulated set of GABA-related proteins (GAD65, SYNPR, DBI, GAT3, SN1, and CPT1A). They synergistically regulate GABA synthesis, release, reuptake, and replenishment. Their downregulation indicates impaired GABA cycle and homeostasis regulated by interneuron-astrocyte communication in adolescence. Our findings on molecular basis of GABA deficits could provide potential drug targets of GABAergic rescue for early prevention and intervention.
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Affiliation(s)
- Xiaodan Wang
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
- Department of Neurology & Institute of Neurology, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ying Hu
- Shenzhi Department of the Fourth Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Wenxin Liu
- College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Yuanyuan Ma
- Shenzhi Department of the Fourth Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Xi Chen
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
| | - Ting Xue
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
| | - Donghong Cui
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai, China
- Brain Science and Technology Research Center, Shanghai Jiao Tong University, Shanghai, China
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13
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Wu K, Han W, Tian Q, Li Y, Lu W. Activity- and sleep-dependent regulation of tonic inhibition by Shisa7. Cell Rep 2021; 34:108899. [PMID: 33761345 PMCID: PMC8025742 DOI: 10.1016/j.celrep.2021.108899] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/22/2020] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
Tonic inhibition mediated by extrasynaptic γ-aminobutyric acid type A receptors (GABAARs) critically regulates neuronal excitability and brain function. However, the mechanisms regulating tonic inhibition remain poorly understood. Here, we report that Shisa7 is critical for tonic inhibition regulation in hippocampal neurons. In juvenile Shisa7 knockout (KO) mice, α5-GABAAR-mediated tonic currents are significantly reduced. Mechanistically, Shisa7 is crucial for α5-GABAAR exocytosis. Additionally, Shisa7 regulation of tonic inhibition requires protein kinase A (PKA) that phosphorylates Shisa7 serine 405 (S405). Importantly, tonic inhibition undergoes activity-dependent regulation, and Shisa7 is required for homeostatic potentiation of tonic inhibition. Interestingly, in young adult Shisa7 KOs, basal tonic inhibition in hippocampal neurons is unaltered, largely due to the diminished α5-GABAAR component of tonic inhibition. However, at this stage, tonic inhibition oscillates during the daily sleep/wake cycle, a process requiring Shisa7. Together, these data demonstrate that intricate signaling mechanisms regulate tonic inhibition at different developmental stages and reveal a molecular link between sleep and tonic inhibition.
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Affiliation(s)
- Kunwei Wu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wenyan Han
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Qingjun Tian
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yan Li
- Proteomics Core Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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14
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George S, Chiou TT, Kanamalla K, De Blas AL. Recruitment of Plasma Membrane GABA-A Receptors by Submembranous Gephyrin/Collybistin Clusters. Cell Mol Neurobiol 2021; 42:1585-1604. [PMID: 33547626 DOI: 10.1007/s10571-021-01050-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/23/2021] [Indexed: 11/29/2022]
Abstract
It has been shown that subunit composition is the main determinant of the synaptic or extrasynaptic localization of GABAA receptors (GABAARs). Synaptic and extrasynaptic GABAARs are involved in phasic and tonic inhibition, respectively. It has been proposed that synaptic GABAARs bind to the postsynaptic gephyrin/collybistin (Geph/CB) lattice, but not the typically extrasynaptic GABAARs. Nevertheless, there are no studies of the direct binding of various types of GABAARs with the submembranous Geph/CB lattice in the absence of other synaptic proteins, some of which are known to interact with GABAARs. We have reconstituted GABAARs of various subunit compositions, together with the Geph/CB scaffold, in HEK293 cells, and have investigated the recruitment of surface GABAARs by submembranous Geph/CB clusters. Results show that the typically synaptic α1β3γ2 GABAARs were trapped by submembranous Geph/CB clusters. The α5β3γ2 GABAARs, which are both synaptic and extrasynaptic, were also trapped by Geph/CB clusters. Extrasynaptic α4β3δ GABAARs consistently showed little or no trapping by the Geph/CB clusters. However, the extrasynaptic α6β3δ, α1β3, α6β3 (and less α4β3) GABAARs were highly trapped by the Geph/CB clusters. AMPA and NMDA glutamate receptors were not trapped. The results suggest: (I) in the absence of other synaptic molecules, the Geph/CB lattice has the capacity to trap not only synaptic but also several typically extrasynaptic GABAARs; (II) the Geph/CB lattice is important but does not play a decisive role in the synaptic localization of GABAARs; and (III) in neurons there must be mechanisms preventing the trapping of several typically extrasynaptic GABAARs by the postsynaptic Geph/CB lattice.
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Affiliation(s)
- Shanu George
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA
| | - Tzu-Ting Chiou
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA
| | - Karthik Kanamalla
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA
| | - Angel L De Blas
- Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, U-3156, Storrs, CT, 06269-3156, USA.
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15
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Abstract
Alcohol dependence is a chronically relapsing disorder characterized by compulsive drug-seeking and drug-taking, loss of control in limiting intake, and the emergence of a withdrawal syndrome in the absence of the drug. Accumulating evidence suggests an important role for synaptic transmission in the central nucleus of the amygdala (CeA) in mediating alcohol-related behaviors and neuroadaptive mechanisms associated with alcohol dependence. Acute alcohol facilitates γ-aminobutyric acid (GABA)ergic transmission in the CeA via both pre- and postsynaptic mechanisms, and chronic alcohol increases baseline GABAergic transmission. Acute alcohol inhibits glutamatergic transmission via effects at N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the CeA, whereas chronic alcohol up-regulates NMDA receptor (NMDAR)-mediated transmission. Pro- (e.g., corticotropin-releasing factor [CRF]) and antistress (e.g., nociceptin/orphanin FQ, oxytocin) neuropeptides affect alcohol- and anxiety-related behaviors, and also alter the alcohol-induced effects on CeA neurotransmission. Alcohol dependence produces plasticity in these neuropeptide systems, reflecting a recruitment of those systems during the transition to alcohol dependence.
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Affiliation(s)
- Marisa Roberto
- Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Dean Kirson
- Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Sophia Khom
- Departments of Molecular Medicine and Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
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16
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Castellano D, Shepard RD, Lu W. Looking for Novelty in an "Old" Receptor: Recent Advances Toward Our Understanding of GABA ARs and Their Implications in Receptor Pharmacology. Front Neurosci 2021; 14:616298. [PMID: 33519367 PMCID: PMC7841293 DOI: 10.3389/fnins.2020.616298] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 12/14/2020] [Indexed: 12/16/2022] Open
Abstract
Diverse populations of GABAA receptors (GABAARs) throughout the brain mediate fast inhibitory transmission and are modulated by various endogenous ligands and therapeutic drugs. Deficits in GABAAR signaling underlie the pathophysiology behind neurological and neuropsychiatric disorders such as epilepsy, anxiety, and depression. Pharmacological intervention for these disorders relies on several drug classes that target GABAARs, such as benzodiazepines and more recently neurosteroids. It has been widely demonstrated that subunit composition and receptor stoichiometry impact the biophysical and pharmacological properties of GABAARs. However, current GABAAR-targeting drugs have limited subunit selectivity and produce their therapeutic effects concomitantly with undesired side effects. Therefore, there is still a need to develop more selective GABAAR pharmaceuticals, as well as evaluate the potential for developing next-generation drugs that can target accessory proteins associated with native GABAARs. In this review, we briefly discuss the effects of benzodiazepines and neurosteroids on GABAARs, their use as therapeutics, and some of the pitfalls associated with their adverse side effects. We also discuss recent advances toward understanding the structure, function, and pharmacology of GABAARs with a focus on benzodiazepines and neurosteroids, as well as newly identified transmembrane proteins that modulate GABAARs.
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Affiliation(s)
- David Castellano
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Ryan David Shepard
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Wei Lu
- Synapse and Neural Circuit Research Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
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17
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Aponte-Santiago NA, Littleton JT. Synaptic Properties and Plasticity Mechanisms of Invertebrate Tonic and Phasic Neurons. Front Physiol 2020; 11:611982. [PMID: 33391026 PMCID: PMC7772194 DOI: 10.3389/fphys.2020.611982] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/24/2020] [Indexed: 12/15/2022] Open
Abstract
Defining neuronal cell types and their associated biophysical and synaptic diversity has become an important goal in neuroscience as a mechanism to create comprehensive brain cell atlases in the post-genomic age. Beyond broad classification such as neurotransmitter expression, interneuron vs. pyramidal, sensory or motor, the field is still in the early stages of understanding closely related cell types. In both vertebrate and invertebrate nervous systems, one well-described distinction related to firing characteristics and synaptic release properties are tonic and phasic neuronal subtypes. In vertebrates, these classes were defined based on sustained firing responses during stimulation (tonic) vs. transient responses that rapidly adapt (phasic). In crustaceans, the distinction expanded to include synaptic release properties, with tonic motoneurons displaying sustained firing and weaker synapses that undergo short-term facilitation to maintain muscle contraction and posture. In contrast, phasic motoneurons with stronger synapses showed rapid depression and were recruited for short bursts during fast locomotion. Tonic and phasic motoneurons with similarities to those in crustaceans have been characterized in Drosophila, allowing the genetic toolkit associated with this model to be used for dissecting the unique properties and plasticity mechanisms for these neuronal subtypes. This review outlines general properties of invertebrate tonic and phasic motoneurons and highlights recent advances that characterize distinct synaptic and plasticity pathways associated with two closely related glutamatergic neuronal cell types that drive invertebrate locomotion.
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Affiliation(s)
- Nicole A. Aponte-Santiago
- The Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, CA, United States
| | - J. Troy Littleton
- The Picower Institute for Learning and Memory, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States
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18
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Pace M, Falappa M, Machado P, Facchin L, Hermann DM, Bassetti CL. Postacute administration of the GABA A α5 antagonist S44819 promotes recovery of peripheral limb fine motor skills after permanent distal middle cerebral artery occlusion in rats. CLINICAL AND TRANSLATIONAL NEUROSCIENCE 2020. [DOI: 10.1177/2514183x20948306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Ischemic stroke causes hypoexcitability in the peri-infarct motor neocortex that stems from increased tonic γ-amino-butyric acid (GABA) activity in neurons. This hypoexcitability, while neuroprotective in the acute phase, may impair neuroplasticity and functional recovery in the subacute phase of stroke. The purpose of this study is to investigate the effect of delayed and prolonged administration of S44819, which is a potent and competitive selective antagonist of GABAA receptors, on the skilled reaching function in a rodent model of stroke. Methods: Male Sprague–Dawley rats ( n = 15) were subjected to permanent middle cerebral artery occlusion. Starting 3 days after stroke, a vehicle or S44819 (3 or 10 mg/kg, BID) was delivered orally twice a day for 28 days. All animals were euthanized 2 weeks later after the washout period. A single pellet reaching task (SPR) was performed before (baseline value) and after the ischemic surgery at several time points (3, 10, 17, 24, 31, 38, and 45 days) to assess the motor deficit. Infarct volume and body changes were also evaluated. Results: S44819, administered at 10 but not 3 mg/kg, significantly improves SPR results over the 45 days after the ischemic surgery. No effect was observed in the infarct size and in the body weight over time between the groups investigated. Conclusion: S44819 at 10 mg/kg significantly enhances motor recovery on a skilled reaching task after sensory-motor cortex lesion. Additionally, our study, in light of the results of the RESTORE BRAIN (Randomized Efficacy and Safety Trial of Oral GABAA α5 antagonist S44819 after Recent ischemic Event) trial, may help clinicians to design clinical studies and stratify variables and patients adequately.
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Affiliation(s)
- Marta Pace
- Genetics and Epigenetics of Behaviour Laboratory, Istituto Italiano di Tecnologia, Genoa, Italy
- Center for Experimental Neurology, Department of Neurology, University Hospital (Inselspital), Bern, Switzerland
| | - Matteo Falappa
- Genetics and Epigenetics of Behaviour Laboratory, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Patricia Machado
- Institut de Recherches Internationales Servier, Suresnes, France
| | - Laura Facchin
- Center for Experimental Neurology, Department of Neurology, University Hospital (Inselspital), Bern, Switzerland
| | - Dirk M Hermann
- Department of Neurology, University Hospital Essen, Essen, Germany
| | - Claudio L Bassetti
- Center for Experimental Neurology, Department of Neurology, University Hospital (Inselspital), Bern, Switzerland
- Department of Neurology, University Hospital-Inselspital, Bern, Switzerland
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19
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Hoshino O, Kameno R, Kubo J, Watanabe K. Spatiotemporal regulation of GABA concentration in extracellular space by gliotransmission crucial for extrasynaptic receptor-mediated improvement of sensory tuning performance in schizophrenia. J Comput Neurosci 2020; 48:317-332. [PMID: 32761409 DOI: 10.1007/s10827-020-00755-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 06/14/2020] [Accepted: 07/07/2020] [Indexed: 10/23/2022]
Abstract
In schizophrenic patients, sensory tuning performance tends to be deteriorated (i.e., flattened sensory tuning), for which impaired intracortical tonic inhibition arising from a reduction in GABA concentration in extracellular space might be responsible. The δ subunit-containing GABAA receptor, located on extrasynaptic sites, is known to be involved in mediating tonic inhibitory currents in cortical pyramidal cells and is considered to be one of the beneficial therapeutic targets for the treatment of schizophrenia. The transporter GAT-1 in glial (astrocytic) membrane controls concentration of GABA molecules by removing them from extracellular space. We speculated that the upregulation of extrasynaptic receptors might compensate for the impaired tonic inhibition and thus improve their sensory tuning performance, in which the astrocytic GABA transporter might play an important role. To test our hypothesis, we simulated a schizophrenic neural network model with a GABAergic gliotransmission (i.e., GABA transport by transporters embedded in astrocytic membranes) mechanism that modulates local ambient (extracellular) GABA levels in a neuronal activity-dependent manner. Upregulating extrasynaptic GABA receptors compensated the impaired tonic inhibition and sharpened the sensory tuning, provided that ambient GABA molecules around stimulus-sensitive pyramidal cells were actively removed during sensory stimulation. We suggest that the upregulation of extrasynaptic GABA receptors can improve the performance of sensory tuning in schizophrenic patients, for which spatiotemporal regulation of ambient GABA concentration by gliotransmission may be crucial.
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Affiliation(s)
- Osamu Hoshino
- Department of Intelligent Systems Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki, 316-8511, Japan. .,Southern Tohoku Research Institute for Neuroscience, Southern Tohoku General Hospital, 7-115 Yatsuyamada, Koriyama, Fukushima, 963-8563, Japan.
| | - Rikiya Kameno
- Southern Tohoku Research Institute for Neuroscience, Southern Tohoku General Hospital, 7-115 Yatsuyamada, Koriyama, Fukushima, 963-8563, Japan
| | - Jin Kubo
- Department of Rehabilitation Medicine, International University of Health and Welfare, Ichikawa Hospital, 6-1-14 Konodai, Ichikawa, Chiba, 272-0827, Japan
| | - Kazuo Watanabe
- Southern Tohoku Research Institute for Neuroscience, Southern Tohoku General Hospital, 7-115 Yatsuyamada, Koriyama, Fukushima, 963-8563, Japan
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20
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Mortensen M, Huckvale R, Pandurangan AP, Baker JR, Smart TG. Optopharmacology reveals a differential contribution of native GABA A receptors to dendritic and somatic inhibition using azogabazine. Neuropharmacology 2020; 176:108135. [PMID: 32445639 PMCID: PMC7482436 DOI: 10.1016/j.neuropharm.2020.108135] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/20/2020] [Accepted: 05/09/2020] [Indexed: 12/13/2022]
Abstract
γ-aminobutyric acid type-A receptors (GABAARs) are inhibitory ligand-gated ion channels in the brain that are crucial for controlling neuronal excitation. To explore their physiological roles in cellular and neural network activity, it is important to understand why specific GABAAR isoforms are distributed not only to various brain regions and cell types, but also to specific areas of the membrane in individual neurons. To address this aim we have developed a novel photosensitive compound, azogabazine, that targets and reversibly inhibits GABAARs. The receptor selectivity of the compound is based on the competitive antagonist, gabazine, and photosensitivity is conferred by a photoisomerisable azobenzene group. Azogabazine can exist in either cis or trans conformations that are controlled by UV and blue light respectively, to affect receptor inhibition. We report that the trans-isomer preferentially binds and inhibits GABAAR function, whilst promotion of the cis-isomer caused unbinding of azogabazine from GABAARs. Using cultured cerebellar granule cells, azogabazine in conjunction with UV light applied to defined membrane domains, revealed higher densities of GABAARs at somatic inhibitory synapses compared to those populating proximal dendritic zones, even though the latter displayed a higher number of synapses per unit area of membrane. Azogabazine also revealed more pronounced GABA-mediated inhibition of action potential firing in proximal dendrites compared to the soma. Overall, azogabazine is a valuable addition to the photochemical toolkit that can be used to interrogate GABAAR function and inhibition.
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Affiliation(s)
- Martin Mortensen
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
| | - Rosemary Huckvale
- The Institute of Cancer Research, 123 Old Brompton Road, London, SW7 3RP, UK
| | - Arun P Pandurangan
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, CB2 0QH, UK
| | - James R Baker
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, UK
| | - Trevor G Smart
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
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21
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Mendes A, Vignoud G, Perez S, Perrin E, Touboul J, Venance L. Concurrent Thalamostriatal and Corticostriatal Spike-Timing-Dependent Plasticity and Heterosynaptic Interactions Shape Striatal Plasticity Map. Cereb Cortex 2020; 30:4381-4401. [DOI: 10.1093/cercor/bhaa024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Abstract
The striatum integrates inputs from the cortex and thalamus, which display concomitant or sequential activity. The striatum assists in forming memory, with acquisition of the behavioral repertoire being associated with corticostriatal (CS) plasticity. The literature has mainly focused on that CS plasticity, and little remains known about thalamostriatal (TS) plasticity rules or CS and TS plasticity interactions. We undertook here the study of these plasticity rules. We found bidirectional Hebbian and anti-Hebbian spike-timing-dependent plasticity (STDP) at the thalamic and cortical inputs, respectively, which were driving concurrent changes at the striatal synapses. Moreover, TS- and CS-STDP induced heterosynaptic plasticity. We developed a calcium-based mathematical model of the coupled TS and CS plasticity, and simulations predict complex changes in the CS and TS plasticity maps depending on the precise cortex–thalamus–striatum engram. These predictions were experimentally validated using triplet-based STDP stimulations, which revealed the significant remodeling of the CS-STDP map upon TS activity, which is notably the induction of the LTD areas in the CS-STDP for specific timing regimes. TS-STDP exerts a greater influence on CS plasticity than CS-STDP on TS plasticity. These findings highlight the major impact of precise timing in cortical and thalamic activity for the memory engram of striatal synapses.
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Affiliation(s)
- Alexandre Mendes
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, 75005, France
| | - Gaetan Vignoud
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, 75005, France
- Department of Mathematics, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 2454-9110, USA
| | - Sylvie Perez
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, 75005, France
| | - Elodie Perrin
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, 75005, France
| | - Jonathan Touboul
- Department of Mathematics, Volen National Center for Complex Systems, Brandeis University, Waltham, MA 2454-9110, USA
| | - Laurent Venance
- Dynamics and Pathophysiology of Neuronal Networks Team, Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS UMR7241, INSERM U1050, PSL Research University, Paris, 75005, France
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22
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Wearne TA, Cornish JL. Inhibitory regulation of the prefrontal cortex following behavioral sensitization to amphetamine and/or methamphetamine psychostimulants: A review of GABAergic mechanisms. Prog Neuropsychopharmacol Biol Psychiatry 2019; 95:109681. [PMID: 31255648 DOI: 10.1016/j.pnpbp.2019.109681] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/18/2019] [Accepted: 06/26/2019] [Indexed: 12/30/2022]
Abstract
Behavioral sensitization to repeated psychostimulant administration has been proposed to reflect many of the neurochemical and behavioral changes that are characteristic of a range of disorders, including drug addiction and psychoses. While previous studies have examined the role of dopamine and glutamate neurotransmission in mediating sensitization, particularly within the prefrontal cortex (PFC), the role of inhibitory GABAergic processing of the PFC in the expression of sensitization is not well understood. Recent research, however, has proposed an emerging role of GABA synthesis, reuptake, ionotropic and metabotropic receptor regulation, and interneuronal changes following sensitization to methamphetamine and/or amphetamine within the PFC. The aim of this review, therefore, is to synthesize research findings on changes to the GABAergic network following sensitization induced by amphetamines (i.e., amphetamine and/or methamphetamine) in the PFC. In addition to providing an overview of global PFC changes, we also provide evidence of regional specific inhibitory influences on sensitized circuitry, focusing on the prelimbic and orbitofrontal cortices. We propose a neural circuit through which inhibitory PFC GABA changes mediate sensitized disease states, focusing on the interaction between the prelimbic and orbitofrontal cortices with subcortical brain structures and the mesolimbic system. Methodological considerations and avenues for future research are also discussed.
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Affiliation(s)
- Travis A Wearne
- Department of Psychology, Macquarie University, Sydney, NSW, Australia; School of Psychology, University of New South Wales, Kensington, NSW, Australia
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23
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Nakajima M, Schmitt LI, Feng G, Halassa MM. Combinatorial Targeting of Distributed Forebrain Networks Reverses Noise Hypersensitivity in a Model of Autism Spectrum Disorder. Neuron 2019; 104:488-500.e11. [PMID: 31648899 DOI: 10.1016/j.neuron.2019.09.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/03/2019] [Accepted: 09/23/2019] [Indexed: 12/29/2022]
Abstract
Autism spectrum disorder (ASD) is associated with noise hypersensitivity, the suboptimal extraction of meaningful signals in noisy environments. Because sensory filtering can involve distinct automatic and executive circuit mechanisms, however, developing circuit-specific therapeutic strategies for ASD noise hypersensitivity can be challenging. Here, we find that both of these processes are individually perturbed in one monogenic form of ASD, Ptchd1 deletion. Although Ptchd1 is preferentially expressed in the thalamic reticular nucleus during development, pharmacological rescue of thalamic perturbations in knockout (KO) mice only normalized automatic sensory filtering. By discovering a separate prefrontal perturbation in these animals and adopting a combinatorial pharmacological approach that also rescued its associated goal-directed noise filtering deficit, we achieved full normalization of noise hypersensitivity in this model. Overall, our work highlights the importance of identifying large-scale functional circuit architectures and utilizing them as access points for behavioral disease correction.
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Affiliation(s)
- Miho Nakajima
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - L Ian Schmitt
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Guoping Feng
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA; The Stanley Center for Psychiatric Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, USA
| | - Michael M Halassa
- McGovern Institute for Brain Research and the Department of Brain and Cognitive Science, Massachusetts Institute of Technology, Cambridge, MA, USA; The Stanley Center for Psychiatric Genetics, Broad Institute of Harvard and MIT, Cambridge, MA, USA.
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24
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Wang YC, Dzyubenko E, Sanchez-Mendoza EH, Sardari M, Silva de Carvalho T, Doeppner TR, Kaltwasser B, Machado P, Kleinschnitz C, Bassetti CL, Hermann DM. Postacute Delivery of GABA A α5 Antagonist Promotes Postischemic Neurological Recovery and Peri-infarct Brain Remodeling. Stroke 2019; 49:2495-2503. [PMID: 30355106 PMCID: PMC6159671 DOI: 10.1161/strokeaha.118.021378] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Supplemental Digital Content is available in the text. Background and Purpose— Poststroke, neuronal excitability is tonically reduced in peri-infarct tissue via inhibitory influences of extrasynaptic GABAA receptors. We hypothesized that GABAA α5 blockade by the competitive antagonist S44819 enhances postischemic neurological recovery, brain remodeling, and neuroplasticity. Methods— In an explorative study followed by a confirmation study, male C57Bl6/j mice were exposed to transient intraluminal middle cerebral artery occlusion. Starting 72 hours poststroke, vehicle or S44819 (3 or 10 mg/kg, BID) was delivered orally for 28 days. Neurological recovery, perilesional tissue remodeling, and contralesional pyramidal tract plasticity were evaluated for 42 days, that is, 14 days after completion of S44819 delivery. Results— S44819, delivered at 10 but not 3 mg/kg, persistently improved motor coordination and spatial memory in both studies. Striatal atrophy was reduced by 10 mg/kg S44819 at 42 days post-treatment onset, and neuronal long-term survival in the peri-infarct striatum was increased. Delayed neuroprotection was associated with reduced peri-infarct astrogliosis, increased peri-infarct brain capillary density, and increased neural precursor cell proliferation and differentiation in proximity to the ipsilesional subventricular zone. Contralesional pyramidal tract plasticity, evaluated by anterograde tract tracing at the level of the red nucleus, was not influenced by S44819. Concentrations of neurotrophic (brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor) and angiogenic (vascular endothelial growth factor and basic fibroblast growth factor) growth factors were elevated by 10 mg/kg S44819 in peri-infarct but not contralesional brain tissue. Conclusions— Our data demonstrate that S44819 enhances neurological recovery and peri-infarct brain remodeling in the postacute stroke phase.
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Affiliation(s)
- Ya-Chao Wang
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | - Egor Dzyubenko
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | - Eduardo H Sanchez-Mendoza
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | - Maryam Sardari
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | - Tayana Silva de Carvalho
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | - Thorsten R Doeppner
- Department of Neurology, University of Goettingen Medical School, Germany (T.R.D.)
| | - Britta Kaltwasser
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | - Patricia Machado
- Institut de Recherches Internationales Servier, Suresnes, France (P.M.)
| | - Christoph Kleinschnitz
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
| | | | - Dirk M Hermann
- From the Department of Neurology, University Hospital Essen, Germany (Y.-c.W., E.D., E.H.S.-M., M.S., T.S.d.C., B.K., C.K., D.M.H.)
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25
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Gender-dependent regulation of anxiety-like behavior by δ subunit-containing GABAA receptor during postnatal development. Neuroreport 2019; 30:753-759. [PMID: 31261237 DOI: 10.1097/wnr.0000000000001192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The δ subunit-containing GABAA receptor [GABAA(δ)R], which is exclusively situated in the extrasynaptic space, has considerable influence on emotion and behavior. Although the expression of this receptor experiences dramatic fluctuation during postnatal development, it remains unknown whether it regulates emotion in a development-dependent manner. Here, by using mice with genetic deletion of GABAA(δ)R (knockout) and their wild-type littermates, we examined the role of GABAA(δ)R in regulating anxiety-like behavior, as measured with open field test (OFT) and elevated plus maze during the transition from puberty to adulthood. We observed that for female mice, the knockout ones at puberty but not adulthood showed increased anxiety-like behavior in the OFT relative to their wild-type littermates. However, such increase was not observed in elevated plus maze. For male mice, no between-genotype differences were observed in both tests at the above two developmental stages. Our results suggest that GABAA(δ)R preferentially affects the anxiety-like behavior in OFT in a development-dependent manner, but only in female mice.
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26
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Saboory E, Mohammadi S, Dindarian S, Mohammadi H. Prenatal stress and elevated seizure susceptibility: Molecular inheritable changes. Epilepsy Behav 2019; 96:122-131. [PMID: 31132613 DOI: 10.1016/j.yebeh.2019.04.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/17/2019] [Accepted: 04/24/2019] [Indexed: 01/08/2023]
Abstract
Stressful episodes are common during early-life and may have a wide range of negative effects on both physical and mental status of the offspring. In addition to various neurobehavioral complications induced by prenatal stress (PS), seizure is a common complication with no fully explained cause. In this study, the association between PS and seizure susceptibility was reviewed focusing on sex differences and various underlying mechanisms. The role of drugs in the initiation of seizure and the effects of PS on the nervous system that prone the brain for seizure, especially the hypothalamic-pituitary-adrenal (HPA) axis, are also discussed in detail by reviewing the papers studying the effect of PS on glutamatergic, gamma-aminobutyric acid (GABA)ergic, and adrenergic systems in the context of seizure and epilepsy. Finally, epigenetic changes in epilepsy are described, and the underlying mechanisms of this change are expanded. As the effects of PS may be life-lasting, it is possible to prevent future psychiatric and behavioral disorders including epilepsy by preventing avoidable PS risk factors.
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Affiliation(s)
- Ehsan Saboory
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran.
| | - Sedra Mohammadi
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran.
| | - Sina Dindarian
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran
| | - Hozan Mohammadi
- Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
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27
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Hermann DM, Saba B, Sors A, Bassetti CL. Preclinical concepts and results with the GABA A antagonist S44819 in a mouse model of middle cerebral artery occlusion. Neural Regen Res 2019; 14:1517-1518. [PMID: 31089046 PMCID: PMC6557109 DOI: 10.4103/1673-5374.255963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Affiliation(s)
- Dirk M Hermann
- Departments of Neurology, University Hospital Essen, Essen, Germany
| | - Barbara Saba
- Institut de Recherches Internationales Servier, Suresnes, France
| | - Aurore Sors
- Institut de Recherches Internationales Servier, Suresnes, France
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28
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Mele M, Costa RO, Duarte CB. Alterations in GABA A-Receptor Trafficking and Synaptic Dysfunction in Brain Disorders. Front Cell Neurosci 2019; 13:77. [PMID: 30899215 PMCID: PMC6416223 DOI: 10.3389/fncel.2019.00077] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/15/2019] [Indexed: 12/12/2022] Open
Abstract
GABAA receptors (GABAAR) are the major players in fast inhibitory neurotransmission in the central nervous system (CNS). Regulation of GABAAR trafficking and the control of their surface expression play important roles in the modulation of the strength of synaptic inhibition. Different pieces of evidence show that alterations in the surface distribution of GABAAR and dysregulation of their turnover impair the activity of inhibitory synapses. A diminished efficacy of inhibitory neurotransmission affects the excitatory/inhibitory balance and is a common feature of various disorders of the CNS characterized by an increased excitability of neuronal networks. The synaptic pool of GABAAR is mainly controlled through regulation of internalization, recycling and lateral diffusion of the receptors. Under physiological condition these mechanisms are finely coordinated to define the strength of GABAergic synapses. In this review article, we focus on the alteration in GABAAR trafficking with an impact on the function of inhibitory synapses in various disorders of the CNS. In particular we discuss how similar molecular mechanisms affecting the synaptic distribution of GABAAR and consequently the excitatory/inhibitory balance may be associated with a wide diversity of pathologies of the CNS, from psychiatric disorders to acute alterations leading to neuronal death. A better understanding of the cellular and molecular mechanisms that contribute to the impairment of GABAergic neurotransmission in these disorders, in particular the alterations in GABAAR trafficking and surface distribution, may lead to the identification of new pharmacological targets and to the development of novel therapeutic strategies.
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Affiliation(s)
- Miranda Mele
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Rui O Costa
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Carlos B Duarte
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Department of Life Sciences, University of Coimbra, Coimbra, Portugal
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29
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Green MV, Thayer SA. HIV gp120 upregulates tonic inhibition through α5-containing GABA ARs. Neuropharmacology 2019; 149:161-168. [PMID: 30797029 DOI: 10.1016/j.neuropharm.2019.02.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/30/2018] [Accepted: 02/17/2019] [Indexed: 12/17/2022]
Abstract
HIV-Associated Neurocognitive disorder (HAND) affects nearly half of infected patients. The HIV envelope protein gp120 is shed by infected cells and is a potent neurotoxin in vitro that reproduces many aspects of HAND when expressed in vivo. Here, we show that HIV gp120 increases the amplitude of a tonic current mediated by γ-aminobutyric acid type-A receptors (GABAARs). Treating rat hippocampal cultures with 600 pM gp120IIIB for 4 h increased a tonic bicuculline-sensitive current, which remained elevated for 24 h. The increased current resulted from upregulation of extrasynaptic α5-containing GABAARs, as indicated by inhibition with the selective inverse agonist basmisanil. Treatment with gp120 increased α5-GABAAR immunoreactivity on the cell surface without new protein synthesis. The increase in tonic inhibition was prevented by a C-X-C chemokine receptor type 4 (CXCR4) antagonist or elimination of microglia from the culture. Treatment with interleukin-1β (IL-1β) increased the tonic current and an IL-1 receptor antagonist blocked the gp120-evoked response. Pharmacological or genetic inhibition of p38 mitogen-activated protein kinase (MAPK) prevented the gp120-evoked increase in tonic current and direct activation of a mutant form of p38 MAPK expressed in neurons increased the current. Collectively, these data show that gp120 activates CXCR4 to stimulate microglia to release IL-1β. Subsequent stimulation of IL-1 receptors activates p38 MAPK in neurons leading to the upregulation of α5-containing GABAARs. Increased tonic inhibition impairs neuroplasticity and inhibition of α5-containing GABAARs improves cognitive function in disease models. Thus, gp120-induced upregulation of α5-containing GABAARs presents a novel therapeutic target for HAND.
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Affiliation(s)
- Matthew V Green
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stanley A Thayer
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA; Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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30
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Zhang X, Green MV, Thayer SA. HIV gp120-induced neuroinflammation potentiates NMDA receptors to overcome basal suppression of inhibitory synapses by p38 MAPK. J Neurochem 2019; 148:499-515. [PMID: 30520043 DOI: 10.1111/jnc.14640] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 11/21/2018] [Accepted: 11/27/2018] [Indexed: 12/18/2022]
Abstract
HIV-associated neurocognitive disorder affects about half of HIV-infected patients. HIV impairs neuronal function through indirect mechanisms mainly mediated by inflammatory cytokines and neurotoxic viral proteins, such as the envelope protein gp120. HIV gp120 elicits a neuroinflammatory response that potentiates NMDA receptor function and induces the loss of excitatory synapses. How gp120 influences neuronal inhibition remains unknown. In this study, we expressed a green fluorescent protein (GFP)-tagged recombinant antibody-like protein that binds to the post-synaptic scaffolding protein gephyrin to label inhibitory synapses in living neurons. Treatment with 600 pM gp120 for 24 h increased the number of labeled inhibitory synapses. HIV gp120 evoked the release of interleukin-1β (IL-1β) from microglia to activate IL-1 receptors on neurons. Subsequent activation of the tyrosine kinase Src and GluN2A-containing NMDA receptors increased the number of inhibitory synapses via a process that required protein synthesis. In naïve cultures, inhibition of neuronal p38 mitogen-activated protein kinase (p38 MAPK) increased the number of inhibitory synapses suggesting that p38 MAPK produces a basal suppression of inhibitory synapses that is overcome in the presence of gp120. Direct activation of a mutant form of p38 MAPK expressed in neurons mimicked basal suppression of inhibitory synapses. This study shows for the first time that gp120-induced neuroinflammation increases the number of inhibitory synapses and that this increase overcomes a basal suppression of synaptic inhibition. Increased inhibition may be an adaptive mechanism enabling neurons to counteract excess excitatory input in order to maintain network homeostasis. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Affiliation(s)
- Xinwen Zhang
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Matthew V Green
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, USA
| | - Stanley A Thayer
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.,Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, Minnesota, USA
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31
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Abstract
γ-aminobutyric acid has become one of the most widely known neurotransmitter molecules in the brain over the last 50 years, recognised for its pivotal role in inhibiting neural excitability. It emerged from studies of crustacean muscle and neurons before its significance to the mammalian nervous system was appreciated. Now, after five decades of investigation, we know that most neurons are γ-aminobutyric-acid-sensitive, it is a cornerstone of neural physiology and dysfunction to γ-aminobutyric acid signalling is increasingly documented in a range of neurological diseases. In this review, we briefly chart the neurodevelopment of γ-aminobutyric acid and its two major receptor subtypes: the γ-aminobutyric acidA and γ-aminobutyric acidB receptors, starting from the humble invertebrate origins of being an 'interesting molecule' acting at a single γ-aminobutyric acid receptor type, to one of the brain's most important neurochemical components and vital drug targets for major therapeutic classes of drugs. We document the period of molecular cloning and the explosive influence this had on the field of neuroscience and pharmacology up to the present day and the production of atomic γ-aminobutyric acidA and γ-aminobutyric acidB receptor structures. γ-Aminobutyric acid is no longer a humble molecule but the instigator of rich and powerful signalling processes that are absolutely vital for healthy brain function.
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Affiliation(s)
- Trevor G Smart
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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32
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Flores-Hernández J, Garzón-Vázquez JA, Hernández-Carballo G, Nieto-Mendoza E, Ruíz-Luna EA, Hernández-Echeagaray E. Striatal Neurodegeneration that Mimics Huntington's Disease Modifies GABA-induced Currents. Brain Sci 2018; 8:E217. [PMID: 30563250 PMCID: PMC6316731 DOI: 10.3390/brainsci8120217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/20/2018] [Accepted: 12/04/2018] [Indexed: 11/17/2022] Open
Abstract
Huntington's Disease (HD) is a degenerative disease which produces cognitive and motor disturbances. Treatment with GABAergic agonists improves the behavior and activity of mitochondrial complexes in rodents treated with 3-nitropropionic acid to mimic HD symptomatology. Apparently, GABA receptors activity may protect striatal medium spiny neurons (MSNs) from excitotoxic damage. This study evaluates whether mitochondrial inhibition with 3-NP that mimics the early stages of HD, modifies the kinetics and pharmacology of GABA receptors in patch clamp recorded dissociated MSNs cells. The results show that MSNs from mice treated with 3-NP exhibited differences in GABA-induced dose-response currents and pharmacological responses that suggests the presence of GABAC receptors in MSNs. Furthermore, there was a reduction in the effect of the GABAC antagonist that demonstrates a lessening of this GABA receptor subtype activity as a result of mitochondria inhibition.
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Affiliation(s)
- Jorge Flores-Hernández
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla C.P.72570, México.
| | | | | | - Elizabeth Nieto-Mendoza
- Laboratorio de neurofisiología del desarrollo y la neurodegeneración, UBIMED, FES-Iztacala, Universidad Nacional Autónoma de México, México, FES-Iztacala, Av. de Los Barrios #1, Los Reyes Iztacala, Tlalnepantla C.P.54090, México.
| | - Evelyn A Ruíz-Luna
- Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla C.P.72570, México.
| | - Elizabeth Hernández-Echeagaray
- Laboratorio de neurofisiología del desarrollo y la neurodegeneración, UBIMED, FES-Iztacala, Universidad Nacional Autónoma de México, México, FES-Iztacala, Av. de Los Barrios #1, Los Reyes Iztacala, Tlalnepantla C.P.54090, México.
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33
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Lorenz-Guertin JM, Bambino MJ, Jacob TC. γ2 GABA AR Trafficking and the Consequences of Human Genetic Variation. Front Cell Neurosci 2018; 12:265. [PMID: 30190672 PMCID: PMC6116786 DOI: 10.3389/fncel.2018.00265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/02/2018] [Indexed: 11/13/2022] Open
Abstract
GABA type A receptors (GABAARs) mediate the majority of fast inhibitory neurotransmission in the central nervous system (CNS). Most prevalent as heteropentamers composed of two α, two β, and a γ2 subunit, these ligand-gated ionotropic chloride channels are capable of extensive genetic diversity (α1-6, β1-3, γ1-3, δ, 𝜀, 𝜃, π, ρ1-3). Part of this selective GABAAR assembly arises from the critical role for γ2 in maintaining synaptic receptor localization and function. Accordingly, mutations in this subunit account for over half of the known epilepsy-associated genetic anomalies identified in GABAARs. Fundamental structure-function studies and cellular pathology investigations have revealed dynamic GABAAR trafficking and synaptic scaffolding as critical regulators of GABAergic inhibition. Here, we introduce in vitro and in vivo findings regarding the specific role of the γ2 subunit in receptor trafficking. We then examine γ2 subunit human genetic variation and assess disease related phenotypes and the potential role of altered GABAAR trafficking. Finally, we discuss new-age imaging techniques and their potential to provide novel insight into critical regulatory mechanisms of GABAAR function.
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Affiliation(s)
- Joshua M Lorenz-Guertin
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Matthew J Bambino
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Tija C Jacob
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
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Li Z, Cogswell M, Hixson K, Brooks-Kayal AR, Russek SJ. Nuclear Respiratory Factor 1 (NRF-1) Controls the Activity Dependent Transcription of the GABA-A Receptor Beta 1 Subunit Gene in Neurons. Front Mol Neurosci 2018; 11:285. [PMID: 30186109 PMCID: PMC6113564 DOI: 10.3389/fnmol.2018.00285] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 07/27/2018] [Indexed: 11/13/2022] Open
Abstract
While the exact role of β1 subunit-containing GABA-A receptors (GABARs) in brain function is not well understood, altered expression of the β1 subunit gene (GABRB1) is associated with neurological and neuropsychiatric disorders. In particular, down-regulation of β1 subunit levels is observed in brains of patients with epilepsy, autism, bipolar disorder and schizophrenia. A pathophysiological feature of these disease states is imbalance in energy metabolism and mitochondrial dysfunction. The transcription factor, nuclear respiratory factor 1 (NRF-1), has been shown to be a key mediator of genes involved in oxidative phosphorylation and mitochondrial biogenesis. Using a variety of molecular approaches (including mobility shift, promoter/reporter assays, and overexpression of dominant negative NRF-1), we now report that NRF-1 regulates transcription of GABRB1 and that its core promoter contains a conserved canonical NRF-1 element responsible for sequence specific binding and transcriptional activation. Our identification of GABRB1 as a new target for NRF-1 in neurons suggests that genes coding for inhibitory neurotransmission may be coupled to cellular metabolism. This is especially meaningful as binding of NRF-1 to its element is sensitive to the kind of epigenetic changes that occur in multiple disorders associated with altered brain inhibition.
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Affiliation(s)
- Zhuting Li
- Laboratory of Translational Epilepsy, Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States.,Department of Biomedical Engineering, College of Engineering, Boston University, Boston, MA, United States
| | - Meaghan Cogswell
- Laboratory of Translational Epilepsy, Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
| | - Kathryn Hixson
- Laboratory of Translational Epilepsy, Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States
| | - Amy R Brooks-Kayal
- Department of Pediatrics, Division of Neurology, School of Medicine, University of Colorado, Aurora, CO, United States.,Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Shelley J Russek
- Laboratory of Translational Epilepsy, Department of Pharmacology and Experimental Therapeutics, School of Medicine, Boston University, Boston, MA, United States.,Department of Biology, Boston University, Boston, MA, United States
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Tran T, Gallagher M, Kirkwood A. Enhanced postsynaptic inhibitory strength in hippocampal principal cells in high-performing aged rats. Neurobiol Aging 2018; 70:92-101. [PMID: 30007169 DOI: 10.1016/j.neurobiolaging.2018.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/28/2018] [Accepted: 06/03/2018] [Indexed: 11/20/2022]
Abstract
Hyperactivity within the hippocampal formation, frequently observed in aged individuals, is thought to be a potential contributing mechanism to the memory decline often associated with aging. Consequently, we evaluated the postsynaptic strength of excitatory and inhibitory synapses in the granule cells of the dentate gyrus and CA1 pyramidal cells of a rat model of aging, in which each individual was behaviorally characterized as aged impaired (AI) or aged unimpaired (AU, with performance comparable to young (Y) individuals). In hippocampal slices of these 3 aged groups (Y, AI, AU), we found that compared to the young, the miniature excitatory and inhibitory currents (mEPSCs and mIPSCs) were larger in amplitude in the granule cells of the AU group and smaller in the AI group. In contrast, in CA1 cells, neither the mEPSCs nor the mIPSCs were affected by age, whereas the extrasynaptic conductance responsible for tonic inhibition was selectively enhanced in CA1 cells of AU individuals. Tonic inhibition conductance was not affected by age in the granule cells. These results support the notion that upregulation of synaptic inhibition could be a necessary condition for the maintenance of performance during aging. These findings also underscore the notions that successful aging requires adaptive upregulation, not merely the preservation of youthful functionality, and that age effects are not homogeneous across hippocampal subfields.
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Affiliation(s)
- Trinh Tran
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, 3400 N. Charles St, Baltimore, MD 21218, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 N. Charles St, Baltimore, MD 21218, USA.
| | - Alfredo Kirkwood
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, 3400 N. Charles St, Baltimore, MD 21218, USA.
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Neurofeedback Control of the Human GABAergic System Using Non-invasive Brain Stimulation. Neuroscience 2018; 380:38-48. [DOI: 10.1016/j.neuroscience.2018.03.051] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 03/27/2018] [Accepted: 03/31/2018] [Indexed: 11/22/2022]
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37
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Nejatbakhsh M, Saboory E, Bagheri M. Effect of prenatal stress on ɑ5 GABA A receptor subunit gene expression in hippocampus and pilocarpine induced seizure in rats. Int J Dev Neurosci 2018; 68:66-71. [PMID: 29758348 DOI: 10.1016/j.ijdevneu.2018.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/04/2018] [Accepted: 05/08/2018] [Indexed: 11/27/2022] Open
Abstract
The GABAergic synapses go through structural and functional maturation during early brain development. Maternal stress alters GABAergic synapses in developing brain, which are associated with the pathophysiology of neuropsychiatric disorders in adults. The present study aimed to investigate the effect of prenatal restraint stress (PS) on pilocarpine-induced seizure and ɑ5 subunit of γ-amino butyric acid type A (GABAA) receptor expression in hippocampus. Pregnant Wistar rats were subjected to PS at gestational days 15-17 and the pups were examined for susceptibility to seizure and ɑ5 subunit of GABAA receptor expression in hippocampus at postnatal days 14 and 21 (P14 and PND 21). Quantitative real-time PCR was used for evaluating the gene expression in the pups. Pilocarpine was injected intraperitoneally into the pups and seizure behaviors were recorded. The results showed that ɑ5 subunit mRNA expression significantly increased in hippocampus at both the P14 and P21 in the stressed rats. However, ɑ5 subunit level was greater at the P21 than at the P14 in both the groups. Latency of first tonic-clonic seizure significantly decreased in the PS group compared to the control pups. Number and duration of tonic-clonic seizures increased in the PS rats compared to the controls. PS led to an increase in total score of seizure at the P14 and P21. It can be concluded that PS increases the seizure susceptibility and GABAA receptor ɑ5 subunit gene expression in offspring; it is likely that the mechanism of increased seizure susceptibility by PS, at least in part, can increase the GABAA receptor ɑ5 subunit gene expression in hippocampus.
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Affiliation(s)
- Mehrdad Nejatbakhsh
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran; Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
| | - Ehsan Saboory
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran; Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran.
| | - Morteza Bagheri
- Cellular and Molecular Research Center, Urmia University of Medical Sciences, Urmia, Iran.
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38
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Zhao Z, He X, Ma C, Wu S, Cuan Y, Sun Y, Bai Y, Huang L, Chen X, Gao T, Zheng X. Excavating Anticonvulsant Compounds from Prescriptions of Traditional Chinese Medicine in the Treatment of Epilepsy. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2018; 46:707-737. [PMID: 29737210 DOI: 10.1142/s0192415x18500374] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Traditional Chinese medicine (TCM) has a long history and been widely used in prevention and treatment of epilepsy in China. This paper is intended to review the advances in the active anticonvulsant compounds isolated from herbs in the prescription of TCM in the treatment of epilepsy. These compounds were introduced with the details including classification, CAS number specific structure and druggability data. Meanwhile, much of the research in these compounds in the last two decades has shown that they exhibited favorable pharmacological properties in treatment of epilepsy both in in vivo and in vitro models. In addition, in this present review, the evaluation of the effects of the anticonvulsant classical TCM prescriptions is discussed. According to these rewarding pharmacological effects and chemical substances, the prescription of TCM herbs could be an effective therapeutic strategy for epilepsy patients, and also could be a promising source for the development of new drugs.
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Affiliation(s)
- Zefeng Zhao
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Xirui He
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China.,‡ Honghui Hospital, Xi'an Jiaotong University, Xi'an 710054, P. R. China
| | - Cuixia Ma
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Shaoping Wu
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Ye Cuan
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Ying Sun
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Yajun Bai
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China.,† College of Chemistry and Materials Science, Northwest University, Xi'an 710069, P. R. China
| | - Linhong Huang
- ‡ Honghui Hospital, Xi'an Jiaotong University, Xi'an 710054, P. R. China
| | - Xufei Chen
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Tian Gao
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
| | - Xiaohui Zheng
- * Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an 710069, P. R. China
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Ali Rodriguez R, Joya C, Hines RM. Common Ribs of Inhibitory Synaptic Dysfunction in the Umbrella of Neurodevelopmental Disorders. Front Mol Neurosci 2018; 11:132. [PMID: 29740280 PMCID: PMC5928253 DOI: 10.3389/fnmol.2018.00132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/03/2018] [Indexed: 01/06/2023] Open
Abstract
The term neurodevelopmental disorder (NDD) is an umbrella term used to group together a heterogeneous class of disorders characterized by disruption in cognition, emotion, and behavior, early in the developmental timescale. These disorders are heterogeneous, yet they share common behavioral symptomatology as well as overlapping genetic contributors, including proteins involved in the formation, specialization, and function of synaptic connections. Advances may arise from bridging the current knowledge on synapse related factors indicated from both human studies in NDD populations, and in animal models. Mounting evidence has shown a link to inhibitory synapse formation, specialization, and function among Autism, Angelman, Rett and Dravet syndromes. Inhibitory signaling is diverse, with numerous subtypes of inhibitory interneurons, phasic and tonic modes of inhibition, and the molecular and subcellular diversity of GABAA receptors. We discuss common ribs of inhibitory synapse dysfunction in the umbrella of NDD, highlighting alterations in the developmental switch to inhibitory GABA, dysregulation of neuronal activity patterns by parvalbumin-positive interneurons, and impaired tonic inhibition. Increasing our basic understanding of inhibitory synapses, and their role in NDDs is likely to produce significant therapeutic advances in behavioral symptom alleviation for interrelated NDDs.
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Affiliation(s)
- Rachel Ali Rodriguez
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Christina Joya
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Rochelle M Hines
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
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Gu X, Lu W. Genetic deletion of NMDA receptors suppresses GABAergic synaptic transmission in two distinct types of central neurons. Neurosci Lett 2018; 668:147-153. [PMID: 29355693 DOI: 10.1016/j.neulet.2018.01.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 12/23/2017] [Accepted: 01/12/2018] [Indexed: 01/30/2023]
Abstract
NMDA-type ionotropic glutamate receptors (NMDARs) play an important role in the regulation of synapse development and function in the brain. Recently we have shown that NMDARs are critical for GABAergic synapse development in developing hippocampal neurons. However, it remains unclear whether NMDARs are important for establishment of GABAergic synaptic transmission in other types of neurons in the brain. Here we report that in both cortical pyramidal neurons and midbrain dopamine neurons in ventral tegmental area (VTA), genetic deletion of the GluN1 subunit, which is required for assembly of functional NMDARs, leads to a strong reduction of GABAergic synaptic transmission. These data demonstrate that NMDARs play an important role in the development of GABAergic synaptic transmission in two types of neurons with distinct developmental origins, and suggest that NMDARs are commonly involved in development of GABAergic synaptic transmission in different types of neurons in the brain.
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Affiliation(s)
- Xinglong Gu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Wei Lu
- Synapse and Neural Circuit Research Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA.
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Pandit S, Lee GS, Park JB. Developmental changes in GABA A tonic inhibition are compromised by multiple mechanisms in preadolescent dentate gyrus granule cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2017; 21:695-702. [PMID: 29200913 PMCID: PMC5709487 DOI: 10.4196/kjpp.2017.21.6.695] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 01/28/2023]
Abstract
The sustained tonic currents (Itonic) generated by γ-aminobutyric acid A receptors (GABAARs) are implicated in diverse age-dependent brain functions. While various mechanisms regulating Itonic in the hippocampus are known, their combined role in Itonic regulation is not well understood in different age groups. In this study, we demonstrated that a developmental increase in GABA transporter (GAT) expression, combined with gradual decrease in GABAAR α5 subunit, resulted in various Itonic in the dentate gyrus granule cells (DGGCs) of preadolescent rats. Both GAT-1 and GAT-3 expression gradually increased at infantile (P6-8 and P13-15) and juvenile (P20-22 and P27-29) stages, with stabilization observed thereafter in adolescents (P34-36) and young adults (P41-43). Itonic facilitation of a selective GAT-1 blocker (NO-711) was significantly less at P6-8 than after P13-15. The facilitation of Itonic by SNAP-5114, a GAT-3 inhibitor, was negligible in the absence of exogenous GABA at all tested ages. In contrast, Itonic in the presence of a nonselective GAT blocker (nipecotic acid, NPA) gradually decreased with age during the preadolescent period, which was mimicked by Itonic changes in the presence of exogenous GABA. Itonic sensitivity to L-655,708, a GABAAR α5 subunit inverse agonist, gradually decreased during the preadolescent period in the presence of NPA or exogenous GABA. Finally, Western blot analysis showed that the expression of the GABAAR α5 subunit in the dentate gyrus gradually decreased with age. Collectively, our results suggested that the Itonic regulation of altered GATs is under the final tune of GABAAR α5 subunit activation in DGGCs at different ages.
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Affiliation(s)
- Sudip Pandit
- Department of Physiology, School of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
| | - Gyu Seung Lee
- Department of Physiology, School of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
| | - Jin Bong Park
- Department of Physiology, School of Medicine and Brain Research Institute, Chungnam National University, Daejeon 35015, Korea
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Vangeel EB, Pishva E, Hompes T, van den Hove D, Lambrechts D, Allegaert K, Freson K, Izzi B, Claes S. Newborn genome-wide DNA methylation in association with pregnancy anxiety reveals a potential role for GABBR1. Clin Epigenetics 2017; 9:107. [PMID: 29026448 PMCID: PMC5627482 DOI: 10.1186/s13148-017-0408-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 09/24/2017] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND There is increasing evidence for the role of prenatal stress in shaping offspring DNA methylation and disease susceptibility. In the current study, we aimed to identify genes and pathways associated with pregnancy anxiety using a genome-wide DNA methylation approach. METHODS We selected 22 versus 23 newborns from our Prenatal Early Life Stress (PELS) cohort, exposed to the lowest or highest degree of maternal pregnancy anxiety, respectively. Cord blood genome-wide DNA methylation was assayed using the HumanMethylation450 BeadChip (HM450, n = 45) and candidate gene methylation using EpiTYPER (n = 80). Cortisol levels were measured at 2, 4, and 12 months of age to test infant stress system (re)activity. RESULTS Data showed ten differentially methylated regions (DMR) when comparing newborns exposed to low versus high pregnancy anxiety scores. We validated a top DMR in the GABA-B receptor subunit 1 gene (GABBR1) revealing the association with pregnancy anxiety particularly in male newborns (most significant CpG Pearson R = 0.517, p = 0.002; average methylation Pearson R = 0.332, p = 0.039). Cord blood GABBR1 methylation was associated with infant cortisol levels in response to a routine vaccination at 4 months old. CONCLUSIONS In conclusion, our results show that pregnancy anxiety is associated with differential DNA methylation patterns in newborns and that our candidate gene GABBR1 is associated with infant hypothalamic-pituitary-adrenal axis response to a stressor. Our findings reveal a potential role for GABBR1 methylation in association with stress and provide grounds for further research.
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Affiliation(s)
- Elise Beau Vangeel
- Department of Neurosciences, Genetic Research About Stress and Psychiatry (GRASP), KU Leuven, Leuven, Belgium
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
| | - Ehsan Pishva
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Titia Hompes
- Department of Neurosciences, Genetic Research About Stress and Psychiatry (GRASP), KU Leuven, Leuven, Belgium
- University Psychiatric Center, Leuven, Belgium
| | - Daniel van den Hove
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands
- Department of Psychiatry, Psychosomatics and Psychotherapy, Laboratory of Translational Neuroscience, University of Wuerzburg, Wuerzburg, Germany
| | - Diether Lambrechts
- Department of Oncology, Laboratory of Translational Genetics, KU Leuven, Leuven, Belgium
- Vesalius Research Center (VRC), VIB, Leuven, Belgium
| | - Karel Allegaert
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Intensive Care and Department of Pediatric Surgery, Erasmus MC—Sophia’s Children’s Hospital, Rotterdam, The Netherlands
| | - Kathleen Freson
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology (CMVB), KU Leuven, Leuven, Belgium
| | - Benedetta Izzi
- Department of Epidemiology and Prevention, IRCCS Instituto Neurologico Mediterraneo Neuromed, Pozzilli, Italy
| | - Stephan Claes
- Department of Neurosciences, Genetic Research About Stress and Psychiatry (GRASP), KU Leuven, Leuven, Belgium
- University Psychiatric Center, Leuven, Belgium
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Wearne TA, Parker LM, Franklin JL, Goodchild AK, Cornish JL. Behavioral sensitization to methamphetamine induces specific interneuronal mRNA pathology across the prelimbic and orbitofrontal cortices. Prog Neuropsychopharmacol Biol Psychiatry 2017; 77:42-48. [PMID: 28351548 DOI: 10.1016/j.pnpbp.2017.03.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/15/2017] [Accepted: 03/23/2017] [Indexed: 12/31/2022]
Abstract
Schizophrenia is associated with significant pathophysiological changes to interneurons within the prefrontal cortex (PFC), with mRNA and protein changes associated with the GABA network localized to specific interneuron subtypes. Methamphetamine is a commonly abused psychostimulant that can induce chronic psychosis and symptoms that are similar to schizophrenia, suggesting that chronic METH induced psychosis may be associated with similar brain pathology to schizophrenia in the PFC. The aim of this study, therefore, was to examine mRNA expression of interneuron markers across two regions of the PFC (prelimbic (PRL) and orbitofrontal cortices (OFC)) following METH sensitization, an animal model of METH psychosis. We also studied the association between GABA mRNA expression and interneuronal mRNA expression to identify whether particular changes to the GABA network could be localized to a specific inhibitory cellular phenotype. METH sensitization increased the transcriptional expression of calbindin, calretinin, somatostatin, cholecyctokinin and vasoactive intestinal peptide in the PRL while parvalbumin, calbindin, cholectokinin and vasoactive intestinal peptide were upregulated in the OFC. Based on our previous findings, we also found significant correlations between GAD67, GAT1 and parvalbumin while GAD67, GAD65 and GAT1 were positively correlated with cholecystokinin in the PRL of METH sensitized rats. Within the OFC, the expression of GABAAα1 was positively correlated with somatostatin while GABAAα5 was negatively associated with somatostatin and calbindin. These findings suggest that METH sensitization differentially changes the expression of mRNAs encoding for multiple peptides and calcium binding proteins across the PRL and the OFC. Furthermore, these findings support that changes to the GABA network may also occur within specific cell types. These results, therefore, provide the first evidence that METH sensitization mediates differential interneuronal pathology across the PRL and OFC and such changes could have profound consequences on behavior and cognitive output.
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Affiliation(s)
- Travis A Wearne
- Department of Psychology, Faculty of Human Sciences, Centre for Emotional Health, Macquarie University, Sydney, NSW, Australia
| | - Lindsay M Parker
- Department of Biomedical Science, Faculty of Medicine and Health Science, Macquarie University, Sydney, NSW, Australia; ARC Center of Excellence for Nanoscale BioPhotonics, Macquarie University, Sydney, NSW, Australia
| | - Jane L Franklin
- Department of Psychology, Faculty of Human Sciences, Centre for Emotional Health, Macquarie University, Sydney, NSW, Australia
| | - Ann K Goodchild
- Department of Biomedical Science, Faculty of Medicine and Health Science, Macquarie University, Sydney, NSW, Australia
| | - Jennifer L Cornish
- Department of Psychology, Faculty of Human Sciences, Centre for Emotional Health, Macquarie University, Sydney, NSW, Australia; ARC Center of Excellence for Nanoscale BioPhotonics, Macquarie University, Sydney, NSW, Australia.
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Vien TN, Moss SJ, Davies PA. Regulating the Efficacy of Inhibition Through Trafficking of γ-Aminobutyric Acid Type A Receptors. Anesth Analg 2017; 123:1220-1227. [PMID: 27285004 DOI: 10.1213/ane.0000000000001349] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Trafficking of anesthetic-sensitive receptors within the plasma membrane, or from one cellular component to another, occurs continuously. Changes in receptor trafficking have implications in altering anesthetic sensitivity. γ-Aminobutyric acid type A receptors (GABAARs) are anion-permeable ion channels and are the major class of receptor in the adult mammalian central nervous system that mediates inhibition. GABAergic signaling allows for precise synchronized firing of action potentials within brain circuits that is critical for cognition, behavior, and consciousness. This precision depends upon tightly controlled trafficking of GABAARs into the membrane. General anesthetics bind to and allosterically enhance GABAARs by prolonging the open state of the receptor and thereby altering neuronal and brain circuit activity. Subunit composition and GABAAR localization strongly influence anesthetic end points; therefore, changes in GABAAR trafficking could have significant consequences to anesthetic sensitivity. GABAARs are not static membrane structures but are in a constant state of flux between extrasynaptic and synaptic locations and are continually endocytosed and recycled from and to the membrane. Neuronal activity, posttranslational modifications, and some naturally occurring and synthetic compounds can influence the expression and trafficking of GABAARs. In this article, we review GABAARs, their trafficking, and how phosphorylation of GABAAR subunits can influence the surface expression and function of the receptor. Ultimately, alterations of GABAAR trafficking could modify anesthetic end points, both unintentionally through pathologic processes but potentially as a therapeutic target to adjust anesthetic-sensitive GABAARs.
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Affiliation(s)
- Thuy N Vien
- From the *Department of Neuroscience, Tufts University School of Medicine, Sackler School of Graduate Biomedical Sciences, Boston, Massachusetts; and †Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts
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Centanni SW, Burnett EJ, Trantham-Davidson H, Chandler LJ. Loss of δ-GABA A receptor-mediated tonic currents in the adult prelimbic cortex following adolescent alcohol exposure. Addict Biol 2017; 22:616-628. [PMID: 26804056 DOI: 10.1111/adb.12353] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 10/29/2015] [Accepted: 11/24/2015] [Indexed: 11/30/2022]
Abstract
Delayed maturation of the adolescent prefrontal cortex may render it particularly vulnerable to insults, including those associated with drugs of abuse. Using a rat model of binge alcohol exposure, the present study examined the effect of adolescent intermittent ethanol (AIE) exposure during postnatal days 28-42 on γ-aminobutyric acid (GABA)ergic neurotransmission in the prelimbic cortex. In control rats, patch-clamp electrophysiology in acute slices obtained at different postnatal ages revealed a developmental increase in the GABAA receptor-mediated tonic current in layer V pyramidal neurons but no change in layers II/III when measured in the adult. In slices from AIE-exposed rats, the amplitude of the tonic current was significantly reduced compared with controls when tested at postnatal days 45, 60 and 90-120. This AIE-induced reduction in tonic current was found to reflect attenuation of currents mediated by δ-subunit containing receptors. Consistent with this, facilitation of the tonic current by bath application of either ethanol or allopregnanolone was attenuated in slices from AIE-exposed adult rats compared with control rats. However, expression of this facilitation as a percent of the amplitude of the total current mediated by δ-GABAA receptors revealed that AIE did not alter their sensitivity to either agonist. Lastly, immunohistochemistry and Western blot analysis revealed no change in the expression of δ-GABAA subunits or their surface expression. Taken together, these studies reveal that AIE exposure results in persistent deficits in δ-GABAA tonic currents in the adult prelimbic cortex that may contribute to deficits in decision-making and behavioral control in adulthood.
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Affiliation(s)
- Samuel W. Centanni
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | - Elizabeth J. Burnett
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
| | | | - L. Judson Chandler
- Department of Neuroscience; Medical University of South Carolina; Charleston SC USA
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Yu YH, Lee K, Sin DS, Park KH, Park DK, Kim DS. Altered functional efficacy of hippocampal interneuron during epileptogenesis following febrile seizures. Brain Res Bull 2017; 131:25-38. [DOI: 10.1016/j.brainresbull.2017.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/17/2017] [Accepted: 02/23/2017] [Indexed: 12/22/2022]
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Developmental control of spike-timing-dependent plasticity by tonic GABAergic signaling in striatum. Neuropharmacology 2017; 121:261-277. [PMID: 28408325 DOI: 10.1016/j.neuropharm.2017.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/20/2017] [Accepted: 04/07/2017] [Indexed: 11/20/2022]
Abstract
Activity-dependent long-term potentiation (LTP) and depression (LTD) of synaptic strength underlie multiple forms of learning and memory. Spike-timing-dependent plasticity (STDP) has been described as a Hebbian synaptic learning rule that could account for experience-dependent changes in neural networks, but little is known about whether and how STDP evolves during development. We previously showed that GABAergic signaling governs STDP polarity and thus operates as a Hebbian/anti-Hebbian switch in the striatum. Although GABAergic networks are subject to important developmental maturation, it remains unclear whether STDP is developmentally shaped by GABAergic signaling. Here, we investigated whether STDP rules are developmentally regulated at corticostriatal synapses in the dorsolateral striatum. We found that striatal STDP displays unidirectional plasticity (Hebbian tLTD) in young rats (P7-10) whereas STDP is bidirectional and anti-Hebbian in juvenile (P20-25) and adult (P60-90) rats. We also provide evidence that the appearance of tonic (extrasynaptic) GABAergic signaling from the juvenile stage is a crucial factor in shaping STDP rules during development, establishing bidirectional anti-Hebbian STDP in the adult striatum. Thus, developmental maturation of GABAergic signaling tightly drives the polarity of striatal plasticity.
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Furukawa T, Shimoyama S, Miki Y, Nikaido Y, Koga K, Nakamura K, Wakabayashi K, Ueno S. Chronic diazepam administration increases the expression of Lcn2 in the CNS. Pharmacol Res Perspect 2017; 5:e00283. [PMID: 28596835 PMCID: PMC5461642 DOI: 10.1002/prp2.283] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 11/03/2016] [Accepted: 11/11/2016] [Indexed: 12/17/2022] Open
Abstract
Benzodiazepines (BZDs), which bind with high affinity to gamma-aminobutyric acid type A receptors (GABAA-Rs) and potentiate the effects of GABA, are widely prescribed for anxiety, insomnia, epileptic discharge, and as anticonvulsants. The long-term use of BZDs is limited due to adverse effects such as tolerance, dependence, withdrawal effects, and impairments in cognition and learning. Additionally, clinical reports have shown that chronic BZD treatment increases the risk of Alzheimer's disease. Unusual GABAA-R subunit expression and GABAA-R phosphorylation are induced by chronic BZD use. However, the gene expression and signaling pathways related to these effects are not completely understood. In this study, we performed a microarray analysis to investigate the mechanisms underlying the effect of chronic BZD administration on gene expression. Diazepam (DZP, a BZD) was chronically administered, and whole transcripts in the brain were analyzed. We found that the mRNA expression levels were significantly affected by chronic DZP administration and that lipocalin 2 (Lcn2) mRNA was the most upregulated gene in the cerebral cortex, hippocampus, and amygdala. Lcn2 is known as an iron homeostasis-associated protein. Immunostained signals of Lcn2 were detected in neuron, astrocyte, microglia, and Lcn2 protein expression levels were consistently upregulated. This upregulation was observed without proinflammatory genes upregulation, and was attenuated by chronic treatment of deferoxamine mesylate (DFO), iron chelator. Our results suggest that chronic DZP administration regulates transcription and upregulates Lcn2 expression levels without an inflammatory response in the mouse brain. Furthermore, the DZP-induced upregulation of Lcn2 expression was influenced by ambient iron.
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Affiliation(s)
- Tomonori Furukawa
- Department of Neurophysiology Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Shuji Shimoyama
- Research Center for Child Mental Development Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Yasuo Miki
- Department of Neuropathology Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Yoshikazu Nikaido
- Department of Neurophysiology Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Kohei Koga
- Department of Neurophysiology Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Kazuhiko Nakamura
- Research Center for Child Mental Development Hirosaki University Graduate School of Medicine Hirosaki Japan.,Department of Neuropsychiatry Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Koichi Wakabayashi
- Department of Neuropathology Hirosaki University Graduate School of Medicine Hirosaki Japan
| | - Shinya Ueno
- Department of Neurophysiology Hirosaki University Graduate School of Medicine Hirosaki Japan.,Research Center for Child Mental Development Hirosaki University Graduate School of Medicine Hirosaki Japan
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Real Time Multiplicative Memory Amplification Mediated by Whole-Cell Scaling of Synaptic Response in Key Neurons. PLoS Comput Biol 2017; 13:e1005306. [PMID: 28103235 PMCID: PMC5245787 DOI: 10.1371/journal.pcbi.1005306] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 12/12/2016] [Indexed: 11/19/2022] Open
Abstract
Intense spiking response of a memory-pattern is believed to play a crucial role both in normal learning and pathology, where it can create biased behavior. We recently proposed a novel model for memory amplification where the simultaneous two-fold increase of all excitatory (AMPAR-mediated) and inhibitory (GABAAR-mediated) synapses in a sub-group of cells that constitutes a memory-pattern selectively amplifies this memory. Here we confirm the cellular basis of this model by validating its major predictions in four sets of experiments, and demonstrate its induction via a whole-cell transduction mechanism. Subsequently, using theory and simulations, we show that this whole-cell two-fold increase of all inhibitory and excitatory synapses functions as an instantaneous and multiplicative amplifier of the neurons’ spiking. The amplification mechanism acts through multiplication of the net synaptic current, where it scales both the average and the standard deviation of the current. In the excitation-inhibition balance regime, this scaling creates a linear multiplicative amplifier of the cell’s spiking response. Moreover, the direct scaling of the synaptic input enables the amplification of the spiking response to be synchronized with rapid changes in synaptic input, and to be independent of previous spiking activity. These traits enable instantaneous real-time amplification during brief elevations of excitatory synaptic input. Furthermore, the multiplicative nature of the amplifier ensures that the net effect of the amplification is large mainly when the synaptic input is mostly excitatory. When induced on all cells that comprise a memory-pattern, these whole-cell modifications enable a substantial instantaneous amplification of the memory-pattern when the memory is activated. The amplification mechanism is induced by CaMKII dependent phosphorylation that doubles the conductance of all GABAA and AMPA receptors in a subset of neurons. This whole-cell transduction mechanism enables both long-term induction of memory amplification when necessary and extinction when not further required. Amplifying the strength of a neuronal assembly that underlies a behavioral choice can lead to a particularly long lasting dominant memory. We report experimental and theoretical evidence for a long-term mechanism that amplifies the response of a neuronal assembly which we termed “memory amplification mechanism”. The amplification mechanism is mediated by doubling the strength of all inhibitory and all excitatory synapses in the cell and is induced by whole-cell phosphorylation of all inhibitory and excitatory synaptic receptors in a subset of cells, via a process that is distinct from memory formation. Computationally, the inherent scaling of both excitation and inhibition yields a robust and stable amplifier of the neuron’s response. When such an amplifier is induced in a set of cells that compose a memory-pattern, it can selectively amplify the response of this memory. The memory amplification mechanism is independent from associative learning. Thus, while associative learning forms a memory that encodes new associations, the amplification mechanism can promote an already formed memory to a dominant memory.
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Glial GABA Transporters as Modulators of Inhibitory Signalling in Epilepsy and Stroke. ADVANCES IN NEUROBIOLOGY 2017; 16:137-167. [PMID: 28828609 DOI: 10.1007/978-3-319-55769-4_7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Imbalances in GABA-mediated tonic inhibition are involved in several pathophysiological conditions. A classical way of controlling tonic inhibition is through pharmacological intervention with extrasynaptic GABAA receptors that sense ambient GABA and mediate a persistent GABAergic conductance. An increase in tonic inhibition may, however, also be obtained indirectly by inhibiting glial GABA transporters (GATs). These are sodium-coupled membrane transport proteins that normally act to terminate GABA neurotransmitter action by taking up GABA into surrounding astrocytes. The aim of the review is to provide an overview of glial GATs in regulating tonic inhibition, especially in epilepsy and stroke. This entails a comprehensive summary of changes known to occur in GAT expression levels and signalling following epileptic and ischemic insults. Further, we discuss the accumulating pharmacological evidence for targeting GATs in these diseases.
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