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Sack AS, Garcia E, Snutch TP. Maturational Stage-Dependent Contributions of the Cav3.2 T-Type Calcium Channel to Dentate Gyrus Granule Cell Excitability. eNeuro 2025; 12:ENEURO.0423-24.2025. [PMID: 40068874 PMCID: PMC11974363 DOI: 10.1523/eneuro.0423-24.2025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2024] [Revised: 02/12/2025] [Accepted: 02/17/2025] [Indexed: 04/06/2025] Open
Abstract
T-Type calcium channels shape neuronal excitability driving burst firing, plasticity, and neuronal oscillations that influence circuit activity. The three biophysically distinct T-type channel subtypes (Cav3.1, Cav3.2, Cav3.3) are differentially expressed in the brain, contributing to divergent physiological processes. Cav3.2 channels are highly expressed in the dentate gyrus (DG) of the hippocampus, and mice lacking Cav3.2 [knock-out (KO)] exhibit impairments in hippocampal dependent learning and memory tasks, as well as attenuated development of pilocarpine induced epilepsy. Owing to neurogenesis, granule cells (GCs) are continuously added to the DG, generating a heterogeneous population of maturational stages with distinct excitability. While initial studies identified the role of Cav3.2 in mature GC burst firing, its functional relevance in the intrinsic excitability of different GC subpopulations has not yet been examined. In this study, we used juvenile Cav3.2 KO mice to examine the contributions of Cav3.2 channels to GC excitability at three different stages of maturation. We recorded from cells throughout the GC layer using their electrophysiological and morphological features to allocate GCs into immature, intermediate, and mature groups. In immature GCs, loss of Cav3.2 channels reduced the proportion of cells that fired low-threshold calcium spikes. Conversely, Cav3.2 KO increased excitability in regular spiking intermediate and mature GCs, enabling higher-frequency firing, with little impact on the frequency-dependent response. Overall, this study shows that Cav3.2 channels differentially regulate GC excitability throughout maturation and suggest that calcium influx via Cav3.2 may have maturation-dependent contributions to DG processes such as GC survival, integration, and memory encoding.
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Affiliation(s)
- Anne-Sophie Sack
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Esperanza Garcia
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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Jang SS, Takahashi F, Huguenard JR. Reticular Thalamic Hyperexcitability Drives Autism Spectrum Disorder Behaviors in the Cntnap2 Model of Autism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.03.21.644680. [PMID: 40166234 PMCID: PMC11957169 DOI: 10.1101/2025.03.21.644680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/02/2025]
Abstract
Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders characterized by social communication deficits, repetitive behaviors, and comorbidities such as sensory abnormalities, sleep disturbances, and seizures. Dysregulation of thalamocortical circuits has been implicated in these comorbid features, yet their precise roles in ASD pathophysiology remain elusive. This study focuses on the reticular thalamic nucleus (RT), a key regulator of thalamocortical interactions, to elucidate its contribution to ASD-related behavioral deficits using a Cntnap2 knockout (KO) mouse model. Our behavioral and EEG analyses comparing Cntnap2 +/+ and Cntnap2 -/- mice demonstrated that Cntnap2 knockout heightened seizure susceptibility, elevated locomotor activity, and produced hallmark ASD phenotypes, including social deficits, and repetitive behaviors. Electrophysiological recordings from thalamic brain slices revealed increased spontaneous and evoked network oscillations with increased RT excitability due to enhanced T-type calcium currents and burst firing. We observed behavior related heightened RT population activity in vivo with fiber photometry. Notably, suppressing RT activity via Z944, a T-type calcium channel blocker, and via C21 and the inhibitory DREADD hM4Di, improved ASD-related behavioral deficits. These findings identify RT hyperexcitability as a mechanistic driver of ASD behaviors and underscore RT as a potential therapeutic target for modulating thalamocortical circuit dysfunction in ASD. Teaser RT hyperexcitability drives ASD behaviors in Cntnap2-/- mice, highlighting RT as a therapeutic target for circuit dysfunction.
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Abdelaal MS, Kato T, Natsubori A, Tanaka KF. Temporal and Potential Predictive Relationships between Sleep Spindle Density and Spike-and-Wave Discharges. eNeuro 2024; 11:ENEURO.0058-24.2024. [PMID: 39256042 PMCID: PMC11412100 DOI: 10.1523/eneuro.0058-24.2024] [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: 01/16/2024] [Revised: 08/27/2024] [Accepted: 08/29/2024] [Indexed: 09/12/2024] Open
Abstract
Spike-and-wave discharges (SWDs) and sleep spindles are characteristic electroencephalographic (EEG) hallmarks of absence seizures and nonrapid eye movement sleep, respectively. They are commonly generated by the cortico-thalamo-cortical network including the thalamic reticular nucleus (TRN). It has been reported that SWD development is accompanied by a decrease in sleep spindle density in absence seizure patients and animal models. However, whether the decrease in sleep spindle density precedes, coincides with, or follows, the SWD development remains unknown. To clarify this, we exploited Pvalb-tetracycline transactivator (tTA)::tetO-ArchT (PV-ArchT) double-transgenic mouse, which can induce an absence seizure phenotype in a time-controllable manner by expressing ArchT in PV neurons of the TRN. In these mice, EEG recordings demonstrated that a decrease in sleep spindle density occurred 1 week before the onset of typical SWDs, with the expression of ArchT. To confirm such temporal relationship observed in these genetic model mice, we used a gamma-butyrolactone (GBL) pharmacological model of SWDs. Prior to GBL administration, we administered caffeine to wild-type mice for 3 consecutive days to induce a decrease in sleep spindle density. We then administered low-dose GBL, which cannot induce SWDs in normally conditioned mice but led to the occurrence of SWDs in caffeine-conditioned mice. These findings indicate a temporal relationship in which the decrease in sleep spindle density consistently precedes SWD development. Furthermore, the decrease in sleep spindle activity may have a role in facilitating the development of SWDs. Our findings suggest that sleep spindle reductions could serve as early indicators of seizure susceptibility.
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Affiliation(s)
- Manal S Abdelaal
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Tomonobu Kato
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
- Department of System Design Engineering, Faculty of Science and Technology, Keio University, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Akiyo Natsubori
- Sleep Disorders Project, Tokyo Metropolitan Institute of Medical Science, Setagaya-Ku, Tokyo 156-8506, Japan
| | - Kenji F Tanaka
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan
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4
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Jeong S, Lee BY, Rhee JS, Lee JH. G protein β subunits regulate Ca v3.3 T-type channel activity and current kinetics via interaction with the Ca v3.3 C-terminus. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184337. [PMID: 38763272 DOI: 10.1016/j.bbamem.2024.184337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/06/2024] [Accepted: 05/13/2024] [Indexed: 05/21/2024]
Abstract
Ca2+ influx through Cav3.3 T-type channel plays crucial roles in neuronal excitability and is subject to regulation by various signaling molecules. However, our understanding of the partners of Cav3.3 and the related regulatory pathways remains largely limited. To address this quest, we employed the rat Cav3.3 C-terminus as bait in yeast-two-hybrid screenings of a cDNA library, identifying rat Gβ2 as an interaction partner. Subsequent assays revealed that the interaction of Gβ2 subunit was specific to the Cav3.3 C-terminus. Through systematic dissection of the C-terminus, we pinpointed a 22 amino acid sequence (amino acids 1789-1810) as the Gβ2 interaction site. Coexpression studies of rat Cav3.3 with various Gβγ compositions were conducted in HEK-293 cells. Patch clamp recordings revealed that coexpression of Gβ2γ2 reduced Cav3.3 current density and accelerated inactivation kinetics. Interestingly, the effects were not unique to Gβ2γ2, but were mimicked by Gβ2 alone as well as other Gβγ dimers, with similar potencies. Deletion of the Gβ2 interaction site abolished the effects of Gβ2γ2. Importantly, these Gβ2 effects were reproduced in human Cav3.3. Overall, our findings provide evidence that Gβ(γ) complexes inhibit Cav3.3 channel activity and accelerate the inactivation kinetics through the Gβ interaction with the Cav3.3 C-terminus.
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Affiliation(s)
- Sua Jeong
- Department of Life Science, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Bo-Young Lee
- Department of Life Science, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Jeong Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute for Multidisciplinary Sciences, Synaptic Physiology Group, Hermann-Rein-Str. 3, 37075 Göttingen, Germany
| | - Jung-Ha Lee
- Department of Life Science, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea.
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Griffith EY, ElSayed M, Dura-Bernal S, Neymotin SA, Uhlrich DJ, Lytton WW, Zhu JJ. Mechanism of an Intrinsic Oscillation in Rat Geniculate Interneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597830. [PMID: 38895250 PMCID: PMC11185623 DOI: 10.1101/2024.06.06.597830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Depolarizing current injections produced a rhythmic bursting of action potentials - a bursting oscillation - in a set of local interneurons in the lateral geniculate nucleus (LGN) of rats. The current dynamics underlying this firing pattern have not been determined, though this cell type constitutes an important cellular component of thalamocortical circuitry, and contributes to both pathologic and non-pathologic brain states. We thus investigated the source of the bursting oscillation using pharmacological manipulations in LGN slices in vitro and in silico. 1. Selective blockade of calcium channel subtypes revealed that high-threshold calcium currentsI L andI P contributed strongly to the oscillation. 2. Increased extracellular K+ concentration (decreased K+currents) eliminated the oscillation. 3. Selective blockade of K+ channel subtypes demonstrated that the calcium-sensitive potassium current (I A H P ) was of primary importance. A morphologically simplified, multicompartment model of the thalamic interneuron characterized the oscillation as follows: 1. The low-threshold calcium currentI T provided the strong initial burst characteristic of the oscillation. 2. Alternating fluxes through high-threshold calcium channels andI A H P then provided the continuing oscillation's burst and interburst periods respectively. This interplay betweenI L andI A H P contrasts with the current dynamics underlying oscillations in thalamocortical and reticularis neurons, which primarily involveI T andI H , orI T andI A H P respectively. These findings thus point to a novel electrophysiological mechanism for generating intrinsic oscillations in a major thalamic cell type. Because local interneurons can sculpt the behavior of thalamocortical circuits, these results suggest new targets for the manipulation of ascending thalamocortical network activity.
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Affiliation(s)
- Erica Y Griffith
- Department of Neural and Behavioral Sciences, SUNY Downstate Health Sciences University, Brooklyn, NY
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
| | - Mohamed ElSayed
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Hanover, NH
- Department of Biomedical Engineering, SUNY Downstate School of Graduate Studies, Brooklyn, NY
- Department of Psychiatry, New Hampshire Hospital, Concord, NH
| | - Salvador Dura-Bernal
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY
| | - Samuel A Neymotin
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Daniel J Uhlrich
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
| | - William W Lytton
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY
- Department of Neurology, Kings County Hospital, Brooklyn, NY
| | - J Julius Zhu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
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6
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Gong Y, Liu R, Zha H, Dong D, Lu N, Yan H, Wan L, Nian Y. Analgesic Buxus alkaloids with Enhanced Selectivity for the Low-Voltage-Gated Calcium Channel Ca v 3.2 over Ca v 3.1 through a New Binding Mode. Angew Chem Int Ed Engl 2024; 63:e202313461. [PMID: 37997012 DOI: 10.1002/anie.202313461] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 11/25/2023]
Abstract
Low-voltage-gated calcium channels (LVGCCs; Cav 3.1-3.3) represent promising drug targets for epilepsy, pain, and essential tremor. At present, modulators with heightened selectivity for a subtype of LVGCCs are still highly desired. In this study we explored three classes of Buxus alkaloids and identified 9(10/19)abeo-artanes Buxusemine H and Buxusemine L (BXSL) as an unprecedented type of Cav 3.2 inhibitors. Particularly, BXSL exhibited Cav 3.2 inhibition comparable to Z944, a non-subtype-selective LVGCCs inhibitor under clinical trial. While lacking specificity for Cav 3.3, BXSL showed a 30-fold selectivity of Cav 3.2 over Cav 3.1. As compared to several well-known inhibitors, the experimental and computational studies suggested BXSL exhibits a distinct binding mode to Cav 3.2, notably through the essential interaction with serine-1543 in domain III. Furthermore, BXSL showed minimal impact on various recombinant and native nociceptive ion channels, while significantly reducing the excitability of isolated mouse dorsal root ganglion neurons. Animal studies in wild-type and Cav 3.2 knock-out mice revealed that BXSL (5 mg/kg), by inhibiting Cav 3.2, exhibits an analgesic effect equivalent to Z944 (10 mg/kg) or mibefradil (10 mg/kg). Moreover, we proposed a structural rationale for the high selectivity of 9(10/19)abeo-artane-type alkaloids towards Cav 3.2 over Cav 3.1. This study introduces a novel analgesic agent and valuable molecular insight for structure-based innovative Cav 3.2 drug development.
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Affiliation(s)
- Ye Gong
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P. R. China
| | - Rui Liu
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P. R. China
| | - Hongjing Zha
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, P. R. China
| | - Ding Dong
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P. R. China
| | - Nihong Lu
- Department of Respiratory Medicine, The Third People's Hospital of Kunming, Kunming, 650041, Yunnan, P. R. China
| | - Hui Yan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P. R. China
| | - Luosheng Wan
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, P. R. China
| | - Yin Nian
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, P. R. China
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7
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Gawande DY, Shelkar GP, Narasimhan KKS, Liu J, Dravid SM. GluN2D subunit-containing NMDA receptors regulate reticular thalamic neuron function and seizure susceptibility. Neurobiol Dis 2023; 181:106117. [PMID: 37031803 DOI: 10.1016/j.nbd.2023.106117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/01/2023] [Accepted: 04/05/2023] [Indexed: 04/11/2023] Open
Abstract
Thalamic regulation of cortical function is important for several behavioral aspects including attention and sensorimotor control. This region has also been studied for its involvement in seizure activity. Among the NMDA receptor subunits GluN2C and GluN2D are particularly enriched in several thalamic nuclei including nucleus reticularis of the thalamus (nRT). We have previously found that GluN2C deletion does not have a strong influence on the basal excitability and burst firing characteristics of reticular thalamus neurons. Here we find that GluN2D ablation leads to reduced depolarization-induced spike frequency and reduced hyperpolarization-induced rebound burst firing in nRT neurons. Furthermore, reduced inhibitory neurotransmission was observed in the ventrobasal thalamus (VB). A model with preferential downregulation of GluN2D from parvalbumin (PV)-positive neurons was generated. Conditional deletion of GluN2D from PV neurons led to a decrease in excitability and burst firing. In addition, reduced excitability and burst firing was observed in the VB neurons together with reduced inhibitory neurotransmission. Finally, young mice with GluN2D downregulation in PV neurons showed significant resistance to pentylenetetrazol-induced seizure and differences in sensitivity to isoflurane anesthesia but were normal in other behaviors. Conditional deletion of GluN2D from PV neurons also affected expression of other GluN2 subunits and GABA receptor in the nRT. Together, these results identify a unique role of GluN2D-containing receptors in the regulation of thalamic circuitry and seizure susceptibility which is relevant to mutations in GRIN2D gene found to be associated with pediatric epilepsy.
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Affiliation(s)
- Dinesh Y Gawande
- Department of Pharmacology and Neuroscience, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
| | - Gajanan P Shelkar
- Department of Pharmacology and Neuroscience, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Kishore Kumar S Narasimhan
- Department of Pharmacology and Neuroscience, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Jinxu Liu
- Department of Pharmacology and Neuroscience, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Shashank M Dravid
- Department of Pharmacology and Neuroscience, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA.
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8
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Sitnikova E, Rutskova E, Smirnov K. Alpha2-Adrenergic Receptors as a Pharmacological Target for Spike-Wave Epilepsy. Int J Mol Sci 2023; 24:1477. [PMID: 36674992 PMCID: PMC9862736 DOI: 10.3390/ijms24021477] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/30/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Spike-wave discharges are the hallmark of idiopathic generalized epilepsy. They are caused by a disorder in the thalamocortical network. Commercially available anti-epileptic drugs have pronounced side effects (i.e., sedation and gastroenterological concerns), which might result from a low selectivity to molecular targets. We suggest a specific subtype of adrenergic receptors (ARs) as a promising anti-epileptic molecular target. In rats with a predisposition to absence epilepsy, alpha2 ARs agonists provoke sedation and enhance spike-wave activity during transitions from awake/sedation. A number of studies together with our own observations bring evidence that the sedative and proepileptic effects require different alpha2 ARs subtypes activation. Here we introduce a new concept on target pharmacotherapy of absence epilepsy via alpha2B ARs which are presented almost exclusively in the thalamus. We discuss HCN and calcium channels as the most relevant cellular targets of alpha2 ARs involved in spike-wave activity generation.
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Affiliation(s)
- Evgenia Sitnikova
- Institute of the Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Butlerova Str., 5A, Moscow 117485, Russia
| | - Elizaveta Rutskova
- Institute of the Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Butlerova Str., 5A, Moscow 117485, Russia
| | - Kirill Smirnov
- Institute of the Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Butlerova Str., 5A, Moscow 117485, Russia
- Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, Bld. 1, Moscow 121205, Russia
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9
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Jeong S, Shim JS, Sin SK, Park KS, Lee JH. Phosphorylation states greatly regulate the activity and gating properties of Ca v 3.1 T-type Ca 2+ channels. J Cell Physiol 2023; 238:210-226. [PMID: 36502489 DOI: 10.1002/jcp.30920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/21/2022] [Accepted: 11/10/2022] [Indexed: 12/14/2022]
Abstract
Cav 3.1 T-type Ca2+ channels play pivotal roles in neuronal low-threshold spikes, visceral pain, and pacemaker activity. Phosphorylation has been reported to potently regulate the activity and gating properties of Cav 3.1 channels. However, systematic identification of phosphorylation sites (phosphosites) in Cav 3.1 channel has been poorly investigated. In this work, we analyzed rat Cav 3.1 protein expressed in HEK-293 cells by mass spectrometry, identified 30 phosphosites located at the cytoplasmic regions, and illustrated them as a Cav 3.1 phosphorylation map which includes the reported mouse Cav 3.1 phosphosites. Site-directed mutagenesis of the phosphosites to Ala residues and functional analysis of the phospho-silent Cav 3.1 mutants expressed in Xenopus oocytes showed that the phospho-silent mutation of the N-terminal Ser18 reduced its current amplitude with accelerated current kinetics and negatively shifted channel availability. Remarkably, the phospho-silent mutations of the C-terminal Ser residues (Ser1924, Ser2001, Ser2163, Ser2166, or Ser2189) greatly reduced their current amplitude without altering the voltage-dependent gating properties. In contrast, the phosphomimetic Asp mutations of Cav 3.1 on the N- and C-terminal Ser residues reversed the effects of the phospho-silent mutations. Collectively, these findings demonstrate that the multiple phosphosites of Cav 3.1 at the N- and C-terminal regions play crucial roles in the regulation of the channel activity and voltage-dependent gating properties.
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Affiliation(s)
- Sua Jeong
- Department of Life Science, Sogang University, Seoul, South Korea
| | - Ji Seon Shim
- Department of Physiology, Kyung-Hee University, Seoul, South Korea
| | - Seok Kyo Sin
- Department of Physiology, Kyung-Hee University, Seoul, South Korea
| | - Kang-Sik Park
- Department of Physiology, Kyung-Hee University, Seoul, South Korea
| | - Jung-Ha Lee
- Department of Life Science, Sogang University, Seoul, South Korea
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10
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Harman T, Udoh M, McElroy DL, Anderson LL, Kevin RC, Banister SD, Ametovski A, Markham J, Bladen C, Doohan PT, Greba Q, Laprairie RB, Snutch TP, McGregor IS, Howland JG, Arnold JC. MEPIRAPIM-derived synthetic cannabinoids inhibit T-type calcium channels with divergent effects on seizures in rodent models of epilepsy. Front Physiol 2023; 14:1086243. [PMID: 37082241 PMCID: PMC10110893 DOI: 10.3389/fphys.2023.1086243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/17/2023] [Indexed: 04/22/2023] Open
Abstract
Background: T-type Ca2+ channels (Cav3) represent emerging therapeutic targets for a range of neurological disorders, including epilepsy and pain. To aid the development and optimisation of new therapeutics, there is a need to identify novel chemical entities which act at these ion channels. A number of synthetic cannabinoid receptor agonists (SCRAs) have been found to exhibit activity at T-type channels, suggesting that cannabinoids may provide convenient chemical scaffolds on which to design novel Cav3 inhibitors. However, activity at cannabinoid type 1 (CB1) receptors can be problematic because of central and peripheral toxicities associated with potent SCRAs. The putative SCRA MEPIRAPIM and its analogues were recently identified as Cav3 inhibitors with only minimal activity at CB1 receptors, opening the possibility that this scaffold may be exploited to develop novel, selective Cav3 inhibitors. Here we present the pharmacological characterisation of SB2193 and SB2193F, two novel Cav3 inhibitors derived from MEPIRAPIM. Methods: The potency of SB2193 and SB2193F was evaluated in vitro using a fluorometric Ca2+ flux assay and confirmed using whole-cell patch-clamp electrophysiology. In silico docking to the cryo-EM structure of Cav3.1 was also performed to elucidate structural insights into T-type channel inhibition. Next, in vivo pharmacokinetic parameters in mouse brain and plasma were determined using liquid chromatography-mass spectroscopy. Finally, anticonvulsant activity was assayed in established genetic and electrically-induced rodent seizure models. Results: Both MEPIRAPIM derivatives produced potent inhibition of Cav3 channels and were brain penetrant, with SB2193 exhibiting a brain/plasma ratio of 2.7. SB2193 was further examined in mouse seizure models where it acutely protected against 6 Hz-induced seizures. However, SB2193 did not reduce spontaneous seizures in the Scn1a +/- mouse model of Dravet syndrome, nor absence seizures in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS). Surprisingly, SB2193 appeared to increase the incidence and duration of spike-and-wave discharges in GAERS animals over a 4 h recording period. Conclusion: These results show that MEPIRAPIM analogues provide novel chemical scaffolds to advance Cav3 inhibitors against certain seizure types.
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Affiliation(s)
- Thomas Harman
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Michael Udoh
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Dan L. McElroy
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lyndsey L. Anderson
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Richard C. Kevin
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Samuel D. Banister
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Adam Ametovski
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Jack Markham
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - Chris Bladen
- Department of Biomedical Sciences, Macquarie University, Sydney, NSW, Australia
| | - Peter T. Doohan
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Quentin Greba
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Robert B. Laprairie
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Terrance P. Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Iain S. McGregor
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- School of Psychology, Faculty of Science, The University of Sydney, Sydney, NSW, Australia
| | - John G. Howland
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jonathon C. Arnold
- The Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, NSW, Australia
- Discipline of Pharmacology, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
- *Correspondence: Jonathon C. Arnold,
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11
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El Ghaleb Y, Flucher BE. Ca V3.3 Channelopathies. Handb Exp Pharmacol 2023; 279:263-288. [PMID: 36592228 DOI: 10.1007/164_2022_631] [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] [Indexed: 01/03/2023]
Abstract
CaV3.3 is the third member of the low-voltage-activated calcium channel family and the last to be recognized as disease gene. Previously, CACNA1I, the gene encoding CaV3.3, had been described as schizophrenia risk gene. More recently, de novo missense mutations in CACNA1I were identified in patients with variable degrees of neurodevelopmental disease with and without epilepsy. Their functional characterization indicated gain-of-function effects resulting in increased calcium load and hyperexcitability of neurons expressing CaV3.3. The amino acids mutated in the CaV3.3 disease variants are located in the vicinity of the channel's activation gate and thus are classified as gate-modifying channelopathy mutations. A persistent calcium leak during rest and prolonged calcium spikes due to increased voltage sensitivity of activation and slowed kinetics of channel inactivation, respectively, may be causal for the neurodevelopmental defects. The prominent expression of CaV3.3 in thalamic reticular nucleus neurons and its essential role in generating the rhythmic thalamocortical network activity are consistent with a role of the mutated channels in the etiology of epileptic seizures and thus suggest T-type channel blockers as a viable treatment option.
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Affiliation(s)
- Yousra El Ghaleb
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria
| | - Bernhard E Flucher
- Institute of Physiology, Medical University Innsbruck, Innsbruck, Austria.
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12
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McArthur JR, Wen J, Hung A, Finol-Urdaneta RK, Adams DJ. µ-Theraphotoxin Pn3a inhibition of Ca V3.3 channels reveals a novel isoform-selective drug binding site. eLife 2022; 11:e74040. [PMID: 35858123 PMCID: PMC9342953 DOI: 10.7554/elife.74040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Low voltage-activated calcium currents are mediated by T-type calcium channels CaV3.1, CaV3.2, and CaV3.3, which modulate a variety of physiological processes including sleep, cardiac pace-making, pain, and epilepsy. CaV3 isoforms' biophysical properties, overlapping expression, and lack of subtype-selective pharmacology hinder the determination of their specific physiological roles in health and disease. We have identified μ-theraphotoxin Pn3a as the first subtype-selective spider venom peptide inhibitor of CaV3.3, with >100-fold lower potency against the other T-type isoforms. Pn3a modifies CaV3.3 gating through a depolarizing shift in the voltage dependence of activation thus decreasing CaV3.3-mediated currents in the normal range of activation potentials. Paddle chimeras of KV1.7 channels bearing voltage sensor sequences from all four CaV3.3 domains revealed preferential binding of Pn3a to the S3-S4 region of domain II (CaV3.3DII). This novel T-type channel pharmacological site was explored through computational docking simulations of Pn3a, site-directed mutagenesis, and full domain II swaps between CaV3 channels highlighting it as a subtype-specific pharmacophore. This research expands our understanding of T-type calcium channel pharmacology and supports the suitability of Pn3a as a molecular tool in the study of the physiological roles of CaV3.3 channels.
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Affiliation(s)
- Jeffrey R McArthur
- Illawarra Health and Medical Research Institute, University of WollongongWollongongAustralia
| | - Jierong Wen
- School of Science, RMIT UniversityMelbourneAustralia
| | - Andrew Hung
- School of Science, RMIT UniversityMelbourneAustralia
| | - Rocio K Finol-Urdaneta
- Illawarra Health and Medical Research Institute, University of WollongongWollongongAustralia
| | - David J Adams
- Illawarra Health and Medical Research Institute, University of WollongongWollongongAustralia
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13
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Baez-Nieto D, Allen A, Akers-Campbell S, Yang L, Budnik N, Pupo A, Shin YC, Genovese G, Liao M, Pérez-Palma E, Heyne H, Lal D, Lipscombe D, Pan JQ. Analysing an allelic series of rare missense variants of CACNA1I in a Swedish schizophrenia cohort. Brain 2022; 145:1839-1853. [PMID: 34919654 PMCID: PMC9166571 DOI: 10.1093/brain/awab443] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/23/2021] [Accepted: 11/11/2021] [Indexed: 11/14/2022] Open
Abstract
CACNA1I is implicated in the susceptibility to schizophrenia by large-scale genetic association studies of single nucleotide polymorphisms. However, the channelopathy of CACNA1I in schizophrenia is unknown. CACNA1I encodes CaV3.3, a neuronal voltage-gated calcium channel that underlies a subtype of T-type current that is important for neuronal excitability in the thalamic reticular nucleus and other regions of the brain. Here, we present an extensive functional characterization of 57 naturally occurring rare and common missense variants of CACNA1I derived from a Swedish schizophrenia cohort of more than 10 000 individuals. Our analysis of this allelic series of coding CACNA1I variants revealed that reduced CaV3.3 channel current density was the dominant phenotype associated with rare CACNA1I coding alleles derived from control subjects, whereas rare CACNA1I alleles from schizophrenia patients encoded CaV3.3 channels with altered responses to voltages. CACNA1I variants associated with altered current density primarily impact the ionic channel pore and those associated with altered responses to voltage impact the voltage-sensing domain. CaV3.3 variants associated with altered voltage dependence of the CaV3.3 channel and those associated with peak current density deficits were significantly segregated across affected and unaffected groups (Fisher's exact test, P = 0.034). Our results, together with recent data from the SCHEMA (Schizophrenia Exome Sequencing Meta-Analysis) cohort, suggest that reduced CaV3.3 function may protect against schizophrenia risk in rare cases. We subsequently modelled the effect of the biophysical properties of CaV3.3 channel variants on thalamic reticular nucleus excitability and found that compared with common variants, ultrarare CaV3.3-coding variants derived from control subjects significantly decreased thalamic reticular nucleus excitability (P = 0.011). When all rare variants were analysed, there was a non-significant trend between variants that reduced thalamic reticular nucleus excitability and variants that either had no effect or increased thalamic reticular nucleus excitability across disease status. Taken together, the results of our functional analysis of an allelic series of >50 CACNA1I variants in a schizophrenia cohort reveal that loss of function of CaV3.3 is a molecular phenotype associated with reduced disease risk burden, and our approach may serve as a template strategy for channelopathies in polygenic disorders.
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Affiliation(s)
- David Baez-Nieto
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Andrew Allen
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Seth Akers-Campbell
- Carney Institute for Brain Science & Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Lingling Yang
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Nikita Budnik
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Amaury Pupo
- Department of Biology, West Virginia University, Morgantown, West Virginia 26506, USA
| | - Young-Cheul Shin
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Giulio Genovese
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Maofu Liao
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Eduardo Pérez-Palma
- Genomic Medicine Institute, Lerner Research institute, Cleveland Clinic, OH 44195, USA
- Centro de Genética y Genómica, Universidad del Desarrollo, Centro de Genética y Genómica, Facultad de Medicina Clínica Alemana, Chile
| | - Henrike Heyne
- Genomic Medicine, Hasso Plattner Institute, Potsdam, 14482, Germany
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research institute, Cleveland Clinic, OH 44195, USA
- Cologne Center for Genomics, University of Cologne, Cologne 50931, Germany
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Diane Lipscombe
- Carney Institute for Brain Science & Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Jen Q. Pan
- Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
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14
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Chang B, Byun J, Kim KK, Lee SE, Lee B, Kim KS, Ryu H, Shin HS, Cheong E. Deletion of Phospholipase C β1 in the Thalamic Reticular Nucleus Induces Absence Seizures. Exp Neurobiol 2022; 31:116-130. [PMID: 35674000 PMCID: PMC9194639 DOI: 10.5607/en22007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/22/2022] [Accepted: 04/05/2022] [Indexed: 11/29/2022] Open
Abstract
Absence seizures are caused by abnormal synchronized oscillations in the thalamocortical (TC) circuit, which result in widespread spike-and-wave discharges (SWDs) on electroencephalography (EEG) as well as impairment of consciousness. Thalamic reticular nucleus (TRN) and TC neurons are known to interact dynamically to generate TC circuitry oscillations during SWDs. Clinical studies have suggested the association of Plcβ1 with early-onset epilepsy, including absence seizures. However, the brain regions and circuit mechanisms related to the generation of absence seizures with Plcβ1 deficiency are unknown. In this study, we found that loss of Plcβ1 in mice caused spontaneous complex-type seizures, including convulsive and absence seizures. Importantly, TRN-specific deletion of Plcβ1 led to the development of only spontaneous SWDs, and no other types of seizures were observed. Ex vivo slice patch recording demonstrated that the number of spikes, an intrinsic TRN neuronal property, was significantly reduced in both tonic and burst firing modes in the absence of Plcβ1. We conclude that the loss of Plcβ1 in the TRN leads to decreased excitability and impairs normal inhibitory neuronal function, thereby disrupting feedforward inhibition of the TC circuitry, which is sufficient to cause hypersynchrony of the TC system and eventually leads to spontaneous absence seizures. Our study not only provides a novel mechanism for the induction of SWDs in Plcβ1-deficient patients but also offers guidance for the development of diagnostic and therapeutic tools for absence epilepsy.
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Affiliation(s)
- Bomi Chang
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea.,Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea.,Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
| | - Junweon Byun
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea
| | - Ko Keun Kim
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea
| | - Seung Eun Lee
- Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Boyoung Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea
| | - Key-Sun Kim
- Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Hoon Ryu
- Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Hee-Sup Shin
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon 34126, Korea
| | - Eunji Cheong
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
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15
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Abdelaal MS, Midorikawa M, Suzuki T, Kobayashi K, Takata N, Miyata M, Mimura M, Tanaka KF. OUP accepted manuscript. Brain Commun 2022; 4:fcac010. [PMID: 35243344 PMCID: PMC8887905 DOI: 10.1093/braincomms/fcac010] [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: 10/27/2021] [Revised: 11/02/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Spike-and-wave discharges and an accompanying loss of consciousness are hallmarks of absence seizure, which is a childhood generalized epilepsy disorder. In absence seizure, dysfunction of the cortico-thalamo-cortico circuitry is thought to engage in abnormal cortical rhythms. Previous studies demonstrated that the thalamic reticular nucleus has a critical role in the formation of normal cortical rhythms; however, whether thalamic reticular nucleus dysfunction leads directly to abnormal rhythms, such as epilepsy, is largely unknown. We found that expressing the inhibitory opsin, archaerhodopsin, including in the thalamic reticular nucleus, caused abnormal cortical rhythms in Pvalb-tetracycline transactivator::tetO-ArchT (PV-ArchT) double transgenic mice. We validated the PV-ArchT line as a new mouse model of absence seizure through physiological and pharmacological analyses, as well as through examining their behavioural features. We then discovered that archaerhodopsin expression exclusively in thalamic reticular nucleus parvalbumin-positive neurons was sufficient to induce cortical spike-and-wave discharges using adeno-associated virus-mediated thalamic reticular nucleus targeting. Furthermore, we found that archaerhodopsin expression impaired rebound burst firing and T-current in thalamic reticular nucleus parvalbumin-positive cells by slice physiology. Although T-current in the thalamic reticular nucleus was impaired, the T-current blocker ethosuximide still had a therapeutic effect in PV-ArchT mice, suggesting a gain of function of T-type calcium channels in this absence seizure model. However, we did not find any over- or misexpression of T-type calcium channel genes in the thalamus or the cortex. Thus, we demonstrated that thalamic reticular nucleus dysfunction led to an absence seizure-like phenotype in mice. In a final set of experiments, we showed that the archaerhodopsin-mediated absence seizure-like phenotype disappeared after the removal of archaerhodopsin by using a time-controllable transgenic system. These data may provide a hint as to why many absence seizures naturally regress.
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Affiliation(s)
- Manal S. Abdelaal
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mitsuharu Midorikawa
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Toru Suzuki
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kenta Kobayashi
- Section of Viral Vector Development, National Institute for Physiological Sciences, Okazaki 444-8585, Japan
| | - Norio Takata
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Mariko Miyata
- Division of Neurophysiology, Department of Physiology, School of Medicine, Tokyo Women’s Medical University, Tokyo 162-8666, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kenji F. Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo 160-8582, Japan
- Division of Brain Sciences, Institute for Advanced Medical Research, Keio University School of Medicine, Tokyo 160-8582, Japan
- Correspondence to: Kenji F. Tanaka, MD, PhD Division of Brain Sciences, Institute for Advanced Medical Research Keio University School of Medicine 35 Shinanomachi Shinjuku-ku Tokyo 160-8582, Japan E-mail:
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16
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Maksemous N, Blayney CD, Sutherland HG, Smith RA, Lea RA, Tran KN, Ibrahim O, McArthur JR, Haupt LM, Cader MZ, Finol-Urdaneta RK, Adams DJ, Griffiths LR. Investigation of CACNA1I Cav3.3 Dysfunction in Hemiplegic Migraine. Front Mol Neurosci 2022; 15:892820. [PMID: 35928792 PMCID: PMC9345121 DOI: 10.3389/fnmol.2022.892820] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/13/2022] [Indexed: 01/12/2023] Open
Abstract
Familial hemiplegic migraine (FHM) is a severe neurogenetic disorder for which three causal genes, CACNA1A, SCN1A, and ATP1A2, have been implicated. However, more than 80% of referred diagnostic cases of hemiplegic migraine (HM) are negative for exonic mutations in these known FHM genes, suggesting the involvement of other genes. Using whole-exome sequencing data from 187 mutation-negative HM cases, we identified rare variants in the CACNA1I gene encoding the T-type calcium channel Cav3.3. Burden testing of CACNA1I variants showed a statistically significant increase in allelic burden in the HM case group compared to gnomAD (OR = 2.30, P = 0.00005) and the UK Biobank (OR = 2.32, P = 0.0004) databases. Dysfunction in T-type calcium channels, including Cav3.3, has been implicated in a range of neurological conditions, suggesting a potential role in HM. Using patch-clamp electrophysiology, we compared the biophysical properties of five Cav3.3 variants (p.R111G, p.M128L, p.D302G, p.R307H, and p.Q1158H) to wild-type (WT) channels expressed in HEK293T cells. We observed numerous functional alterations across the channels with Cav3.3-Q1158H showing the greatest differences compared to WT channels, including reduced current density, right-shifted voltage dependence of activation and inactivation, and slower current kinetics. Interestingly, we also found significant differences in the conductance properties exhibited by the Cav3.3-R307H and -Q1158H variants compared to WT channels under conditions of acidosis and alkalosis. In light of these data, we suggest that rare variants in CACNA1I may contribute to HM etiology.
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Affiliation(s)
- Neven Maksemous
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Claire D Blayney
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Heidi G Sutherland
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Robert A Smith
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Rod A Lea
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kim Ngan Tran
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Omar Ibrahim
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Jeffrey R McArthur
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Larisa M Haupt
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - M Zameel Cader
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Rocio K Finol-Urdaneta
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia
| | - Lyn R Griffiths
- Genomics Research Centre, The Centre for Genomics and Personalised Health, School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
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17
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Coulter I, Timic Stamenic T, Eggan P, Fine BR, Corrigan T, Covey DF, Yang L, Pan JQ, Todorovic SM. Different roles of T-type calcium channel isoforms in hypnosis induced by an endogenous neurosteroid epipregnanolone. Neuropharmacology 2021; 197:108739. [PMID: 34339750 PMCID: PMC8478885 DOI: 10.1016/j.neuropharm.2021.108739] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 07/09/2021] [Accepted: 07/29/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND Many neuroactive steroids induce sedation/hypnosis by potentiating γ-aminobutyric acid (GABAA) currents. However, we previously demonstrated that an endogenous neuroactive steroid epipregnanolone [(3β,5β)-3-hydroxypregnan-20-one] (EpiP) exerts potent peripheral analgesia and blocks T-type calcium currents while sparing GABAA currents in rat sensory neurons. This study seeks to investigate the behavioral effects elicited by systemic administration of EpiP and to characterize its use as an adjuvant agent to commonly used general anesthetics (GAs). METHODS Here, we utilized electroencephalographic (EEG) recordings to characterize thalamocortical oscillations, as well as behavioral assessment and mouse genetics with wild-type (WT) and different knockout (KO) models of T-channel isoforms to investigate potential sedative/hypnotic and immobilizing properties of EpiP. RESULTS Consistent with increased oscillations in slower EEG frequencies, EpiP induced an hypnotic state in WT mice when injected alone intra-peritoneally (i.p.) and effectively facilitated anesthetic effects of isoflurane (ISO) and sevoflurane (SEVO). The CaV3.1 (Cacna1g) KO mice demonstrated decreased sensitivity to EpiP-induced hypnosis when compared to WT mice, whereas no significant difference was noted between CaV3.2 (Cacna1h), CaV3.3 (Cacna1i) and WT mice. Finally, when compared to WT mice, onset of EpiP-induced hypnosis was delayed in CaV3.2 KO mice but not in CaV3.1 and CaV3.3 KO mice. CONCLUSION We posit that EpiP may have an important role as novel hypnotic and/or adjuvant to volatile anesthetic agents. We speculate that distinct hypnotic effects of EpiP across all three T-channel isoforms is due to their differential expression in thalamocortical circuitry.
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Affiliation(s)
- Ian Coulter
- Department of Anesthesiology, University of Colorado,
Anschutz Medical Campus, Aurora 80045
| | - Tamara Timic Stamenic
- Department of Anesthesiology, University of Colorado,
Anschutz Medical Campus, Aurora 80045
| | - Pierce Eggan
- Department of Anesthesiology, University of Colorado,
Anschutz Medical Campus, Aurora 80045
| | - Brier R. Fine
- Department of Anesthesiology, University of Colorado,
Anschutz Medical Campus, Aurora 80045
| | - Timothy Corrigan
- Department of Pediatrics, Division of Neurology,
Translational Epilepsy Research Program, University of Colorado, Anschutz Medical
Campus, Aurora, CO 80045, USA
| | - Douglas F. Covey
- Department of Developmental Biology, Washington University
School of Medicine, St. Louis, MO 63110, USA;,Taylor Family Institute for Innovative Psychiatric
Research, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Lingling Yang
- Stanley Center for Psychiatric Research, Broad Institute of
Harvard and MIT
| | - Jen Q. Pan
- Stanley Center for Psychiatric Research, Broad Institute of
Harvard and MIT
| | - Slobodan M. Todorovic
- Department of Anesthesiology, University of Colorado,
Anschutz Medical Campus, Aurora 80045;,Neuroscience, University of Colorado, Anschutz Medical
Campus, Aurora 80045;,Pharmacology Graduate Programs, University of Colorado,
Anschutz Medical Campus, Aurora 80045
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18
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Global genetic deletion of Ca V3.3 channels facilitates anaesthetic induction and enhances isoflurane-sparing effects of T-type calcium channel blockers. Sci Rep 2020; 10:21510. [PMID: 33299036 PMCID: PMC7725806 DOI: 10.1038/s41598-020-78488-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/13/2020] [Indexed: 01/02/2023] Open
Abstract
We previously documented that the CaV3.3 isoform of T-type calcium channels (T-channels) is inhibited by clinically relevant concentrations of volatile anaesthetics, including isoflurane. However, little is understood about the functional role of CaV3.3 channels in anaesthetic-induced hypnosis and underlying neuronal oscillations. To address this issue, we used CaV3.3 knock-out (KO) mice and a panselective T-channel blocker 3,5-dichloro-N-[1-(2,2-dimethyltetrahydro-pyran-4-ylmethyl)-4-fluoro-piperidin-4-ylmethyl]-benzamide (TTA-P2). We found that mutant mice injected with the vehicle showed faster induction of hypnosis than wild-type (WT) mice, while the percent isoflurane at which hypnosis and immobility occurred was not different between two genotypes. Furthermore, we found that TTA-P2 facilitated isoflurane induction of hypnosis in the CaV3.3 KO mice more robustly than in the WT mice. Isoflurane-induced hypnosis following injections of TTA-P2 was accompanied with more prominent delta and theta EEG oscillations in the mutant mice, and reached burst-suppression pattern earlier when compared to the WT mice. Our findings point to a relatively specific value of CaV3.3 channels in anaesthetic induced hypnosis. Furthermore, we propose that T-channel blockers may be further explored as a valuable adjunct to reducing the usage of potent volatile anaesthetics, thereby improving their safety.
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19
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Lory P, Nicole S, Monteil A. Neuronal Cav3 channelopathies: recent progress and perspectives. Pflugers Arch 2020; 472:831-844. [PMID: 32638069 PMCID: PMC7351805 DOI: 10.1007/s00424-020-02429-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/08/2020] [Accepted: 06/26/2020] [Indexed: 12/22/2022]
Abstract
T-type, low-voltage activated, calcium channels, now designated Cav3 channels, are involved in a wide variety of physiological functions, especially in nervous systems. Their unique electrophysiological properties allow them to finely regulate neuronal excitability and to contribute to sensory processing, sleep, and hormone and neurotransmitter release. In the last two decades, genetic studies, including exploration of knock-out mouse models, have greatly contributed to elucidate the role of Cav3 channels in normal physiology, their regulation, and their implication in diseases. Mutations in genes encoding Cav3 channels (CACNA1G, CACNA1H, and CACNA1I) have been linked to a variety of neurodevelopmental, neurological, and psychiatric diseases designated here as neuronal Cav3 channelopathies. In this review, we describe and discuss the clinical findings and supporting in vitro and in vivo studies of the mutant channels, with a focus on de novo, gain-of-function missense mutations recently discovered in CACNA1G and CACNA1H. Overall, the studies of the Cav3 channelopathies help deciphering the pathogenic mechanisms of corresponding diseases and better delineate the properties and physiological roles Cav3 channels.
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Affiliation(s)
- Philippe Lory
- Institut de Génomique Fonctionnelle, CNRS, INSERM, University Montpellier, 141, rue de la Cardonille, 34094, Montpellier, France. .,LabEx 'Ion Channel Science and Therapeutics' (ICST), Montpellier, France.
| | - Sophie Nicole
- Institut de Génomique Fonctionnelle, CNRS, INSERM, University Montpellier, 141, rue de la Cardonille, 34094, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics' (ICST), Montpellier, France
| | - Arnaud Monteil
- Institut de Génomique Fonctionnelle, CNRS, INSERM, University Montpellier, 141, rue de la Cardonille, 34094, Montpellier, France.,LabEx 'Ion Channel Science and Therapeutics' (ICST), Montpellier, France
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20
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Pathophysiological roles and therapeutic potential of voltage-gated ion channels (VGICs) in pain associated with herpesvirus infection. Cell Biosci 2020; 10:70. [PMID: 32489585 PMCID: PMC7247163 DOI: 10.1186/s13578-020-00430-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/13/2020] [Indexed: 02/06/2023] Open
Abstract
Herpesvirus is ranked as one of the grand old members of all pathogens. Of all the viruses in the superfamily, Herpes simplex virus type 1 (HSV-1) is considered as a model virus for a variety of reasons. In a permissive non-neuronal cell culture, HSV-1 concludes the entire life cycle in approximately 18–20 h, encoding approximately 90 unique transcriptional units. In latency, the robust viral gene expression is suppressed in neurons by a group of noncoding RNA. Historically the lesions caused by the virus can date back to centuries ago. As a neurotropic pathogen, HSV-1 is associated with painful oral lesions, severe keratitis and lethal encephalitis. Transmission of pain signals is dependent on the generation and propagation of action potential in sensory neurons. T-type Ca2+ channels serve as a preamplifier of action potential generation. Voltage-gated Na+ channels are the main components for action potential production. This review summarizes not only the voltage-gated ion channels in neuropathic disorders but also provides the new insights into HSV-1 induced pain.
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21
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Ghoshal A, Uygun DS, Yang L, McNally JM, Lopez-Huerta VG, Arias-Garcia MA, Baez-Nieto D, Allen A, Fitzgerald M, Choi S, Zhang Q, Hope JM, Yan K, Mao X, Nicholson TB, Imaizumi K, Fu Z, Feng G, Brown RE, Strecker RE, Purcell SM, Pan JQ. Effects of a patient-derived de novo coding alteration of CACNA1I in mice connect a schizophrenia risk gene with sleep spindle deficits. Transl Psychiatry 2020; 10:29. [PMID: 32066662 PMCID: PMC7026444 DOI: 10.1038/s41398-020-0685-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 10/25/2019] [Accepted: 11/06/2019] [Indexed: 11/09/2022] Open
Abstract
CACNA1I, a schizophrenia risk gene, encodes a subtype of voltage-gated T-type calcium channel CaV3.3. We previously reported that a patient-derived missense de novo mutation (R1346H) of CACNA1I impaired CaV3.3 channel function. Here, we generated CaV3.3-RH knock-in animals, along with mice lacking CaV3.3, to investigate the biological impact of R1346H (RH) variation. We found that RH mutation altered cellular excitability in the thalamic reticular nucleus (TRN), where CaV3.3 is abundantly expressed. Moreover, RH mutation produced marked deficits in sleep spindle occurrence and morphology throughout non-rapid eye movement (NREM) sleep, while CaV3.3 haploinsufficiency gave rise to largely normal spindles. Therefore, mice harboring the RH mutation provide a patient derived genetic model not only to dissect the spindle biology but also to evaluate the effects of pharmacological reagents in normalizing sleep spindle deficits. Importantly, our analyses highlighted the significance of characterizing individual spindles and strengthen the inferences we can make across species over sleep spindles. In conclusion, this study established a translational link between a genetic allele and spindle deficits during NREM observed in schizophrenia patients, representing a key step toward testing the hypothesis that normalizing spindles may be beneficial for schizophrenia patients.
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Affiliation(s)
- Ayan Ghoshal
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - David S. Uygun
- Department of Psychiatry, VA Boston Healthcare System & Harvard Medical School, Boston, MA USA
| | - Lingling Yang
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - James M. McNally
- Department of Psychiatry, VA Boston Healthcare System & Harvard Medical School, Boston, MA USA
| | - Violeta G. Lopez-Huerta
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA USA
- Present Address: Department of Neurodevelopment and Physiology, Institute of Cellular Physiology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Mario A. Arias-Garcia
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA USA
- Present Address: Department of Neurodevelopment and Physiology, Institute of Cellular Physiology, National Autonomous University of Mexico, Mexico City, Mexico
| | - David Baez-Nieto
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - Andrew Allen
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - Megan Fitzgerald
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - Soonwook Choi
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA USA
| | - Qiangge Zhang
- McGovern Institute for Brain Research, MIT, Cambridge, MA USA
| | - Jen M. Hope
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - Karena Yan
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
| | - Xiaohong Mao
- Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139 USA
| | - Thomas B. Nicholson
- Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139 USA
| | | | - Zhanyan Fu
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA USA
| | - Guoping Feng
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
- McGovern Institute for Brain Research, MIT, Cambridge, MA USA
| | - Ritchie E. Brown
- Department of Psychiatry, VA Boston Healthcare System & Harvard Medical School, Boston, MA USA
| | - Robert E. Strecker
- Department of Psychiatry, VA Boston Healthcare System & Harvard Medical School, Boston, MA USA
| | - Shaun M. Purcell
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA USA
| | - Jen Q. Pan
- Stanley Center for Psychiatric Research, Broad Institute, Cambridge, MA USA
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22
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Miao QL, Herlitze S, Mark MD, Noebels JL. Adult loss of Cacna1a in mice recapitulates childhood absence epilepsy by distinct thalamic bursting mechanisms. Brain 2020; 143:161-174. [PMID: 31800012 PMCID: PMC6935748 DOI: 10.1093/brain/awz365] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/09/2019] [Accepted: 09/29/2019] [Indexed: 12/15/2022] Open
Abstract
Inborn errors of CACNA1A-encoded P/Q-type calcium channels impair synaptic transmission, producing early and lifelong neurological deficits, including childhood absence epilepsy, ataxia and dystonia. Whether these impairments owe their pathologies to defective channel function during the critical period for thalamic network stabilization in immature brain remains unclear. Here we show that mice with tamoxifen-induced adult-onset ablation of P/Q channel alpha subunit (iKOp/q) display identical patterns of dysfunction, replicating the inborn loss-of-function phenotypes and, therefore demonstrate that these neurological defects do not rely upon developmental abnormality. Unexpectedly, unlike the inborn model, the adult-onset pattern of excitability changes believed to be pathogenic within the thalamic network is non-canonical. Specifically, adult ablation of P/Q channels does not promote Cacna1g-mediated burst firing or T-type calcium current (IT) in the thalamocortical relay neurons; however, burst firing in thalamocortical relay neurons remains essential as iKOp/q mice generated on a Cacna1g deleted background show substantially diminished seizure generation. Moreover, in thalamic reticular nucleus neurons, burst firing is impaired accompanied by attenuated IT. Interestingly, inborn deletion of thalamic reticular nucleus-enriched, human childhood absence epilepsy-linked gene Cacna1h in iKOp/q mice reduces thalamic reticular nucleus burst firing and promotes rather than reduces seizure, indicating an epileptogenic role for loss-of-function Cacna1h gene variants reported in human childhood absence epilepsy cases. Together, our results demonstrate that P/Q channels remain critical for maintaining normal thalamocortical oscillations and motor control in the adult brain, and suggest that the developmental plasticity of membrane currents regulating pathological rhythmicity is both degenerate and age-dependent.
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Affiliation(s)
- Qing-Long Miao
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston TX, USA
| | - Stefan Herlitze
- Department of Zoology and Neurobiology, Ruhr University of Bochum, Bochum, Germany
| | - Melanie D Mark
- Department of Zoology and Neurobiology, Ruhr University of Bochum, Bochum, Germany
| | - Jeffrey L Noebels
- Developmental Neurogenetics Laboratory, Department of Neurology, Baylor College of Medicine, Houston TX, USA
- Department of Neuroscience, Baylor College of Medicine, Houston TX, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston TX, USA
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23
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Herlopian A, Cash SS, Eskandar EM, Jennings T, Cole AJ. Responsive neurostimulation targeting anterior thalamic nucleus in generalized epilepsy. Ann Clin Transl Neurol 2019; 6:2104-2109. [PMID: 31508904 PMCID: PMC6801174 DOI: 10.1002/acn3.50858] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 07/03/2019] [Accepted: 07/10/2019] [Indexed: 11/17/2022] Open
Abstract
Responsive neurostimulation (RNS) has emerged as an adjunctive treatment modality for patients with intractable focal epilepsy who are not surgical candidates or have more than one ictal onset focus. We report a 34‐year‐old patient with intractable, childhood‐onset, genetic generalized epilepsy (GGE) with tonic, atonic, myoclonic and absence seizures treated with RNS. Strip electrodes over the right posterior frontal cortex and depth electrodes placed in the right anterior nucleus were used for event detection and responsive stimulation. Two‐year follow‐up revealed 90–95% clinical seizure reduction. This case suggests that refractory GGE may be effectively treated with RNS targeting thalamocortical networks.
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Affiliation(s)
- Aline Herlopian
- MGH Epilepsy Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, ACC 739L, Boston, Massachusetts, 02114.,Department of Neurology, Yale Comprehensive Epilepsy Center, Yale University School of Medicine, 15 York St, LCI-7, New Haven, Connecticut, 06510
| | - Sydney S Cash
- MGH Epilepsy Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, ACC 739L, Boston, Massachusetts, 02114
| | - Emad M Eskandar
- Department of Neurosurgery, Massachusetts General Hospital, 55 Fruit St, Wang 7, Boston, Massachusetts, 02114.,Department of Neurosurgical Sciences, Montefiore Medical Center, 3316 Rochambeau Avenue, Bronx, New York, 10467
| | - Tara Jennings
- MGH Epilepsy Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, ACC 739L, Boston, Massachusetts, 02114
| | - Andrew J Cole
- MGH Epilepsy Service, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, ACC 739L, Boston, Massachusetts, 02114
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24
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Liu J, Shelkar GP, Zhao F, Clausen RP, Dravid SM. Modulation of burst firing of neurons in nucleus reticularis of the thalamus by GluN2C-containing NMDA receptors. Mol Pharmacol 2019; 96:mol.119.116780. [PMID: 31160332 PMCID: PMC6620419 DOI: 10.1124/mol.119.116780] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/17/2019] [Accepted: 05/24/2019] [Indexed: 12/11/2022] Open
Abstract
The GluN2C subunit of the NMDA receptor is enriched in the neurons in nucleus reticularis of the thalamus (nRT), but its role in regulating their function is not well understood. We found that deletion of GluN2C subunit did not affect spike frequency in response to depolarizing current injection or hyperpolarization-induced rebound burst firing of nRT neurons. D-cycloserine or CIQ (GluN2C/GluN2D positive allosteric modulator) did not affect the depolarization-induced spike frequency in nRT neurons. A newly identified highly potent and efficacious co-agonist of GluN1/GluN2C NMDA receptors, AICP, was found to reduce the spike frequency and burst firing of nRT neurons in wildtype but not GluN2C knockout. This effect was potentially due to facilitation of GluN2C-containing receptors because inhibition of NMDA receptors by AP5 did not affect spike frequency in nRT neurons. We evaluated the effect of intracerebroventricular injection of AICP. AICP did not affect basal locomotion or prepulse inhibition but facilitated MK-801-induced hyperlocomotion. This effect was observed in wildtype but not in GluN2C knockout mice demonstrating that AICP produces GluN2C-selective effects in vivo Using a chemogenetic approach we examined the role of nRT in this behavioral effect. Gq or Gi coupled DREADDs were selectively expressed in nRT neurons using cre-dependent viral vectors and PV-Cre mouse line. We found that similar to AICP effect, activation of Gq but not Gi coupled DREADD facilitated MK-801-induced hyperlocomotion. Together, these results identify a unique role of GluN2C-containing receptors in the regulation of nRT neurons and suggest GluN2C-selective in vivo targeting of NMDA receptors by AICP. SIGNIFICANCE STATEMENT: The nucleus reticularis of the thalamus composed of GABAergic neurons is termed as guardian of the gateway and is an important regulator of corticothalamic communication which may be impaired in autism, non-convulsive seizures and other conditions. We found that strong facilitation of tonic activity of GluN2C subtype of NMDA receptors using AICP, a newly identified glycine-site agonist of NMDA receptors, modulates the function of reticular thalamus neurons. AICP was also able to produce GluN2C-dependent behavioral effects in vivo. Together, these finding identify a novel mechanism and a pharmacological tool to modulate activity of reticular thalamic neurons in disease states.
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25
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Zhou R, Jiang G, Tian X, Wang X. Progress in the molecular mechanisms of genetic epilepsies using patient-induced pluripotent stem cells. Epilepsia Open 2018; 3:331-339. [PMID: 30187003 PMCID: PMC6119748 DOI: 10.1002/epi4.12238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2018] [Indexed: 12/29/2022] Open
Abstract
Research findings on the molecular mechanisms of epilepsy almost always originate from animal experiments, and the development of induced pluripotent stem cell (iPSC) technology allows the use of human cells with genetic defects for studying the molecular mechanisms of genetic epilepsy (GE) for the first time. With iPSC technology, terminally differentiated cells collected from GE patients with specific genetic etiologies can be differentiated into many relevant cell subtypes that carry all of the GE patient's genetic information. iPSCs have opened up a new research field involving the pathogenesis of GE. Using this approach, studies have found that gene mutations induce GE by altering the balance between neuronal excitation and inhibition, which is associated. among other factors, with neuronal developmental disturbances, ion channel abnormalities, and synaptic dysfunction. Simultaneously, astrocyte activation, mitochondrial dysfunction, and abnormal signaling pathway activity are also important factors in the molecular mechanisms of GE.
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Affiliation(s)
- Ruijiao Zhou
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
| | - Guohui Jiang
- Department of Neurology Institute of Neurological Diseases Affiliated Hospital of North Sichuan Medical College Nanchong China
| | - Xin Tian
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
| | - Xuefeng Wang
- Department of Neurology the First Affiliated Hospital of Chongqing Medical University Chongqing Key Laboratory of Neurology Chongqing China
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26
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Affiliation(s)
- László Acsády
- Laboratory of Thalamus Research, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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27
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Krol A, Wimmer RD, Halassa MM, Feng G. Thalamic Reticular Dysfunction as a Circuit Endophenotype in Neurodevelopmental Disorders. Neuron 2018; 98:282-295. [PMID: 29673480 PMCID: PMC6886707 DOI: 10.1016/j.neuron.2018.03.021] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 01/30/2018] [Accepted: 03/12/2018] [Indexed: 02/06/2023]
Abstract
Diagnoses of behavioral disorders such as autism spectrum disorder and schizophrenia are based on symptomatic descriptions that have been difficult to connect to mechanism. Although psychiatric genetics provide insight into the genetic underpinning of such disorders, with a majority of cases explained by polygenic factors, it remains difficult to design rational treatments. In this review, we highlight the value of understanding neural circuit function both as an intermediate level of explanatory description that links gene to behavior and as a pathway for developing rational diagnostics and therapeutics for behavioral disorders. As neural circuits perform hierarchically organized computational functions and give rise to network-level processes (e.g., macroscopic rhythms and goal-directed or homeostatic behaviors), correlated network-level deficits may indicate perturbation of a specific circuit. Therefore, identifying such correlated deficits or a circuit endophenotype would provide a mechanistic point of entry, enhancing both diagnosis and treatment of a given behavioral disorder. We focus on a circuit endophenotype of the thalamic reticular nucleus (TRN) and how its impairment in neurodevelopmental disorders gives rise to a correlated set of readouts across sleep and attention. Because TRN neurons express several disorder-relevant genes identified through genome-wide association studies, exploring the consequences of different TRN disruptions may be of broad translational significance.
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Affiliation(s)
- Alexandra Krol
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Ralf D Wimmer
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Michael M Halassa
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
| | - Guoping Feng
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
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28
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McCafferty C, David F, Venzi M, Lőrincz ML, Delicata F, Atherton Z, Recchia G, Orban G, Lambert RC, Di Giovanni G, Leresche N, Crunelli V. Cortical drive and thalamic feed-forward inhibition control thalamic output synchrony during absence seizures. Nat Neurosci 2018; 21:744-756. [PMID: 29662216 PMCID: PMC6278913 DOI: 10.1038/s41593-018-0130-4] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 03/08/2018] [Indexed: 11/09/2022]
Abstract
Behaviorally and pathologically relevant cortico-thalamo-cortical oscillations are driven by diverse interacting cell-intrinsic and synaptic processes. However, the mechanism that gives rise to the paroxysmal oscillations of absence seizures (ASs) remains unknown. Here we report that, during ASs in behaving animals, cortico-thalamic excitation drives thalamic firing by preferentially eliciting tonic rather than T-type Ca 2+ channel (T-channel)-dependent burst firing in thalamocortical (TC) neurons and by temporally framing thalamic output via feedforward reticular thalamic (NRT)-to-TC neuron inhibition. In TC neurons, overall ictal firing was markedly reduced and bursts rarely occurred. Moreover, blockade of T-channels in cortical and NRT neurons suppressed ASs, but such blockade in TC neurons had no effect on seizures or on ictal thalamic output synchrony. These results demonstrate ictal bidirectional cortico-thalamic communications and provide the first mechanistic understanding of cortico-thalamo-cortical network firing dynamics during ASs in behaving animals.
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Affiliation(s)
- Cian McCafferty
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK. .,Department of Neurology, Yale University School of Medicine, New Haven, CT, USA.
| | - François David
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK.,Team Waking, Lyon Neuroscience Research Center, CRNL, INSERM U1028, CNRS UMR5292, University of Lyon 1, Lyon, France
| | - Marcello Venzi
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK
| | - Magor L Lőrincz
- Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - Francis Delicata
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK.,Department of Physiology and Biochemistry, University of Malta, Msida, Malta
| | - Zoe Atherton
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK
| | - Gregorio Recchia
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK
| | - Gergely Orban
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK.,Department of Physiology and Biochemistry, University of Malta, Msida, Malta
| | - Régis C Lambert
- Sorbonne Université, CNRS, Inserm, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Giuseppe Di Giovanni
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK.,Department of Physiology and Biochemistry, University of Malta, Msida, Malta
| | - Nathalie Leresche
- Sorbonne Université, CNRS, Inserm, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Vincenzo Crunelli
- Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK. .,Department of Physiology and Biochemistry, University of Malta, Msida, Malta.
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29
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Cain SM, Tyson JR, Choi H, Ko R, Lin PJC, LeDue JM, Powell KL, Bernier L, Rungta RL, Yang Y, Cullis PR, O'Brien TJ, MacVicar BA, Snutch TP. Ca V 3.2 drives sustained burst-firing, which is critical for absence seizure propagation in reticular thalamic neurons. Epilepsia 2018; 59:778-791. [PMID: 29468672 PMCID: PMC5900875 DOI: 10.1111/epi.14018] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Genetic alterations have been identified in the CACNA1H gene, encoding the CaV 3.2 T-type calcium channel in patients with absence epilepsy, yet the precise mechanisms relating to seizure propagation and spike-wave-discharge (SWD) pacemaking remain unknown. Neurons of the thalamic reticular nucleus (TRN) express high levels of CaV 3.2 calcium channels, and we investigated whether a gain-of-function mutation in the Cacna1h gene in Genetic Absence Epilepsy Rats from Strasbourg (GAERS) contributes to seizure propagation and pacemaking in the TRN. METHODS Pathophysiological contributions of CaV 3.2 calcium channels to burst firing and absence seizures were assessed in vitro using acute brain slice electrophysiology and quantitative real-time polymerase chain reaction (PCR) and in vivo using free-moving electrocorticography recordings. RESULTS TRN neurons from GAERS display sustained oscillatory burst-firing that is both age- and frequency-dependent, occurring only in the frequencies overlapping with GAERS SWDs and correlating with the expression of a CaV 3.2 mutation-sensitive splice variant. In vivo knock-down of CaV 3.2 using direct thalamic injection of lipid nanoparticles containing CaV 3.2 dicer small interfering (Dsi) RNA normalized TRN burst-firing, and in free-moving GAERS significantly shortened seizures. SIGNIFICANCE This supports a role for TRN CaV 3.2 T-type channels in propagating thalamocortical network seizures and setting the pacemaking frequency of SWDs.
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Affiliation(s)
- Stuart M. Cain
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - John R. Tyson
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Hyun‐Beom Choi
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Rebecca Ko
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Paulo J. C. Lin
- Life Sciences InstituteUniversity of British ColumbiaVancouverBCCanada
| | - Jeffrey M. LeDue
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Kim L. Powell
- The Department of NeuroscienceCentral Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Louis‐Philippe Bernier
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Ravi L. Rungta
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Yi Yang
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Pieter R. Cullis
- Life Sciences InstituteUniversity of British ColumbiaVancouverBCCanada
| | - Terence J. O'Brien
- The Department of NeuroscienceCentral Clinical SchoolMonash UniversityMelbourneVictoriaAustralia
| | - Brian A. MacVicar
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
| | - Terrance P. Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
- Djavad Mowafaghian Centre for Brain HealthUniversity of British ColumbiaVancouverBCCanada
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30
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Bús B, Antal K, Emri Z. Intrathalamic connections shape spindle activity - a modelling study. ACTA BIOLOGICA HUNGARICA 2018; 69:16-28. [PMID: 29575912 DOI: 10.1556/018.68.2018.1.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Spindle oscillations are generated predominantly during sleep state II, through cyclical interactions between thalamocortical and reticular neurons. Inhibition from reticular cells is critical for this activity; it enables burst firing by the de-inactivation of T-type Ca2+ channels. While the effect of different channelopathies on spindling is extensively investigated, our knowledge about the role of intrathalamic connections is limited. Therefore, we explored how the connection pattern and the density of reticular inhibitory synapses affect spindle activity in a thalamic network model. With more intrareticular connections, synchronous firing of reticular cells, and intraspindle burst frequency decreased, spindles lengthened. In models with strong intrareticular inhibition spindle activity was impaired, and a sustained 6-8 Hz oscillation was generated instead. The strength of reticular innervation onto thalamocortical cells played a key role in the generation of oscillations; it determined the amount of thalamocortical cell bursts, and consequently spindle length. Focal inputs supported bursts but affected only a few cells thus barely reinforced network activity, while diffuse contacts aided bursts only when a sufficient number of reticular cells fired synchronously. According to our study, alterations in the connection pattern influence thalamic activities and may contribute to pathological conditions, or alternatively, they serve as a compensatory mechanism.
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Affiliation(s)
- Bálint Bús
- Department of Zoology, Eszterházy Károly University, Leányka u. 6, H-3300 Eger, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly University, Leányka u. 6, H-3300 Eger, Hungary
| | - Zsuzsa Emri
- Department of Zoology, Eszterházy Károly University, Leányka u. 6, H-3300 Eger, Hungary
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31
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Knox AT, Glauser T, Tenney J, Lytton WW, Holland K. Modeling pathogenesis and treatment response in childhood absence epilepsy. Epilepsia 2017; 59:135-145. [PMID: 29265352 DOI: 10.1111/epi.13962] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/29/2017] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Childhood absence epilepsy (CAE) is a genetic generalized epilepsy syndrome with polygenic inheritance, with genes for γ-aminobutyric acid (GABA) receptors and T-type calcium channels implicated in the disorder. Previous studies of T-type calcium channel electrophysiology have shown genetic changes and medications have multiple effects. The aim of this study was to use an established thalamocortical computer model to determine how T-type calcium channels work in concert with cortical excitability to contribute to pathogenesis and treatment response in CAE. METHODS The model is comprised of cortical pyramidal, cortical inhibitory, thalamocortical relay, and thalamic reticular single-compartment neurons, implemented with Hodgkin-Huxley model ion channels and connected by AMPA, GABAA , and GABAB synapses. Network behavior was simulated for different combinations of T-type calcium channel conductance, inactivation time, steady state activation/inactivation shift, and cortical GABAA conductance. RESULTS Decreasing cortical GABAA conductance and increasing T-type calcium channel conductance converted spindle to spike and wave oscillations; smaller changes were required if both were changed in concert. In contrast, left shift of steady state voltage activation/inactivation did not lead to spike and wave oscillations, whereas right shift reduced network propensity for oscillations of any type. SIGNIFICANCE These results provide a window into mechanisms underlying polygenic inheritance in CAE, as well as a mechanism for treatment effects and failures mediated by these channels. Although the model is a simplification of the human thalamocortical network, it serves as a useful starting point for predicting the implications of ion channel electrophysiology in polygenic epilepsy such as CAE.
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Affiliation(s)
- Andrew T Knox
- Department of Neurology, University of Wisconsin, Madison, WI, USA
| | - Tracy Glauser
- Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,The University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Jeffrey Tenney
- Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,The University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - William W Lytton
- Departments of Neurology and Physiology & Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY, USA.,Department Neurology, Kings County Hospital Center, Brooklyn, NY, USA
| | - Katherine Holland
- Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,The University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Kim S, Lee B, Choi JH, Kim JH, Kim CH, Shin HS. Deficiency of a brain-specific chemokine-like molecule, SAM3, induces cardinal phenotypes of autism spectrum disorders in mice. Sci Rep 2017; 7:16503. [PMID: 29184127 PMCID: PMC5705707 DOI: 10.1038/s41598-017-16769-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 11/12/2017] [Indexed: 12/29/2022] Open
Abstract
Chemokines are small secreted signaling proteins produced by a broad range of cells, including immune cells. Several studies have recently suggested potential roles of chemokines and their receptors in the pathophysiology of autism spectrum disorders (ASDs). SAM3 is a novel brain-specific chemokine-like molecule with an unknown physiological function. We explored the relevance of chemokines in the development of ASD in mice, with a focus on SAM3. We generated Sam3 gene knockout (KO) mice and characterized their behavioral phenotypes, with a focus on those relevant to ASD. Sam3-deficient mice displayed all three core phenotypes of ASD: impaired responses to social novelty, defects in social communication, and increased repetitive behavior. In addition, they showed increased anxiety. Interestingly, gender differences were identified for several behaviors: only male Sam3 KO mice exhibited increased anxiety and increased repetitive behaviors. Sam3 KO mice did not exhibit changes in other behaviors, including locomotor activities, fear learning and memory, and object recognition memory. These findings indicate that a deficiency of SAM3, a novel brain-specific chemokine-like molecule, may lead to the pathogenesis of ASDs and suggest the possibility that SAM3, a soluble factor, could be a novel therapeutic target for ASD treatment.
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Affiliation(s)
- Sujin Kim
- Center for Cognition and Sociality, Institute for Basic Science, Yuseong-gu, Daejeon, 34141, Republic of Korea
- Basic Science, IBS School, University of Science and Technology, Daejeon, 34113, Republic of Korea
| | - Boyoung Lee
- Center for Cognition and Sociality, Institute for Basic Science, Yuseong-gu, Daejeon, 34141, Republic of Korea
| | - Jung-Hwa Choi
- Department of Biology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Jong-Hyun Kim
- Center for Cognition and Sociality, Institute for Basic Science, Yuseong-gu, Daejeon, 34141, Republic of Korea
- Center for Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, 02797, Republic of Korea
- Laboratory of Cell Death and Human Diseases, Department of Life Sciences, School of Life Sciences, Korea University, Seoul, 02841, Republic of Korea
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, 34134, Republic of Korea.
| | - Hee-Sup Shin
- Center for Cognition and Sociality, Institute for Basic Science, Yuseong-gu, Daejeon, 34141, Republic of Korea.
- Basic Science, IBS School, University of Science and Technology, Daejeon, 34113, Republic of Korea.
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Lee N, Jeong S, Kim KC, Kim JA, Park JY, Kang HW, Perez-Reyes E, Lee JH. Ca 2+ Regulation of Ca v3.3 T-type Ca 2+ Channel Is Mediated by Calmodulin. Mol Pharmacol 2017; 92:347-357. [PMID: 28696213 PMCID: PMC11033943 DOI: 10.1124/mol.117.108530] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 07/03/2017] [Indexed: 01/19/2023] Open
Abstract
Calcium-dependent inactivation of high voltage-activated Ca2+ channels plays a crucial role in limiting rises in intracellular calcium (Ca2+i). A key mediator of these effects is calmodulin, which has been found to bind the C-terminus of the pore-forming α subunit. In contrast, little is known about how Ca2+i can regulate low voltage-activated T-type Ca2+ channels. Using whole cell patch clamp, we examined the biophysical properties of Ca2+ current through the three T-type Ca2+ channel isoforms, Cav3.1, Cav3.2, or Cav3.3, comparing internal solutions containing 27 nM and l μM free Ca2+ Both activation and inactivation kinetics of Cav3.3 current in l μM Ca2+i solution were more rapid than those in 27 nM Ca2+i solution. In addition, both activation and steady-state inactivation curves of Cav3.3 were negatively shifted in the higher Ca2+i solution. In contrast, the biophysical properties of Cav3.1 and Cav3.2 isoforms were not significantly different between the two internal solutions. Overexpression of CaM1234 (a calmodulin mutant that doesn't bind Ca2+) occluded the effects of l μM Ca2+i on Cav3.3, implying that CaM is involved in the Ca2+i regulation effects on Cav3.3. Yeast two-hybrid screening and co-immunoprecipitation experiments revealed a direct interaction of CaM with the carboxyl terminus of Cav3.3. Taken together, our results suggest that Cav3.3 T-type channel is potently regulated by Ca2+i via interaction of Ca2+/CaM with the carboxyl terminus of Cav3.3.
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Affiliation(s)
- Narae Lee
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Sua Jeong
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Kang-Chang Kim
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Jin-Ah Kim
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Jin-Yong Park
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Ho-Won Kang
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Edward Perez-Reyes
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
| | - Jung-Ha Lee
- Department of Life Science and Research Institute for Basic Science, Sogang University, Mapo-gu, Seoul, Republic of Korea (N.L., S.J., K.-C.K., J.-A.K., J.-Y.P., H.-W.K., J.-H.L.) and Department of Pharmacology, University of Virginia, Charlottesville, Virginia (E.P.-R.)
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Xu W, Liu Y, Chen J, Guo Q, Liu K, Wen Z, Zhou Z, Song Z, Zhou J, He L, Yi Q, Shi Y. Genetic risk between the CACNA1I gene and schizophrenia in Chinese Uygur population. Hereditas 2017; 155:5. [PMID: 28725167 PMCID: PMC5513035 DOI: 10.1186/s41065-017-0037-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/07/2017] [Indexed: 01/28/2023] Open
Abstract
Background Schizophrenia (SCZ) is a common mental disorder with high heritability, and genetic factors play a major role in the pathogenesis. Recent researches indicated that the CACNA1I involved in calcium channels probably affect the potential pathogenesis of SCZ. Results In this study, we attempted to investigate whether the CACNA1I gene contributes the risk to SCZ in the Uighur Chinese population, and performed a case-control study involving 985 patient samples and 1218 normal controls to analyze nine SNPs within the CACNA1I gene. Among these sites, six SNPs were significantly associated with SCZ in the allele distribution: rs132575 (adjusted Pallele = 0.039, OR = 1.159), rs713860 (adjusted Pallele = 0.039, OR = 0.792), rs738168 (adjusted Pallele = 0.039, OR = 0.785), rs136805 (adjusted Pallele = 0.014, OR = 1.212), rs5757760 (adjusted Pallele = 0.042, OR = 0.873) and rs5750871 (adjusted Pallele = 0.039, OR = 0.859). In addition, two SNPs turned to be risk factors for SCZ not only in the allele distribution, but also in the genotype distribution: rs132575 (adjusted Pgenotype = 0.037) and rs136805 (adjusted Pgenotype = 0.037). Conclusions Overall, the present study provided evidence that significant association exists between the CACNA1I gene and SCZ in the Uighur Chinese population, subsequent validation of functional analysis and genetic association studies are needed to further extend this study.
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Affiliation(s)
- Wei Xu
- Department of biology, School of Life Science, Anhui Medical University, 81 meishan road, Hefei, Anhui 230031 China.,Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Yahui Liu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Jianhua Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, 200030 People's Republic of China
| | - Qingli Guo
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Ke Liu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Zujia Wen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Zhaowei Zhou
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Zhijian Song
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Juan Zhou
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Lin He
- Department of biology, School of Life Science, Anhui Medical University, 81 meishan road, Hefei, Anhui 230031 China.,Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
| | - Qizhong Yi
- Psychological Medicine Center, The First Affiliated Hospital of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, Xinjiang, 830054 China
| | - Yongyong Shi
- Department of biology, School of Life Science, Anhui Medical University, 81 meishan road, Hefei, Anhui 230031 China.,Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education) and the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai, 200030 People's Republic of China
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Cain SM, Ahn S, Garcia E, Zhang Y, Waheed Z, Tyson JR, Yang Y, Van Sung T, Phillips AG, Snutch TP. Heantos-4, a natural plant extract used in the treatment of drug addiction, modulates T-type calcium channels and thalamocortical burst-firing. Mol Brain 2016; 9:94. [PMID: 27919294 PMCID: PMC5139062 DOI: 10.1186/s13041-016-0274-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/21/2016] [Indexed: 11/10/2022] Open
Abstract
Heantos-4 is a refined combination of plant extracts currently approved to treat opiate addiction in Vietnam. In addition to its beneficial effects on withdrawal and prevention of relapse, reports of sedation during clinical treatment suggest that arousal networks in the brain may be recruited during Heantos administration. T-type calcium channels are implicated in the generation of sleep rhythms and in this study we examined whether a Heantos-4 extraction modulates T-type calcium channel currents generated by the Cav3.1, Cav3.2 and Ca3.3 subtypes. Utilizing whole-cell voltage clamp on exogenously expressed T-type calcium channels we find that Heantos inhibits Cav3.1 and Cav3.3 currents, while selectively potentiating Cav3.2 currents. We further examined the effects of Heantos-4 extract on low-threshold burst-firing in thalamic neurons which contribute to sleep oscillations. Using whole-cell current clamp in acute thalamic brain slices Heantos-4 suppressed rebound burst-firing in ventrobasal thalamocortical neurons, which express primarily Cav3.1 channels. Conversely, Heantos-4 had no significant effect on the burst-firing properties of thalamic reticular neurons, which express a mixed population of Cav3.2 and Cav3.3 channels. Examining Heantos-4 effects following oral administration in a model of absence epilepsy revealed the potential to exacerbate seizure activity. Together, the findings indicate that Heantos-4 has selective effects both on specific T-type calcium channel isoforms and distinct populations of thalamic neurons providing a putative mechanism underlying its effects on sedation and on the thalamocortical network.
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Affiliation(s)
- Stuart M Cain
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Soyon Ahn
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Esperanza Garcia
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Yiming Zhang
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Zeina Waheed
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - John R Tyson
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Yi Yang
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Tran Van Sung
- Institute of Chemistry, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | - Anthony G Phillips
- Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 219-2185 East Mall, Vancouver, BC, V6T 1Z4, Canada. .,Department of Psychiatry, University of British Columbia, Vancouver, Canada.
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Andrade A, Hope J, Allen A, Yorgan V, Lipscombe D, Pan JQ. A rare schizophrenia risk variant of CACNA1I disrupts Ca V3.3 channel activity. Sci Rep 2016; 6:34233. [PMID: 27756899 PMCID: PMC5069464 DOI: 10.1038/srep34233] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 09/07/2016] [Indexed: 02/04/2023] Open
Abstract
CACNA1I is a candidate schizophrenia risk gene. It encodes the pore-forming human CaV3.3 α1 subunit, a subtype of voltage-gated calcium channel that contributes to T-type currents. Recently, two de novo missense variations, T797M and R1346H, of hCaV3.3 were identified in individuals with schizophrenia. Here we show that R1346H, but not T797M, is associated with lower hCaV3.3 protein levels, reduced glycosylation, and lower membrane surface levels of hCaV3.3 when expressed in human cell lines compared to wild-type. Consistent with our biochemical analyses, whole-cell hCaV3.3 currents in cells expressing the R1346H variant were ~50% of those in cells expressing WT hCaV3.3, and neither R1346H nor T797M altered channel biophysical properties. Employing the NEURON simulation environment, we found that reducing hCaV3.3 current densities by 22% or more eliminates rebound bursting in model thalamic reticular nucleus (TRN) neurons. Our analyses suggest that a single copy of Chr22: 39665939G > A CACNA1I has the capacity to disrupt CaV3.3 channel-dependent functions, including rebound bursting in TRN neurons, with potential implications for schizophrenia pathophysiology.
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Affiliation(s)
- A Andrade
- Department of Biological Sciences, College of Life Sciences and Agriculture, University of New Hampshire, Durham, NH 03824, USA.,Brown Institute for Brain Science, Providence, RI 02912, USA
| | - J Hope
- Stanley Center of Psychiatric Research, Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA
| | - A Allen
- Stanley Center of Psychiatric Research, Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA
| | - V Yorgan
- Brown Institute for Brain Science, Providence, RI 02912, USA
| | - D Lipscombe
- Brown Institute for Brain Science, Providence, RI 02912, USA
| | - J Q Pan
- Stanley Center of Psychiatric Research, Broad Institute of Harvard and MIT, 75 Ames Street, Cambridge, MA 02142, USA
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Jung JY, Lee SE, Hwang EM, Lee CJ. Neuronal Expression and Cell-Type-Specific Gene-Silencing of Best1 in Thalamic Reticular Nucleus Neurons Using pSico-Red System. Exp Neurobiol 2016; 25:120-9. [PMID: 27358580 PMCID: PMC4923356 DOI: 10.5607/en.2016.25.3.120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 05/30/2016] [Accepted: 05/31/2016] [Indexed: 12/22/2022] Open
Abstract
Assessing the cell-type expression pattern of a certain gene can be achieved by using cell-type-specific gene manipulation. Recently, cre-recombinase-dependent gene-silencing tool, pSico has become popular in neuroscientific research. However, pSico has a critical limitation that gene-silenced cell cannot be identified by fluorescence, due to an excision of the reporter gene for green fluorescence protein (GFP). To overcome this limitation, we newly developed pSico-Red, with mCherry gene as a reporter outside two loxP sites, so that red mCherry signal is detected in all transfected cells. When a cell expresses cre, GFP is excised and shRNA is enabled, resulting in disappearance of GFP. This feature of pSico-Red provides not only cell-type-specific gene-silencing but also identification of cre expressing cells. Using this system, we demonstrated for the first time the neuronal expression of the Bestrophin-1 (Best1) in thalamic reticular nucleus (TRN) and TRN-neuron-specific gene-silencing of Best1. We combined adeno-associated virus (AAV) carrying Best1-shRNA in pSico-Red vector and transgenic mouse expressing cre under the promoter of distal-less homeobox 5/6 (DLX5/6), a marker for inhibitory neurons. Firstly, we found that almost all of inhibitory neurons in TRN express Best1 by immunohistochemistry. Using pSico-Red virus, we found that 80% of infected TRN neurons were DLX5/6-cre positive but parvalbumin negative. Finally, we found that Best1 in DLX5/6-cre positive neurons were significantly reduced by Best1-shRNA. Our study demonstrates that TRN neurons strongly express Best1 and that pSico-Red is a valuable tool for cell-type-specific gene manipulation and identification of specific cell population.
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Affiliation(s)
- Jae-Young Jung
- Center for Neuroscience and Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.; Neuroscience Program, University of Science and Technology (UST), Daejeon 34113, Korea
| | - Seung Eun Lee
- Research Animal Resource Center, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea
| | - Eun Mi Hwang
- Center for Neuroscience and Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.; Neuroscience Program, University of Science and Technology (UST), Daejeon 34113, Korea
| | - C Justin Lee
- Center for Neuroscience and Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea.; Neuroscience Program, University of Science and Technology (UST), Daejeon 34113, Korea.; KU-KIST School of Converging Science and Technology, Korea University, Seoul 02841, Korea
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Cell-Type-Selective Effects of Intramembrane Cavitation as a Unifying Theoretical Framework for Ultrasonic Neuromodulation. eNeuro 2016; 3:eN-NWR-0136-15. [PMID: 27390775 PMCID: PMC4917736 DOI: 10.1523/eneuro.0136-15.2016] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/30/2016] [Accepted: 05/10/2016] [Indexed: 11/21/2022] Open
Abstract
Diverse translational and research applications could benefit from the noninvasive ability to reversibly modulate (excite or suppress) CNS activity using ultrasound pulses, however, without clarifying the underlying mechanism, advanced design-based ultrasonic neuromodulation remains elusive. Recently, intramembrane cavitation within the bilayer membrane was proposed to underlie both the biomechanics and the biophysics of acoustic bio-effects, potentially explaining cortical stimulation results through a neuronal intramembrane cavitation excitation (NICE) model. Here, NICE theory is shown to provide a detailed predictive explanation for the ability of ultrasonic (US) pulses to also suppress neural circuits through cell-type-selective mechanisms: according to the predicted mechanism T-type calcium channels boost charge accumulation between short US pulses selectively in low threshold spiking interneurons, promoting net cortical network inhibition. The theoretical results fit and clarify a wide array of earlier empirical observations in both the cortex and thalamus regarding the dependence of ultrasonic neuromodulation outcomes (excitation-suppression) on stimulation and network parameters. These results further support a unifying hypothesis for ultrasonic neuromodulation, highlighting the potential of advanced waveform design for obtaining cell-type-selective network control.
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Pellegrini C, Lecci S, Lüthi A, Astori S. Suppression of Sleep Spindle Rhythmogenesis in Mice with Deletion of CaV3.2 and CaV3.3 T-type Ca(2+) Channels. Sleep 2016; 39:875-85. [PMID: 26612388 DOI: 10.5665/sleep.5646] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 10/28/2015] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Low-threshold voltage-gated T-type Ca(2+) channels (T-channels or CaV3 channels) sustain oscillatory discharges of thalamocortical (TC) and nucleus Reticularis thalami (nRt) cells. The CaV3.3 subtype dominates nRt rhythmic bursting and mediates a substantial fraction of spindle power in the NREM sleep EEG. CaV3.2 channels are also found in nRt, but whether these contribute to nRt-dependent spindle generation is unexplored. We investigated thalamic rhythmogenesis in mice lacking this subtype in isolation (CaV3.2KO mice) or in concomitance with CaV3.3 deletion (CaV3.double-knockout (DKO) mice). METHODS We examined discharge characteristics of thalamic cells and intrathalamic evoked synaptic transmission in brain slices from wild-type, CaV3.2KO and CaV3.DKO mice through patch-clamp recordings. The sleep profile of freely behaving CaV3.2KO and CaV3.DKO mice was assessed by polysomnographic recordings. RESULTS CaV3.2 channel deficiency left nRt discharge properties largely unaltered, but additional deletion of CaV3.3 channels fully abolished low-threshold whole-cell Ca(2+) currents and bursting, and suppressed burst-mediated inhibitory responses in TC cells. CaV3.DKO mice had more fragmented sleep, with shorter NREM sleep episodes and more frequent microarousals. The NREM sleep EEG power spectrum displayed a relative suppression of the σ frequency band (10-15 Hz), which was accompanied by an increase in the δ band (1-4 Hz). CONCLUSIONS Consistent with previous findings, CaV3.3 channels dominate nRt rhythmogenesis, but the lack of CaV3.2 channels further aggravates neuronal, synaptic, and EEG deficits. Therefore, CaV3.2 channels can boost intrathalamic synaptic transmission, and might play a modulatory role adjusting the relative presence of NREM sleep EEG rhythms.
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Affiliation(s)
- Chiara Pellegrini
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Sandro Lecci
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Anita Lüthi
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Simone Astori
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
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Elies J, Scragg JL, Boyle JP, Gamper N, Peers C. Regulation of the T-type Ca(2+) channel Cav3.2 by hydrogen sulfide: emerging controversies concerning the role of H2 S in nociception. J Physiol 2016; 594:4119-29. [PMID: 26804000 DOI: 10.1113/jp270963] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/26/2015] [Indexed: 12/22/2022] Open
Abstract
Ion channels represent a large and growing family of target proteins regulated by gasotransmitters such as nitric oxide, carbon monoxide and, as described more recently, hydrogen sulfide. Indeed, many of the biological actions of these gases can be accounted for by their ability to modulate ion channel activity. Here, we report recent evidence that H2 S is a modulator of low voltage-activated T-type Ca(2+) channels, and discriminates between the different subtypes of T-type Ca(2+) channel in that it selectively modulates Cav3.2, whilst Cav3.1 and Cav3.3 are unaffected. At high concentrations, H2 S augments Cav3.2 currents, an observation which has led to the suggestion that H2 S exerts its pro-nociceptive effects via this channel, since Cav3.2 plays a central role in sensory nerve excitability. However, at more physiological concentrations, H2 S is seen to inhibit Cav3.2. This inhibitory action requires the presence of the redox-sensitive, extracellular region of the channel which is responsible for tonic metal ion binding and which particularly distinguishes this channel isoform from Cav3.1 and 3.3. Further studies indicate that H2 S may act in a novel manner to alter channel activity by potentiating the zinc sensitivity/affinity of this binding site. This review discusses the different reports of H2 S modulation of T-type Ca(2+) channels, and how such varying effects may impact on nociception given the role of this channel in sensory activity. This subject remains controversial, and future studies are required before the impact of T-type Ca(2+) channel modulation by H2 S might be exploited as a novel approach to pain management.
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Affiliation(s)
- Jacobo Elies
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Jason L Scragg
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - John P Boyle
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Nikita Gamper
- Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, UK.,Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Chris Peers
- Faculty of Medicine and Health, University of Leeds, Leeds, UK
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Park AH, Lee SH, Lee C, Kim J, Lee HE, Paik SB, Lee KJ, Kim D. Optogenetic Mapping of Functional Connectivity in Freely Moving Mice via Insertable Wrapping Electrode Array Beneath the Skull. ACS NANO 2016; 10:2791-802. [PMID: 26735496 DOI: 10.1021/acsnano.5b07889] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Spatiotemporal mapping of neural interactions through electrocorticography (ECoG) is the key to understanding brain functions and disorders. For the entire brain cortical areas, this approach has been challenging, especially in freely moving states, owing to the need for extensive craniotomy. Here, we introduce a flexible microelectrode array system, termed iWEBS, which can be inserted through a small cranial slit and stably wrap onto the curved cortical surface. Using iWEBS, we measured dynamic changes of signals across major cortical domains, namely, somatosensory, motor, visual and retrosplenial areas, in freely moving mice. iWEBS robustly displayed somatosensory evoked potentials (SEPs) in corresponding cortical areas to specific somatosensory stimuli. We also used iWEBS for mapping functional interactions between cortical areas in the propagation of spike-and-wave discharges (SWDs), the neurological marker of absence seizures, triggered by optogenetic inhibition of a specific thalamic nucleus. This demonstrates that iWEBS represents a significant improvement over conventional ECoG recording methodologies and, therefore, is a competitive recording system for mapping wide-range brain connectivity under various behavioral conditions.
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Affiliation(s)
- Ah Hyung Park
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Seung Hyun Lee
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Changju Lee
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jeongjin Kim
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Han Eol Lee
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Se-Bum Paik
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Keon Jae Lee
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Daesoo Kim
- Department of Biological Sciences, ‡Department of Materials Science and Engineering, and §Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST) , 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
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42
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Zamponi GW. Targeting voltage-gated calcium channels in neurological and psychiatric diseases. Nat Rev Drug Discov 2015; 15:19-34. [DOI: 10.1038/nrd.2015.5] [Citation(s) in RCA: 254] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Wang G, Bochorishvili G, Chen Y, Salvati KA, Zhang P, Dubel SJ, Perez-Reyes E, Snutch TP, Stornetta RL, Deisseroth K, Erisir A, Todorovic SM, Luo JH, Kapur J, Beenhakker MP, Zhu JJ. CaV3.2 calcium channels control NMDA receptor-mediated transmission: a new mechanism for absence epilepsy. Genes Dev 2015. [PMID: 26220996 PMCID: PMC4526737 DOI: 10.1101/gad.260869.115] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
CaV3.2 T-type calcium channels, encoded by CACNA1H, are expressed throughout the brain, yet their general function remains unclear. We discovered that CaV3.2 channels control NMDA-sensitive glutamatergic receptor (NMDA-R)-mediated transmission and subsequent NMDA-R-dependent plasticity of AMPA-R-mediated transmission at rat central synapses. Interestingly, functional CaV3.2 channels primarily incorporate into synapses, replace existing CaV3.2 channels, and can induce local calcium influx to control NMDA transmission strength in an activity-dependent manner. Moreover, human childhood absence epilepsy (CAE)-linked hCaV3.2(C456S) mutant channels have a higher channel open probability, induce more calcium influx, and enhance glutamatergic transmission. Remarkably, cortical expression of hCaV3.2(C456S) channels in rats induces 2- to 4-Hz spike and wave discharges and absence-like epilepsy characteristic of CAE patients, which can be suppressed by AMPA-R and NMDA-R antagonists but not T-type calcium channel antagonists. These results reveal an unexpected role of CaV3.2 channels in regulating NMDA-R-mediated transmission and a novel epileptogenic mechanism for human CAE.
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Affiliation(s)
- Guangfu Wang
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Genrieta Bochorishvili
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Yucai Chen
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Kathryn A Salvati
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Peng Zhang
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Steve J Dubel
- Laboratoire de Génomique Fonctionnelle, Département de Physiologie, Unité Propre de Recherche 2580, Centre National de la Recherche Scientifique, 34396 Montpellier, France
| | - Edward Perez-Reyes
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Terrance P Snutch
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Ruth L Stornetta
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Karl Deisseroth
- Department of Bioengineering, Stanford University, Stanford, California 94305, USA; Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - Alev Erisir
- Department of Psychology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Slobodan M Todorovic
- Department of Anesthesiology, University of Virginia, Charlottesville, Virginia 22908, USA; Department of Neuroscience, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Jian-Hong Luo
- Department of Neurobiology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jaideep Kapur
- Department of Neurology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Mark P Beenhakker
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA
| | - J Julius Zhu
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia 22908, USA; Department of Neuroscience, University of Virginia, Charlottesville, Virginia 22908, USA
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Zamponi GW, Striessnig J, Koschak A, Dolphin AC. The Physiology, Pathology, and Pharmacology of Voltage-Gated Calcium Channels and Their Future Therapeutic Potential. Pharmacol Rev 2015; 67:821-70. [PMID: 26362469 PMCID: PMC4630564 DOI: 10.1124/pr.114.009654] [Citation(s) in RCA: 790] [Impact Index Per Article: 79.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated calcium channels are required for many key functions in the body. In this review, the different subtypes of voltage-gated calcium channels are described and their physiologic roles and pharmacology are outlined. We describe the current uses of drugs interacting with the different calcium channel subtypes and subunits, as well as specific areas in which there is strong potential for future drug development. Current therapeutic agents include drugs targeting L-type Ca(V)1.2 calcium channels, particularly 1,4-dihydropyridines, which are widely used in the treatment of hypertension. T-type (Ca(V)3) channels are a target of ethosuximide, widely used in absence epilepsy. The auxiliary subunit α2δ-1 is the therapeutic target of the gabapentinoid drugs, which are of value in certain epilepsies and chronic neuropathic pain. The limited use of intrathecal ziconotide, a peptide blocker of N-type (Ca(V)2.2) calcium channels, as a treatment of intractable pain, gives an indication that these channels represent excellent drug targets for various pain conditions. We describe how selectivity for different subtypes of calcium channels (e.g., Ca(V)1.2 and Ca(V)1.3 L-type channels) may be achieved in the future by exploiting differences between channel isoforms in terms of sequence and biophysical properties, variation in splicing in different target tissues, and differences in the properties of the target tissues themselves in terms of membrane potential or firing frequency. Thus, use-dependent blockers of the different isoforms could selectively block calcium channels in particular pathologies, such as nociceptive neurons in pain states or in epileptic brain circuits. Of important future potential are selective Ca(V)1.3 blockers for neuropsychiatric diseases, neuroprotection in Parkinson's disease, and resistant hypertension. In addition, selective or nonselective T-type channel blockers are considered potential therapeutic targets in epilepsy, pain, obesity, sleep, and anxiety. Use-dependent N-type calcium channel blockers are likely to be of therapeutic use in chronic pain conditions. Thus, more selective calcium channel blockers hold promise for therapeutic intervention.
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Affiliation(s)
- Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Joerg Striessnig
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Alexandra Koschak
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Annette C Dolphin
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
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Unbalanced Peptidergic Inhibition in Superficial Neocortex Underlies Spike and Wave Seizure Activity. J Neurosci 2015; 35:9302-14. [PMID: 26109655 DOI: 10.1523/jneurosci.4245-14.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Slow spike and wave discharges (0.5-4 Hz) are a feature of many epilepsies. They are linked to pathology of the thalamocortical axis and a thalamic mechanism has been elegantly described. Here we present evidence for a separate generator in local circuits of associational areas of neocortex manifest from a background, sleep-associated delta rhythm in rat. Loss of tonic neuromodulatory excitation, mediated by nicotinic acetylcholine or serotonin (5HT3A) receptors, of 5HT3-immunopositive interneurons caused an increase in amplitude and slowing of the delta rhythm until each period became the "wave" component of the spike and wave discharge. As with the normal delta rhythm, the wave of a spike and wave discharge originated in cortical layer 5. In contrast, the "spike" component of the spike and wave discharge originated from a relative failure of fast inhibition in layers 2/3-switching pyramidal cell action potential outputs from single, sparse spiking during delta rhythms to brief, intense burst spiking, phase-locked to the field spike. The mechanisms underlying this loss of superficial layer fast inhibition, and a concomitant increase in slow inhibition, appeared to be precipitated by a loss of neuropeptide Y (NPY)-mediated local circuit inhibition and a subsequent increase in vasoactive intestinal peptide (VIP)-mediated disinhibition. Blockade of NPY Y1 receptors was sufficient to generate spike and wave discharges, whereas blockade of VIP receptors almost completely abolished this form of epileptiform activity. These data suggest that aberrant, activity-dependent neuropeptide corelease can have catastrophic effects on neocortical dynamics.
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