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Andreatta T, Armini RS, Salaroli R, Vieira GM, Tavares CVC, Sanches H, Aguiar RM, Campos FV, Schenberg LC. Role of L- and T-type voltage-dependent calcium channels in the hierarchical organization of defensive responses to electrical stimulation of the rat dorsolateral periaqueductal gray. Neuropharmacology 2024; 258:110059. [PMID: 38992791 DOI: 10.1016/j.neuropharm.2024.110059] [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: 01/05/2024] [Revised: 06/23/2024] [Accepted: 06/30/2024] [Indexed: 07/13/2024]
Abstract
Stimulation of the dorsal half of the rat periaqueductal gray (DPAG) with 60-Hz pulses of increasing intensity, 30-μA pulses of increasing frequency, or increasing doses of an excitatory amino acid elicits sequential defensive responses of exophthalmia, immobility, trotting, galloping, and jumping. These responses may be controlled by voltage-gated calcium channel-specific firing patterns. Indeed, a previous study showed that microinjection of the DPAG with 15 nmol of verapamil, a putative blocker of L-type calcium channels, attenuated all defensive responses to electrical stimulation at the same site as the injection. Accordingly, here we investigated the effects of microinjection of lower doses (0.7 and 7 nmol) of both verapamil and mibefradil, a preferential blocker of T-type calcium channels, on DPAG-evoked defensive behaviors of the male rat. Behaviors were recorded either 24 h before or 10 min, 24 h, and 48 h after microinjection. Effects were analyzed by both threshold logistic analysis and repeated measures analysis of variance for treatment by session interactions. Data showed that the electrodes were all located within the dorsolateral PAG. Compared to the effects of saline, verapamil significantly attenuated exophthalmia, immobility, and trotting. Mibefradil significantly attenuated exophthalmia and marginally attenuated immobility while facilitating trotting. While galloping was not attenuated by either antagonist, jumping was unexpectedly attenuated by 0.7 nmol verapamil only. These results suggest that T-type calcium channels are involved in the low-threshold freezing responses of exophthalmia and immobility, whereas L-type calcium channels are involved in the trotting response that precedes the full-fledged escape responses of galloping and jumping.
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Affiliation(s)
- Tatiani Andreatta
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil.
| | - Rubia Souza Armini
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil.
| | - Ruam Salaroli
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil.
| | - Guilherme Machado Vieira
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil.
| | | | - Hugo Sanches
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil.
| | - Rafael Moraes Aguiar
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil; Department of Biochemistry and Immunology, Health Science Center, Federal University of Minas Gerais, Brazil.
| | - Fabiana Vasconcelos Campos
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil; Department of Morphology, Health Science Center, Federal University of Espírito Santo, Brazil.
| | - Luiz Carlos Schenberg
- Department of Physiological Sciences, Health Science Center, Federal University of Espírito Santo, Brazil.
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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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Ojha P, Panda S. Resting-state Quantitative EEG Spectral Patterns in Migraine During Ictal Phase Reveal Deviant Brain Oscillations: Potential Role of Density Spectral Array. Clin EEG Neurosci 2024; 55:362-370. [PMID: 36474355 DOI: 10.1177/15500594221142951] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background. Migraine headache may have a substantial bearing on the brain functions and rhythms. Electrophysiological methods can detect changes in brain oscillation. The present work examined the frequency band power through quantitative electroencephalogram (qEEG) and density spectral array (DSA) to elucidate the resting state neuronal oscillations in migraine. Methods. Clinical details were inquired, and EEG was recorded in migraineurs and healthy controls. The acquired data were analyzed to determine power spectral density values and obtain DSA graphs. The absolute and relative powers for the alpha, theta, and delta frequencies in frontocentral, parieto-occipital, and temporal regions were determined. A correlation of significant EEG findings with clinical features of migraine was sought. Results. Forty-five participants were enrolled in the study. The spectrum analysis revealed an increase in the relative theta power (P < .001) and a reduction in relative alpha power (P < .001) in the observed cortical areas among the migraineurs as compared to the healthy controls. Relative delta power was increased over the frontocentral region (P = .001), slightly more on the symptomatic side of the head. In addition, frontocentral delta power had a moderate positive correlation (r = .697, n = 22, P = .000) with migraine severity. Conclusion. The study supports the evidence of a neuronal dysfunction existing in the resting state during the ictal phase of migraine. qEEG can reveal these aberrant oscillations. Utility of DSA to depict the changes in brain activity in migraine is a potential area for research. The information can help formulate new therapeutic strategies towards alteration in cortical excitability using brain stimulation techniques.
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Affiliation(s)
- Pooja Ojha
- Department of Physiology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
| | - Samhita Panda
- Department of Neurology, All India Institute of Medical Sciences, Jodhpur, Rajasthan, India
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Ulgen Temel E, Ozbudak P, Serdaroglu A, Arhan E. Sleep Spindle Alterations in Children With Migraine. Pediatr Neurol 2024; 152:184-188. [PMID: 38301321 DOI: 10.1016/j.pediatrneurol.2023.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 12/16/2023] [Indexed: 02/03/2024]
Abstract
BACKGROUND The modulation of thalamocortical activity is the most important site of several levels of interference between sleep spindles and migraine. Thalamocortical circuits are responsible for the electrophysiological phenomenon of sleep spindles. Spindle alterations may be used as a beneficial marker in the diagnosis and follow-up of children with migraine. We aimed to formulate the hypothesis that there is a shared mechanism that underlies migraine and sleep spindle activity. METHODS We analyzed the amplitude, frequency, duration, density, and activity of sleep spindles in non-rapid eye movement stage 2 sleep in patients with migraine without aura when compared with healthy control subjects. RESULTS The amplitudes of average, slow, and fast sleep spindles were higher in children with migraine without aura (P = 0.020, 0.013, and 0.033, respectively). The frequency of fast spindles was lower in children with migraines without aura when compared with the control group (P = 0.03). Although not statistically significant, the fast sleep spindle duration in the migraine group was shorter (P = 0.055). Multivariate analysis revealed an increased risk of migraine associated with increased mean spindle amplitude and decreased fast spindle frequency and duration. CONCLUSIONS Our data suggest that spindle alterations may correlate with the vulnerability to develop migraine and may be used as a model for future research about the association between the thalamocortical networks and migraine.
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Affiliation(s)
- Esra Ulgen Temel
- Division of Child Neurology, Cengiz Gökçek Maternity and Children's Hospital, Gaziantep, Turkey
| | - Pinar Ozbudak
- Division of Child Neurology, Etlik City Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Ayse Serdaroglu
- Department of Child Neurology, Gazi University Faculty of Medicine, Ankara, Turkey
| | - Ebru Arhan
- Department of Child Neurology, Gazi University Faculty of Medicine, Ankara, Turkey.
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Sheroziya M, Khazipov R. Synaptic Origin of Early Sensory-evoked Oscillations in the Immature Thalamus. Neuroscience 2023; 532:50-64. [PMID: 37769898 DOI: 10.1016/j.neuroscience.2023.09.005] [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: 06/10/2023] [Revised: 08/22/2023] [Accepted: 09/08/2023] [Indexed: 10/03/2023]
Abstract
During the critical period of postnatal development, brain maturation is extremely sensitive to external stimuli. Newborn rodents already have functional somatosensory pathways and the thalamus, but the cortex is still forming. Immature thalamic synapses may produce large postsynaptic potentials in immature neurons, while non-synaptic membrane currents remain relatively weak and slow. The thalamocortical system generates spontaneous and evoked early gamma and spindle-burst oscillations in newborn rodents. How relatively strong synapses and weak intrinsic currents interact with each other and how they contribute to early thalamic activities remains largely unknown. Here, we performed local field potential (LFP), juxtacellular, and patch-clamp recordings in the somatosensory thalamus of urethane-anesthetized rat pups at postnatal days 6-7 with one whisker stimulation. We removed the overlying cortex and hippocampus to reach the thalamus with electrodes. Deflection of only one (the principal) whisker induced spikes in a particular thalamic cell. Whisker deflection evoked a group of large-amplitude excitatory events, likely originating from lemniscal synapses and multiple inhibitory postsynaptic events in thalamocortical cells. Large-amplitude excitatory events produced a group of spike bursts and could evoke a depolarization block. Juxtacellular recordings confirmed the partial inactivation of spikes. Inhibitory events prevented inactivation of action potentials and gamma-modulated neuronal firing. We conclude that the interplay of strong excitatory and inhibitory synapses and relatively weak intrinsic currents produces sensory-evoked early gamma oscillations in thalamocortical cells. We also propose that sensory-evoked large-amplitude excitatory events contribute to evoked spindle-bursts.
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Affiliation(s)
- Maxim Sheroziya
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia.
| | - Roustem Khazipov
- Laboratory of Neurobiology, Kazan Federal University, Kazan, Russia; Aix Marseille University, INSERM, INMED, Marseille, France
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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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Joksimovic SL, Jevtovic-Todorovic V, Todorovic SM. The role of voltage-gated calcium channels in the mechanisms of anesthesia and perioperative analgesia. Curr Opin Anaesthesiol 2022; 35:436-441. [PMID: 35787588 PMCID: PMC9616208 DOI: 10.1097/aco.0000000000001159] [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: 11/26/2022]
Abstract
PURPOSE OF REVIEW A family of neuronal voltage-gated calcium channels (VGCCs) have received only recently a significant consideration regarding the mechanisms of anesthesia because VGCC inhibition may be important in anesthetic action by decreasing neuronal excitability and presynaptic excitatory transmission. The T-type VGCCs channels (T-channels), although rarely involved in synaptic neurotransmitter release, play an important role in controlling neuronal excitability and in generating spontaneous oscillatory bursting of groups of neurons in the thalamus thought to be involved in regulating the state of arousal and sleep. Furthermore, these channels are important regulators of neuronal excitability in pain pathway. This review will provide an overview of historic perspective and the recent literature on the role of VGCCs and T-channel inhibition in particular in the mechanisms of action of anesthetics and analgesics. RECENT FINDINGS Recent research in the field of novel mechanisms of hypnotic action of anesthetics revealed significant contribution of the Ca V 3.1 isoform of T-channels expressed in the thalamus. Furthermore, perioperative analgesia can be achieved by targeting Ca V 3.2 isoform of these channels that is abundantly expressed in pain pathways. SUMMARY The review summarizes current knowledge regarding the contribution of T-channels in hypnosis and analgesia. Further preclinical and clinical studies are needed to validate their potential for developing novel anesthetics and new perioperative pain therapies.
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Affiliation(s)
- Sonja L. Joksimovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
| | - Slobodan M. Todorovic
- Department of Anesthesiology, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
- Neuroscience Graduate Program, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA
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Brécier A, Borel M, Urbain N, Gentet LJ. Vigilance and Behavioral State-Dependent Modulation of Cortical Neuronal Activity throughout the Sleep/Wake Cycle. J Neurosci 2022; 42:4852-4866. [PMID: 35552234 PMCID: PMC9188387 DOI: 10.1523/jneurosci.1400-21.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 04/27/2022] [Accepted: 04/29/2022] [Indexed: 01/27/2023] Open
Abstract
GABAergic inhibitory neurons, through their molecular, anatomic, and physiological diversity, provide a substrate for the modulation of ongoing cortical circuit activity throughout the sleep/wake cycle. Here, we investigated neuronal activity dynamics of parvalbumin (PV), vasoactive intestinal polypeptide (VIP), and somatostatin (SST) neurons in naturally sleeping head-restrained mice at the level of layer 2/3 of the primary somatosensory barrel cortex of mice. Through calcium imaging and targeted single-unit loose-patch or whole-cell recordings, we found that PV action potential firing activity was largest during both rapid eye movement (REM) and nonrapid eye movement (NREM) sleep stages, that VIP neurons were most active during REM sleep, and that the overall activity of SST neurons remained stable throughout the sleep/wake cycle. Analysis of neuronal activity dynamics uncovered rapid decreases in PV cell firing at wake onset followed by a progressive recovery during wake. Simultaneous local field potential (LFP) recordings further revealed that except for SST neurons, a large proportion of neurons were modulated by ongoing delta and theta oscillations. During NREM sleep spindles, PV and SST activity increased and decreased, respectively. Finally, we uncovered the presence of whisking behavior in mice during REM sleep and show that the activity of VIP and SST is differentially modulated during awake and sleeping whisking bouts, which may provide a neuronal substrate for internal brain representations occurring during sleep.SIGNIFICANCE STATEMENT In the sensory cortex, the balance between excitation and inhibition is believed to be highly dynamic throughout the sleep/wake cycle, shaping the response of cortical circuits to external stimuli while allowing the formation of newly encoded memory. Using in vivo two-photon calcium imaging or targeted single-unit recordings combined with LFP recordings, we describe the vigilance state and whisking-behavior-dependent activity of excitatory pyramidal and inhibitory GABAergic neurons in the supragranular layers of mouse somatosensory cortex. Interneuronal activity was found to be differentially modulated by ongoing delta and theta waves, sleep spindles, and a novel type of whisking observed during REM sleep, potentially providing a neuronal substrate for internal brain representations occurring during sleep.
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Affiliation(s)
| | | | - Nadia Urbain
- Physiopathology of Sleep Networks, Lyon Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale U1028-Centre National de la Recherche Scientifique Mixed Research Unit 5292, Université Claude-Bernard Lyon 1, 69372 Lyon, France
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Scott L, Puryear CB, Belfort GM, Raines S, Hughes ZA, Matthews LG, Ravina B, Wittmann M. Translational Pharmacology of PRAX-944, a Novel T-Type Calcium Channel Blocker in Development for the Treatment of Essential Tremor. Mov Disord 2022; 37:1193-1201. [PMID: 35257414 PMCID: PMC9310641 DOI: 10.1002/mds.28969] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 12/16/2021] [Accepted: 01/13/2022] [Indexed: 12/15/2022] Open
Abstract
Background Essential tremor is the most common movement disorder with clear unmet need. Mounting evidence indicates tremor is caused by increased neuronal burst firing and oscillations in cerebello‐thalamo‐cortical circuitry and may be dependent on T‐type calcium channel activity. T‐type calcium channels regulate sigma band electroencephalogram (EEG) power during non‐rapid eye movement sleep, representing a potential biomarker of channel activity. PRAX‐944 is a novel T‐type calcium channel blocker in development for essential tremor. Objectives Using a rat tremor model and sigma‐band EEG power, we assessed pharmacodynamically‐active doses of PRAX‐944 and their translation into clinically tolerated doses in healthy participants, informing dose selection for future efficacy trials. Methods Harmaline‐induced tremor and spontaneous locomotor activity were used to assess PRAX‐944 efficacy and tolerability, respectively, in rats. Sigma‐power was used as a translational biomarker of T‐type calcium channel blockade in rats and, subsequently, in a phase 1 trial assessing pharmacologic activity and tolerability in healthy participants. Results In rats, PRAX‐944 dose‐dependently reduced tremor by 50% and 72% at 1 and 3 mg/kg doses, respectively, without locomotor side effects. These doses also reduced sigma‐power by ~30% to 50% in rats. In healthy participants, sigma‐power was similarly reduced by 34% to 50% at 10 to 100 mg, with no further reduction at 120 mg. All doses were well tolerated. Conclusions In rats, PRAX‐944 reduced sigma‐power at concentrations that reduced tremor without locomotor side effects. In healthy participants, comparable reductions in sigma‐power indicate that robust T‐type calcium channel blockade was achieved at well‐tolerated doses that may hold promise for reducing tremor in patients with essential tremor. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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Affiliation(s)
- Liam Scott
- Praxis Precision Medicines, Boston, Massachusetts, USA
| | | | | | - Shane Raines
- Praxis Precision Medicines, Boston, Massachusetts, USA
| | - Zoë A Hughes
- Praxis Precision Medicines, Boston, Massachusetts, USA
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Thalamic T-Type Calcium Channels as Targets for Hypnotics and General Anesthetics. Int J Mol Sci 2022; 23:ijms23042349. [PMID: 35216466 PMCID: PMC8876360 DOI: 10.3390/ijms23042349] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 12/19/2022] Open
Abstract
General anesthetics mainly act by modulating synaptic inhibition on the one hand (the potentiation of GABA transmission) or synaptic excitation on the other (the inhibition of NMDA receptors), but they can also have effects on numerous other proteins, receptors, and channels. The effects of general anesthetics on ion channels have been the subject of research since the publication of reports of direct actions of these drugs on ion channel proteins. In particular, there is considerable interest in T-type voltage-gated calcium channels that are abundantly expressed in the thalamus, where they control patterns of cellular excitability and thalamocortical oscillations during awake and sleep states. Here, we summarized and discussed our recent studies focused on the CaV3.1 isoform of T-channels in the nonspecific thalamus (intralaminar and midline nuclei), which acts as a key hub through which natural sleep and general anesthesia are initiated. We used mouse genetics and in vivo and ex vivo electrophysiology to study the role of thalamic T-channels in hypnosis induced by a standard general anesthetic, isoflurane, as well as novel neuroactive steroids. From the results of this study, we conclude that CaV3.1 channels contribute to thalamocortical oscillations during anesthetic-induced hypnosis, particularly the slow-frequency range of δ oscillations (0.5–4 Hz), by generating “window current” that contributes to the resting membrane potential. We posit that the role of the thalamic CaV3.1 isoform of T-channels in the effects of various classes of general anesthetics warrants consideration.
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Czekus C, Steullet P, Orero López A, Bozic I, Rusterholz T, Bandarabadi M, Do KQ, Gutierrez Herrera C. Alterations in TRN-anterodorsal thalamocortical circuits affect sleep architecture and homeostatic processes in oxidative stress vulnerable Gclm -/- mice. Mol Psychiatry 2022; 27:4394-4406. [PMID: 35902628 PMCID: PMC9734061 DOI: 10.1038/s41380-022-01700-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 06/22/2022] [Accepted: 07/01/2022] [Indexed: 12/14/2022]
Abstract
Schizophrenia is associated with alterations of sensory integration, cognitive processing and both sleep architecture and sleep oscillations in mouse models and human subjects, possibly through changes in thalamocortical dynamics. Oxidative stress (OxS) damage, including inflammation and the impairment of fast-spiking gamma-aminobutyric acid neurons have been hypothesized as a potential mechanism responsible for the onset and development of schizophrenia. Yet, the link between OxS and perturbation of thalamocortical dynamics and sleep remains unclear. Here, we sought to investigate the effects of OxS on sleep regulation by characterizing the dynamics of thalamocortical networks across sleep-wake states in a mouse model with a genetic deletion of the modifier subunit of glutamate-cysteine ligase (Gclm knockout, KO) using high-density electrophysiology in freely-moving mice. We found that Gcml KO mice exhibited a fragmented sleep architecture and impaired sleep homeostasis responses as revealed by the increased NREM sleep latencies, decreased slow-wave activities and spindle rate after sleep deprivation. These changes were associated with altered bursting activity and firing dynamics of neurons from the thalamic reticularis nucleus, anterior cingulate and anterodorsal thalamus. Administration of N-acetylcysteine (NAC), a clinically relevant antioxidant, rescued the sleep fragmentation and spindle rate through a renormalization of local neuronal dynamics in Gclm KO mice. Collectively, these findings provide novel evidence for a link between OxS and the deficits of frontal TC network dynamics as a possible mechanism underlying sleep abnormalities and impaired homeostatic responses observed in schizophrenia.
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Affiliation(s)
- Christina Czekus
- grid.411656.10000 0004 0479 0855Center for Experimental Neurology, Department of Neurology, Inselspital University Hospital, Bern, Switzerland
| | - Pascal Steullet
- grid.8515.90000 0001 0423 4662Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital, Site de Cery, CH-1008 Prilly-Lausanne, Switzerland
| | - Albert Orero López
- grid.411656.10000 0004 0479 0855Center for Experimental Neurology, Department of Neurology, Inselspital University Hospital, Bern, Switzerland
| | - Ivan Bozic
- grid.5734.50000 0001 0726 5157Department for Biomedical Research, University of Bern, Bern, Switzerland
| | - Thomas Rusterholz
- grid.411656.10000 0004 0479 0855Center for Experimental Neurology, Department of Neurology, Inselspital University Hospital, Bern, Switzerland
| | - Mojtaba Bandarabadi
- grid.411656.10000 0004 0479 0855Center for Experimental Neurology, Department of Neurology, Inselspital University Hospital, Bern, Switzerland ,grid.9851.50000 0001 2165 4204Present Address: Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Kim Q. Do
- grid.8515.90000 0001 0423 4662Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital, Site de Cery, CH-1008 Prilly-Lausanne, Switzerland
| | - Carolina Gutierrez Herrera
- Center for Experimental Neurology, Department of Neurology, Inselspital University Hospital, Bern, Switzerland. .,Department for Biomedical Research, University of Bern, Bern, Switzerland.
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12
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Sinha M, Narayanan R. Active Dendrites and Local Field Potentials: Biophysical Mechanisms and Computational Explorations. Neuroscience 2021; 489:111-142. [PMID: 34506834 PMCID: PMC7612676 DOI: 10.1016/j.neuroscience.2021.08.035] [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: 04/27/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 10/27/2022]
Abstract
Neurons and glial cells are endowed with membranes that express a rich repertoire of ion channels, transporters, and receptors. The constant flux of ions across the neuronal and glial membranes results in voltage fluctuations that can be recorded from the extracellular matrix. The high frequency components of this voltage signal contain information about the spiking activity, reflecting the output from the neurons surrounding the recording location. The low frequency components of the signal, referred to as the local field potential (LFP), have been traditionally thought to provide information about the synaptic inputs that impinge on the large dendritic trees of various neurons. In this review, we discuss recent computational and experimental studies pointing to a critical role of several active dendritic mechanisms that can influence the genesis and the location-dependent spectro-temporal dynamics of LFPs, spanning different brain regions. We strongly emphasize the need to account for the several fast and slow dendritic events and associated active mechanisms - including gradients in their expression profiles, inter- and intra-cellular spatio-temporal interactions spanning neurons and glia, heterogeneities and degeneracy across scales, neuromodulatory influences, and activitydependent plasticity - towards gaining important insights about the origins of LFP under different behavioral states in health and disease. We provide simple but essential guidelines on how to model LFPs taking into account these dendritic mechanisms, with detailed methodology on how to account for various heterogeneities and electrophysiological properties of neurons and synapses while studying LFPs.
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Affiliation(s)
- Manisha Sinha
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India.
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13
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Yu D, Febbo IG, Maroteaux MJ, Wang H, Song Y, Han X, Sun C, Meyer EE, Rowe S, Chen Y, Canavier CC, Schrader LA. The Transcription Factor Shox2 Shapes Neuron Firing Properties and Suppresses Seizures by Regulation of Key Ion Channels in Thalamocortical Neurons. Cereb Cortex 2021; 31:3194-3212. [PMID: 33675359 DOI: 10.1093/cercor/bhaa414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/16/2020] [Accepted: 12/24/2020] [Indexed: 01/02/2023] Open
Abstract
Thalamocortical neurons (TCNs) play a critical role in the maintenance of thalamocortical oscillations, dysregulation of which can result in certain types of seizures. Precise control over firing rates of TCNs is foundational to these oscillations, yet the transcriptional mechanisms that constrain these firing rates remain elusive. We hypothesized that Shox2 is a transcriptional regulator of ion channels important for TCN function and that loss of Shox2 alters firing frequency and activity, ultimately perturbing thalamocortical oscillations into an epilepsy-prone state. In this study, we used RNA sequencing and quantitative PCR of control and Shox2 knockout mice to determine Shox2-affected genes and revealed a network of ion channel genes important for neuronal firing properties. Protein regulation was confirmed by Western blotting, and electrophysiological recordings showed that Shox2 KO impacted the firing properties of a subpopulation of TCNs. Computational modeling showed that disruption of these conductances in a manner similar to Shox2's effects modulated frequency of oscillations and could convert sleep spindles to near spike and wave activity, which are a hallmark for absence epilepsy. Finally, Shox2 KO mice were more susceptible to pilocarpine-induced seizures. Overall, these results reveal Shox2 as a transcription factor important for TCN function in adult mouse thalamus.
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Affiliation(s)
- Diankun Yu
- Neuroscience Program, Brain Institute, Tulane University, USA
| | | | | | - Hanyun Wang
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Yingnan Song
- Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Xiao Han
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Cheng Sun
- Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Emily E Meyer
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Stuart Rowe
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Yiping Chen
- Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Carmen C Canavier
- Cell Biology and Anatomy, LSU Health Sciences Center, New Orleans, LA 70112, USA
| | - Laura A Schrader
- Neuroscience Program, Brain Institute, Tulane University, USA.,Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
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14
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Fricker B, Heckman E, Cunningham PC, Wang H, Haas JS. Activity-dependent long-term potentiation of electrical synapses in the mammalian thalamus. J Neurophysiol 2020; 125:476-488. [PMID: 33146066 DOI: 10.1152/jn.00471.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Activity-dependent changes of synapse strength have been extensively characterized at chemical synapses, but the relationship between physiological forms of activity and strength at electrical synapses remains poorly characterized and understood. For mammalian electrical synapses comprising hexamers of connexin36, physiological forms of neuronal activity in coupled pairs have thus far only been linked to long-term depression; activity that results in strengthening of electrical synapses has not yet been identified. Here, we performed dual whole-cell current-clamp recordings in acute slices of P11-P15 Sprague-Dawley rats of electrically coupled neurons of the thalamic reticular nucleus (TRN), a central brain area that regulates cortical input from and attention to the sensory surround. Using TTA-A2 to limit bursting, we show that tonic spiking in one neuron of a pair results in long-term potentiation of electrical synapses. We use experiments and computational modeling to show that the magnitude of plasticity expressed alters the functionality of the synapse. Potentiation is expressed asymmetrically, indicating that regulation of connectivity depends on the direction of use. Furthermore, calcium pharmacology and imaging indicate that potentiation depends on calcium flux. We thus propose a calcium-based activity rule for bidirectional plasticity of electrical synapse strength. Because electrical synapses dominate intra-TRN connectivity, these synapses and their activity-dependent modifications are key dynamic regulators of thalamic attention circuitry. More broadly, we speculate that bidirectional modifications of electrical synapses may be a widespread and powerful principle for ongoing, dynamic reorganization of neuronal circuitry across the brain.NEW & NOTEWORTHY This work reveals a physiologically relevant form of activity pairing in coupled neurons that results in long-term potentiation of mammalian electrical synapses. These findings, in combination with previous work, allow the authors to propose a bidirectional calcium-based rule for plasticity of electrical synapses, similar to those demonstrated for chemical synapses. These new insights inform the field on how electrical synapse plasticity may modify the neural circuits that incorporate them.
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Affiliation(s)
- Brandon Fricker
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
| | - Emily Heckman
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
| | | | - Huaixing Wang
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
| | - Julie S Haas
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania
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15
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Javitt DC, Siegel SJ, Spencer KM, Mathalon DH, Hong LE, Martinez A, Ehlers CL, Abbas AI, Teichert T, Lakatos P, Womelsdorf T. A roadmap for development of neuro-oscillations as translational biomarkers for treatment development in neuropsychopharmacology. Neuropsychopharmacology 2020; 45:1411-1422. [PMID: 32375159 PMCID: PMC7360555 DOI: 10.1038/s41386-020-0697-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 03/16/2020] [Accepted: 04/27/2020] [Indexed: 02/08/2023]
Abstract
New treatment development for psychiatric disorders depends critically upon the development of physiological measures that can accurately translate between preclinical animal models and clinical human studies. Such measures can be used both as stratification biomarkers to define pathophysiologically homogeneous patient populations and as target engagement biomarkers to verify similarity of effects across preclinical and clinical intervention. Traditional "time-domain" event-related potentials (ERP) have been used translationally to date but are limited by the significant differences in timing and distribution across rodent, monkey and human studies. By contrast, neuro-oscillatory responses, analyzed within the "time-frequency" domain, are relatively preserved across species permitting more precise translational comparisons. Moreover, neuro-oscillatory responses are increasingly being mapped to local circuit mechanisms and may be useful for investigating effects of both pharmacological and neuromodulatory interventions on excitatory/inhibitory balance. The present paper provides a roadmap for development of neuro-oscillatory responses as translational biomarkers in neuropsychiatric treatment development.
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Affiliation(s)
- Daniel C Javitt
- Department of Psychiatry, Columbia University Medical Center, New York, NY, 10032, USA.
- Schizophrenia Research Division, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10954, USA.
| | - Steven J Siegel
- Department of Psychiatry and Behavioral Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Kevin M Spencer
- Research Service, VA Boston Healthcare System, and Dept. of Psychiatry, Harvard Medical School, Boston, MA, 02130, USA
| | - Daniel H Mathalon
- VA San Francisco Healthcare System, University of California, San Francisco, San Francisco, CA, 94121, USA
| | - L Elliot Hong
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Antigona Martinez
- Department of Psychiatry, Columbia University Medical Center, New York, NY, 10032, USA
- Schizophrenia Research Division, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10954, USA
| | - Cindy L Ehlers
- Department of Neuroscience, The Scripps Research Institute, 10550 N Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Atheir I Abbas
- VA Portland Health Care System, Portland, OR, 97239, USA
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
- Department of Psychiatry, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Tobias Teichert
- Departments of Psychiatry and Bioengineering, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Peter Lakatos
- Schizophrenia Research Division, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, 10954, USA
| | - Thilo Womelsdorf
- Department of Psychology, Vanderbilt University, Nashville, TN, 37203, USA
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16
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A single psychotomimetic dose of ketamine decreases thalamocortical spindles and delta oscillations in the sedated rat. Schizophr Res 2020; 222:362-374. [PMID: 32507548 DOI: 10.1016/j.schres.2020.04.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/18/2020] [Accepted: 04/19/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND In patients with psychotic disorders, sleep spindles are reduced, supporting the hypothesis that the thalamus and glutamate receptors play a crucial etio-pathophysiological role, whose underlying mechanisms remain unknown. We hypothesized that a reduced function of NMDA receptors is involved in the spindle deficit observed in schizophrenia. METHODS An electrophysiological multisite cell-to-network exploration was used to investigate, in pentobarbital-sedated rats, the effects of a single psychotomimetic dose of the NMDA glutamate receptor antagonist ketamine in the sensorimotor and associative/cognitive thalamocortical (TC) systems. RESULTS Under the control condition, spontaneously-occurring spindles (intra-frequency: 10-16 waves/s) and delta-frequency (1-4 Hz) oscillations were recorded in the frontoparietal cortical EEG, in thalamic extracellular recordings, in dual juxtacellularly recorded GABAergic thalamic reticular nucleus (TRN) and glutamatergic TC neurons, and in intracellularly recorded TC neurons. The TRN cells rhythmically exhibited robust high-frequency bursts of action potentials (7 to 15 APs at 200-700 Hz). A single administration of low-dose ketamine fleetingly reduced TC spindles and delta oscillations, amplified ongoing gamma-(30-80 Hz) and higher-frequency oscillations, and switched the firing pattern of both TC and TRN neurons from a burst mode to a single AP mode. Furthermore, ketamine strengthened the gamma-frequency band TRN-TC connectivity. The antipsychotic clozapine consistently prevented the ketamine effects on spindles, delta- and gamma-/higher-frequency TC oscillations. CONCLUSION The present findings support the hypothesis that NMDA receptor hypofunction is involved in the reduction in sleep spindles and delta oscillations. The ketamine-induced swift conversion of ongoing TC-TRN activities may have involved at least both the ascending reticular activating system and the corticothalamic pathway.
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17
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Menicucci D, Piarulli A, Laurino M, Zaccaro A, Agrimi J, Gemignani A. Sleep slow oscillations favour local cortical plasticity underlying the consolidation of reinforced procedural learning in human sleep. J Sleep Res 2020; 29:e13117. [PMID: 32592318 DOI: 10.1111/jsr.13117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 11/29/2022]
Abstract
We investigated changes of slow-wave activity and sleep slow oscillations in the night following procedural learning boosted by reinforcement learning, and how these changes correlate with behavioural output. In the Task session, participants had to reach a visual target adapting cursor's movements to compensate an angular deviation introduced experimentally, while in the Control session no deviation was applied. The task was repeated at 13:00 hours, 17:00 hours and 23:00 hours before sleep, and at 08:00 hours after sleep. The deviation angle was set at 15° (13:00 hours and 17:00 hours) and increased to 45° (reinforcement) at 23:00 hours and 08:00 hours. Both for Task and Control nights, high-density electroencephalogram sleep recordings were carried out (23:30-19:30 hours). The Task night as compared with the Control night showed increases of: (a) slow-wave activity (absolute power) over the whole scalp; (b) slow-wave activity (relative power) in left centro-parietal areas; (c) sleep slow oscillations rate in sensorimotor and premotor areas; (d) amplitude of pre-down and up states in premotor regions, left sensorimotor and right parietal regions; (e) sigma crowning the up state in right parietal regions. After Task night, we found an improvement of task performance showing correlations with sleep slow oscillations rate in right premotor, sensorimotor and parietal regions. These findings suggest a key role of sleep slow oscillations in procedural memories consolidation. The diverse components of sleep slow oscillations selectively reflect the network activations related to the reinforced learning of a procedural visuomotor task. Indeed, areas specifically involved in the task stand out as those with a significant association between sleep slow oscillations rate and overnight improvement in task performance.
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Affiliation(s)
- Danilo Menicucci
- Department of Surgical, Medical, Molecular Pathology and Critical Medicine, University of Pisa, Pisa, Italy
| | - Andrea Piarulli
- Department of Surgical, Medical, Molecular Pathology and Critical Medicine, University of Pisa, Pisa, Italy.,Coma Science Group, GIGA-Consciousness, University of Liège and University Hospital of Liège, Liège, Belgium
| | - Marco Laurino
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Andrea Zaccaro
- Department of Surgical, Medical, Molecular Pathology and Critical Medicine, University of Pisa, Pisa, Italy
| | - Jacopo Agrimi
- Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Angelo Gemignani
- Department of Surgical, Medical, Molecular Pathology and Critical Medicine, University of Pisa, Pisa, Italy.,Institute of Clinical Physiology, National Research Council, Pisa, Italy.,Azienda Ospedaliero-Universitaria Pisana, Pisa, Italy
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18
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Weiss N, Zamponi GW. Genetic T-type calcium channelopathies. J Med Genet 2020; 57:1-10. [PMID: 31217264 PMCID: PMC6929700 DOI: 10.1136/jmedgenet-2019-106163] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/02/2019] [Accepted: 05/18/2019] [Indexed: 12/13/2022]
Abstract
T-type channels are low-voltage-activated calcium channels that contribute to a variety of cellular and physiological functions, including neuronal excitability, hormone and neurotransmitter release as well as developmental aspects. Several human conditions including epilepsy, autism spectrum disorders, schizophrenia, motor neuron disorders and aldosteronism have been traced to variations in genes encoding T-type channels. In this short review, we present the genetics of T-type channels with an emphasis on structure-function relationships and associated channelopathies.
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Affiliation(s)
- Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Praha, Czech Republic
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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19
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Takata N. Thalamic reticular nucleus in the thalamocortical loop. Neurosci Res 2019; 156:32-40. [PMID: 31812650 DOI: 10.1016/j.neures.2019.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/23/2019] [Accepted: 11/16/2019] [Indexed: 11/19/2022]
Abstract
Dynamic binding of different brain areas is critical for various cognitive functions. The thalamic reticular nucleus (TRN) is a GABAergic nucleus that constrains information flow through thalamocortical loop by providing inhibitory innervation to the thalamus. In this review, I summarize anatomical and single-cell-level physiological studies of the rodent TRN. Diversity and heterogeneity of TRN neurons in terms of axonal innervation, molecular expression, and physiological characteristics are described. I also outline thalamocortical and cortico-cortical connections with emphasis on interaction with the TRN. In summary, it is proposed that functional connectivity among brain regions are modulated with gating of transthalamic information flow by the TRN.
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Affiliation(s)
- Norio Takata
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan.
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20
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Munro Krull E, Sakata S, Toyoizumi T. Theta Oscillations Alternate With High Amplitude Neocortical Population Within Synchronized States. Front Neurosci 2019; 13:316. [PMID: 31037053 PMCID: PMC6476345 DOI: 10.3389/fnins.2019.00316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 03/20/2019] [Indexed: 12/16/2022] Open
Abstract
Synchronized states are marked by large-amplitude low-frequency oscillations in the cortex. These states can be seen during quiet waking or slow-wave sleep. Within synchronized states, previous studies have noted a plethora of different types of activity, including delta oscillations (0.5-4 Hz) and slow oscillations (<1 Hz) in the neocortex and large- and small- irregular activity in the hippocampus. However, it is not still fully characterized how neural populations contribute to the synchronized state. Here we apply independent component analysis to parse which populations are involved in different kinds of neocortical activity, and find two populations that alternate throughout synchronized states. One population broadly affects neocortical deep layers, and is associated with larger amplitude slower neocortical oscillations. The other population exhibits theta-frequency oscillations that are not easily observed in raw field potential recordings. These theta oscillations apparently come from below the neocortex, suggesting hippocampal origin, and are associated with smaller amplitude faster neocortical oscillations. Relative involvement of these two alternating populations may indicate different modes of operation within synchronized states.
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Affiliation(s)
- Erin Munro Krull
- RIKEN Center for Brain Science, Tokyo, Japan
- Beloit College, Beloit, WI, United States
| | - Shuzo Sakata
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
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21
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Langille JJ. Remembering to Forget: A Dual Role for Sleep Oscillations in Memory Consolidation and Forgetting. Front Cell Neurosci 2019; 13:71. [PMID: 30930746 PMCID: PMC6425990 DOI: 10.3389/fncel.2019.00071] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 02/13/2019] [Indexed: 12/20/2022] Open
Abstract
It has been known since the time of patient H. M. and Karl Lashley's equipotentiality studies that the hippocampus and cortex serve mnestic functions. Current memory models maintain that these two brain structures accomplish unique, but interactive, memory functions. Specifically, most modeling suggests that memories are rapidly acquired during waking experience by the hippocampus, before being later consolidated into the cortex for long-term storage. Sleep has been shown to be critical for the transfer and consolidation of memories in the cortex. Like memory consolidation, a role for sleep in adaptive forgetting has both historical precedent, as Francis Crick suggested in 1983 that sleep was for "reverse-learning," and recent empirical support. In this article I review the evidence indicating that the same brain activity involved in sleep replay associated memory consolidation is responsible for sleep-dependent forgetting. In reviewing the literature, it became clear that both a cellular mechanism for systems consolidation and an agreed upon general, as well as cellular, mechanism for sleep-dependent forgetting is seldom discussed or is lacking. I advocate here for a candidate cellular systems consolidation mechanism wherein changes in calcium kinetics and the activation of consolidative signaling cascades arise from the triple phase locking of non-rapid eye movement sleep (NREMS) slow oscillation, sleep spindle and sharp-wave ripple rhythms. I go on to speculatively consider several sleep stage specific forgetting mechanisms and conclude by discussing a notional function of NREM-rapid eye movement sleep (REMS) cycling. The discussed model argues that the cyclical organization of sleep functions to first lay down and edit and then stabilize and integrate engrams. All things considered, it is increasingly clear that hallmark sleep stage rhythms, including several NREMS oscillations and the REMS hippocampal theta rhythm, serve the dual function of enabling simultaneous memory consolidation and adaptive forgetting. Specifically, the same sleep rhythms that consolidate new memories, in the cortex and hippocampus, simultaneously organize the adaptive forgetting of older memories in these brain regions.
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Affiliation(s)
- Jesse J Langille
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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22
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Fukunaga K, Izumi H, Yabuki Y, Shinoda Y, Shioda N, Han F. Alzheimer's disease therapeutic candidate SAK3 is an enhancer of T-type calcium channels. J Pharmacol Sci 2019; 139:51-58. [DOI: 10.1016/j.jphs.2018.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 11/16/2018] [Accepted: 11/20/2018] [Indexed: 12/27/2022] Open
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Electroacupuncture Treatment Alleviates the Remifentanil-Induced Hyperalgesia by Regulating the Activities of the Ventral Posterior Lateral Nucleus of the Thalamus Neurons in Rats. Neural Plast 2018; 2018:6109723. [PMID: 30534151 PMCID: PMC6252233 DOI: 10.1155/2018/6109723] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 09/04/2018] [Indexed: 11/17/2022] Open
Abstract
Mechanisms underlying remifentanil- (RF-) induced hyperalgesia, a phenomenon that is generally named as opioid-induced hyperalgesia (OIH), still remain elusive. The ventral posterior lateral nucleus (VPL) of the thalamus, a key relay station for the transmission of nociceptive information to the cerebral cortex, is activated by RF infusion. Electroacupuncture (EA) is an effective method for the treatment of pain. This study aimed to explore the role of VPL in the development of OIH and the effect of EA treatment on OIH in rats. RF was administered to rats via the tail vein for OIH induction. Paw withdrawal threshold (PWT) in response to mechanical stimuli and paw withdrawal latency (PWL) to thermal stimulation were tested in rats for the assessment of mechanical allodynia and thermal hyperalgesia, respectively. Spontaneous neuronal activity and local field potential (LFP) in VPL were recorded in freely moving rats using the in vivo multichannel recording technique. EA at 2 Hz frequency (pulse width 0.6 ms, 1-3 mA) was applied to the bilateral acupoints "Zusanli" (ST.36) and "Sanyinjiao" (SP.6) in rats. The results showed that both the PWT and PWL were significantly decreased after RF infusion to rats. Meanwhile, both the spontaneous neuronal firing rate and the theta band oscillation in VPL LFP were increased on day 3 post-RF infusion, indicating that the VPL may promote the development of RF-induced hyperalgesia by regulating the pain-related cortical activity. Moreover, 2 Hz-EA reversed the RF-induced decrease both in PWT and PWL of rats and also abrogated the RF-induced augmentation of the spontaneous neuronal activity and the power spectral density (PSD) of the theta band oscillation in VPL LFP. These results suggested that 2 Hz-EA attenuates the remifentanil-induced hyperalgesia via reducing the excitability of VPL neurons and the low-frequency (theta band) oscillation in VPL LFP.
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Drion G, Dethier J, Franci A, Sepulchre R. Switchable slow cellular conductances determine robustness and tunability of network states. PLoS Comput Biol 2018; 14:e1006125. [PMID: 29684009 PMCID: PMC5940245 DOI: 10.1371/journal.pcbi.1006125] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 05/08/2018] [Accepted: 04/06/2018] [Indexed: 11/21/2022] Open
Abstract
Neuronal information processing is regulated by fast and localized fluctuations of brain states. Brain states reliably switch between distinct spatiotemporal signatures at a network scale even though they are composed of heterogeneous and variable rhythms at a cellular scale. We investigated the mechanisms of this network control in a conductance-based population model that reliably switches between active and oscillatory mean-fields. Robust control of the mean-field properties relies critically on a switchable negative intrinsic conductance at the cellular level. This conductance endows circuits with a shared cellular positive feedback that can switch population rhythms on and off at a cellular resolution. The switch is largely independent from other intrinsic neuronal properties, network size and synaptic connectivity. It is therefore compatible with the temporal variability and spatial heterogeneity induced by slower regulatory functions such as neuromodulation, synaptic plasticity and homeostasis. Strikingly, the required cellular mechanism is available in all cell types that possess T-type calcium channels but unavailable in computational models that neglect the slow kinetics of their activation. Brain information processing involves electrophysiological signals at multiple temporal and spatial timescales, from the single neuron level to whole brain areas. A fast and local control of these signals by neurochemicals called neuromodulators is essential in complex tasks such as movement initiation and attentional focus. The neuromodulators act at the cellular scale to control signals that propagate at potentially much larger scales. The present paper highlights the critical role of a cellular switch of excitability for the fast and localized control of cellular and network states. By turning ON and OFF the cellular switch, neuromodulators can robustly switch large populations between distinct network states. We stress the importance of controlling the switch at a cellular level and independently of the connectivity to allow for tunable spatiotemporal signatures of the network states.
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Affiliation(s)
- Guillaume Drion
- Department of Electrical Engineering and Computer Science, University of Liege, Liege, Belgium
| | - Julie Dethier
- Department of Electrical Engineering and Computer Science, University of Liege, Liege, Belgium
| | - Alessio Franci
- National Autonomous University of Mexico, Science Faculty, Department of Mathematics, Coyoacán, D.F., México
| | - Rodolphe Sepulchre
- Department of Engineering, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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25
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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: 31] [Impact Index Per Article: 5.2] [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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26
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Varin C, Luppi PH, Fort P. Melanin-concentrating hormone-expressing neurons adjust slow-wave sleep dynamics to catalyze paradoxical (REM) sleep. Sleep 2018; 41:4956246. [DOI: 10.1093/sleep/zsy068] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/19/2018] [Indexed: 12/14/2022] Open
Affiliation(s)
- Christophe Varin
- Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, CNRS, INSERM, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Pierre-Hervé Luppi
- Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, CNRS, INSERM, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
| | - Patrice Fort
- Centre de Recherche en Neurosciences de Lyon (CRNL), SLEEP Team, CNRS, INSERM, Lyon, France
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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27
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EEG Indices in Children with Primary Headache Disorders. NEUROPHYSIOLOGY+ 2018. [DOI: 10.1007/s11062-018-9694-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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28
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Crunelli V, Lőrincz ML, Connelly WM, David F, Hughes SW, Lambert RC, Leresche N, Errington AC. Dual function of thalamic low-vigilance state oscillations: rhythm-regulation and plasticity. Nat Rev Neurosci 2018; 19:107-118. [PMID: 29321683 DOI: 10.1038/nrn.2017.151] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
During inattentive wakefulness and non-rapid eye movement (NREM) sleep, the neocortex and thalamus cooperatively engage in rhythmic activities that are exquisitely reflected in the electroencephalogram as distinctive rhythms spanning a range of frequencies from <1 Hz slow waves to 13 Hz alpha waves. In the thalamus, these diverse activities emerge through the interaction of cell-intrinsic mechanisms and local and long-range synaptic inputs. One crucial feature, however, unifies thalamic oscillations of different frequencies: repetitive burst firing driven by voltage-dependent Ca2+ spikes. Recent evidence reveals that thalamic Ca2+ spikes are inextricably linked to global somatodendritic Ca2+ transients and are essential for several forms of thalamic plasticity. Thus, we propose herein that alongside their rhythm-regulation function, thalamic oscillations of low-vigilance states have a plasticity function that, through modifications of synaptic strength and cellular excitability in local neuronal assemblies, can shape ongoing oscillations during inattention and NREM sleep and may potentially reconfigure thalamic networks for faithful information processing during attentive wakefulness.
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Affiliation(s)
- Vincenzo Crunelli
- Department of Physiology and Biochemistry, University of Malta, Msida, Malta; and the Neuroscience Division, School of Bioscience, Cardiff University, Cardiff, UK
| | - Magor L Lőrincz
- Research Group for Cellular and Network Neurophysiology of the Hungarian Academy of Sciences, Department of Physiology, Anatomy and Neuroscience, University of Szeged, Szeged, Hungary
| | - William M Connelly
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, Australian National University, Canberra, Australia
| | - François David
- Lyon Neuroscience Research Center, Centre national de la recherche scientifique (CNRS) unité mixte de recherche (UMR) 5292- INSERM U1028-Université Claude Bernard, Lyon, France
| | | | - Régis C Lambert
- Sorbonne Universités, University Pierre and Marie Curie (UPMC) Univ. Paris 06, INSERM, Centre national de la recherche scientifique (CNRS), Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Nathalie Leresche
- Sorbonne Universités, University Pierre and Marie Curie (UPMC) Univ. Paris 06, INSERM, Centre national de la recherche scientifique (CNRS), Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris, France
| | - Adam C Errington
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, UK
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29
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Proft J, Rzhepetskyy Y, Lazniewska J, Zhang FX, Cain SM, Snutch TP, Zamponi GW, Weiss N. The Cacna1h mutation in the GAERS model of absence epilepsy enhances T-type Ca 2+ currents by altering calnexin-dependent trafficking of Ca v3.2 channels. Sci Rep 2017; 7:11513. [PMID: 28912545 PMCID: PMC5599688 DOI: 10.1038/s41598-017-11591-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 08/29/2017] [Indexed: 12/12/2022] Open
Abstract
Low-voltage-activated T-type calcium channels are essential contributors to the functioning of thalamocortical neurons by supporting burst-firing mode of action potentials. Enhanced T-type calcium conductance has been reported in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS) and proposed to be causally related to the overall development of absence seizure activity. Here, we show that calnexin, an endoplasmic reticulum integral membrane protein, interacts with the III-IV linker region of the Cav3.2 channel to modulate the sorting of the channel to the cell surface. We demonstrate that the GAERS missense mutation located in the Cav3.2 III-IV linker alters the Cav3.2/calnexin interaction, resulting in an increased surface expression of the channel and a concomitant elevation in calcium influx. Our study reveals a novel mechanism that controls the expression of T-type channels, and provides a molecular explanation for the enhancement of T-type calcium conductance in GAERS.
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Affiliation(s)
- Juliane Proft
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Yuriy Rzhepetskyy
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Joanna Lazniewska
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Fang-Xiong Zhang
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, T2N 4N1, Canada
| | - Stuart M Cain
- Michael Smith Laboratories and the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Terrance P Snutch
- Michael Smith Laboratories and the Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, T2N 4N1, Canada.
| | - Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic.
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30
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Scheib CM. Brainstem Influence on Thalamocortical Oscillations during Anesthesia Emergence. Front Syst Neurosci 2017; 11:66. [PMID: 28959192 PMCID: PMC5603712 DOI: 10.3389/fnsys.2017.00066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 08/31/2017] [Indexed: 12/23/2022] Open
Abstract
Theories of mechanisms that impair or prevent consciousness during anesthesia that are related to thalamocortical oscillations have been proposed. Many methods of EEG analysis have been proposed as measures of anesthetic effects but only a few have potential to provide measures of those anesthetic effects that are directly related to thalamocortical oscillations. Some of these methods will be explained and demonstrated with examples chosen to provide evidence for or against two of the proposed mechanisms. The first of the two mechanisms to be addressed is the “traveling peak” (Ching et al., 2010), which relates to anesthetic agents synchronizing neural oscillations that occur in subjects who are awake and reducing their frequency from the gamma (25–40 Hz) to the beta range (13–24 Hz) as a state of sedation develops. The mechanism continues to lower the frequency of this oscillation to the alpha (8–12 Hz) range. In the alpha frequency range, responses to sounds and words stop. It has been proposed that the mechanism changes fundamentally at this point and the oscillations are not compatible with consciousness. The second mechanism that will be addressed is a modification of the generally accepted mechanism for the spindle oscillations that occur during natural sleep (Steriade et al., 1993a,b). These two different mechanisms imply two different patterns for changes in the frequency of the thalamocortical oscillations during emergence. The first mechanism implies that the frequency of the oscillations should increase from the alpha range to the beta range during emergence. The “spindle” mechanism implies that the frequency of the oscillation would not increase much beyond the alpha range. Examples of EEG recordings during anesthesia and emergence from anesthesia were found which were consistent with either mechanism alone or both mechanisms at the same time. Neither theory was able to explain all examples. It is possible that both mechanisms can occur and that brainstem activity may influence the characteristics of emergence. The brainstem activity in question may be influenced by nociception and analgesic supplementation. It may be possible to control the path of emergence by controlling brainstem activity with opioids and other agents in order to allow the patient to awaken without going through an excitement phase or delirium at the transition to consciousness.
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Affiliation(s)
- Christopher M Scheib
- Anesthesia Department, W. G. (Bill) Hefner VA Medical CenterSalisbury, NC, United States
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31
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Sen-Bhattacharya B, Serrano-Gotarredona T, Balassa L, Bhattacharya A, Stokes AB, Rowley A, Sugiarto I, Furber S. A Spiking Neural Network Model of the Lateral Geniculate Nucleus on the SpiNNaker Machine. Front Neurosci 2017; 11:454. [PMID: 28848380 PMCID: PMC5552764 DOI: 10.3389/fnins.2017.00454] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/25/2017] [Indexed: 01/23/2023] Open
Abstract
We present a spiking neural network model of the thalamic Lateral Geniculate Nucleus (LGN) developed on SpiNNaker, which is a state-of-the-art digital neuromorphic hardware built with very-low-power ARM processors. The parallel, event-based data processing in SpiNNaker makes it viable for building massively parallel neuro-computational frameworks. The LGN model has 140 neurons representing a "basic building block" for larger modular architectures. The motivation of this work is to simulate biologically plausible LGN dynamics on SpiNNaker. Synaptic layout of the model is consistent with biology. The model response is validated with existing literature reporting entrainment in steady state visually evoked potentials (SSVEP)-brain oscillations corresponding to periodic visual stimuli recorded via electroencephalography (EEG). Periodic stimulus to the model is provided by: a synthetic spike-train with inter-spike-intervals in the range 10-50 Hz at a resolution of 1 Hz; and spike-train output from a state-of-the-art electronic retina subjected to a light emitting diode flashing at 10, 20, and 40 Hz, simulating real-world visual stimulus to the model. The resolution of simulation is 0.1 ms to ensure solution accuracy for the underlying differential equations defining Izhikevichs neuron model. Under this constraint, 1 s of model simulation time is executed in 10 s real time on SpiNNaker; this is because simulations on SpiNNaker work in real time for time-steps dt ⩾ 1 ms. The model output shows entrainment with both sets of input and contains harmonic components of the fundamental frequency. However, suppressing the feed-forward inhibition in the circuit produces subharmonics within the gamma band (>30 Hz) implying a reduced information transmission fidelity. These model predictions agree with recent lumped-parameter computational model-based predictions, using conventional computers. Scalability of the framework is demonstrated by a multi-node architecture consisting of three "nodes," where each node is the "basic building block" LGN model. This 420 neuron model is tested with synthetic periodic stimulus at 10 Hz to all the nodes. The model output is the average of the outputs from all nodes, and conforms to the above-mentioned predictions of each node. Power consumption for model simulation on SpiNNaker is ≪1 W.
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Affiliation(s)
- Basabdatta Sen-Bhattacharya
- Advanced Processor Technologies Group, School of Computer Science, University of ManchesterManchester, United Kingdom
| | | | | | | | - Alan B. Stokes
- Advanced Processor Technologies Group, School of Computer Science, University of ManchesterManchester, United Kingdom
| | - Andrew Rowley
- Advanced Processor Technologies Group, School of Computer Science, University of ManchesterManchester, United Kingdom
| | - Indar Sugiarto
- Advanced Processor Technologies Group, School of Computer Science, University of ManchesterManchester, United Kingdom
| | - Steve Furber
- Advanced Processor Technologies Group, School of Computer Science, University of ManchesterManchester, United Kingdom
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32
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A Neurophysiological Perspective on a Preventive Treatment against Schizophrenia Using Transcranial Electric Stimulation of the Corticothalamic Pathway. Brain Sci 2017; 7:brainsci7040034. [PMID: 28350371 PMCID: PMC5406691 DOI: 10.3390/brainsci7040034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/11/2017] [Accepted: 03/24/2017] [Indexed: 12/16/2022] Open
Abstract
Schizophrenia patients are waiting for a treatment free of detrimental effects. Psychotic disorders are devastating mental illnesses associated with dysfunctional brain networks. Ongoing brain network gamma frequency (30–80 Hz) oscillations, naturally implicated in integrative function, are excessively amplified during hallucinations, in at-risk mental states for psychosis and first-episode psychosis. So, gamma oscillations represent a bioelectrical marker for cerebral network disorders with prognostic and therapeutic potential. They accompany sensorimotor and cognitive deficits already present in prodromal schizophrenia. Abnormally amplified gamma oscillations are reproduced in the corticothalamic systems of healthy humans and rodents after a single systemic administration, at a psychotomimetic dose, of the glutamate N-methyl-d-aspartate receptor antagonist ketamine. These translational ketamine models of prodromal schizophrenia are thus promising to work out a preventive noninvasive treatment against first-episode psychosis and chronic schizophrenia. In the present essay, transcranial electric stimulation (TES) is considered an appropriate preventive therapeutic modality because it can influence cognitive performance and neural oscillations. Here, I highlight clinical and experimental findings showing that, together, the corticothalamic pathway, the thalamus, and the glutamatergic synaptic transmission form an etiopathophysiological backbone for schizophrenia and represent a potential therapeutic target for preventive TES of dysfunctional brain networks in at-risk mental state patients against psychotic disorders.
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33
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Smith CL, Abdallah S, Wong YY, Le P, Harracksingh AN, Artinian L, Tamvacakis AN, Rehder V, Reese TS, Senatore A. Evolutionary insights into T-type Ca 2+ channel structure, function, and ion selectivity from the Trichoplax adhaerens homologue. J Gen Physiol 2017; 149:483-510. [PMID: 28330839 PMCID: PMC5379919 DOI: 10.1085/jgp.201611683] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Accepted: 02/07/2017] [Indexed: 12/31/2022] Open
Abstract
The role of T-type calcium channels in animals without nervous systems is unknown. Smith et al. characterize TCav3 from Trichoplax adhaerens, finding expression in neurosecretory-like cells and preference for Ca2+ over Na+ via strong extracellular Ca2+ block, despite low selectivity for Ca2+ in the pore. Four-domain voltage-gated Ca2+ (Cav) channels play fundamental roles in the nervous system, but little is known about when or how their unique properties and cellular roles evolved. Of the three types of metazoan Cav channels, Cav1 (L-type), Cav2 (P/Q-, N- and R-type) and Cav3 (T-type), Cav3 channels are optimized for regulating cellular excitability because of their fast kinetics and low activation voltages. These same properties permit Cav3 channels to drive low-threshold exocytosis in select neurons and neurosecretory cells. Here, we characterize the single T-type calcium channel from Trichoplax adhaerens (TCav3), an early diverging animal that lacks muscle, neurons, and synapses. Co-immunolocalization using antibodies against TCav3 and neurosecretory cell marker complexin labeled gland cells, which are hypothesized to play roles in paracrine signaling. Cloning and in vitro expression of TCav3 reveals that, despite roughly 600 million years of divergence from other T-type channels, it bears the defining structural and biophysical features of the Cav3 family. We also characterize the channel’s cation permeation properties and find that its pore is less selective for Ca2+ over Na+ compared with the human homologue Cav3.1, yet it exhibits a similar potent block of inward Na+ current by low external Ca2+ concentrations (i.e., the Ca2+ block effect). A comparison of the permeability features of TCav3 with other cloned channels suggests that Ca2+ block is a locus of evolutionary change in T-type channel cation permeation properties and that mammalian channels distinguish themselves from invertebrate ones by bearing both stronger Ca2+ block and higher Ca2+ selectivity. TCav3 is the most divergent metazoan T-type calcium channel and thus provides an evolutionary perspective on Cav3 channel structure–function properties, ion selectivity, and cellular physiology.
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Affiliation(s)
- Carolyn L Smith
- National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Salsabil Abdallah
- University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Yuen Yan Wong
- University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | - Phuong Le
- University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
| | | | | | | | | | - Thomas S Reese
- National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Adriano Senatore
- University of Toronto Mississauga, Mississauga, Ontario L5L 1C6, Canada
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Yabuki Y, Matsuo K, Izumi H, Haga H, Yoshida T, Wakamori M, Kakei A, Sakimura K, Fukuda T, Fukunaga K. Pharmacological properties of SAK3, a novel T-type voltage-gated Ca 2+ channel enhancer. Neuropharmacology 2017; 117:1-13. [PMID: 28093211 DOI: 10.1016/j.neuropharm.2017.01.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Revised: 12/27/2016] [Accepted: 01/12/2017] [Indexed: 11/30/2022]
Abstract
T-type voltage-gated Ca2+ channels (T-VGCCs) function in the pathophysiology of epilepsy, pain and sleep. However, their role in cognitive function remains unclear. We previously reported that the cognitive enhancer ST101, which stimulates T-VGCCs in rat cortical slices, was a potential Alzheimer's disease therapeutic. Here, we introduce a more potent T-VGCC enhancer, SAK3 (ethyl 8'-methyl-2',4-dioxo-2-(piperidin-1-yl)-2'H-spiro[cyclopentane-1,3'-imidazo [1,2-a]pyridin]-2-ene-3-carboxylate), and characterize its pharmacological properties in brain. Based on whole cell patch-clamp analysis, SAK3 (0.01-10 nM) significantly enhanced Cav3.1 currents in neuro2A cells ectopically expressing Cav3.1. SAK3 (0.1-10 nM nM) also enhanced Cav3.3 but not Cav3.2 currents in the transfected cells. Notably, Cav3.1 and Cav3.3 T-VGCCs were localized in cholinergic neurve systems in hippocampus and in the medial septum. Indeed, acute oral administration of SAK3 (0.5 mg/kg, p.o.), but not ST101 (0.5 mg/kg, p.o.) significantly enhanced acetylcholine (ACh) release in the hippocampal CA1 region of naïve mice. Moreover, acute SAK3 (0.5 mg/kg, p.o.) administration significantly enhanced hippocampal ACh levels in olfactory-bulbectomized (OBX) mice, rescuing impaired memory-related behaviors. Treatment of OBX mice with the T-VGCC-specific blocker NNC 55-0396 (12.5 mg/kg, i.p.) antagonized both enhanced ACh release and memory improvements elicited by SAK3 administration. We also observed that SAK3-induced ACh releases were significantly blocked in the hippocampus from Cav3.1 knockout (KO) mice. These findings suggest overall that T-VGCCs play a key role in cognition by enhancing hippocampal ACh release and that the cognitive enhancer SAK3 could be a candidate therapeutic in Alzheimer's disease.
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Affiliation(s)
- Yasushi Yabuki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Kazuya Matsuo
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Hisanao Izumi
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Hidaka Haga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Takashi Yoshida
- Department of Oral Biology, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Minoru Wakamori
- Department of Oral Biology, Graduate School of Dentistry, Tohoku University, Sendai, Japan
| | - Akikazu Kakei
- Department of Chemistry and Material Engineering, Faculty of Engineering, Shinshu University, Nagano, Japan
| | - Kenji Sakimura
- Department of Cellular Neurobiology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Takaichi Fukuda
- Department of Anatomy and Neurobiology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Kohji Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan.
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Escitalopram but not placebo modulates brain rhythmic oscillatory activity in the first week of treatment of Major Depressive Disorder. J Psychiatr Res 2017; 84:174-183. [PMID: 27770740 DOI: 10.1016/j.jpsychires.2016.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 09/23/2016] [Accepted: 10/06/2016] [Indexed: 01/15/2023]
Abstract
Serotonin modulates brain oscillatory activity, and serotonergic projections to the thalamus and cortex modulate the frequency of prefrontal rhythmic oscillations. Changes in serotonergic tone have been reported to shift oscillations between the combined delta-theta (2.5-8 Hz) and the alpha (8-12 Hz) frequency ranges. Such frequency shifts may constitute a useful biomarker for the effects of selective serotonin reuptake inhibitor (SSRI) medications in Major Depressive Disorder (MDD). We utilized quantitative electroencephalography (qEEG) to measure shifts in prefrontal rhythmic oscillations early in treatment with either the SSRI escitalopram or placebo, and examined the relationship between these changes and remission of depressive symptoms. Prefrontal delta-theta and alpha power were calculated for 194 subjects with moderate MDD prior to and one week after start of treatment. Changes at one week in delta-theta and alpha power, as well as the delta-theta/alpha ratio, were examined in three cohorts: initial (N = 70) and replication (N = 76) cohorts treated with escitalopram, and a cohort treated with placebo (N = 48). Mean delta-theta power significantly increased and alpha power decreased after one week of escitalopram treatment, but did not significantly change with placebo treatment. The delta-theta/alpha ratio change was a specific predictor of the likelihood of remission after seven weeks of medication treatment: a large increase in this ratio was associated with non-remission in escitalopram-treated subjects, but not placebo-treated subjects. Escitalopram and placebo treatment have differential effects on delta-theta and alpha frequency oscillations. Early increase in delta-theta/alpha may constitute a replicable biomarker for non-remission during SSRI treatment of MDD.
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A Neural Mass Computational Framework to Study Synaptic Mechanisms Underlying Alpha and Theta Rhythms. COMPUTATIONAL NEUROLOGY AND PSYCHIATRY 2017. [DOI: 10.1007/978-3-319-49959-8_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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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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Bhattacharya BS, Bond TP, O'Hare L, Turner D, Durrant SJ. Causal Role of Thalamic Interneurons in Brain State Transitions: A Study Using a Neural Mass Model Implementing Synaptic Kinetics. Front Comput Neurosci 2016; 10:115. [PMID: 27899890 PMCID: PMC5110554 DOI: 10.3389/fncom.2016.00115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 10/26/2016] [Indexed: 11/30/2022] Open
Abstract
Experimental studies on the Lateral Geniculate Nucleus (LGN) of mammals and rodents show that the inhibitory interneurons (IN) receive around 47.1% of their afferents from the retinal spiking neurons, and constitute around 20–25% of the LGN cell population. However, there is a definite gap in knowledge about the role and impact of IN on thalamocortical dynamics in both experimental and model-based research. We use a neural mass computational model of the LGN with three neural populations viz. IN, thalamocortical relay (TCR), thalamic reticular nucleus (TRN), to study the causality of IN on LGN oscillations and state-transitions. The synaptic information transmission in the model is implemented with kinetic modeling, facilitating the linking of low-level cellular attributes with high-level population dynamics. The model is parameterized and tuned to simulate alpha (8–13 Hz) rhythm that is dominant in both Local Field Potential (LFP) of LGN and electroencephalogram (EEG) of visual cortex in an awake resting state with eyes closed. The results show that: First, the response of the TRN is suppressed in the presence of IN in the circuit; disconnecting the IN from the circuit effects a dramatic change in the model output, displaying high amplitude synchronous oscillations within the alpha band in both TCR and TRN. These observations conform to experimental reports implicating the IN as the primary inhibitory modulator of LGN dynamics in a cognitive state, and that reduced cognition is achieved by suppressing the TRN response. Second, the model validates steady state visually evoked potential response in humans corresponding to periodic input stimuli; however, when the IN is disconnected from the circuit, the output power spectra do not reflect the input frequency. This agrees with experimental reports underpinning the role of IN in efficient retino-geniculate information transmission. Third, a smooth transition from alpha to theta band is observed by progressive decrease of neurotransmitter concentrations in the synaptic clefts; however, the transition is abrupt with removal of the IN circuitry in the model. The results imply a role of IN toward maintaining homeostasis in the LGN by suppressing any instability that may arise due to anomalous synaptic attributes.
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Affiliation(s)
| | - Thomas P Bond
- School of Engineering, University of Lincoln Lincoln, UK
| | - Louise O'Hare
- School of Psychology, University of Lincoln Lincoln, UK
| | - Daniel Turner
- School of Engineering, University of Lincoln Lincoln, UK
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Cooperative roles of glucose and asparagine-linked glycosylation in T-type calcium channel expression. Pflugers Arch 2016; 468:1837-1851. [DOI: 10.1007/s00424-016-1881-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 09/04/2016] [Accepted: 09/07/2016] [Indexed: 12/15/2022]
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Abstract
The role of T-type calcium currents is rarely considered in the extensive literature covering the mechanisms of long-term synaptic plasticity. This situation reflects the lack of suitable T-type channel antagonists that till recently has hampered investigations of the functional roles of these channels. However, with the development of new pharmacological and genetic tools, a clear involvement of T-type channels in synaptic plasticity is starting to emerge. Here, we review a number of studies showing that T-type channels participate to numerous homo- and hetero-synaptic plasticity mechanisms that involve different molecular partners and both pre- and post-synaptic modifications. The existence of T-channel dependent and independent plasticity at the same synapse strongly suggests a subcellular localization of these channels and their partners that allows specific interactions. Moreover, we illustrate the functional importance of T-channel dependent synaptic plasticity in neocortex and thalamus.
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Affiliation(s)
- Nathalie Leresche
- a Sorbonne Universités, Université Pierre et Marie Curie (UPMC) UM119, CNRS UMR8246, INSERM U1130, Neuroscience Paris Seine (NPS) , Paris , France
| | - Régis C Lambert
- a Sorbonne Universités, Université Pierre et Marie Curie (UPMC) UM119, CNRS UMR8246, INSERM U1130, Neuroscience Paris Seine (NPS) , Paris , France
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Rzhepetskyy Y, Lazniewska J, Blesneac I, Pamphlett R, Weiss N. CACNA1H missense mutations associated with amyotrophic lateral sclerosis alter Cav3.2 T-type calcium channel activity and reticular thalamic neuron firing. Channels (Austin) 2016; 10:466-77. [PMID: 27331657 DOI: 10.1080/19336950.2016.1204497] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. In a recent study by Steinberg and colleagues, 2 recessive missense mutations were identified in the Cav3.2 T-type calcium channel gene (CACNA1H), in a family with an affected proband (early onset, long duration ALS) and 2 unaffected parents. We have introduced and functionally characterized these mutations using transiently expressed human Cav3.2 channels in tsA-201 cells. Both of these mutations produced mild but significant changes on T-type channel activity that are consistent with a loss of channel function. Computer modeling in thalamic reticular neurons suggested that these mutations result in decreased neuronal excitability of thalamic structures. Taken together, these findings implicate CACNA1H as a susceptibility gene in amyotrophic lateral sclerosis.
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Affiliation(s)
- Yuriy Rzhepetskyy
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Joanna Lazniewska
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Iulia Blesneac
- b Nuffield Department of Clinical Neurosciences , John Radcliffe Hospital, University of Oxford , Oxford , UK
| | - Roger Pamphlett
- c The Stacey MND Laboratory, Discipline of Pathology, The University of Sydney , Sydney , NSW , Australia
| | - Norbert Weiss
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
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Dissecting the Role of P/Q-Type Calcium Channels in Corticothalamic Circuit Dysfunction and Absence Epilepsy. J Neurosci 2016; 36:5677-9. [PMID: 27225758 DOI: 10.1523/jneurosci.0753-16.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/11/2016] [Indexed: 11/21/2022] Open
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Rzhepetskyy Y, Lazniewska J, Proft J, Campiglio M, Flucher BE, Weiss N. A Ca v3.2/Stac1 molecular complex controls T-type channel expression at the plasma membrane. Channels (Austin) 2016; 10:346-354. [PMID: 27149520 DOI: 10.1080/19336950.2016.1186318] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Low-voltage-activated T-type calcium channels are essential contributors to neuronal physiology where they play complex yet fundamentally important roles in shaping intrinsic excitability of nerve cells and neurotransmission. Aberrant neuronal excitability caused by alteration of T-type channel expression has been linked to a number of neuronal disorders including epilepsy, sleep disturbance, autism, and painful chronic neuropathy. Hence, there is increased interest in identifying the cellular mechanisms and actors that underlie the trafficking of T-type channels in normal and pathological conditions. In the present study, we assessed the ability of Stac adaptor proteins to associate with and modulate surface expression of T-type channels. We report the existence of a Cav3.2/Stac1 molecular complex that relies on the binding of Stac1 to the amino-terminal region of the channel. This interaction potently modulates expression of the channel protein at the cell surface resulting in an increased T-type conductance. Altogether, our data establish Stac1 as an important modulator of T-type channel expression and provide new insights into the molecular mechanisms underlying the trafficking of T-type channels to the plasma membrane.
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Affiliation(s)
- Yuriy Rzhepetskyy
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Joanna Lazniewska
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Juliane Proft
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
| | - Marta Campiglio
- b Division of Physiology, Department of Physiology and Medical Physics, Medical University Innsbruck , Innsbruck , Austria
| | - Bernhard E Flucher
- b Division of Physiology, Department of Physiology and Medical Physics, Medical University Innsbruck , Innsbruck , Austria
| | - Norbert Weiss
- a Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic , Prague , Czech Republic
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Abstract
Sleep is a complex physiological process that is regulated globally, regionally, and locally by both cellular and molecular mechanisms. It occurs to some extent in all animals, although sleep expression in lower animals may be co-extensive with rest. Sleep regulation plays an intrinsic part in many behavioral and physiological functions. Currently, all researchers agree there is no single physiological role sleep serves. Nevertheless, it is quite evident that sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state. This review details the physiological processes involved in sleep regulation and the possible functions that sleep may serve. This description of the brain circuitry, cell types, and molecules involved in sleep regulation is intended to further the reader's understanding of the functions of sleep.
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Affiliation(s)
- Mark R. Zielinski
- Veterans Affairs Boston Healthcare System, West Roxbury, MA 02132, USA and Harvard Medical School, Department of Psychiatry
| | - James T. McKenna
- Veterans Affairs Boston Healthcare System, West Roxbury, MA 02132, USA and Harvard Medical School, Department of Psychiatry
| | - Robert W. McCarley
- Veterans Affairs Boston Healthcare System, Brockton, MA 02301, USA and Harvard Medical School, Department of Psychiatry
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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: 28] [Impact Index Per Article: 3.5] [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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Neyer C, Herr D, Kohmann D, Budde T, Pape HC, Coulon P. mGluR-mediated calcium signalling in the thalamic reticular nucleus. Cell Calcium 2016; 59:312-23. [PMID: 27041217 DOI: 10.1016/j.ceca.2016.03.009] [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] [Received: 10/13/2015] [Revised: 03/22/2016] [Accepted: 03/23/2016] [Indexed: 10/22/2022]
Abstract
The thalamic reticular nucleus (TRN) plays a major role in modulating the transfer of information from the thalamus to the cortex. GABAergic inhibition via the TRN is differentially regulated by metabotropic glutamate receptors (mGluRs) and the effect of mGluRs on the membrane potential, on ion channels, and on the plasticity of electrical coupling of TRN neurons has been studied previously. Although mGluRs are generally known to trigger Ca(2+) transients, mGluR-mediated Ca(2+)-transients in TRN neurons have not yet been investigated. In this study, we show that mGluRs can trigger Ca(2+)-transients in TRN neurons, that these transients depend on intracellular Ca(2+)-stores, and are mediated by IP3 receptors. Ca(2+) transients caused by the group I mGluR agonist DHPG elicit a current that is sensitive to flufenamic acid and has a reversal potential around -40mV. Our results add mGluR-mediated Ca(2+)-signalling in the TRN to the state-dependent modulators of the thalamocortical system.
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Affiliation(s)
- Christina Neyer
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - David Herr
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Denise Kohmann
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Thomas Budde
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Hans-Christian Pape
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Philippe Coulon
- Institut für Physiologie I, Westfälische Wilhelms-Universität, Münster, Germany; Center For Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA.
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David F, Crunelli V, Leresche N, Lambert RC. Dynamic Analysis of the Conditional Oscillator Underlying Slow Waves in Thalamocortical Neurons. Front Neural Circuits 2016; 10:10. [PMID: 26941611 PMCID: PMC4766279 DOI: 10.3389/fncir.2016.00010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 02/08/2016] [Indexed: 11/29/2022] Open
Abstract
During non-REM sleep the EEG shows characteristics waves that are generated by the dynamic interactions between cortical and thalamic oscillators. In thalamic neurons, low-threshold T-type Ca(2+) channels play a pivotal role in almost every type of neuronal oscillations, including slow (< 1 Hz) waves, sleep spindles and delta waves. The transient opening of T channels gives rise to the low threshold spikes (LTSs), and associated high frequency bursts of action potentials, that are characteristically present during sleep spindles and delta waves, whereas the persistent opening of a small fraction of T channels, (i.e., ITwindow) is responsible for the membrane potential bistability underlying sleep slow oscillations. Surprisingly thalamocortical (TC) neurons express a very high density of T channels that largely exceed the amount required to generate LTSs and therefore, to support certain, if not all, sleep oscillations. Here, to clarify the relationship between T current density and sleep oscillations, we systematically investigated the impact of the T conductance level on the intrinsic rhythmic activities generated in TC neurons, combining in vitro experiments and TC neuron simulation. Using bifurcation analysis, we provide insights into the dynamical processes taking place at the transition between slow and delta oscillations. Our results show that although stable delta oscillations can be evoked with minimal T conductance, the full range of slow oscillation patterns, including groups of delta oscillations separated by Up states ("grouped-delta slow waves") requires a high density of T channels. Moreover, high levels of T conductance ensure the robustness of different types of slow oscillations.
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Affiliation(s)
- François David
- Neuroscience Division, School of Biosciences, Cardiff UniversityCardiff, UK
- Lyon Neuroscience Research Center, Centre National de la Recherche Scientifique UMR 5292Lyon, France
- Lyon Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale U1028Lyon, France
- Faculté de Médecine, Université Claude BernardLyon, France
- Sorbonne Universités, UPMC Université Paris 06, UM 119, Neuroscience Paris SeineParis, France
- Centre National de la Recherche Scientifique, UMR 8246, Neuroscience Paris SeineParis, France
- Institut National de la Santé et de la Recherche Médicale, U1130, Neuroscience Paris SeineParis, France
| | - Vincenzo Crunelli
- Neuroscience Division, School of Biosciences, Cardiff UniversityCardiff, UK
- Department of Physiology and Biochemistry, University of MaltaMsida, Malta
| | - Nathalie Leresche
- Sorbonne Universités, UPMC Université Paris 06, UM 119, Neuroscience Paris SeineParis, France
- Centre National de la Recherche Scientifique, UMR 8246, Neuroscience Paris SeineParis, France
- Institut National de la Santé et de la Recherche Médicale, U1130, Neuroscience Paris SeineParis, France
| | - Régis C. Lambert
- Sorbonne Universités, UPMC Université Paris 06, UM 119, Neuroscience Paris SeineParis, France
- Centre National de la Recherche Scientifique, UMR 8246, Neuroscience Paris SeineParis, France
- Institut National de la Santé et de la Recherche Médicale, U1130, Neuroscience Paris SeineParis, France
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Ondacova K, Karmazinova M, Lazniewska J, Weiss N, Lacinova L. Modulation of Cav3.2 T-type calcium channel permeability by asparagine-linked glycosylation. Channels (Austin) 2016; 10:175-84. [PMID: 26745591 DOI: 10.1080/19336950.2016.1138189] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Low-voltage-gated T-type calcium channels are expressed throughout the nervous system where they play an essential role in shaping neuronal excitability. Defects in T-type channel expression have been linked to various neuronal disorders including neuropathic pain and epilepsy. Currently, little is known about the cellular mechanisms controlling the expression and function of T-type channels. Asparagine-linked glycosylation has recently emerged as an essential signaling pathway by which the cellular environment can control expression of T-type channels. However, the role of N-glycans in the conducting function of T-type channels remains elusive. In the present study, we used human Cav3.2 glycosylation-deficient channels to assess the role of N-glycosylation on the gating of the channel. Patch-clamp recordings of gating currents revealed that N-glycans attached to hCav3.2 channels have a minimal effect on the functioning of the channel voltage-sensor. In contrast, N-glycosylation on specific asparagine residues may have an essential role in the conducting function of the channel by enhancing the channel permeability and / or the pore opening of the channel. Our data suggest that modulation of N-linked glycosylation of hCav3.2 channels may play an important physiological role, and could also support the alteration of T-type currents observed in disease states.
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Affiliation(s)
- Katarina Ondacova
- a Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Maria Karmazinova
- a Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences , Bratislava , Slovakia
| | - Joanna Lazniewska
- b Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. , Prague , Czech Republic
| | - Norbert Weiss
- b Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. , Prague , Czech Republic
| | - Lubica Lacinova
- a Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences , Bratislava , Slovakia
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Leuchter AF, Hunter AM, Krantz DE, Cook IA. Intermediate phenotypes and biomarkers of treatment outcome in major depressive disorder. DIALOGUES IN CLINICAL NEUROSCIENCE 2015. [PMID: 25733956 PMCID: PMC4336921 DOI: 10.31887/dcns.2014.16.4/aleuchter] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Major depressive disorder (MDD) is a pleomorphic illness originating from gene x environment interactions. Patients with differing symptom phenotypes receive the same diagnosis and similar treatment recommendations without regard to genomics, brain structure or function, or other physiologic or psychosocial factors. Using this present approach, only one third of patients enter remission with the first medication prescribed, and patients may take longer than 1 year to enter remission with repeated trials. Research to improve treatment effectiveness recently has focused on identification of intermediate phenotypes (IPs) that could parse the heterogeneous population of patients with MDD into subgroups with more homogeneous responses to treatment. Such IPs could be used to develop biomarkers that could be applied clinically to match patients with the treatment that would be most likely to lead to remission. Putative biomarkers include genetic polymorphisms, RNA and protein expression (transcriptome and proteome), neurotransmitter levels (metabolome), additional measures of signaling cascades, oscillatory synchrony, neuronal circuits and neural pathways (connectome), along with other possible physiologic measures. All of these measures represent components of a continuum that extends from proximity to the genome to proximity to the clinical phenotype of depression, and there are many levels along this continuum at which useful IPs may be defined. Because of the highly integrative nature of brain systems and the complex neurobiology of depression, the most useful biomarkers are likely to be those with intermediate proximity both to the genome and the clinical phenotype of MDD. Translation of findings across the spectrum from genotype to phenotype promises to better characterize the complex disruptions in signaling and neuroplasticity that accompany MDD, and ultimately to lead to greater understanding of the causes of depressive illness.
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Affiliation(s)
- Andrew F Leuchter
- Laboratory of Brain, Behavior, and Pharmacology, and the Depression Research and Clinical Program, Semel Institute for Neuroscience and Human Behavior, UCLA; the Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Aimee M Hunter
- Laboratory of Brain, Behavior, and Pharmacology, and the Depression Research and Clinical Program, Semel Institute for Neuroscience and Human Behavior, UCLA; the Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - David E Krantz
- Laboratory of Brain, Behavior, and Pharmacology, and the Depression Research and Clinical Program, Semel Institute for Neuroscience and Human Behavior, UCLA; the Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA, Los Angeles, California, USA
| | - Ian A Cook
- Laboratory of Brain, Behavior, and Pharmacology, and the Depression Research and Clinical Program, Semel Institute for Neuroscience and Human Behavior, UCLA; the Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, UCLA; the Department of Bioengineering, Henry Samueli School of Engineering and Applied Sciences, UCLA, Los Angeles, California, USA
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Kim CH. Cav3.1 T-type calcium channel modulates the epileptogenicity of hippocampal seizures in the kainic acid-induced temporal lobe epilepsy model. Brain Res 2015; 1622:204-16. [PMID: 26111648 DOI: 10.1016/j.brainres.2015.06.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 10/23/2022]
Abstract
The molecular mechanism of temporal lobe epilepsy has not been clearly identified. T-type calcium channels play a role in burst firing in neurons and have been implicated in several seizure models. In this study, the role of Cav3.1 T-type (α1G) calcium channel has been investigated in the kainic acid (KA)-induced temporal lobe epilepsy model (TLE) by using conventional α1G knock-out (ko) mice. After intraperitoneal (i.p.) administration or intrahippocampal injection of KA, depth hippocampal and cortical electroencephalogram (EEG) and behavioral monitoring were recorded, and timm and Nissl staining of brain sections were made later. Seizure was mainly identified by EEG signals, rather than behaviorally, with analytic criteria. During the acute status epilepticus (SE) period, both the duration and the frequency of hippocampal seizures were significantly reduced and increased, respectively, in αlG ko mice compared to those of wild type mice. Epileptogenicity, the total period of seizures (hr(-1)), was also significantly reduced in α1G ko mice. However, the latency of seizure occurrence was not significantly different between wild type and ko mice. These differential effects were not observed in cortical seizures. Furthermore, the injection of KA caused a strong increase in δ rhythm power spectrum density (PSD) of EEG in αlG ko mice compared to that in wild type mice. The results with conventional ko mice indicate that α1G T-type calcium channel plays a modulatory role in the duration and frequency of hippocampal seizures as well as the epileptogenicity of KA-induced TLE in mice, mostly during acute periods.
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Affiliation(s)
- Chong-Hyun Kim
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science & Technology, Seoul 136-791, Republic of Korea; Department of Neuroscience, Korea University of Science & Technology, Daejeon 305-333, Republic of Korea.
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