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Hleihil M, Bhat MA, Grampp T, Benke D. Optimization of neuron-specific interfering peptides targeting GABA B receptor downregulation for proteolytic stability for conferring neuroprotection in a mouse model of cerebral ischemia. Front Pharmacol 2025; 16:1576884. [PMID: 40356975 PMCID: PMC12066480 DOI: 10.3389/fphar.2025.1576884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2025] [Accepted: 04/09/2025] [Indexed: 05/15/2025] Open
Abstract
Background Cerebral ischemia triggers a cascade of detrimental events, leading to brain damage mainly due to the over-excitation of neurons. Currently, clinically applicable neuroprotective treatments to stop progressive neuronal death remain elusive. The GABAB receptor, crucial for neuronal inhibition, is a promising target for neuroprotection because it inhibits neuronal over-excitation which otherwise leads to excitotoxic death. However, ischemic conditions impair GABAB receptor function by downregulating the receptors via pathologically altered trafficking events. Previously, we developed interfering peptides to inhibit the interaction of GABAB receptors with key interacting proteins, leading to the pathological downregulation of the receptors. These interfering peptides restored GABAB receptor expression and function, resulting in reduced excitability and death of neurons in in-vitro and ex-vivo models of cerebral ischemia. However, the interfering peptides were not effective in-vivo because of their limited proteolytic stability after systemic application. Methods/results Here, we aimed to render three interfering peptides resistant to proteolytic degradation by replacing natural L-amino acids by D-amino acids. Additionally, we optimized a blood brain barrier shuttle (BBBpS) sequence derived from the Rabies virus glycoprotein (RVG) that mediates neuron-specific uptake and blood-brain barrier crossing of these interfering peptides. By optimizing the peptides, we developed stable, neuron-specific interfering peptides that successfully restored GABAB receptors expression and prevented neuronal death following excitotoxic stress in cultured neurons. In vivo testing in the middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia demonstrated the neuroprotective activity of the optimized peptides by a significantly reduced infarct size. Conclusion These findings confirm the potential of these peptides as neuroprotective agents and emphasize the importance of proteolytic stability of peptide drugs for their successful in-vivo application.
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Affiliation(s)
- Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Musadiq A. Bhat
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Thomas Grampp
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zurich, Switzerland
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2
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Carmi I, Zoabi S, Bittan AM, Kellner S, Oz S, Heinrich R, Berlin S. A genetically encoded secreted toxin potentiates synaptic NMDA receptors in hippocampal neurons and confers neuroprotection. PNAS NEXUS 2025; 4:pgaf041. [PMID: 39959712 PMCID: PMC11826341 DOI: 10.1093/pnasnexus/pgaf041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2024] [Accepted: 01/27/2025] [Indexed: 02/18/2025]
Abstract
NMDA receptors (NMDARs) play essential roles in neuronal development, survival, and synaptic plasticity, to name a few. However, dysregulation in receptors' activity can lead to neuronal and synaptic damage, contributing to the development of various brain pathologies. Current pharmacological treatments targeting NMDARs remain limited, for instance due to insufficient receptor selectivity and poor spatial targeting. Genetic approaches hold promise to overcome some of these issues; however, require genetically encodable NMDAR-modulating peptides, which are scarce. Here, we explored NMDAR-selective peptide toxins from marine cone snails, which resulted in the necessary engineering of a posttranslational modification-free variant of Conantokin-P (naked Con-P). The naked form is essential for expression in mammalian cells. We systematically explored the naked variant and discovered that naked Con-P maintains its ability to inhibit GluN2B-containing receptors, but uniquely acquired the ability to potentiate GluN2A-containing synaptic receptors. We then engineered a secreted naked Con-P that readily enhances NMDAR-mediated synaptic events in primary hippocampal neurons, and mitigates neuronal damage induced by staurosporine. We therefore provide a genetically encodable, subtype selective, and secreted bimodulator of NMDARs. This new variant and approach should pave the way for the development of additional genetic tools, specifically tailored to target NMDARs within distinct cellular populations in the brain.
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Affiliation(s)
- Ido Carmi
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
| | - Shaden Zoabi
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
| | - Asaf M Bittan
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
| | - Shai Kellner
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
| | - Shimrit Oz
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
| | - Ronit Heinrich
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
| | - Shai Berlin
- Department of Neuroscience, Ruth and Bruce Rappaport Faculty of Medicine, Technion—Israel Institute of Technology, Haifa 3525433, Israel
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3
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Bhat MA, Hleihil M, Mondéjar I, Grampp T, Benke D. The E3 ubiquitin ligase MARCH1 mediates downregulation of plasma membrane GABA B receptors under ischemic conditions by inhibiting fast receptor recycling. Sci Rep 2025; 15:1330. [PMID: 39779794 PMCID: PMC11711762 DOI: 10.1038/s41598-025-85842-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Accepted: 01/06/2025] [Indexed: 01/11/2025] Open
Abstract
GABAB receptors mediate prolonged inhibition in the brain and are important for keeping neuronal excitation and inhibition in a healthy balance. However, under excitotoxic/ischemic conditions, GABAB receptors are downregulated by dysregulated endocytic trafficking and can no longer counteract the severely enhanced excitation, eventually triggering neuronal death. Recently, we developed interfering peptides targeting protein-protein interactions involved in downregulating the receptors. Treatment with these peptides restored GABAB receptor expression after an ischemic insult and thereby inhibited neuronal overexcitation and progressive neuronal death. In this study, we searched for GABAB receptor interactions that specifically occur under ischemic conditions. We found that the E3 ubiquitin ligase MARCH1 is specifically upregulated under ischemic/excitotoxic conditions. Upregulated MARCH1 interacts with GABAB receptors and triggered downregulation of plasma membrane GABAB receptors by inhibiting fast recycling of the receptors. We developed an interfering peptide that inhibits the MARCH1/GABAB receptor interaction. Treatment of cultured neurons subjected to ischemic stress with this peptide restored receptor expression and as a consequence stopped progressive neuronal death. Thus, inhibiting the interaction of GABAB receptors with MARCH1 to restore cell surface receptor expression might be a promising strategy to prevent progressive neuronal death induced by ischemic conditions.
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Affiliation(s)
- Musadiq A Bhat
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Irene Mondéjar
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Thomas Grampp
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
- Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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4
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Fritzius T, Tureček R, Fernandez-Fernandez D, Isogai S, Rem PD, Kralikova M, Gassmann M, Bettler B. Preassembly of specific Gβγ subunits at GABA B receptors through auxiliary KCTD proteins accelerates channel gating. Biochem Pharmacol 2024; 228:116176. [PMID: 38555036 DOI: 10.1016/j.bcp.2024.116176] [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: 01/19/2024] [Revised: 03/15/2024] [Accepted: 03/26/2024] [Indexed: 04/02/2024]
Abstract
GABAB receptors (GBRs) are G protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the brain. GBRs regulate fast synaptic transmission by gating Ca2+ and K+ channels via the Gβγ subunits of the activated G protein. It has been demonstrated that auxiliary GBR subunits, the KCTD proteins, shorten onset and rise time and increase desensitization of receptor-induced K+ currents. KCTD proteins increase desensitization of K+ currents by scavenging Gβγ from the channel, yet the mechanism responsible for the rapid activation of K+ currents has remained elusive. In this study, we demonstrate that KCTD proteins preassemble Gβγ at GBRs. The preassembly obviates the need for diffusion-limited G protein recruitment to the receptor, thereby accelerating G protein activation and, as a result, K+ channel activation. Preassembly of Gβγ at the receptor relies on the interaction of KCTD proteins with a loop protruding from the seven-bladed propeller of Gβ subunits. The binding site is shared between Gβ1 and Gβ2, limiting the interaction of KCTD proteins to these particular Gβ isoforms. Substituting residues in the KCTD binding site of Gβ1 with those from Gβ3 hinders the preassembly of Gβγ with GBRs, delays onset and prolongs rise time of receptor-activated K+ currents. The KCTD-Gβ interface, therefore, represents a target for pharmacological modulation of channel gating by GBRs.
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Affiliation(s)
| | - Rostislav Tureček
- Department of Biomedicine, University of Basel, Basel, Switzerland; Department of Auditory Neuroscience, Institute of Experimental Medicine CAS, Prague, Czech Republic
| | | | - Shin Isogai
- Microbial Downstream Process Development, Lonza AG, Visp, Switzerland
| | - Pascal D Rem
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Michaela Kralikova
- Department of Auditory Neuroscience, Institute of Experimental Medicine CAS, Prague, Czech Republic
| | - Martin Gassmann
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Basel, Switzerland.
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5
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Wu C, Xie J, Yao Q, Song Y, Yang G, Zhao J, Zhang R, Wang T, Jiang X, Cai X, Gao Y. Intrahippocampal Supramolecular Assemblies Directed Bioorthogonal Liberation of Neurotransmitters to Suppress Seizures in Freely Moving Mice. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2314310. [PMID: 38655719 DOI: 10.1002/adma.202314310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 04/22/2024] [Indexed: 04/26/2024]
Abstract
The precise delivery of anti-seizure medications (ASM) to epileptic loci remains the major challenge to treat epilepsy without causing adverse drug reactions. The unprovoked nature of epileptic seizures raises the additional need to release ASMs in a spatiotemporal controlled manner. Targeting the oxidative stress in epileptic lesions, here the reactive oxygen species (ROS) induced in situ supramolecular assemblies that synergized bioorthogonal reactions to deliver inhibitory neurotransmitter (GABA) on-demand, are developed. Tetrazine-bearing assembly precursors undergo oxidation and selectively self-assemble under pathological conditions inside primary neurons and mice brains. Assemblies induce local accumulation of tetrazine in the hippocampus CA3 region, which allows the subsequent bioorthogonal release of inhibitory neurotransmitters. For induced acute seizures, the sustained release of GABA extends the suppression than the direct supply of GABA. In the model of permanent damage of CA3, bioorthogonal ligation on assemblies provides a reservoir of GABA that behaves prompt release upon 365 nm irradiation. Incorporated with the state-of-the-art microelectrode arrays, it is elucidated that the bioorthogonal release of GABA shifts the neuron spike waveforms to suppress seizures at the single-neuron precision. The strategy of in situ supramolecular assemblies-directed bioorthogonal prodrug activation shall be promising for the effective delivery of ASMs to treat epilepsy.
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Affiliation(s)
- Chengling Wu
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
- CAS Key Laboratory of Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Jingyu Xie
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qingxin Yao
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- CAS Key Laboratory of Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Yilin Song
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gucheng Yang
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Zhao
- CAS Key Laboratory of Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Ruijia Zhang
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- CAS Key Laboratory of Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Ting Wang
- CAS Key Laboratory of Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Xingyu Jiang
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, 518055, China
| | - Xinxia Cai
- State Key Laboratory of Transducer Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, 100190, China
- School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuan Gao
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
- CAS Key Laboratory of Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing, 100190, China
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6
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Trovò L, Kouvaros S, Schwenk J, Fernandez-Fernandez D, Fritzius T, Rem PD, Früh S, Gassmann M, Fakler B, Bischofberger J, Bettler B. Synaptotagmin-11 facilitates assembly of a presynaptic signaling complex in post-Golgi cargo vesicles. EMBO Rep 2024; 25:2610-2634. [PMID: 38698221 PMCID: PMC11169412 DOI: 10.1038/s44319-024-00147-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 05/05/2024] Open
Abstract
GABAB receptors (GBRs), the G protein-coupled receptors for GABA, regulate synaptic transmission throughout the brain. A main synaptic function of GBRs is the gating of Cav2.2-type Ca2+ channels. However, the cellular compartment where stable GBR/Cav2.2 signaling complexes form remains unknown. In this study, we demonstrate that the vesicular protein synaptotagmin-11 (Syt11) binds to both the auxiliary GBR subunit KCTD16 and Cav2.2 channels. Through these dual interactions, Syt11 recruits GBRs and Cav2.2 channels to post-Golgi vesicles, thus facilitating assembly of GBR/Cav2.2 signaling complexes. In addition, Syt11 stabilizes GBRs and Cav2.2 channels at the neuronal plasma membrane by inhibiting constitutive internalization. Neurons of Syt11 knockout mice exhibit deficits in presynaptic GBRs and Cav2.2 channels, reduced neurotransmitter release, and decreased GBR-mediated presynaptic inhibition, highlighting the critical role of Syt11 in the assembly and stable expression of GBR/Cav2.2 complexes. These findings support that Syt11 acts as a vesicular scaffold protein, aiding in the assembly of signaling complexes from low-abundance components within transport vesicles. This mechanism enables insertion of pre-assembled functional signaling units into the synaptic membrane.
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Affiliation(s)
- Luca Trovò
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | | | - Jochen Schwenk
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | | | | | - Simon Früh
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Martin Gassmann
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Center for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation, Freiburg, Germany
| | | | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Basel, Switzerland.
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7
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Kanayama H, Tominaga T, Tominaga Y, Kato N, Yoshimura H. Action of GABA B receptor on local network oscillation in somatosensory cortex of oral part: focusing on NMDA receptor. J Physiol Sci 2024; 74:16. [PMID: 38475711 PMCID: PMC10935845 DOI: 10.1186/s12576-024-00911-w] [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: 12/11/2023] [Accepted: 03/01/2024] [Indexed: 03/14/2024]
Abstract
The balance of activity between glutamatergic and GABAergic networks is particularly important for oscillatory neural activities in the brain. Here, we investigated the roles of GABAB receptors in network oscillation in the oral somatosensory cortex (OSC), focusing on NMDA receptors. Neural oscillation at the frequency of 8-10 Hz was elicited in rat brain slices after caffeine application. Oscillations comprised a non-NMDA receptor-dependent initial phase and a later NMDA receptor-dependent oscillatory phase, with the oscillator located in the upper layer of the OSC. Baclofen was applied to investigate the actions of GABAB receptors. The later NMDA receptor-dependent oscillatory phase completely disappeared, but the initial phase did not. These results suggest that GABAB receptors mainly act on NMDA receptor, in which metabotropic actions of GABAB receptors may contribute to the attenuation of NMDA receptor activities. A regulatory system for network oscillation involving GABAB receptors may be present in the OSC.
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Affiliation(s)
- Hiroyuki Kanayama
- Department of Molecular Oral Physiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8504, Japan
- Department of Oral and Maxillofacial Surgery, National Hospital Organization Osaka National Hospital, Osaka, 540-0006, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Shido, Kagawa, 769-2123, Japan
| | - Yoko Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Shido, Kagawa, 769-2123, Japan
| | - Nobuo Kato
- Department of Physiology, Kanazawa Medical University, Uchinada-Cho, Ishikawa, 920-0293, Japan
| | - Hiroshi Yoshimura
- Department of Molecular Oral Physiology, Institute of Biomedical Sciences, Tokushima University Graduate School, 3-18-15 Kuramoto, Tokushima, 770-8504, Japan.
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8
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Javadova A, Felmy F. GABA B receptor-mediated modulation in the developing dorsal nucleus of the lateral lemniscus. Eur J Neurosci 2024; 59:966-981. [PMID: 38180306 DOI: 10.1111/ejn.16246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 11/30/2023] [Accepted: 12/18/2023] [Indexed: 01/06/2024]
Abstract
The dorsal nucleus of the lateral lemniscus (DNLL) is a GABAergic, reciprocally connected auditory brainstem structure that continues to develop postnatally in rodents. One key feature of the DNLL is the generation of a strong, prolonged, ionotropic, GABAA receptor-mediated inhibition. Possible GABAB receptor-mediated signalling is unexplored in the DNLL. Here, we used Mongolian gerbils of either sex to describe GABAB receptor-mediated modulation of postsynaptic potassium currents and synaptic inputs in postnatal (P) animals of days 10/11 and 23-28. Throughout development, we observed the presence of a Baclofen-activated GABAB receptor-enhanced potassium outward conductance that is capable of suppressing action potential generation. In P10/11, old gerbils GABAB receptor activation enhances glutamatergic and suppresses ionotropic GABAergic synaptic transmission. During development, this differential modulation becomes less distinct, because in P22-28, old animals Baclofen-activated GABAB receptors rather enhance ionotropic GABAergic synaptic transmission, whereas glutamatergic transmission is both enhanced and suppressed. Blocking GABAB receptors causes an increase in ionotropic GABAergic transmission in P10/11 old gerbils that was independent on stimulation frequency but depended on the type of short-term plasticity. Together with the lack of Baclofen-induced changes in the synaptic paired-pulse ratio of either input type, we suggest that GABAB receptor-mediated modulation is predominantly postsynaptic and activates different signalling cascades. Thus, we argue that in DNLL neurons, the GABAB receptor is a post-synaptically located signalling hub that alters signalling cascades during development for distinct targets.
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Affiliation(s)
- Amina Javadova
- Institute for Zoology, University of Veterinary Medicine Foundation, Hannover, Hannover, Germany
- Infection Medicine and Veterinary Sciences (HGNI), Hannover Graduate School for Neurosciences, Hannover, Germany
| | - Felix Felmy
- Institute for Zoology, University of Veterinary Medicine Foundation, Hannover, Hannover, Germany
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9
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Hleihil M, Benke D. Restoring GABA B receptor expression in the ventral tegmental area of methamphetamine addicted mice inhibits locomotor sensitization and drug seeking behavior. Front Mol Neurosci 2024; 17:1347228. [PMID: 38384279 PMCID: PMC10879384 DOI: 10.3389/fnmol.2024.1347228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/15/2024] [Indexed: 02/23/2024] Open
Abstract
Repeated exposure to psychostimulants such as methamphetamine (METH) induces neuronal adaptations in the mesocorticolimbic dopamine system, including the ventral tegmental area (VTA). These changes lead to persistently enhanced neuronal activity causing increased dopamine release and addictive phenotypes. A factor contributing to increased dopaminergic activity in this system appears to be reduced GABAB receptor-mediated neuronal inhibition in the VTA. Dephosphorylation of serine 783 (Ser783) of the GABAB2 subunit by protein phosphatase 2A (PP2A) appears to trigger the downregulation GABAB receptors in psychostimulant-addicted rodents. Therefore, preventing the interaction of GABAB receptors with PP2A using an interfering peptide is a promising strategy to restore GABAB receptor-mediated neuronal inhibition. We have previously developed an interfering peptide (PP2A-Pep) that inhibits the GABAB receptors/PP2A interaction and thereby restores receptor expression under pathological conditions. Here, we tested the hypothesis that restoration of GABAB receptor expression in the VTA of METH addicted mice reduce addictive phenotypes. We found that the expression of GABAB receptors was significantly reduced in the VTA and nucleus accumbens but not in the hippocampus and somatosensory cortex of METH-addicted mice. Infusion of PP2A-Pep into the VTA of METH-addicted mice restored GABAB receptor expression in the VTA and inhibited METH-induced locomotor sensitization as assessed in the open field test. Moreover, administration of PP2A-Pep into the VTA also reduced drug seeking behavior in the conditioned place preference test. These observations underscore the importance of VTA GABAB receptors in controlling addictive phenotypes. Furthermore, this study illustrates the value of interfering peptides targeting diseases-related protein-protein interactions as an alternative approach for a potential development of selective therapeutic interventions.
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Affiliation(s)
- Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University of Zurich, Zürich, Switzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, Zürich, Switzerland
- Neuroscience Center Zurich, University and ETH Zurich, Zürich, Switzerland
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10
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Wang J, Liu X, Lan Y, Que T, Li J, Yue B, Fan Z. DNA methylation and transcriptome analysis reveal epigenomic differences among three macaque species. Evol Appl 2024; 17:e13604. [PMID: 38343783 PMCID: PMC10853583 DOI: 10.1111/eva.13604] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2024] Open
Abstract
Macaques (genus Macaca) are the most widely distributed non-human primates, and their evolutionary history, gene expression profiles, and genetic differences have been extensively studied. However, the DNA methylomes of macaque species are not available in public databases, which hampers understanding of epigenetic differences among macaque species. Epigenetic modifications can potentially affect development, physiology, behavior, and evolution. Here, we investigated the methylation patterns of the Tibetan macaque (M. thibetana; TM), Chinese rhesus macaque (M. mulatta lasiota; CR), and crab-eating macaque (M. fascicularis; CE) through whole-genome bisulfite sequencing from peripheral blood. We compared genome-wide methylation site information for the three species. We identified 12,128 (CR vs. CE), 59,165 (CR vs. TM), and 39,751 (CE vs. TM) differentially methylated regions (DMRs) in the three macaques. Furthermore, we obtained the differentially expressed genes (DEGs) among the three macaque species. The differences between CR and CE were smaller at both the methylome and transcriptome levels than compared with TM (CR vs. TM and CE vs. TM). We also found a change in the density of single nucleotide mutations in DMRs relative to their flanking regions, indicating a potential mechanism through which genomic alterations may modulate methylation landscapes, thereby influencing the transcriptome. Functional enrichment analyses showed the DMR-related genes were enriched in developmental processes and neurological functions, such as the growth hormone-related pathway, insulin secretion pathway, thyroid hormone synthesis pathway, morphine addiction, and GABAergic synapses. These differences may be associated with variations in physiology and habitat among the macaques. Our study provides one of the first genome-wide comparisons of genetic, gene expression, and epigenetic variations across different macaques. Our results should facilitate further research on comparative genomic and genetic differences in macaque species.
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Affiliation(s)
- Jiao Wang
- Key Laboratory of Bioresources and Eco‐Environment (Ministry of Education), College of Life SciencesSichuan UniversitySichuanChengduChina
| | - Xuyuan Liu
- Key Laboratory of Bioresources and Eco‐Environment (Ministry of Education), College of Life SciencesSichuan UniversitySichuanChengduChina
| | - Yue Lan
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life SciencesSichuan UniversitySichuanChengduChina
| | - Tengcheng Que
- Terrestrial Wildlife Rescue and Epidemic Diseases Surveillance Center of GuangxiGuangxiNanningChina
- Faculty of Data ScienceCity University of MacauMacauTaipaChina
| | - Jing Li
- Key Laboratory of Bioresources and Eco‐Environment (Ministry of Education), College of Life SciencesSichuan UniversitySichuanChengduChina
| | - Bisong Yue
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life SciencesSichuan UniversitySichuanChengduChina
| | - Zhenxin Fan
- Key Laboratory of Bioresources and Eco‐Environment (Ministry of Education), College of Life SciencesSichuan UniversitySichuanChengduChina
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life SciencesSichuan UniversitySichuanChengduChina
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11
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Bugnon T, Mayner WGP, Cirelli C, Tononi G. Sleep and wake in a model of the thalamocortical system with Martinotti cells. Eur J Neurosci 2024; 59:703-736. [PMID: 36215116 PMCID: PMC10083195 DOI: 10.1111/ejn.15836] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 08/26/2022] [Accepted: 10/05/2022] [Indexed: 12/14/2022]
Abstract
The mechanisms leading to the alternation between active (UP) and silent (DOWN) states during sleep slow waves (SWs) remain poorly understood. Previous models have explained the transition to the DOWN state by a progressive failure of excitation because of the build-up of adaptation currents or synaptic depression. However, these models are at odds with recent studies suggesting a role for presynaptic inhibition by Martinotti cells (MaCs) in generating SWs. Here, we update a classical large-scale model of sleep SWs to include MaCs and propose a different mechanism for the generation of SWs. In the wake mode, the network exhibits irregular and selective activity with low firing rates (FRs). Following an increase in the strength of background inputs and a modulation of synaptic strength and potassium leak potential mimicking the reduced effect of acetylcholine during sleep, the network enters a sleep-like regime in which local increases of network activity trigger bursts of MaC activity, resulting in strong disfacilitation of the local network via presynaptic GABAB1a -type inhibition. This model replicates findings on slow wave activity (SWA) during sleep that challenge previous models, including low and skewed FRs that are comparable between the wake and sleep modes, higher synchrony of transitions to DOWN states than to UP states, the possibility of triggering SWs by optogenetic stimulation of MaCs, and the local dependence of SWA on synaptic strength. Overall, this work points to a role for presynaptic inhibition by MaCs in the generation of DOWN states during sleep.
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Affiliation(s)
- Tom Bugnon
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719 USA
- Neuroscience Training Program, University of Wisconsin, Madison
| | - William G. P. Mayner
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719 USA
- Neuroscience Training Program, University of Wisconsin, Madison
| | - Chiara Cirelli
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719 USA
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719 USA
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12
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Villalobos N. Disinhibition Is an Essential Network Motif Coordinated by GABA Levels and GABA B Receptors. Int J Mol Sci 2024; 25:1340. [PMID: 38279339 PMCID: PMC10816949 DOI: 10.3390/ijms25021340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/16/2024] [Accepted: 01/19/2024] [Indexed: 01/28/2024] Open
Abstract
Network dynamics are crucial for action and sensation. Changes in synaptic physiology lead to the reorganization of local microcircuits. Consequently, the functional state of the network impacts the output signal depending on the firing patterns of its units. Networks exhibit steady states in which neurons show various activities, producing many networks with diverse properties. Transitions between network states determine the output signal generated and its functional results. The temporal dynamics of excitation/inhibition allow a shift between states in an operational network. Therefore, a process capable of modulating the dynamics of excitation/inhibition may be functionally important. This process is known as disinhibition. In this review, we describe the effect of GABA levels and GABAB receptors on tonic inhibition, which causes changes (due to disinhibition) in network dynamics, leading to synchronous functional oscillations.
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Affiliation(s)
- Nelson Villalobos
- Academia de Fisiología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, Ciudad de México 11340, Mexico;
- Sección de Estudios Posgrado e Investigación de la Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, Ciudad de Mexico 11340, Mexico
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13
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Bhat MA, Grampp T, Benke D. ERK1/2-Dependent Phosphorylation of GABA B1(S867/T872), Controlled by CaMKIIβ, Is Required for GABA B Receptor Degradation under Physiological and Pathological Conditions. Int J Mol Sci 2023; 24:13436. [PMID: 37686242 PMCID: PMC10488028 DOI: 10.3390/ijms241713436] [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] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/10/2023] Open
Abstract
GABAB receptor-mediated inhibition is indispensable for maintaining a healthy neuronal excitation/inhibition balance. Many neurological diseases are associated with a disturbed excitation/inhibition balance and downregulation of GABAB receptors due to enhanced sorting of the receptors to lysosomal degradation. A key event triggering the downregulation of the receptors is the phosphorylation of S867 in the GABAB1 subunit mediated by CaMKIIβ. Interestingly, close to S867 in GABAB1 exists another phosphorylation site, T872. Therefore, the question arose as to whether phosphorylation of T872 is involved in downregulating the receptors and whether phosphorylation of this site is also mediated by CaMKIIβ or by another protein kinase. Here, we show that mutational inactivation of T872 in GABAB1 prevented the degradation of the receptors in cultured neurons. We found that, in addition to CaMKIIβ, also ERK1/2 is involved in the degradation pathway of GABAB receptors under physiological and ischemic conditions. In contrast to our previous view, CaMKIIβ does not appear to directly phosphorylate S867. Instead, the data support a mechanism in which CaMKIIβ activates ERK1/2, which then phosphorylates S867 and T872 in GABAB1. Blocking ERK activity after subjecting neurons to ischemic stress completely restored downregulated GABAB receptor expression to normal levels. Thus, preventing ERK1/2-mediated phosphorylation of S867/T872 in GABAB1 is an opportunity to inhibit the pathological downregulation of the receptors after ischemic stress and is expected to restore a healthy neuronal excitation/inhibition balance.
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Affiliation(s)
- Musadiq A. Bhat
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland; (M.A.B.); (T.G.)
| | - Thomas Grampp
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland; (M.A.B.); (T.G.)
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, 8057 Zurich, Switzerland; (M.A.B.); (T.G.)
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
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14
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Tureček R, Melichar A, Králíková M, Hrušková B. The role of GABA B receptors in the subcortical pathways of the mammalian auditory system. Front Endocrinol (Lausanne) 2023; 14:1195038. [PMID: 37635966 PMCID: PMC10456889 DOI: 10.3389/fendo.2023.1195038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 07/24/2023] [Indexed: 08/29/2023] Open
Abstract
GABAB receptors are G-protein coupled receptors for the inhibitory neurotransmitter GABA. Functional GABAB receptors are formed as heteromers of GABAB1 and GABAB2 subunits, which further associate with various regulatory and signaling proteins to provide receptor complexes with distinct pharmacological and physiological properties. GABAB receptors are widely distributed in nervous tissue, where they are involved in a number of processes and in turn are subject to a number of regulatory mechanisms. In this review, we summarize current knowledge of the cellular distribution and function of the receptors in the inner ear and auditory pathway of the mammalian brainstem and midbrain. The findings suggest that in these regions, GABAB receptors are involved in processes essential for proper auditory function, such as cochlear amplifier modulation, regulation of spontaneous activity, binaural and temporal information processing, and predictive coding. Since impaired GABAergic inhibition has been found to be associated with various forms of hearing loss, GABAB dysfunction could also play a role in some pathologies of the auditory system.
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Affiliation(s)
- Rostislav Tureček
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Adolf Melichar
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
- Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Michaela Králíková
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Bohdana Hrušková
- Department of Auditory Neuroscience, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czechia
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15
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Sitzia G, Abrahao KP, Liput D, Calandra GM, Lovinger DM. Distinct mechanisms of CB1 and GABA B receptor presynaptic modulation of striatal indirect pathway projections to mouse globus pallidus. J Physiol 2023; 601:195-209. [PMID: 36412169 PMCID: PMC10107704 DOI: 10.1113/jp283614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Presynaptic modulation is a fundamental process regulating synaptic transmission. Striatal indirect pathway projections originate from A2A-expressing spiny projection neurons (iSPNs), targeting the globus pallidus external segment (GPe) and control the firing of the tonically active GPe neurons via GABA release. It is unclear if and how the presynaptic G-protein-coupled receptors (GPCRs), GABAB and CB1 receptors modulate iSPN-GPe projections. Here we used an optogenetic platform to study presynaptic Ca2+ and GABAergic transmission at iSPN projections, using a genetic strategy to express the calcium sensor GCaMP6f or the excitatory channelrhodopsin (hChR2) on iSPNs. We found that P/Q-type calcium channels are the primary voltage-gated Ca2+ channel (VGCC) subtype controlling presynaptic calcium and GABA release at iSPN-GPe projections. N-type and L-type VGCCs also contribute to GABA release at iSPN-GPe synapses. GABAB receptor activation resulted in a reversible inhibition of presynaptic Ca2+ transients (PreCaTs) and an inhibition of GABAergic transmission at iSPN-GPe synapses. CB1 receptor activation did not inhibit PreCaTs but inhibited GABAergic transmission at iSPN-GPe projections. CB1 effects on GABAergic transmission persisted in experiments where NaV and KV 1 were blocked, indicating a VGCC- and KV 1-independent presynaptic mechanism of action of CB1 receptors. Taken together, presynaptic modulation of iSPN-GPe projections by CB1 and GABAB receptors is mediated by distinct mechanisms. KEY POINTS: P/Q-type are the predominant voltage-gated Ca2+ channels controlling presynaptic Ca2+ and GABA release on the striatal indirect pathway projections. GABAB receptors modulate iSPN-GPe projections via a VGCC-dependent mechanism. CB1 receptors modulate iSPN-GPe projections via a VGCC-independent mechanism.
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Affiliation(s)
- Giacomo Sitzia
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismUS National Institutes of HealthRockvilleMarylandUSA
- Molecular Neurophysiology LaboratoryDepartment of Physiology and PharmacologyKarolinska InstitutetStockholmSweden
| | - Karina Possa Abrahao
- Departamento de PsicobiologiaUniversidade Federal de São PauloSão PauloSao PauloBrazil
| | - Daniel Liput
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismUS National Institutes of HealthRockvilleMarylandUSA
| | - Gian Marco Calandra
- Institute for Stroke and Dementia ResearchLudwig‐Maximilians‐UniversitätMunichGermany
| | - David M. Lovinger
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismUS National Institutes of HealthRockvilleMarylandUSA
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16
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Hleihil M, Balakrishnan K, Benke D. Protein phosphatase 2A regulation of GABAB receptors normalizes ischemia-induced aberrant receptor trafficking and provides neuroprotection. Front Mol Neurosci 2022; 15:1015906. [PMID: 36311027 PMCID: PMC9607930 DOI: 10.3389/fnmol.2022.1015906] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
One major factor regulating the strength of GABAB receptor signaling and thereby neuronal excitability is the dynamic control of their cell surface expression. GABAB receptors are constitutively internalized and recycled back to the plasma membrane to maintain a stable number of receptors at cell surface for appropriate signaling. Protein phosphatase 2A (PP2A) dependent dephosphorylation of serine 783 (S783) in the GABAB2 subunit is a key event for downregulating GABAB receptor cell surface expression particularly under conditions associated with excitotoxicity. Here, we investigated the role of PP2A in regulating GABAB receptor cell surface expression under physiological and excitotoxic conditions. For this purpose, we developed an interfering peptide (PP2A-Pep) that inhibits the interaction of GABAB receptors with PP2A. Using cultured cortical neurons, we found that PP2A downregulates GABAB receptor cell surface expression by inhibiting recycling of the receptors and thereby promoting degradation of the receptors. Inhibition of the GABAB receptor/PP2A interaction by PP2A-Pep in cultured cortical neurons restored GABAB receptor cell surface expression after excitotoxic stress and inhibited progressing neuronal death even when added 48 h after the insult. To explore the therapeutic potential of PP2A-Pep, we further analyzed effect of PP2A-Pep in the middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia. Incubation of brain slices prepared from MCAO-treated mice with PP2A-Pep restored normal GABAB receptor expression and GABAB receptor-mediated inhibition, reduced ischemic-induced overexcitability of neurons, and prevented neuronal death in the ischemic penumbra. This data illustrates the crucial role of regulating GABAB receptor phosphorylation by PP2A for controlling neuronal inhibition and excitability. The results further suggest that interfering with the GABAB receptor/PP2A interaction is a promising strategy for the development of specific therapeutic interventions to treat neurological diseases associated with a disturbed excitation/inhibition balance and downregulation of GABAB receptors.
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Affiliation(s)
- Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zürich, Zurich, Switzerland
| | - Karthik Balakrishnan
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zürich, Zurich, Switzerland
- Drug Discovery Network Zurich, Zurich, Switzerland
- *Correspondence: Dietmar Benke,
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17
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Bellusci L, Kim E, Garcia DuBar S, Gillis RA, Vicini S, Sahibzada N. Brainstem activation of GABAB receptors in the nucleus tractus solitarius increases gastric motility. Front Neurosci 2022; 16:961042. [PMID: 35983226 PMCID: PMC9379309 DOI: 10.3389/fnins.2022.961042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/11/2022] [Indexed: 12/01/2022] Open
Abstract
Background and aim Local GABAergic signaling in the dorsal vagal complex (DVC) is essential to control gastric function. While the inhibitory GABAA receptor action on motility in the DVC is well-documented, the role of the GABAB receptor on gastric function is less well-established. Microinjection of baclofen, a selective GABAB receptor agonist, in the dorsal motor nucleus of the vagus (DMV) increases gastric tone and motility, while the effect on motility in the nucleus tractus solitarius (NTS) needs to be investigated. Previous in vitro studies showed that GABAB receptors exert a local inhibitory effect in unidentified NTS neurons. Since the NTS and DMV nuclei have differential control of gastric motility, we compared GABAB receptor activation in the NTS to that reported in the DMV. We microinjected baclofen unilaterally in the NTS while monitoring intragastric pressure and compared its action to optogenetic activation of somatostatin (SST) neurons in transgenic sst-Cre::channelrhodopsin-2 (ChR2) mice. We also performed patch-clamp recordings from SST and DMV neurons in brainstem slices from these mice. Methods In vivo drug injections and optogenetic stimulation were performed in fasted urethane/α-chloralose anesthetized male mice. Gastric tone and motility were monitored by an intragastric balloon inserted in the antrum and inflated with warm water to provide a baseline intragastric pressure (IGP). Coronal brainstem slices were obtained from the sst-Cre::ChR2 mice for interrogation with optogenetics and pharmacology using electrophysiology. Results The unilateral microinjection of baclofen into the NTS caused a robust increase in gastric tone and motility that was not affected by ipsilateral vagotomy. Optogenetic activation of SST neurons that followed baclofen effectively suppresses the gastric motility in vivo. In brain slices, baclofen suppressed spontaneous and light-activated inhibitory postsynaptic currents in SST and gastrointestinal-projection DMV neurons and produced outward currents. Conclusion Our results show that GABAB receptors in the NTS strongly increase gastric tone and motility. Optogenetic stimulation in vivo and in vitro suggests that these receptors activated by baclofen suppress the glutamatergic sensory vagal afferents in the NTS and also inhibit the interneurons and the inhibitory neurons that project to the DMV, which, in turn, increase motility via a cholinergic excitatory pathway to the stomach.
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18
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Shen W, Li Z, Tang Y, Han P, Zhu F, Dong J, Ma T, Zhao K, Zhang X, Xie Y, Zeng LH. Somatostatin interneurons inhibit excitatory transmission mediated by astrocytic GABA B and presynaptic GABA B and adenosine A 1 receptors in the hippocampus. J Neurochem 2022; 163:310-326. [PMID: 35775994 DOI: 10.1111/jnc.15662] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/14/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022]
Abstract
GABAergic network activity has been established to be involved in numerous physiological processes and pathological conditions. Extensive studies have corroborated that GABAergic network activity regulates excitatory synaptic networks by activating presynaptic GABAB receptors (GABAB Rs). It is well documented that astrocytes express GABAB Rs and respond to GABAergic network activity. However, little is known about whether astrocytic GABAB Rs regulate excitatory synaptic transmission mediated by GABAergic network activity. To address this issue, we combined whole-cell recordings, optogenetics, calcium imaging, and pharmacological approaches to specifically activate hippocampal somatostatin-expressing interneurons (SOM-INs), a type of interneuron that targets pyramidal cell dendrites, while monitoring excitatory synaptic transmission in CA1 pyramidal cells. We found that optogenetic stimulation of SOM-INs increases astrocyte Ca2+ signaling via the activation of astrocytic GABAB Rs and GAT-3. SOM-INs depress excitatory neurotransmission by activating presynaptic GABAB Rs and astrocytic GABAB Rs, the latter inducing the release of ATP/adenosine. In turn, adenosine inhibits excitatory synaptic transmission by activating presynaptic adenosine A1 receptors (A1 Rs). Overall, our results reveal a novel mechanism that SOM-INs activation-induced synaptic depression is partially mediated by the activation of astrocytic GABAB Rs.
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Affiliation(s)
- Weida Shen
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Zijing Li
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Yejiao Tang
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Pufan Han
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Feng Zhu
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Jingyin Dong
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Tianyu Ma
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Kai Zhao
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Xin Zhang
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Yicheng Xie
- The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Ling-Hui Zeng
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
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19
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Balakrishnan K, Hleihil M, Bhat MA, Ganley RP, Vaas M, Klohs J, Zeilhofer HU, Benke D. Targeting the interaction of GABA B receptors with CaMKII with an interfering peptide restores receptor expression after cerebral ischemia and inhibits progressive neuronal death in mouse brain cells and slices. Brain Pathol 2022; 33:e13099. [PMID: 35698024 PMCID: PMC9836377 DOI: 10.1111/bpa.13099] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/29/2022] [Indexed: 01/21/2023] Open
Abstract
Cerebral ischemia is the leading cause for long-term disability and mortality in adults due to massive neuronal death. Currently, there is no pharmacological treatment available to limit progressive neuronal death after stroke. A major mechanism causing ischemia-induced neuronal death is the excessive release of glutamate and the associated overexcitation of neurons (excitotoxicity). Normally, GABAB receptors control neuronal excitability in the brain via prolonged inhibition. However, excitotoxic conditions rapidly downregulate GABAB receptors via a CaMKII-mediated mechanism and thereby diminish adequate inhibition that could counteract neuronal overexcitation and neuronal death. To prevent the deleterious downregulation of GABAB receptors, we developed a cell-penetrating synthetic peptide (R1-Pep) that inhibits the interaction of GABAB receptors with CaMKII. Administration of this peptide to cultured cortical neurons exposed to excitotoxic conditions restored cell surface expression and function of GABAB receptors. R1-Pep did not affect CaMKII expression or activity but prevented its T286 autophosphorylation that renders it autonomously and persistently active. Moreover, R1-Pep counteracted the aberrant downregulation of G protein-coupled inwardly rectifying K+ channels and the upregulation of N-type voltage-gated Ca2+ channels, the main effectors of GABAB receptors. The restoration of GABAB receptors activated the Akt survival pathway and inhibited excitotoxic neuronal death with a wide time window in cultured neurons. Restoration of GABAB receptors and neuroprotective activity of R1-Pep was verified by using brain slices prepared from mice after middle cerebral artery occlusion (MCAO). Treatment with R1-Pep restored normal GABAB receptor expression and GABA receptor-mediated K+ channel currents. This reduced MCAO-induced neuronal excitability and inhibited neuronal death. These results support the hypothesis that restoration of GABAB receptor expression under excitatory conditions provides neuroprotection and might be the basis for the development of a selective intervention to inhibit progressive neuronal death after ischemic stroke.
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Affiliation(s)
- Karthik Balakrishnan
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland,Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland,Present address:
Dewpoint Therapeutics GMBHDresdenGermany
| | - Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland,Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland
| | - Musadiq A. Bhat
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland
| | - Robert P. Ganley
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland
| | - Markus Vaas
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland,Present address:
Clinical Trial Center ZurichUniversity Hospital of ZurichZurichSwitzerland
| | - Jan Klohs
- Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland,Institute for Biomedical Engineering, University of Zurich and ETH ZurichZurichSwitzerland
| | - Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland,Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland,Drug Discovery Network ZurichZurichSwitzerland,Institute of Pharmaceutical Sciences, ETH ZurichZurichSwitzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of ZurichZurichSwitzerland,Neuroscience Center ZurichUniversity of Zurich and ETH ZurichZurichSwitzerland,Drug Discovery Network ZurichZurichSwitzerland
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20
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Bhat MA, Esmaeili A, Neumann E, Balakrishnan K, Benke D. Targeting the Interaction of GABA B Receptors With CHOP After an Ischemic Insult Restores Receptor Expression and Inhibits Progressive Neuronal Death. Front Pharmacol 2022; 13:870861. [PMID: 35422706 PMCID: PMC9002115 DOI: 10.3389/fphar.2022.870861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/14/2022] [Indexed: 01/01/2023] Open
Abstract
GABAB receptors control neuronal excitability via slow and prolonged inhibition in the central nervous system. One important function of GABAB receptors under physiological condition is to prevent neurons from shifting into an overexcitation state which can lead to excitotoxic death. However, under ischemic conditions, GABAB receptors are downregulated, fostering over-excitation and excitotoxicity. One mechanism downregulating GABAB receptors is mediated via the interaction with the endoplasmic reticulum (ER) stress-induced transcription factor CHOP. In this study, we investigated the hypothesis that preventing the interaction of CHOP with GABAB receptors after an ischemic insult restores normal expression of GABAB receptors and reduces neuronal death. For this, we designed an interfering peptide (R2-Pep) that restored the CHOP-induced downregulation of cell surface GABAB receptors in cultured cortical neurons subjected to oxygen and glucose deprivation (OGD). Administration of R2-Pep after OGD restored normal cell surface expression of GABAB receptors as well as GABAB receptor-mediated inhibition. As a result, R2-Pep reduced enhanced neuronal activity and inhibited progressive neuronal death in OGD stressed cultures. Thus, targeting diseases relevant protein-protein interactions might be a promising strategy for developing highly specific novel therapeutics.
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Affiliation(s)
- Musadiq A Bhat
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Abolghasem Esmaeili
- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran
| | - Elena Neumann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Karthik Balakrishnan
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland.,Drug Discovery Network Zurich (DDNZ), Zurich, Switzerland
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21
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Stoby KS, Rafique SA, Oeltzschner G, Steeves JKE. Continuous and intermittent theta burst stimulation to the visual cortex do not alter GABA and glutamate concentrations measured by magnetic resonance spectroscopy. Brain Behav 2022; 12:e2478. [PMID: 35029058 PMCID: PMC8865152 DOI: 10.1002/brb3.2478] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/07/2021] [Accepted: 12/14/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Theta burst stimulation (TBS), a form of repetitive transcranial magnetic stimulation (rTMS), uses repeated high-frequency bursts to non-invasively modulate neural processes in the brain. An intermittent TBS (iTBS) protocol is generally considered "excitatory," while continuous TBS (cTBS) is considered "inhibitory." However, the majority of work that has led to these effects being associated with the respective protocols has been done in the motor cortex, and it is well established that TMS can have variable effects across the brain. OBJECTIVES AND METHOD We investigated the effects of iTBS and cTBS to the primary visual cortex (V1) on composite levels of gamma-aminobutyric acid + co-edited macromolecules (GABA+) and glutamate + glutamine (Glx) since these are key inhibitory and excitatory neurotransmitters, respectively. Participants received a single session of cTBS, iTBS, or sham TBS to V1. GABA+ and Glx were quantified in vivo at the stimulation site using spectral-edited proton magnetic resonance spectroscopy (1 H-MRS) at 3T. Baseline pre-TBS GABA+ and Glx levels were compared to immediate post-TBS and 1 h post-TBS levels. RESULTS There were no significant changes in GABA+ or Glx following either of the TBS conditions. Visual cortical excitability, measured using phosphene thresholds, remained unchanged following both cTBS and iTBS conditions. There was no relationship between excitability thresholds and GABA+ or Glx levels. However, TBS did alter the relationship between GABA+ and Glx for up to 1 h following stimulation. CONCLUSIONS These findings demonstrate that a single session of TBS to the visual cortex can be used without significant effects on the tonic levels of these key neurotransmitters; and add to our understanding that TBS has differential effects at visual, motor, and frontal cortices.
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Affiliation(s)
- Karlene S Stoby
- Centre for Vision Research and Department of Psychology, York University, Toronto, ON, Canada
| | - Sara A Rafique
- Centre for Vision Research and Department of Psychology, York University, Toronto, ON, Canada
| | - Georg Oeltzschner
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA
| | - Jennifer K E Steeves
- Centre for Vision Research and Department of Psychology, York University, Toronto, ON, Canada
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Abstract
In 1959, E. G. Gray described two different types of synapses in the brain for the first time: symmetric and asymmetric. Later on, symmetric synapses were associated with inhibitory terminals, and asymmetric synapses to excitatory signaling. The balance between these two systems is critical to maintain a correct brain function. Likewise, the modulation of both types of synapses is also important to maintain a healthy equilibrium. Cerebral circuitry responds differently depending on the type of damage and the timeline of the injury. For example, promoting symmetric signaling following ischemic damage is beneficial only during the acute phase; afterwards, it further increases the initial damage. Synapses can be also altered by players not directly related to them; the chronic and long-term neurodegeneration mediated by tau proteins primarily targets asymmetric synapses by decreasing neuronal plasticity and functionality. Dopamine represents the main modulating system within the central nervous system. Indeed, the death of midbrain dopaminergic neurons impairs locomotion, underlying the devastating Parkinson’s disease. Herein, we will review studies on symmetric and asymmetric synapses plasticity after three different stressors: symmetric signaling under acute damage—ischemic stroke; asymmetric signaling under chronic and long-term neurodegeneration—Alzheimer’s disease; symmetric and asymmetric synapses without modulation—Parkinson’s disease.
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Hleihil M, Vaas M, Bhat MA, Balakrishnan K, Benke D. Sustained Baclofen-Induced Activation of GABA B Receptors After Cerebral Ischemia Restores Receptor Expression and Function and Limits Progressing Loss of Neurons. Front Mol Neurosci 2021; 14:726133. [PMID: 34539344 PMCID: PMC8440977 DOI: 10.3389/fnmol.2021.726133] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/12/2021] [Indexed: 11/13/2022] Open
Abstract
One important function of GABAB receptors is the control of neuronal activity to prevent overexcitation and thereby excitotoxic death, which is a hallmark of cerebral ischemia. Consequently, sustained activation of GABAB receptors with the selective agonist baclofen provides neuroprotection in in vitro and in vivo models of cerebral ischemia. However, excitotoxic conditions severely downregulate the receptors, which would compromise the neuroprotective effectiveness of baclofen. On the other hand, recent work suggests that sustained activation of GABAB receptors stabilizes receptor expression. Therefore, we addressed the question whether sustained activation of GABAB receptors reduces downregulation of the receptor under excitotoxic conditions and thereby preserves GABAB receptor-mediated inhibition. In cultured neurons subjected to oxygen and glucose deprivation (OGD), to mimic cerebral ischemia, GABAB receptors were severely downregulated. Treatment of the cultures with baclofen after OGD restored GABAB receptor expression and reduced loss of neurons. Restoration of GABAB receptors was due to enhanced fast recycling of the receptors, which reduced OGD-induced sorting of the receptors to lysosomal degradation. Utilizing the middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia, we verified the severe downregulation of GABAB receptors in the affected cortex and a partial restoration of the receptors after systemic injection of baclofen. Restored receptor expression recovered GABAB receptor-mediated currents, normalized the enhanced neuronal excitability observed after MCAO and limited progressive loss of neurons. These results suggest that baclofen-induced restoration of GABAB receptors provides the basis for the neuroprotective activity of baclofen after an ischemic insult. Since GABAB receptors regulate multiple beneficial pathways, they are promising targets for a neuroprotective strategy in acute cerebral ischemia.
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Affiliation(s)
- Mohammad Hleihil
- Institute of Pharmacology and Toxicology, University Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich, University of Zurich, Zurich, Switzerland
| | - Markus Vaas
- Institute of Pharmacology and Toxicology, University Zurich, Zurich, Switzerland
| | - Musadiq A Bhat
- Institute of Pharmacology and Toxicology, University Zurich, Zurich, Switzerland
| | - Karthik Balakrishnan
- Institute of Pharmacology and Toxicology, University Zurich, Zurich, Switzerland
| | - Dietmar Benke
- Institute of Pharmacology and Toxicology, University Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, ETH Zurich, University of Zurich, Zurich, Switzerland
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24
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Tahir MS, Porto-Neto LR, Gondro C, Shittu OB, Wockner K, Tan AWL, Smith HR, Gouveia GC, Kour J, Fortes MRS. Meta-Analysis of Heifer Traits Identified Reproductive Pathways in Bos indicus Cattle. Genes (Basel) 2021; 12:768. [PMID: 34069992 PMCID: PMC8157873 DOI: 10.3390/genes12050768] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Fertility traits measured early in life define the reproductive potential of heifers. Knowledge of genetics and biology can help devise genomic selection methods to improve heifer fertility. In this study, we used ~2400 Brahman cattle to perform GWAS and multi-trait meta-analysis to determine genomic regions associated with heifer fertility. Heifer traits measured were pregnancy at first mating opportunity (PREG1, a binary trait), first conception score (FCS, score 1 to 3) and rebreeding score (REB, score 1 to 3.5). The heritability estimates were 0.17 (0.03) for PREG1, 0.11 (0.05) for FCS and 0.28 (0.05) for REB. The three traits were highly genetically correlated (0.75-0.83) as expected. Meta-analysis was performed using SNP effects estimated for each of the three traits, adjusted for standard error. We identified 1359 significant SNPs (p-value < 9.9 × 10-6 at FDR < 0.0001) in the multi-trait meta-analysis. Genomic regions of 0.5 Mb around each significant SNP from the meta-analysis were annotated to create a list of 2560 positional candidate genes. The most significant SNP was in the vicinity of a genomic region on chromosome 8, encompassing the genes SLC44A1, FSD1L, FKTN, TAL2 and TMEM38B. The genomic region in humans that contains homologs of these genes is associated with age at puberty in girls. Top significant SNPs pointed to additional fertility-related genes, again within a 0.5 Mb region, including ESR2, ITPR1, GNG2, RGS9BP, ANKRD27, TDRD12, GRM1, MTHFD1, PTGDR and NTNG1. Functional pathway enrichment analysis resulted in many positional candidate genes relating to known fertility pathways, including GnRH signaling, estrogen signaling, progesterone mediated oocyte maturation, cAMP signaling, calcium signaling, glutamatergic signaling, focal adhesion, PI3K-AKT signaling and ovarian steroidogenesis pathway. The comparison of results from this study with previous transcriptomics and proteomics studies on puberty of the same cattle breed (Brahman) but in a different population identified 392 genes in common from which some genes-BRAF, GABRA2, GABR1B, GAD1, FSHR, CNGA3, PDE10A, SNAP25, ESR2, GRIA2, ORAI1, EGFR, CHRNA5, VDAC2, ACVR2B, ORAI3, CYP11A1, GRIN2A, ATP2B3, CAMK2A, PLA2G, CAMK2D and MAPK3-are also part of the above-mentioned pathways. The biological functions of the positional candidate genes and their annotation to known pathways allowed integrating the results into a bigger picture of molecular mechanisms related to puberty in the hypothalamus-pituitary-ovarian axis. A reasonable number of genes, common between previous puberty studies and this study on early reproductive traits, corroborates the proposed molecular mechanisms. This study identified the polymorphism associated with early reproductive traits, and candidate genes that provided a visualization of the proposed mechanisms, coordinating the hypothalamic, pituitary, and ovarian functions for reproductive performance in Brahman cattle.
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Affiliation(s)
- Muhammad S. Tahir
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
| | - Laercio R. Porto-Neto
- Commonwealth Scientific and Industrial Research Organization, Brisbane, QLD 4072, Australia;
| | - Cedric Gondro
- Department of Animal Science, Michigan State University, East Lansing, MI 48824, USA;
| | - Olasege B. Shittu
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
| | - Kimberley Wockner
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
| | - Andre W. L. Tan
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
| | - Hugo R. Smith
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
| | - Gabriela C. Gouveia
- Animal Science Department, Veterinary School, Federal University of Minas Gerais, Belo Horizonte 31270-901, Brazil;
| | - Jagish Kour
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
| | - Marina R. S. Fortes
- School of Chemistry and Molecular Bioscience, The University of Queensland Australia, Brisbane, QLD 4072, Australia; (M.S.T.); (O.B.S.); (K.W.); (A.W.L.T.); (H.R.S.); (J.K.)
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25
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The role of GABAergic signalling in neurodevelopmental disorders. Nat Rev Neurosci 2021; 22:290-307. [PMID: 33772226 PMCID: PMC9001156 DOI: 10.1038/s41583-021-00443-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 02/08/2023]
Abstract
GABAergic inhibition shapes the connectivity, activity and plasticity of the brain. A series of exciting new discoveries provides compelling evidence that disruptions in a number of key facets of GABAergic inhibition have critical roles in the aetiology of neurodevelopmental disorders (NDDs). These facets include the generation, migration and survival of GABAergic neurons, the formation of GABAergic synapses and circuit connectivity, and the dynamic regulation of the efficacy of GABAergic signalling through neuronal chloride transporters. In this Review, we discuss recent work that elucidates the functions and dysfunctions of GABAergic signalling in health and disease, that uncovers the contribution of GABAergic neural circuit dysfunction to NDD aetiology and that leverages such mechanistic insights to advance precision medicine for the treatment of NDDs.
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26
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Neurexins regulate presynaptic GABA B-receptors at central synapses. Nat Commun 2021; 12:2380. [PMID: 33888718 PMCID: PMC8062527 DOI: 10.1038/s41467-021-22753-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 03/20/2021] [Indexed: 11/28/2022] Open
Abstract
Diverse signaling complexes are precisely assembled at the presynaptic active zone for dynamic modulation of synaptic transmission and synaptic plasticity. Presynaptic GABAB-receptors nucleate critical signaling complexes regulating neurotransmitter release at most synapses. However, the molecular mechanisms underlying assembly of GABAB-receptor signaling complexes remain unclear. Here we show that neurexins are required for the localization and function of presynaptic GABAB-receptor signaling complexes. At four model synapses, excitatory calyx of Held synapses in the brainstem, excitatory and inhibitory synapses on hippocampal CA1-region pyramidal neurons, and inhibitory basket cell synapses in the cerebellum, deletion of neurexins rendered neurotransmitter release significantly less sensitive to GABAB-receptor activation. Moreover, deletion of neurexins caused a loss of GABAB-receptors from the presynaptic active zone of the calyx synapse. These findings extend the role of neurexins at the presynaptic active zone to enabling GABAB-receptor signaling, supporting the notion that neurexins function as central organizers of active zone signaling complexes. Neurexins are evolutionarily conserved cell adhesion molecules that tune synapse formation and specification. Here the authors show that neurexins play similar roles in regulating presynaptic GABAB receptors at multiple CNS synapses.
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Peng SY, Shi Z, Zhou DS, Wang XY, Li XX, Liu XL, Wang WD, Lin GN, Pan BX, Voon V, Grace AA, Heilig M, Wong ML, Yuan TF. Reduced motor cortex GABA BR function following chronic alcohol exposure. Mol Psychiatry 2021; 26:383-395. [PMID: 33432190 DOI: 10.1038/s41380-020-01009-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 01/29/2023]
Abstract
The GABAB receptor (GABABR) agonist baclofen has been used to treat alcohol and several other substance use disorders (AUD/SUD), yet its underlying neural mechanism remains unclear. The present study aimed to investigate cortical GABABR dynamics following chronic alcohol exposure. Ex vivo brain slice recordings from mice chronically exposed to alcohol revealed a reduction in GABABR-mediated currents, as well as a decrease of GABAB1/2R and G-protein-coupled inwardly rectifying potassium channel 2 (GIRK2) activities in the motor cortex. Moreover, our data indicated that these alterations could be attributed to dephosphorylation at the site of serine 783 (ser-783) in GABAB2 subunit, which regulates the surface expression of GABABR. Furthermore, a human study using paired-pulse-transcranial magnetic stimulation (TMS) analysis further demonstrated a reduced cortical inhibition mediated by GABABR in patients with AUD. Our findings provide the first evidence that chronic alcohol exposure is associated with significantly impaired cortical GABABR function. The ability to promote GABABR signaling may account for the therapeutic efficacy of baclofen in AUD.
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Affiliation(s)
- Shi-Yu Peng
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Zhe Shi
- Division of Stem Cell Regulation and Application, Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | | | - Xin-Yue Wang
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xing-Xing Li
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Xiao-Li Liu
- Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Wei-Di Wang
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Guan-Ning Lin
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.,School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Bing-Xing Pan
- Institute of Life Sciences, Nanchang University, Nanchang, Jiangxi, China
| | - Valerie Voon
- Department of Psychiatry, University of Cambridge, Cambridge, UK
| | - Anthony A Grace
- Center for Neuroscience, Psychiatry and Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Markus Heilig
- Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences,, Linköping University, Linköping, Sweden
| | - Ma-Li Wong
- Department of Psychiatry and Behavioral Sciences, State University of New York Upstate Medical University, Syracuse, NY, USA
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, China. .,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu, China. .,TianQiao and Chrissy Chen Institute for Translational Research, Shanghai, China. .,The State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China.
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28
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Therapeutic potential of targeting G protein-gated inwardly rectifying potassium (GIRK) channels in the central nervous system. Pharmacol Ther 2021; 223:107808. [PMID: 33476640 DOI: 10.1016/j.pharmthera.2021.107808] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 01/05/2021] [Indexed: 12/15/2022]
Abstract
G protein-gated inwardly rectifying potassium channels (Kir3/GirK) are important for maintaining resting membrane potential, cell excitability and inhibitory neurotransmission. Coupled to numerous G protein-coupled receptors (GPCRs), they mediate the effects of many neurotransmitters, neuromodulators and hormones contributing to the general homeostasis and particular synaptic plasticity processes, learning, memory and pain signaling. A growing number of behavioral and genetic studies suggest a critical role for the appropriate functioning of the central nervous system, as well as their involvement in many neurologic and psychiatric conditions, such as neurodegenerative diseases, mood disorders, attention deficit hyperactivity disorder, schizophrenia, epilepsy, alcoholism and drug addiction. Hence, GirK channels emerge as a very promising tool to be targeted in the current scenario where these conditions already are or will become a global public health problem. This review examines recent findings on the physiology, function, dysfunction, and pharmacology of GirK channels in the central nervous system and highlights the relevance of GirK channels as a worthful potential target to improve therapies for related diseases.
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29
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Deng SL, Hu ZL, Mao L, Gao B, Yang Q, Wang F, Chen JG. The effects of Kctd12, an auxiliary subunit of GABA B receptor in dentate gyrus on behavioral response to chronic social defeat stress in mice. Pharmacol Res 2021; 163:105355. [PMID: 33285230 DOI: 10.1016/j.phrs.2020.105355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 11/17/2020] [Accepted: 12/01/2020] [Indexed: 12/28/2022]
Abstract
Adaptive responses to stress are critical to enhance physical and mental well-being, but excessive or prolonged stress may cause inadaptability and increase the risks of psychiatric disorders, such as depression. GABABR signaling is fundamental to brain function and has been identified in neuropsychiatric disorders. KCTD12 is a critical auxiliary subunit in GABABR signaling, but its role in mental disorders, such as depression is unclear. In the present study, we used a well-validated mice model, chronic social defeat stress (CSDS) to investigate behavioral responses to stress and explore the role of Kctd12 in stress response, as well as the relevant mechanisms. We found that CSDS increased the expression of Kctd12 in the dentate gyrus (DG), a subregion of hippocampus. Overexpression of Kctd12 in DG induced higher responsiveness to acute stress and increased vulnerability to social stress in mice, whereas knock-down of Kctd12 in DG prevented the social avoidance. Furthermore, an increased expression of GABAB receptor 2 (GB2) in the DG of CSDS-treated mice was observed, and CGP35348, an antagonist of GABABR, improved the stress-induced behavior responses along with suppressing the excess expression of Kctd12. In addition, Kctd12 regulated the excitability of granule cell in DG, and the stimulation of neuronal activity by silencing Kctd12 contributed to the antidepressant-like effect of fluoxetine. These findings identify that the Kctd12 in DG works as a critical mediator of stress responses, providing a promising therapeutic target in stress-related psychiatric disorders, including depression.
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Affiliation(s)
- Si-Long Deng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhuang-Li Hu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (HUST), Wuhan, 430030, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China; The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, China
| | - Li Mao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Bo Gao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qiong Yang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (HUST), Wuhan, 430030, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China; The Collaborative-Innovation Center for Brain Science, Wuhan, 430030, China; The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, China.
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China; Hubei Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation (HUST), Wuhan, 430030, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, China; The Collaborative-Innovation Center for Brain Science, Wuhan, 430030, China; The Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, China.
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30
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Rafique SA, Steeves JKE. Assessing differential effects of single and accelerated low-frequency rTMS to the visual cortex on GABA and glutamate concentrations. Brain Behav 2020; 10:e01845. [PMID: 32964685 PMCID: PMC7749615 DOI: 10.1002/brb3.1845] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND The application of repetitive transcranial magnetic stimulation (rTMS) for therapeutic use in visual-related disorders and its underlying mechanisms in the visual cortex is under-investigated. Additionally, there is little examination of rTMS adverse effects particularly with regards to visual and cognitive function. Neural plasticity is key in rehabilitation and recovery of function; thus, effective therapeutic strategies must be capable of modulating plasticity. Glutamate and γ-aminobutyric acid (GABA)-mediated changes in the balance between excitation and inhibition are prominent features in visual cortical plasticity. OBJECTIVES AND METHOD We investigated the effects of low-frequency (1 Hz) rTMS to the visual cortex on levels of neurotransmitters GABA and glutamate to determine the therapeutic potential of 1 Hz rTMS for visual-related disorders. Two rTMS regimes commonly used in clinical applications were investigated: participants received rTMS to the visual cortex either in a single 20-min session or five accelerated 20-min sessions (not previously investigated at the visual cortex). Proton (1H) magnetic resonance spectroscopy for in vivo quantification of GABA (assessed via GABA+) and glutamate (assessed via Glx) concentrations was performed pre- and post-rTMS. RESULTS GABA+ and Glx concentrations were unaltered following a single session of rTMS to the visual cortex. One day of accelerated rTMS significantly reduced GABA+ concentration for up to 24 hr, with levels returning to baseline by 1-week post-rTMS. Basic visual and cognitive function remained largely unchanged. CONCLUSION Accelerated 1 Hz rTMS to the visual cortex has greater potential for approaches targeting plasticity or in cases with altered GABAergic responses in visual disorders. Notably, these results provide preliminary insight into a critical window of plasticity with accelerated rTMS (e.g., 24 hr) in which adjunct therapies may offer better functional outcome. We describe detailed procedures to enable further exploration of these protocols.
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Affiliation(s)
- Sara A. Rafique
- Department of Psychology and Centre for Vision ResearchYork UniversityTorontoONCanada
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31
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Kwan C, Sia A, O'Gorman C. Status epilepticus from GABA BR antibody positive encephalitis due to de novo mixed small cell and adenocarcinoma of the prostate. BMJ Case Rep 2020; 13:13/11/e238172. [PMID: 33257388 PMCID: PMC7705536 DOI: 10.1136/bcr-2020-238172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We present a case study of a 67-year-old man who presented with a new onset of recurrent tonic-clonic seizures. He had tested positive to gamma-aminobutyric acid B receptor antibodies in his blood and cerebrospinal fluid, and subsequent CT imaging and transrectal biopsy confirmed the presence of a locally advanced mixed small cell and Gleason 9 adenocarcinoma of the prostate. His seizures remained resistant to treatment with multiple antiepileptic drugs, including sodium valproate, clobazam, topiramate, carbamazepine, phenytoin and lacosamide. He progressed to status epilepticus, which required intravenous immunoglobulin and steroids, followed by plasma exchange 1 week later. The status epilepticus was refractory and required multiple admissions to the intensive care unit.
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Affiliation(s)
- Christopher Kwan
- Department of Internal Medicine and Clinical Epidemiology, Princess Alexandra Hospital Health Service District, Brisbane, Queensland, Australia
| | - Aaron Sia
- Department of Neurology and Stroke, Princess Alexandra Hospital Health Service District, Brisbane, Queensland, Australia
| | - Cullen O'Gorman
- Department of Neurology and Stroke, Princess Alexandra Hospital Health Service District, Brisbane, Queensland, Australia
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32
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Li Y, Wang C, Wang P, Li X, Zhou L. Effects of febrile seizures in mesial temporal lobe epilepsy with hippocampal sclerosis on gene expression using bioinformatical analysis. ACTA EPILEPTOLOGICA 2020. [DOI: 10.1186/s42494-020-00027-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractBackgroundTo investigate the effect of long-term febrile convulsions on gene expression in mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and explore the molecular mechanism of MTLE-HS.MethodsMicroarray data of MTLE-HS were obtained from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) between MTLE-HS with and without febrile seizure history were screened by the GEO2R software. Pathway enrichment and gene ontology of the DEGs were analyzed using the DAVID online database and FunRich software. Protein–protein interaction (PPI) networks among DEGs were constructed using the STRING database and analyzed by Cytoscape.ResultsA total of 515 DEGs were identified in MTLE-HS samples with a febrile seizure history compared to MTLE-HS samples without febrile seizure, including 25 down-regulated and 490 up-regulated genes. These DEGs were expressed mostly in plasma membrane and synaptic vesicles. The major molecular functions of those genes were voltage-gated ion channel activity, extracellular ligand-gated ion channel activity and calcium ion binding. The DEGs were mainly involved in biological pathways of cell communication signal transduction and transport. Five genes (SNAP25, SLC32A1, SYN1, GRIN1,andGRIA1) were significantly expressed in the MTLE-HS with prolonged febrile seizures.ConclusionThe pathogenesis of MTLE-HS involves multiple genes, and prolonged febrile seizures could cause differential expression of genes. Thus, investigations of those genes may provide a new perspective into the mechanism of MTLE-HS.
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33
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Korczak M, Kurowski P, Leśniak A, Grönbladh A, Filipowska A, Bujalska-Zadrożny M. GABA B receptor intracellular signaling: novel pathways for depressive disorder treatment? Eur J Pharmacol 2020; 885:173531. [PMID: 32871173 DOI: 10.1016/j.ejphar.2020.173531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/22/2022]
Abstract
Affecting over 320 million people around the world, depression has become a formidable challenge for modern medicine. In addition, an increasing number of studies cast doubt on the monoamine theory of depressive disorder and, worryingly, antidepressant medications only significantly benefit patients with severe depression. Thus, it is not surprising that researchers have shown an increased interest in new theories attempting to explain the pathogenesis of this disease. One example is the excitatory/inhibitory transmission imbalance theory. These abnormalities involve glutamate and γ-aminobutyric acid (GABA) signaling. Studies on GABAB receptors and their antagonists are particularly promising for the treatment of depressive disorders. In this paper, intracellular pathways controlled by GABAB receptors and their links to depression are described, including the impact of ketamine on GABAergic synaptic transmission.
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Affiliation(s)
- Maciej Korczak
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, The Medical University of Warsaw, Warsaw, Poland
| | - Przemysław Kurowski
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, The Medical University of Warsaw, Warsaw, Poland.
| | - Anna Leśniak
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, The Medical University of Warsaw, Warsaw, Poland
| | - Alfhild Grönbladh
- The Beijer Laboratory, Biological Research on Drug Dependence, Department of Pharmaceutical Biosciences, The Uppsala University, Uppsala, Sweden
| | - Anna Filipowska
- Department of Biosensors and Processing of Biomedical Signals, The Silesian University of Technology, Zabrze, Poland
| | - Magdalena Bujalska-Zadrożny
- Department of Pharmacodynamics, Centre for Preclinical Research and Technology, The Medical University of Warsaw, Warsaw, Poland
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Trompoukis G, Papatheodoropoulos C. Dorsal-Ventral Differences in Modulation of Synaptic Transmission in the Hippocampus. Front Synaptic Neurosci 2020; 12:24. [PMID: 32625076 PMCID: PMC7316154 DOI: 10.3389/fnsyn.2020.00024] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022] Open
Abstract
Functional diversification along the longitudinal axis of the hippocampus is a rapidly growing concept. Modulation of synaptic transmission by neurotransmitter receptors may importantly contribute to specialization of local intrinsic network function along the hippocampus. In the present study, using transverse slices from the dorsal and the ventral hippocampus of adult rats and recordings of evoked field postsynaptic excitatory potentials (fEPSPs) from the CA1 stratum radiatum, we aimed to compare modulation of synaptic transmission between the dorsal and the ventral hippocampus. We found that transient heterosynaptic depression (tHSD, <2 s), a physiologically relevant phenomenon of regulation of excitatory synaptic transmission induced by paired stimulation of two independent inputs to stratum radiatum of CA1 field, has an increased magnitude and duration in the ventral hippocampus, presumably contributing to increased input segregation in this segment of the hippocampus. GABAB receptors, GABAA receptors, adenosine A1 receptors and L-type voltage-gated calcium channels appear to contribute differently to tHSD in the two hippocampal segments; GABABRs play a predominant role in the ventral hippocampus while both GABABRs and A1Rs play important roles in the dorsal hippocampus. Activation of GABAB receptors by an exogenous agonist, baclofen, robustly and reversibly modulated both the initial fast and the late slow components of excitatory synaptic transmission, expressed by the fEPSPslope and fEPSP decay time constant (fEPSPτ), respectively. Specifically, baclofen suppressed fEPSP slope more in the ventral than in the dorsal hippocampus and enhanced fEPSPτ more in the dorsal than in the ventral hippocampus. Also, baclofen enhanced paired-pulse facilitation in the two hippocampal segments similarly. Blockade of GABAB receptors did not affect basal paired-pulse facilitation in either hippocampal segment. We propose that the revealed dorsal-ventral differences in modulation of synaptic transmission may provide a means for specialization of information processing in the local neuronal circuits, thereby significantly contributing to diversifying neuronal network functioning along the dorsal-ventral axis of hippocampus.
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Affiliation(s)
- George Trompoukis
- Laboratory of Physiology, Department of Medicine, University of Patras, Patras, Greece
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35
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Bonnycastle K, Davenport EC, Cousin MA. Presynaptic dysfunction in neurodevelopmental disorders: Insights from the synaptic vesicle life cycle. J Neurochem 2020; 157:179-207. [PMID: 32378740 DOI: 10.1111/jnc.15035] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
The activity-dependent fusion, retrieval and recycling of synaptic vesicles is essential for the maintenance of neurotransmission. Until relatively recently it was believed that most mutations in genes that were essential for this process would be incompatible with life, because of this fundamental role. However, an ever-expanding number of mutations in this very cohort of genes are being identified in individuals with neurodevelopmental disorders, including autism, intellectual disability and epilepsy. This article will summarize the current state of knowledge linking mutations in presynaptic genes to neurodevelopmental disorders by sequentially covering the various stages of the synaptic vesicle life cycle. It will also discuss how perturbations of specific stages within this recycling process could translate into human disease. Finally, it will also provide perspectives on the potential for future therapy that are targeted to presynaptic function.
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Affiliation(s)
- Katherine Bonnycastle
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Elizabeth C Davenport
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
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36
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Sun K, Mu Q, Chang H, Zhang C, Wang Y, Rong S, Liu S, Zuo D, He Z, Wan D, Yang H, Wang F, Sun T. Postretrieval Microinjection of Baclofen Into the Agranular Insular Cortex Inhibits Morphine-Induced CPP by Disrupting Reconsolidation. Front Pharmacol 2020; 11:743. [PMID: 32508658 PMCID: PMC7248341 DOI: 10.3389/fphar.2020.00743] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 05/04/2020] [Indexed: 12/15/2022] Open
Abstract
Environmental cues associated with drug abuse are powerful mediators of drug craving and relapse in substance-abuse disorders. Consequently, attenuating the strength of cue-drug memories could reduce the number of factors that cause drug craving and relapse. Interestingly, impairing cue-drug memory reconsolidation is a generally accepted strategy aimed at reducing the intensity of cues that trigger drug-seeking and drug-taking behaviors. In addition, the agranular insular cortex (AI) is an important component of the neural circuits underlying drug-related memory reconsolidation. GABAB receptors (GABABRs) are potential targets for the treatment of addiction, and baclofen (BLF) is the only prototypical GABAB agonist available for application in clinical addiction treatment. Furthermore, ΔFosB is considered a biomarker for the evaluation of potential therapeutic interventions for addiction. Here, we used the morphine-induced conditioned place preference (CPP) paradigm to investigate whether postretrieval microinjections of BLF into the AI could affect reconsolidation of drug-reward memory, reinstatement of CPP, and the level of ΔFosB in mice. Our results showed that BLF infused into the AI immediately following morphine CPP memory retrieval, but not 6 h postretrieval or following nonretrieval, could eliminate the expression of a morphine CPP memory. This effect persisted in a morphine-priming–induced reinstatement test, suggesting that BLF in the AI was capable of preventing the reconsolidation of the morphine CPP memory. Our results also showed that the elimination of morphine CPP memory was associated with reduced morphine-associated ΔFosB expression in the longer term. Taken together, the results of our research provide evidence to support that GABABRs in the AI have an important role in drug-cue memory reconsolidation and further our understanding of the role of the AI in drug-related learning and memory.
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Affiliation(s)
- Kuisheng Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, The People's Hospital of Gaozhou, Gaozhou, China
| | - Qingchun Mu
- Department of Neurosurgery, The People's Hospital of Gaozhou, Gaozhou, China
| | - Haigang Chang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Chun Zhang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Yehua Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Shikuo Rong
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Shenhai Liu
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Di Zuo
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Zhenquan He
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China
| | - Ding Wan
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Hua Yang
- Department of Critical Care Medicine, The People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, China
| | - Feng Wang
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Tao Sun
- Ningxia Key Laboratory of Cerebrocranial Disease, Incubation Base of National Key Laboratory, Ningxia Medical University, Yinchuan, China.,Department of Neurosurgery, General Hospital of Ningxia Medical University, Yinchuan, China
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37
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Neonatal Clonazepam Administration Induced Long-Lasting Changes in GABA A and GABA B Receptors. Int J Mol Sci 2020; 21:ijms21093184. [PMID: 32366006 PMCID: PMC7246485 DOI: 10.3390/ijms21093184] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/24/2020] [Accepted: 04/28/2020] [Indexed: 11/17/2022] Open
Abstract
Benzodiazepines (BZDs) are widely used in patients of all ages. Unlike adults, neonatal animals treated with BZDs exhibit a variety of behavioral deficits later in life; however, the mechanisms underlying these deficits are poorly understood. This study aims to examine whether administration of clonazepam (CZP; 1 mg/kg/day) in 7-11-day-old rats affects Gama aminobutyric acid (GABA)ergic receptors in both the short and long terms. Using RT-PCR and quantitative autoradiography, we examined the expression of the selected GABAA receptor subunits (α1, α2, α4, γ2, and δ) and the GABAB B2 subunit, and GABAA, benzodiazepine, and GABAB receptor binding 48 h, 1 week, and 2 months after treatment discontinuation. Within one week after CZP cessation, the expression of the α2 subunit was upregulated, whereas that of the δ subunit was downregulated in both the hippocampus and cortex. In the hippocampus, the α4 subunit was downregulated after the 2-month interval. Changes in receptor binding were highly dependent on the receptor type, the interval after treatment cessation, and the brain structure. GABAA receptor binding was increased in almost all of the brain structures after the 48-h interval. BZD-binding was decreased in many brain structures involved in the neuronal networks associated with emotional behavior, anxiety, and cognitive functions after the 2-month interval. Binding of the GABAB receptors changed depending on the interval and brain structure. Overall, the described changes may affect both synaptic development and functioning and may potentially cause behavioral impairment.
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Beckmann D, Feldmann M, Shchyglo O, Manahan-Vaughan D. Hippocampal Synaptic Plasticity, Spatial Memory, and Neurotransmitter Receptor Expression Are Profoundly Altered by Gradual Loss of Hearing Ability. Cereb Cortex 2020; 30:4581-4596. [PMID: 32202614 PMCID: PMC7325716 DOI: 10.1093/cercor/bhaa061] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/20/2020] [Accepted: 02/12/2020] [Indexed: 12/27/2022] Open
Abstract
Sensory information comprises the substrate from which memories are created. Memories of spatial sensory experience are encoded by means of synaptic plasticity in the hippocampus. Hippocampal dependency on sensory information is highlighted by the fact that sudden and complete loss of a sensory modality results in an impairment of hippocampal function that persists for months. Effects are accompanied by extensive changes in the expression of neurotransmitter receptors in cortex and hippocampus, consistent with a substantial adaptive reorganization of cortical function. Whether gradual sensory loss affects hippocampal function is unclear. Progressive age-dependent hearing loss (presbycusis) is a risk factor for cognitive decline. Here, we scrutinized C57BL/6 mice that experience hereditary and cumulative deafness starting in young adulthood. We observed that 2–4 months postnatally, increases in the cortical and hippocampal expression of GluN2A and GluN2B subunits of the N-methyl-D-aspartate receptor occurred compared to control mice that lack sensory deficits. Furthermore, GABA and metabotropic glutamate receptor expression were significantly altered. Hippocampal synaptic plasticity was profoundly impaired and mice exhibited significant deficits in spatial memory. These data show that during cortical adaptation to cumulative loss of hearing, plasticity-related neurotransmitter expression is extensively altered in the cortex and hippocampus. Furthermore, cumulative sensory loss compromises hippocampal function.
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Affiliation(s)
- Daniela Beckmann
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum 44780, Germany
| | - Mirko Feldmann
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum 44780, Germany
| | - Olena Shchyglo
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany
| | - Denise Manahan-Vaughan
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum 44780, Germany
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Jullié D, Stoeber M, Sibarita JB, Zieger HL, Bartol TM, Arttamangkul S, Sejnowski TJ, Hosy E, von Zastrow M. A Discrete Presynaptic Vesicle Cycle for Neuromodulator Receptors. Neuron 2020; 105:663-677.e8. [PMID: 31837915 PMCID: PMC7035187 DOI: 10.1016/j.neuron.2019.11.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 08/02/2019] [Accepted: 11/11/2019] [Indexed: 01/27/2023]
Abstract
A major function of GPCRs is to inhibit presynaptic neurotransmitter release, requiring ligand-activated receptors to couple locally to effectors at terminals. The current understanding of how this is achieved is through receptor immobilization on the terminal surface. Here, we show that opioid peptide receptors, GPCRs that mediate highly sensitive presynaptic inhibition, are instead dynamic in axons. Opioid receptors diffuse rapidly throughout the axon surface and internalize after ligand-induced activation specifically at presynaptic terminals. We delineate a parallel regulated endocytic cycle for GPCRs operating at the presynapse, separately from the synaptic vesicle cycle, which clears activated receptors from the surface of terminals and locally reinserts them to maintain the diffusible surface pool. We propose an alternate strategy for achieving local control of presynaptic effectors that, opposite to using receptor immobilization and enforced proximity, is based on lateral mobility of receptors and leverages the inherent allostery of GPCR-effector coupling.
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Affiliation(s)
- Damien Jullié
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California 94158, USA,Department of Psychiatry, University of California, San Francisco School of Medicine, San Francisco, California 94158, USA
| | - Miriam Stoeber
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California 94158, USA,Department of Psychiatry, University of California, San Francisco School of Medicine, San Francisco, California 94158, USA,Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva, Switzerland
| | - Jean-Baptiste Sibarita
- Interdisciplinary Institute for Neuroscience, UMR 5297, Centre National de la Recherche Scientifique, 33077 Bordeaux, France,Interdisciplinary Institute for Neuroscience, University of Bordeaux, 33077 Bordeaux, France
| | - Hanna L. Zieger
- Interdisciplinary Institute for Neuroscience, UMR 5297, Centre National de la Recherche Scientifique, 33077 Bordeaux, France,Interdisciplinary Institute for Neuroscience, University of Bordeaux, 33077 Bordeaux, France
| | - Thomas M. Bartol
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Seksiri Arttamangkul
- The Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Terrence J. Sejnowski
- Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Eric Hosy
- Interdisciplinary Institute for Neuroscience, UMR 5297, Centre National de la Recherche Scientifique, 33077 Bordeaux, France,Interdisciplinary Institute for Neuroscience, University of Bordeaux, 33077 Bordeaux, France
| | - Mark von Zastrow
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco School of Medicine, San Francisco, California 94158, USA,Department of Psychiatry, University of California, San Francisco School of Medicine, San Francisco, California 94158, USA,Lead contact,Correspondence:
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40
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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: 2.8] [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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41
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Cieślik P, Domin H, Chocyk A, Gruca P, Litwa E, Płoska A, Radulska A, Pelikant-Małecka I, Brański P, Kalinowski L, Wierońska JM. Simultaneous activation of mGlu 2 and muscarinic receptors reverses MK-801-induced cognitive decline in rodents. Neuropharmacology 2019; 174:107866. [PMID: 31785263 DOI: 10.1016/j.neuropharm.2019.107866] [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: 02/14/2019] [Revised: 10/09/2019] [Accepted: 11/25/2019] [Indexed: 12/19/2022]
Abstract
The activity of an allosteric agonist of muscarinic M1 receptor, VU0357017, and a positive allosteric modulator (PAM) of M5 receptor, VU0238429, were investigated alone or in combination with the mGlu2 receptor PAM, LY487379 using the following behavioural tests: prepulse inhibition (PPI), novel object recognition (NOR), and spatial delayed alternation (SDA). VU0357017 (10 and 20 mg/kg) and VU0238429 (5 and 10 mg/kg) reversed deficits in PPI while VU0238429 (2.5 and 5 mg/kg) was effective in SDA. The simultaneous administration of subeffective doses of M1 or M5 activators (5, 1, or 0.25 mg/kg) with LY487379 (0.5 mg/kg) induced the same effect as that observed for the active dose of each compound. Selective M1 or M5 receptor blockers antagonized the effect exerted by these combinations, and pharmacokinetic studies confirmed independent transport through the blood-brain barrier. The expression of both receptors (M1 and M5) was established in brain structures involved in cognition (neocortex, hippocampus, and entorhinal cortex) in both the rat and the mouse brains by immunofluorescence staining. Specifically, double neuronal staining of mGlu2-M1 and mGlu2-M5 receptors was observed in many areas of the rat brain, while the number of double-stained mGlu2-M1 receptors was moderate in the mouse brain with no mGlu2-M5 colocalization. Finally, the combined administration of subeffective doses of the compounds did not alter prolactin levels or motor coordination, in contrast to the compounds given alone at the highest dose or in combination with standard neuroleptics.
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Affiliation(s)
- Paulina Cieślik
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland
| | - Helena Domin
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland
| | - Agnieszka Chocyk
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland
| | - Piotr Gruca
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland
| | - Ewa Litwa
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland
| | - Agata Płoska
- Department of Medical Laboratory Diagnostics, Medical University of Gdansk, Dębinki 7, 80-211, Gdańsk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdańsk, Poland
| | - Adrianna Radulska
- Department of Medical Laboratory Diagnostics, Medical University of Gdansk, Dębinki 7, 80-211, Gdańsk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdańsk, Poland
| | - Iwona Pelikant-Małecka
- Department of Medical Laboratory Diagnostics, Medical University of Gdansk, Dębinki 7, 80-211, Gdańsk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdańsk, Poland
| | - Piotr Brański
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland
| | - Leszek Kalinowski
- Department of Medical Laboratory Diagnostics, Medical University of Gdansk, Dębinki 7, 80-211, Gdańsk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdańsk, Poland
| | - Joanna M Wierońska
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, 31-343, Kraków, 12 Smetna Street, Poland.
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42
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Bulut H. A New Psychoactive Substance, Gamma Hydroxybutyrate (GHB): A Case Report. ACTA ACUST UNITED AC 2019; 56:229-231. [PMID: 31523153 DOI: 10.29399/npa.23198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/09/2018] [Indexed: 11/07/2022]
Abstract
Gamma Hydroxybutyrate (GHB) is a central nervous system depressant effecting GABA-B receptors. GHB is taken along with other psychoactive substances like alcohol, cocaine, ecstasy, and amphetamines especially during parties. Due to the fact that it has been linked to sexual assault, GHB has drawn attention in recent years. This substance is often taken by youngsters and results in euphoric states of mind, signs of relief, easiness in communication, increases in sexual appetite, and experiences of different states of mind. Dizziness, hypotension, bradycardia, nauseation, and vomiting are typical toxication symptoms of GHB. Also, epileptic seizures, respirotary depression, and deaths have been reported as a result of taking GHB. It is widely known that the use of GHB in our country has increased gradually. This case report is important as it summarizes the anamnesis, penetration, and clinical symptoms of GHB. In order to prevent the use of GHB, it would be appropriate to develop psycho-education methodologies, establish legislative regulations, and include GHB tests in substance screening analyses.
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Affiliation(s)
- Hüseyin Bulut
- SBÜ Kanuni Sultan Süleyman Training and Research Hospital, Department of Psychiatry, İstanbul, Turkey
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43
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Dornbierer DA, Boxler M, Voegel CD, Stucky B, Steuer AE, Binz TM, Baumgartner MR, Baur DM, Quednow BB, Kraemer T, Seifritz E, Landolt HP, Bosch OG. Nocturnal Gamma-Hydroxybutyrate Reduces Cortisol-Awakening Response and Morning Kynurenine Pathway Metabolites in Healthy Volunteers. Int J Neuropsychopharmacol 2019; 22:631-639. [PMID: 31504554 PMCID: PMC6822136 DOI: 10.1093/ijnp/pyz047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 08/03/2019] [Accepted: 08/27/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Gamma-hydroxybutyrate (GHB; or sodium oxybate) is an endogenous GHB-/gamma-aminobutyric acid B receptor agonist. It is approved for application in narcolepsy and has been proposed for the potential treatment of Alzheimer's disease, Parkinson's disease, fibromyalgia, and depression, all of which involve neuro-immunological processes. Tryptophan catabolites (TRYCATs), the cortisol-awakening response (CAR), and brain-derived neurotrophic factor (BDNF) have been suggested as peripheral biomarkers of neuropsychiatric disorders. GHB has been shown to induce a delayed reduction of T helper and natural killer cell counts and alter basal cortisol levels, but GHB's effects on TRYCATs, CAR, and BDNF are unknown. METHODS Therefore, TRYCAT and BDNF serum levels, as well as CAR and the affective state (Positive and Negative Affect Schedule [PANAS]) were measured in the morning after a single nocturnal dose of GHB (50 mg/kg body weight) in 20 healthy male volunteers in a placebo-controlled, balanced, randomized, double-blind, cross-over design. RESULTS In the morning after nocturnal GHB administration, the TRYCATs indolelactic acid, kynurenine, kynurenic acid, 3-hydroxykynurenine, and quinolinic acid; the 3-hydroxykynurenine to kynurenic acid ratio; and the CAR were significantly reduced (P < 0.05-0.001, Benjamini-Hochberg corrected). The quinolinic acid to kynurenic acid ratio was reduced by trend. Serotonin, tryptophan, and BDNF levels, as well as PANAS scores in the morning, remained unchanged after a nocturnal GHB challenge. CONCLUSIONS GHB has post-acute effects on peripheral biomarkers of neuropsychiatric disorders, which might be a model to explain some of its therapeutic effects in disorders involving neuro-immunological pathologies. This study was registered at ClinicalTrials.gov as NCT02342366.
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Affiliation(s)
- D A Dornbierer
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland,Department of Forensic Pharmacology and Toxicology, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland,Sleep & Health Zurich, University Center of Competence, University of Zurich, Zurich, Switzerland,Correspondence: Dario A. Dornbierer, MSc, Experimental and Clinical Pharmacopsychology, Department of Psychiatry, Psychotherapy and Psychosomatics Psychiatric Hospital, University of Zurich Lenggstrasse 31, CH-8032 Zurich, Switzerland ()
| | - M Boxler
- Department of Forensic Pharmacology and Toxicology, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - C D Voegel
- Center for Forensic Hair Analytics, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - B Stucky
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland,Sleep & Health Zurich, University Center of Competence, University of Zurich, Zurich, Switzerland
| | - A E Steuer
- Department of Forensic Pharmacology and Toxicology, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - T M Binz
- Center for Forensic Hair Analytics, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - M R Baumgartner
- Center for Forensic Hair Analytics, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - D M Baur
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland,Sleep & Health Zurich, University Center of Competence, University of Zurich, Zurich, Switzerland
| | - B B Quednow
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland,Neuroscience Center Zurich, University Zurich and Swiss Federal Institute of Technology, Zurich, Switzerland
| | - T Kraemer
- Department of Forensic Pharmacology and Toxicology, Zurich Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - E Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland,Sleep & Health Zurich, University Center of Competence, University of Zurich, Zurich, Switzerland,Neuroscience Center Zurich, University Zurich and Swiss Federal Institute of Technology, Zurich, Switzerland
| | - H P Landolt
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland,Sleep & Health Zurich, University Center of Competence, University of Zurich, Zurich, Switzerland,Neuroscience Center Zurich, University Zurich and Swiss Federal Institute of Technology, Zurich, Switzerland
| | - O G Bosch
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
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44
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Teng X, Aouacheria A, Lionnard L, Metz KA, Soane L, Kamiya A, Hardwick JM. KCTD: A new gene family involved in neurodevelopmental and neuropsychiatric disorders. CNS Neurosci Ther 2019; 25:887-902. [PMID: 31197948 PMCID: PMC6566181 DOI: 10.1111/cns.13156] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/02/2019] [Accepted: 05/13/2019] [Indexed: 12/12/2022] Open
Abstract
The underlying molecular basis for neurodevelopmental or neuropsychiatric disorders is not known. In contrast, mechanistic understanding of other brain disorders including neurodegeneration has advanced considerably. Yet, these do not approach the knowledge accrued for many cancers with precision therapeutics acting on well-characterized targets. Although the identification of genes responsible for neurodevelopmental and neuropsychiatric disorders remains a major obstacle, the few causally associated genes are ripe for discovery by focusing efforts to dissect their mechanisms. Here, we make a case for delving into mechanisms of the poorly characterized human KCTD gene family. Varying levels of evidence support their roles in neurocognitive disorders (KCTD3), neurodevelopmental disease (KCTD7), bipolar disorder (KCTD12), autism and schizophrenia (KCTD13), movement disorders (KCTD17), cancer (KCTD11), and obesity (KCTD15). Collective knowledge about these genes adds enhanced value, and critical insights into potential disease mechanisms have come from unexpected sources. Translation of basic research on the KCTD-related yeast protein Whi2 has revealed roles in nutrient signaling to mTORC1 (KCTD11) and an autophagy-lysosome pathway affecting mitochondria (KCTD7). Recent biochemical and structure-based studies (KCTD12, KCTD13, KCTD16) reveal mechanisms of regulating membrane channel activities through modulation of distinct GTPases. We explore how these seemingly varied functions may be disease related.
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Affiliation(s)
- Xinchen Teng
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical SciencesSoochow UniversitySuzhouChina
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
| | - Abdel Aouacheria
- ISEM, Institut des Sciences de l'Evolution de Montpellier, CNRS, EPHE, IRDUniversité de MontpellierMontpellierFrance
| | - Loïc Lionnard
- ISEM, Institut des Sciences de l'Evolution de Montpellier, CNRS, EPHE, IRDUniversité de MontpellierMontpellierFrance
| | - Kyle A. Metz
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
- Present address:
Feinberg School of MedicineNorthwestern UniversityChicagoUSA
| | - Lucian Soane
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
| | - Atsushi Kamiya
- Department of Psychiatry and Behavioral SciencesJohns Hopkins School of MedicineBaltimoreMaryland
| | - J. Marie Hardwick
- W. Harry Feinstone Department of Molecular Microbiology and ImmunologyJohns Hopkins University Bloomberg School of Public HealthBaltimoreMaryland
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45
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Tang BL. Amyloid Precursor Protein (APP) and GABAergic Neurotransmission. Cells 2019; 8:E550. [PMID: 31174368 PMCID: PMC6627941 DOI: 10.3390/cells8060550] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 05/25/2019] [Accepted: 06/06/2019] [Indexed: 12/16/2022] Open
Abstract
The amyloid precursor protein (APP) is the parent polypeptide from which amyloid-beta (Aβ) peptides, key etiological agents of Alzheimer's disease (AD), are generated by sequential proteolytic processing involving β- and γ-secretases. APP mutations underlie familial, early-onset AD, and the involvement of APP in AD pathology has been extensively studied. However, APP has important physiological roles in the mammalian brain, particularly its modulation of synaptic functions and neuronal survival. Recent works have now shown that APP could directly modulate γ-aminobutyric acid (GABA) neurotransmission in two broad ways. Firstly, APP is shown to interact with and modulate the levels and activity of the neuron-specific Potassium-Chloride (K+-Cl-) cotransporter KCC2/SLC12A5. The latter is key to the maintenance of neuronal chloride (Cl-) levels and the GABA reversal potential (EGABA), and is therefore important for postsynaptic GABAergic inhibition through the ionotropic GABAA receptors. Secondly, APP binds to the sushi domain of metabotropic GABAB receptor 1a (GABABR1a). In this regard, APP complexes and is co-transported with GABAB receptor dimers bearing GABABR1a to the axonal presynaptic plasma membrane. On the other hand, secreted (s)APP generated by secretase cleavages could act as a GABABR1a-binding ligand that modulates presynaptic vesicle release. The discovery of these novel roles and activities of APP in GABAergic neurotransmission underlies the physiological importance of APP in postnatal brain function.
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Affiliation(s)
- Bor Luen Tang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore.
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117597, Singapore.
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46
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Burke KJ, Bender KJ. Modulation of Ion Channels in the Axon: Mechanisms and Function. Front Cell Neurosci 2019; 13:221. [PMID: 31156397 PMCID: PMC6533529 DOI: 10.3389/fncel.2019.00221] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/01/2019] [Indexed: 12/11/2022] Open
Abstract
The axon is responsible for integrating synaptic signals, generating action potentials (APs), propagating those APs to downstream synapses and converting them into patterns of neurotransmitter vesicle release. This process is mediated by a rich assortment of voltage-gated ion channels whose function can be affected on short and long time scales by activity. Moreover, neuromodulators control the activity of these proteins through G-protein coupled receptor signaling cascades. Here, we review cellular mechanisms and signaling pathways involved in axonal ion channel modulation and examine how changes to ion channel function affect AP initiation, AP propagation, and the release of neurotransmitter. We then examine how these mechanisms could modulate synaptic function by focusing on three key features of synaptic information transmission: synaptic strength, synaptic variability, and short-term plasticity. Viewing these cellular mechanisms of neuromodulation from a functional perspective may assist in extending these findings to theories of neural circuit function and its neuromodulation.
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Affiliation(s)
| | - Kevin J. Bender
- Neuroscience Graduate Program and Department of Neurology, Kavli Institute for Fundamental Neuroscience, Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, United States
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47
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Cieślik P, Woźniak M, Tokarski K, Kusek M, Pilc A, Płoska A, Radulska A, Pelikant-Małecka I, Żołnowska B, Sławiński J, Kalinowski L, Wierońska JM. Simultaneous activation of muscarinic and GABA B receptors as a bidirectional target for novel antipsychotics. Behav Brain Res 2018; 359:671-685. [PMID: 30267715 DOI: 10.1016/j.bbr.2018.09.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/08/2018] [Accepted: 09/22/2018] [Indexed: 12/11/2022]
Abstract
Recent preclinical studies point to muscarinic and GABAB receptors as novel therapeutic targets for the treatment of schizophrenia. This study was aimed to assess the role of muscarinic and GABAB receptor interactions in animal models of schizophrenia, using positive allosteric modulators (PAMs) of GABAB receptor (GS39783), muscarinic M4 (VU0152100) and M5 (VU0238429) receptor, and partial allosteric agonist of M1 receptor (VU0357017). DOI-induced head twitches, social interaction and novel object recognition tests were used as the models of schizophrenia. Analyses of DOI-induced increases in sEPSCs (spontaneous excitatory postsynaptic currents) were performed as complementary experiments to the DOI-induced head twitch studies. Haloperidol-induced catalepsy and the rotarod test were used to examine the adverse effects of the drugs. All three activators of muscarinic receptors were active in DOI-induced head twitches. When administered together with GS39783 in subeffective doses, only the co-administration of VU0152100 and GS39783 was effective. The combination also reduced the frequency but not the amplitude of DOI-induced sEPSCs. Neither VU0357017 nor VU0238429 were active in social interaction test when given alone, and also the combination of VU0152100 and GS39783 failed to reverse MK-801-induced deficits observed in this test. All muscarinic activators when administered alone or in combination with GS39783 reversed the MK-801-induced disruption of memory in the novel object recognition test, and their actions were blocked by specific antagonists. None of the tested compounds or their combinations influenced the motor coordination of the animals. The compounds had no effect on haloperidol-induced catalepsy and did not induce catalepsy when administered alone. Pharmacokinetic analysis confirmed lack of possible drug-drug interactions after combined administration of GS39783 with VU0357017 or VU0152100; however, when the drug was co-administered with VU0238429 its ability to pass the blood-brain barrier slightly decreased, suggesting potential drug-drug interactions. Our data show that modulation of cholinergic and GABAergic systems can potentially be beneficial in the treatment of the positive and cognitive symptoms of schizophrenia without inducing the adverse effects typical for presently used antipsychotics.
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Affiliation(s)
- Paulina Cieślik
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland
| | - Monika Woźniak
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland
| | - Krzysztof Tokarski
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland
| | - Magdalena Kusek
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland
| | - Andrzej Pilc
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland; Health Sciences Faculty, Institute of Public Health, Jagiellonian University Medical College, Kraków, Poland
| | - Agata Płoska
- Department of Medical Laboratory Diagnostics - Biobank, Medical University of Gdansk, Gdansk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdansk, Poland
| | - Adrianna Radulska
- Department of Medical Laboratory Diagnostics - Biobank, Medical University of Gdansk, Gdansk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdansk, Poland
| | - Iwona Pelikant-Małecka
- Department of Medical Laboratory Diagnostics - Biobank, Medical University of Gdansk, Gdansk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdansk, Poland
| | - Beata Żołnowska
- Department of Organic Chemistry, Medical University of Gdansk, Gdańsk, Poland
| | - Jarosław Sławiński
- Department of Organic Chemistry, Medical University of Gdansk, Gdańsk, Poland
| | - Leszek Kalinowski
- Department of Medical Laboratory Diagnostics - Biobank, Medical University of Gdansk, Gdansk, Poland; Biobanking and Biomolecular Resources Research Infrastructure Poland (BBMRI.PL), Gdansk, Poland
| | - Joanna M Wierońska
- Institute of Pharmacology, Polish Academy of Sciences, 31-343 Kraków, Poland.
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Burke KJ, Keeshen CM, Bender KJ. Two Forms of Synaptic Depression Produced by Differential Neuromodulation of Presynaptic Calcium Channels. Neuron 2018; 99:969-984.e7. [PMID: 30122380 PMCID: PMC7874512 DOI: 10.1016/j.neuron.2018.07.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/03/2018] [Accepted: 07/18/2018] [Indexed: 01/09/2023]
Abstract
Neuromodulators are important regulators of synaptic transmission throughout the brain. At the presynaptic terminal, neuromodulation of calcium channels (CaVs) can affect transmission not only by changing neurotransmitter release probability, but also by shaping short-term plasticity (STP). Indeed, changes in STP are often considered a requirement for defining a presynaptic site of action. Nevertheless, some synapses exhibit non-canonical forms of neuromodulation, where release probability is altered without a corresponding change in STP. Here, we identify biophysical mechanisms whereby both canonical and non-canonical presynaptic neuromodulation can occur at the same synapse. At a subset of glutamatergic terminals in prefrontal cortex, GABAB and D1/D5 dopamine receptors suppress release probability with and without canonical increases in short-term facilitation by modulating different aspects of presynaptic CaV function. These findings establish a framework whereby signaling from multiple neuromodulators can converge on presynaptic CaVs to differentially tune release dynamics at the same synapse.
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Affiliation(s)
- Kenneth J Burke
- Neuroscience Graduate Program, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Caroline M Keeshen
- Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Kevin J Bender
- Neuroscience Graduate Program, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA; Weill Institute for Neurosciences, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
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49
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Kulik Á, Booker SA, Vida I. Differential distribution and function of GABABRs in somato-dendritic and axonal compartments of principal cells and interneurons in cortical circuits. Neuropharmacology 2018; 136:80-91. [DOI: 10.1016/j.neuropharm.2017.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 12/24/2022]
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50
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Koppensteiner P, Melani R, Ninan I. A Cooperative Mechanism Involving Ca 2+-Permeable AMPA Receptors and Retrograde Activation of GABA B Receptors in Interpeduncular Nucleus Plasticity. Cell Rep 2018; 20:1111-1122. [PMID: 28768196 DOI: 10.1016/j.celrep.2017.07.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/29/2017] [Accepted: 07/07/2017] [Indexed: 11/28/2022] Open
Abstract
The medial habenula-interpeduncular nucleus (MHb-IPN) pathway, which connects the limbic forebrain to the midbrain, has recently been implicated in aversive behaviors. The MHb-IPN circuit is characterized by a unique topographical organization, an excitatory role of GABA, and a prominent co-release of neurotransmitters and neuropeptides. However, little is known about synaptic plasticity in this pathway. An application of a high-frequency stimulation resulted in a long-lasting potentiation of glutamate release in IPN neurons. Our experiments reveal that a Ca2+-permeable AMPA receptor (CPAR)-dependent release of GABA from IPN neurons and a retrograde activation of GABAB receptors on MHb terminals result in a long-lasting enhancement of glutamate release. Strikingly, adolescent IPN neurons lacked CPARs and exhibited an inability to undergo plasticity. In addition, fear conditioning suppressed an activity-dependent potentiation of MHb-IPN synapses, whereas fear extinction reversed this plasticity deficit, suggesting a role of the MHb-IPN synaptic plasticity in the regulation of aversive behaviors.
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Affiliation(s)
- Peter Koppensteiner
- Department of Psychiatry, NYU Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Riccardo Melani
- Department of Psychiatry, NYU Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA
| | - Ipe Ninan
- Department of Psychiatry, NYU Neuroscience Institute, NYU Langone Medical Center, New York, NY 10016, USA.
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