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Pleil KE, Grant KA, Cuzon Carlson VC, Kash TL. Chronic alcohol consumption alters sex-dependent BNST neuron function in rhesus macaques. Neurobiol Stress 2024; 31:100638. [PMID: 38737421 PMCID: PMC11088190 DOI: 10.1016/j.ynstr.2024.100638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/11/2024] [Accepted: 04/29/2024] [Indexed: 05/14/2024] Open
Abstract
Repeated alcohol drinking contributes to a number of neuropsychiatric diseases, including alcohol use disorder and co-expressed anxiety and mood disorders. Women are more susceptible to the development and expression of these diseases with the same history of alcohol exposure as men, suggesting they may be more sensitive to alcohol-induced plasticity in limbic brain regions controlling alcohol drinking, stress responsivity, and reward processing, among other behaviors. Using a translational model of alcohol drinking in rhesus monkeys, we examined sex differences in the basal function and plasticity of neurons in the bed nucleus of the stria terminalis (BNST), a brain region in the extended amygdala shown to be a hub circuit node dysregulated in individuals with anxiety and alcohol use disorder. We performed slice electrophysiology recordings from BNST neurons in male and female monkeys following daily "open access" (22 h/day) to 4% ethanol and water for more than one year or control conditions. We found that BNST neurons from control females had reduced overall current density, hyperpolarization-activated depolarizing current (Ih), and inward rectification, as well as higher membrane resistance and greater synaptic glutamatergic release and excitatory drive, than those from control males, suggesting that female BNST neurons are more basally excited than those from males. Chronic alcohol drinking produced a shift in these measures in both sexes, decreasing current density, Ih, and inward rectification and increasing synaptic excitation. In addition, network activity-dependent synaptic inhibition was basally higher in BNST neurons of males than females, and alcohol exposure increased this in both sexes, a putative homeostatic mechanism to counter hyperexcitability. Altogether, these results suggest that the rhesus BNST is more basally excited in females than males and chronic alcohol drinking produces an overall increase in excitability and synaptic excitation. These results shed light on the mechanisms contributing to the female-biased susceptibility to neuropsychiatric diseases including co-expressed anxiety and alcohol use disorder.
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Affiliation(s)
- Kristen E. Pleil
- Department of Pharmacology, Weill Cornell Medicine, Cornell University, New York, NY, 10065, USA
- Department of Pharmacology and Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, 27514, USA
| | - Kathleen A. Grant
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006, USA
| | - Verginia C. Cuzon Carlson
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR, 97006, USA
| | - Thomas L. Kash
- Department of Pharmacology and Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill, NC, 27514, USA
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Johnson CS, Chapp AD, Lind EB, Thomas MJ, Mermelstein PG. Sex differences in mouse infralimbic cortex projections to the nucleus accumbens shell. Biol Sex Differ 2023; 14:87. [PMID: 38082417 PMCID: PMC10712109 DOI: 10.1186/s13293-023-00570-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND The nucleus accumbens (NAc) is an important region in motivation and reward. Glutamatergic inputs from the infralimbic cortex (ILC) to the shell region of the NAc (NAcSh) have been implicated in driving the motivation to seek reward through repeated action-based behavior. While this has primarily been studied in males, observed sex differences in motivational circuitry and behavior suggest that females may be more sensitive to rewarding stimuli. These differences have been implicated for the observed vulnerability in women to substance use disorders. METHODS We used an optogenetic self-stimulation task in addition to ex vivo electrophysiological recordings of NAcSh neurons in mouse brain slices to investigate potential sex differences in ILC-NAcSh circuitry in reward-seeking behavior. Glutamatergic neurons in the ILC were infected with an AAV delivering DNA encoding for channelrhodopsin. Entering the designated active corner of an open field arena resulted in photostimulation of the ILC terminals in the NAcSh. Self-stimulation occurred during two consecutive days of testing over three consecutive weeks: first for 10 Hz, then 20 Hz, then 30 Hz. Whole-cell recordings of medium spiny neurons in the NAcSh assessed both optogenetically evoked local field potentials and intrinsic excitability. RESULTS Although both sexes learned to seek the active zone, within the first day, females entered the zone more than males, resulting in a greater amount of photostimulation. Increasing the frequency of optogenetic stimulation amplified female reward-seeking behavior. Males were less sensitive to ILC stimulation, with higher frequencies and repeated days required to increase male reward-seeking behavior. Unexpectedly, ex vivo optogenetic local field potentials in the NAcSh were greater in slices from male animals. In contrast, female medium-spiny neurons (MSNs) displayed significantly greater intrinsic neuronal excitability. CONCLUSIONS Taken together, these data indicate that there are sex differences in the motivated behavior driven by glutamate within the ILC-NAcSh circuit. Though glutamatergic signaling was greater in males, heightened intrinsic excitability in females appears to drive this sex difference.
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Affiliation(s)
- Caroline S Johnson
- Department of Neuroscience, School of Medicine, University of Minnesota, 4-140 Jackson Hall, 321 Church St SE, Minneapolis, MN, 55455, USA
| | - Andrew D Chapp
- Department of Neuroscience, School of Medicine, University of Minnesota, 4-140 Jackson Hall, 321 Church St SE, Minneapolis, MN, 55455, USA
- Medical Discovery Team on Addiction, University of Minnesota, 3-432 McGuire Translational Research Facility, 2001 6th St SE, Minneapolis, MN, 55455, USA
| | - Erin B Lind
- Department of Neuroscience, School of Medicine, University of Minnesota, 4-140 Jackson Hall, 321 Church St SE, Minneapolis, MN, 55455, USA
- Medical Discovery Team on Addiction, University of Minnesota, 3-432 McGuire Translational Research Facility, 2001 6th St SE, Minneapolis, MN, 55455, USA
| | - Mark J Thomas
- Department of Neuroscience, School of Medicine, University of Minnesota, 4-140 Jackson Hall, 321 Church St SE, Minneapolis, MN, 55455, USA
- Medical Discovery Team on Addiction, University of Minnesota, 3-432 McGuire Translational Research Facility, 2001 6th St SE, Minneapolis, MN, 55455, USA
| | - Paul G Mermelstein
- Department of Neuroscience, School of Medicine, University of Minnesota, 4-140 Jackson Hall, 321 Church St SE, Minneapolis, MN, 55455, USA.
- Medical Discovery Team on Addiction, University of Minnesota, 3-432 McGuire Translational Research Facility, 2001 6th St SE, Minneapolis, MN, 55455, USA.
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Huang D, Ma YY. Increased Excitability of Layer 2 Cortical Pyramidal Neurons in the Supplementary Motor Cortex Underlies High Cocaine-Seeking Behaviors. Biol Psychiatry 2023; 94:875-887. [PMID: 37330163 PMCID: PMC10721734 DOI: 10.1016/j.biopsych.2023.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 05/29/2023] [Accepted: 06/07/2023] [Indexed: 06/19/2023]
Abstract
BACKGROUND Most efforts in addiction research have focused on the involvement of the medial prefrontal cortex, including the infralimbic, prelimbic, and anterior cingulate cortical areas, in cocaine-seeking behaviors. However, no effective prevention or treatment for drug relapse is available. METHODS We focused instead on the motor cortex, including both the primary and supplementary motor areas (M1 and M2, respectively). Addiction risk was evaluated by testing cocaine seeking after intravenous self-administration (IVSA) of cocaine in Sprague Dawley rats. The causal relationship between the excitability of cortical pyramidal neurons (CPNs) in M1/M2 and addiction risk was explored by ex vivo whole-cell patch clamp recordings and in vivo pharmacological or chemogenetic manipulation. RESULTS Our recordings showed that on withdrawal day 45 (WD45) after IVSA, cocaine, but not saline, increased the excitability of CPNs in the cortical superficial layers (primarily layer 2, denoted L2) but not in layer 5 (L5) in M2. Bilateral microinjection of the GABAA (gamma-aminobutyric acid A) receptor agonist muscimol to the M2 area attenuated cocaine seeking on WD45. More specifically, chemogenetic inhibition of CPN excitability in L2 of M2 (denoted M2-L2) by the DREADD (designer receptor exclusively activated by designer drugs) agonist compound 21 prevented drug seeking on WD45 after cocaine IVSA. This chemogenetic inhibition of M2-L2 CPNs had no effects on sucrose seeking. In addition, neither pharmacological nor chemogenetic inhibition manipulations altered general locomotor activity. CONCLUSIONS Our results indicate that cocaine IVSA induces hyperexcitability in the motor cortex on WD45. Importantly, the increased excitability in M2, particularly in L2, could be a novel target for preventing drug relapse during withdrawal.
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Affiliation(s)
- Donald Huang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana
| | - Yao-Ying Ma
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana.
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Corbett CM, Miller EN, Wannen EE, Rood BD, Chandler DJ, Loweth JA. Cocaine Exposure Increases Excitatory Synaptic Transmission and Intrinsic Excitability in the Basolateral Amygdala in Male and Female Rats and across the Estrous Cycle. Neuroendocrinology 2023; 113:1127-1139. [PMID: 37271140 PMCID: PMC10623393 DOI: 10.1159/000531351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 05/10/2023] [Indexed: 06/06/2023]
Abstract
INTRODUCTION Sex and ovarian hormones influence cocaine seeking and relapse vulnerability, but less is known regarding the cellular and synaptic mechanisms contributing to these behavioral sex differences. One factor thought to influence cue-induced seeking behavior following withdrawal is cocaine-induced changes in the spontaneous activity of pyramidal neurons in the basolateral amygdala (BLA). However, the mechanisms underlying these changes, including potential sex or estrous cycle effects, are unknown. METHODS Ex vivo whole-cell patch clamp electrophysiology was conducted to investigate the effects of cocaine exposure, sex, and estrous cycle fluctuations on two properties that can influence spontaneous activity of BLA pyramidal neurons: (1) frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs) and (2) intrinsic excitability. Recordings of BLA pyramidal neurons were conducted in adult male and female rats and across the estrous cycle following 2-4 weeks of withdrawal from extended-access cocaine self-administration (6 h/day for 10 days) or drug-naïve conditions. RESULTS In both sexes, cocaine exposure increased the frequency, but not amplitude, of sEPSCs and neuronal intrinsic excitability. Across the estrous cycle, sEPSC frequency and intrinsic excitability were significantly elevated only in cocaine-exposed females in the estrus stage of the cycle, a stage when cocaine-seeking behavior is known to be enhanced. CONCLUSIONS Here, we identify potential mechanisms underlying cocaine-induced alterations in the spontaneous activity of BLA pyramidal neurons in both sexes along with changes in these properties across the estrous cycle.
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Affiliation(s)
- Claire M. Corbett
- Graduate School of Biomedical Sciences, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Emily N.D. Miller
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Erin E. Wannen
- Graduate School of Biomedical Sciences, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Benjamin D Rood
- Graduate School of Biomedical Sciences, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Daniel J. Chandler
- Graduate School of Biomedical Sciences, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
| | - Jessica A. Loweth
- Graduate School of Biomedical Sciences, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
- Department of Cell Biology and Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, New Jersey, USA
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Sterlini B, Franchi F, Morinelli L, Corradi B, Parodi C, Albini M, Bianchi A, Marte A, Baldelli P, Alberini G, Maragliano L, Valente P, Benfenati F, Corradi A. Missense mutations in the membrane domain of PRRT2 affect its interaction with Nav1.2 voltage-gated sodium channels. Neurobiol Dis 2023:106177. [PMID: 37271286 DOI: 10.1016/j.nbd.2023.106177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/16/2023] [Accepted: 05/27/2023] [Indexed: 06/06/2023] Open
Abstract
PRRT2 is a neuronal protein that controls neuronal excitability and network stability by modulating voltage-gated Na+ channel (Nav). PRRT2 pathogenic variants cause pleiotropic syndromes including epilepsy, paroxysmal kinesigenic dyskinesia and episodic ataxia attributable to loss-of-function pathogenetic mechanism. Based on the evidence that the transmembrane domain of PRRT2 interacts with Nav1.2/1.6, we focused on eight missense mutations located within the domain that show expression and membrane localization similar to the wild-type protein. Molecular dynamics simulations showed that the mutants do not alter the structural stability of the PRRT2 membrane domain and preserve its conformation. Using affinity assays, we found that the A320V and V286M mutants displayed respectively decreased and increased binding to Nav1.2. Accordingly, surface biotinylation showed an increased Nav1.2 surface exposure induced by the A320V mutant. Electrophysiological analysis confirmed the lack of modulation of Nav1.2 biophysical properties by the A320V mutant with a loss-of-function phenotype, while the V286M mutant displayed a gain-of-function with respect to wild-type PRRT2 with a more pronounced left-shift of the inactivation kinetics and delayed recovery from inactivation. The data confirm the key role played by the PRRT2-Nav interaction in the pathogenesis of the PRRT2-linked disorders and suggest an involvement of the A320 and V286 residues in the interaction site. Given the similar clinical phenotype caused by the two mutations, we speculate that circuit instability and paroxysmal manifestations may arise when PRRT2 function is outside the physiological range.
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Affiliation(s)
- Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Francesca Franchi
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Lisastella Morinelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Beatrice Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Chiara Parodi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy
| | - Martina Albini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy
| | - Alessandra Bianchi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Giulio Alberini
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy; Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova 16132, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genova 16132, Italy.
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, Genova 16132, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, Genova 16132, Italy.
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Nimitvilai-Roberts S, Gioia D, Lopez MF, Glaser CM, Woodward JJ. Chronic intermittent ethanol exposure differentially alters the excitability of neurons in the orbitofrontal cortex and basolateral amygdala that project to the dorsal striatum. Neuropharmacology 2023; 228:109463. [PMID: 36792030 PMCID: PMC10006395 DOI: 10.1016/j.neuropharm.2023.109463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/09/2023] [Accepted: 02/10/2023] [Indexed: 02/15/2023]
Abstract
Alcohol use disorder is associated with altered neuron function including those in orbitofrontal cortex (OFC) and basolateral amygdala (BLA) that send glutamatergic inputs to areas of the dorsal striatum (DS) that mediate goal and habit directed actions. Previous studies reported that chronic intermittent (CIE) exposure to ethanol alters the electrophysiological properties of OFC and BLA neurons, although projection targets for these neurons were not identified. In this study, we used male and female mice and recorded current-evoked spiking of retrobead labeled DS-projecting OFC and BLA neurons in the same animals following air or CIE treatment. DS-projecting OFC neurons were hyperexcitable 3- and 7-days following CIE exposure and spiking returned to control levels after 14 days of withdrawal. In contrast, firing was decreased in DS-projecting BLA neurons at 3-days withdrawal, increased at 7- and 14-days and returned to baseline at 28 days post-CIE. CIE exposure enhanced the amplitude and frequency of spontaneous excitatory postsynaptic currents (sEPSCs) of DS-projecting OFC neurons but had no effect on inhibitory postsynaptic currents (sIPSCs). In DS-projecting BLA neurons, the amplitude and frequency of sIPSCs was enhanced 3 days post-CIE with no change in sEPSCs while at 7-days post-withdrawal, sEPSC amplitude and frequency were increased and sIPSCs had returned to normal. Finally, in CIE-treated mice, acute ethanol no longer inhibited spike firing of DS-projecting OFC and BLA neurons. Overall, these results suggest that CIE-induced changes in the excitability of DS-projecting OFC and BLA neurons could underlie deficits in behavioral control often observed in alcohol-dependent individuals.
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Affiliation(s)
| | - Dominic Gioia
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Marcelo F Lopez
- Department of Psychiatry and Behavioral Sciences, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Christina M Glaser
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - John J Woodward
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA; Department of Psychiatry and Behavioral Sciences, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, 29425, USA.
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Power EM, Ganeshan D, Iremonger KJ. Estradiol regulates voltage-gated potassium currents in corticotropin-releasing hormone neurons. J Exp Biol 2023; 226:287072. [PMID: 36805713 PMCID: PMC10038157 DOI: 10.1242/jeb.245222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/08/2023] [Indexed: 02/22/2023]
Abstract
Corticotropin-releasing hormone (CRH) neurons are the primary neural population controlling the hypothalamic-pituitary-adrenal (HPA) axis and the secretion of adrenal stress hormones. Previous work has demonstrated that stress hormone secretion can be regulated by circulating levels of estradiol. However, the effect of estradiol on CRH neuron excitability is less clear. Here, we show that chronic estradiol replacement following ovariectomy increases two types of potassium channel currents in CRH neurons: fast inactivating voltage-gated A-type K+ channel currents (IA) and non-inactivating M-type K+ channel currents (IM). Despite the increase in K+ currents following estradiol replacement, there was no overall change in CRH neuron spiking excitability assessed with either frequency-current curves or current ramps. Together, these data reveal a complex picture whereby ovariectomy and estradiol replacement differentially modulate distinct aspects of CRH neuron and HPA axis function.
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Affiliation(s)
- Emmet M Power
- Centre for Neuroendocrinology, Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin9016, New Zealand
| | - Dharshini Ganeshan
- Centre for Neuroendocrinology, Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin9016, New Zealand
| | - Karl J Iremonger
- Centre for Neuroendocrinology, Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin9016, New Zealand
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Jorratt P, Ricny J, Leibold C, Ovsepian SV. Endogenous Modulators of NMDA Receptor Control Dendritic Field Expansion of Cortical Neurons. Mol Neurobiol 2023; 60:1440-1452. [PMID: 36462136 PMCID: PMC9899188 DOI: 10.1007/s12035-022-03147-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 11/21/2022] [Indexed: 12/05/2022]
Abstract
Impairments of N-methyl-D-aspartate receptor (NMDAR) activity have been implicated in several neuropsychiatric disorders, with pharmacological inhibition of NMDAR-mediated currents and associated neurobehavioral changes considered as a model of schizophrenia. We analyzed the effects of brief and long-term exposure of rat cortical cultures to the most prevalent endogenous modulators of NMDAR (kynurenic acid, pregnenolone sulfate, spermidine, and zinc) on neuronal viability, stimulation-induced release of glutamate, and dendritic morphology with synaptic density. Both, glutamate release and neuronal viability studies revealed no difference between the test and control groups. No differences were also observed in the number of dendritic branching and length, or density of synaptic connections and neuronal soma size. Comparison of the extent of dendritic projections and branching patterns, however, revealed enhanced distal arborization with the expansion of the dendritic area under prolonged treatment of cultures with physiological concentrations of NMDAR modulators, with differences reaching significance in spermidine and pregnenolone sulfate tests. Measurements of the density of glutamatergic synapses showed consistency across all neuronal groups, except those treated with pregnenolone sulfate, which showed a reduction of PSD-95-positive elements. Overall, our data suggest that constitutive glutamatergic activity mediated by NMDAR controls the dendritic field expansion and can influence the integrative properties of cortical neurons.
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Affiliation(s)
- Pascal Jorratt
- grid.447902.cNational Institute of Mental Health, Klecany, Czech Republic ,grid.4491.80000 0004 1937 116XThird Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Ricny
- grid.447902.cNational Institute of Mental Health, Klecany, Czech Republic
| | - Christian Leibold
- grid.5963.9Faculty of Biology and Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Saak V. Ovsepian
- grid.36316.310000 0001 0806 5472Faculty of Science and Engineering, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB UK
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Valente P, Marte A, Franchi F, Sterlini B, Casagrande S, Corradi A, Baldelli P, Benfenati F. A Push-Pull Mechanism Between PRRT2 and β4-subunit Differentially Regulates Membrane Exposure and Biophysical Properties of NaV1.2 Sodium Channels. Mol Neurobiol 2023; 60:1281-1296. [PMID: 36441479 PMCID: PMC9899197 DOI: 10.1007/s12035-022-03112-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/26/2022] [Indexed: 11/29/2022]
Abstract
Proline-rich transmembrane protein 2 (PRRT2) is a neuron-specific protein implicated in the control of neurotransmitter release and neural network stability. Accordingly, PRRT2 loss-of-function mutations associate with pleiotropic paroxysmal neurological disorders, including paroxysmal kinesigenic dyskinesia, episodic ataxia, benign familial infantile seizures, and hemiplegic migraine. PRRT2 is a negative modulator of the membrane exposure and biophysical properties of Na+ channels NaV1.2/NaV1.6 predominantly expressed in brain glutamatergic neurons. NaV channels form complexes with β-subunits that facilitate the membrane targeting and the activation of the α-subunits. The opposite effects of PRRT2 and β-subunits on NaV channels raises the question of whether PRRT2 and β-subunits interact or compete for common binding sites on the α-subunit, generating Na+ channel complexes with distinct functional properties. Using a heterologous expression system, we have observed that β-subunits and PRRT2 do not interact with each other and act as independent non-competitive modulators of NaV1.2 channel trafficking and biophysical properties. PRRT2 antagonizes the β4-induced increase in expression and functional activation of the transient and persistent NaV1.2 currents, without affecting resurgent current. The data indicate that β4-subunit and PRRT2 form a push-pull system that finely tunes the membrane expression and function of NaV channels and the intrinsic neuronal excitability.
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Affiliation(s)
- Pierluigi Valente
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132, Genova, Italy. .,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Antonella Marte
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Francesca Franchi
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Bruno Sterlini
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Silvia Casagrande
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, Section of Physiology, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Fabio Benfenati
- IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genova, Italy. .,Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132, Genova, Italy.
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10
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Griego E, Segura-Villalobos D, Lamas M, Galván EJ. Maternal immune activation increases excitability via downregulation of A-type potassium channels and reduces dendritic complexity of hippocampal neurons of the offspring. Brain Behav Immun 2022; 105:67-81. [PMID: 35803480 DOI: 10.1016/j.bbi.2022.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/29/2022] [Accepted: 07/03/2022] [Indexed: 11/29/2022] Open
Abstract
The epidemiological association between bacterial or viral maternal infections during pregnancy and increased risk for developing psychiatric disorders in offspring is well documented. Numerous rodent and non-human primate studies of viral- or, to a lesser extent, bacterial-induced maternal immune activation (MIA) have documented a series of neurological alterations that may contribute to understanding the pathophysiology of schizophrenia and autism spectrum disorders. Long-term neuronal and behavioral alterations are now ascribed to the effect of maternal proinflammatory cytokines rather than the infection itself. However, detailed electrophysiological alterations in brain areas relevant to psychiatric disorders, such as the dorsal hippocampus, are lacking in response to bacterial-induced MIA. This study determined if electrophysiological and morphological alterations converge in CA1 pyramidal cells (CA1 PC) from the dorsal hippocampus in bacterial-induced MIA offspring. A series of changes in the functional expression of K+ and Na+ ion channels altered the passive and active membrane properties and triggered hyperexcitability of CA1 PC. Contributing to the hyperexcitability, the somatic A-type potassium current (IA) was decreased in MIA CA1 PC. Likewise, the spontaneous glutamatergic and GABAergic inputs were dysregulated and biased toward increased excitation, thereby reshaping the excitation-inhibition balance. Consistent with these findings, the dendritic branching complexity of MIA CA1 PC was reduced. Together, these morphophysiological alterations modify CA1 PC computational capabilities and contribute to explaining cellular alterations that may underlie the cognitive symptoms of MIA-associated psychiatric disorders.
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Affiliation(s)
- Ernesto Griego
- Departamento de Farmacobiología, CINVESTAV Unidad Sur, Ciudad de México, Mexico
| | | | - Mónica Lamas
- Departamento de Farmacobiología, CINVESTAV Unidad Sur, Ciudad de México, Mexico
| | - Emilio J Galván
- Departamento de Farmacobiología, CINVESTAV Unidad Sur, Ciudad de México, Mexico.
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11
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Qin X, Liu XX, Wang Y, Wang D, Song Y, Zou JX, Pan HQ, Zhai XZ, Zhang YM, Zhang YB, Hu P, Zhang WH. Early life stress induces anxiety-like behavior during adulthood through dysregulation of neuronal plasticity in the basolateral amygdala. Life Sci 2021; 285:119959. [PMID: 34536496 DOI: 10.1016/j.lfs.2021.119959] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 02/07/2023]
Abstract
AIMS Early life stress (ELS) increases the risk of psychiatric diseases such as anxiety disorders and depression in later life. Hyperactivation of the basolateral amygdala (BLA) neurons plays a pivotal role in the pathogenesis of stress-related diseases. However, the functional roles of BLA neurons in ELS-induced anxiety disorders are not completely understood. MAIN METHODS Mice were subjected to maternal separation (MS) during postnatal days 3 to 21 to mimic ELS. Anxiety-like behavior was tested by open field test (OFT), elevated plus maze (EPM), and novelty suppressed feeding (NSF). Then, c-fos expression, a proxy for neuronal activity, was evaluated by immunofluorescence. Finally, synaptic transmission and intrinsic excitability were measured by whole-cell patch-clamp recordings. KEY FINDINGS MS significantly increased anxiety-like behavior in adulthood, as indicated by less time spent in the center area of the OFT, less time spent in and fewer entries to the open arms of the EPM, and increased latency to feed in NSF. Mechanistically, MS increased the expression of c-fos in BLA. MS enhanced the excitatory, but not inhibitory, synaptic transmission onto BLA projection neurons (PNs), which was caused by enhanced presynaptic glutamate release. Moreover, MS also markedly increased the intrinsic neuronal excitability of BLA PNs, probably due to the reduced medium afterhyperpolarization (mAHP) in BLA PNs. SIGNIFICANCE Our results suggest that the changes of neuronal activity and synaptic transmission in the BLA PNs may play a crucial role in ELS-induced anxiety-like behavior, and these findings provide new insights into the pathological mechanisms of stress-related anxiety disorders.
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Affiliation(s)
- Xia Qin
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China; Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Xiao-Xuan Liu
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China; Neurology Department, the Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Yu Wang
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Dan Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Ying Song
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Jia-Xin Zou
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Han-Qing Pan
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Xiao-Zhou Zhai
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China
| | - Yong-Mei Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu 221004, China
| | - Yang-Bo Zhang
- Department of Neurology, the Second Affiliated Hospital of Nanchang University, Nanchang 330006, China
| | - Ping Hu
- Institute of Translational Medicine, Nanchang University, Nanchang 330001, China.
| | - Wen-Hua Zhang
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, Nanchang University, Nanchang 330031, China.
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12
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Nimitvilai-Roberts S, Gioia D, Zamudio PA, Woodward JJ. Ethanol inhibition of lateral orbitofrontal cortex neuron excitability is mediated via dopamine D1/D5 receptor-induced release of astrocytic glycine. Neuropharmacology 2021; 192:108600. [PMID: 33965399 DOI: 10.1016/j.neuropharm.2021.108600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/16/2021] [Accepted: 04/30/2021] [Indexed: 01/25/2023]
Abstract
Recent findings from this laboratory demonstrate that ethanol reduces the intrinsic excitability of orbitofrontal cortex (OFC) neurons via activation of strychnine-sensitive glycine receptors. Although the mechanism linking ethanol to the release of glycine is currently unknown, astrocytes are a source of neurotransmitters including glycine and activation of dopamine D1-like receptors has been reported to enhance extracellular levels of glycine via a functional reversal of the astrocytic glycine transporter GlyT1. We recently reported that like ethanol, dopamine or a D1/D5 receptor agonist increases a tonic current in lateral OFC (lOFC) neurons. Therefore, in this study, we used whole-cell patch-clamp electrophysiology to examine whether ethanol inhibition of OFC spiking involves the release of glycine from astrocytes and whether this release is dopamine receptor dependent. Ethanol, applied acutely, decreased spiking of lOFC neurons and this effect was blocked by antagonists of GlyT1, the norepinephrine transporter or D1-like but not D2-like receptors. Ethanol enhanced the tonic current of OFC neurons and occluded the effect of dopamine suggesting that ethanol and dopamine may share a common pathway. Altering astrocyte function by suppressing intracellular astrocytic calcium signaling or blocking the astrocyte-specific Kir4.1 potassium channels reduced but did not completely abolish ethanol inhibition of OFC neuron firing. However, when both astrocytic calcium signaling and Kir4.1 channels were inhibited, ethanol had no effect on firing. Ethanol inhibition was also prevented by inhibitors of phospholipase C and conventional isoforms of protein kinase C (cPKC) previously shown to block D1R-induced GlyT1 reversal and PKC inhibition of Kir4.1 channels. Finally, the membrane potential of OFC astrocytes was depolarized by bath application of a Kir4.1 blocker, a D1 agonist or ethanol and ethanol effect was blocked by a D1 antagonist. Together, these findings suggest that acute ethanol inhibits OFC neuron excitability via a D1 receptor-mediated dysregulation of astrocytic glycine transport.
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Kim KR, Kim Y, Jeong HJ, Kang JS, Lee SH, Kim Y, Lee SH, Ho WK. Impaired pattern separation in Tg2576 mice is associated with hyperexcitable dentate gyrus caused by Kv4.1 downregulation. Mol Brain 2021; 14:62. [PMID: 33785038 PMCID: PMC8011083 DOI: 10.1186/s13041-021-00774-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/23/2021] [Indexed: 12/05/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that causes memory loss. Most AD researches have focused on neurodegeneration mechanisms. Considering that neurodegenerative changes are not reversible, understanding early functional changes before neurodegeneration is critical to develop new strategies for early detection and treatment of AD. We found that Tg2576 mice exhibited impaired pattern separation at the early preclinical stage. Based on previous studies suggesting a critical role of dentate gyrus (DG) in pattern separation, we investigated functional changes in DG of Tg2576 mice. We found that granule cells in DG (DG-GCs) in Tg2576 mice showed increased action potential firing in response to long depolarizations and reduced 4-AP sensitive K+-currents compared to DG-GCs in wild-type (WT) mice. Among Kv4 family channels, Kv4.1 mRNA expression in DG was significantly lower in Tg2576 mice. We confirmed that Kv4.1 protein expression was reduced in Tg2576, and this reduction was restored by antioxidant treatment. Hyperexcitable DG and impaired pattern separation in Tg2576 mice were also recovered by antioxidant treatment. These results highlight the hyperexcitability of DG-GCs as a pathophysiologic mechanism underlying early cognitive deficits in AD and Kv4.1 as a new target for AD pathogenesis in relation to increased oxidative stress.
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Affiliation(s)
- Kyung-Ran Kim
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
| | - Yoonsub Kim
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
| | - Hyeon-Ju Jeong
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Jong-Sun Kang
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Sang Hun Lee
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Yujin Kim
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Korea
| | - Suk-Ho Lee
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Korea
- Department of Brain and Cognitive Science, Seoul National University College of Natural Science, Seoul, Korea
| | - Won-Kyung Ho
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, Korea.
- Department of Brain and Cognitive Science, Seoul National University College of Natural Science, Seoul, Korea.
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14
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Jiang N, Cupolillo D, Grosjean N, Muller E, Deforges S, Mulle C, Amédée T. Impaired plasticity of intrinsic excitability in the dentate gyrus alters spike transfer in a mouse model of Alzheimer's disease. Neurobiol Dis 2021; 154:105345. [PMID: 33766653 DOI: 10.1016/j.nbd.2021.105345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline related to deficits in synaptic transmission and plasticity. We report in APP/PS1 mice, a double transgenic mouse model of AD, that females displayed an early burden of Aβ plaques load in the stratum moleculare of the dentate gyrus (DG) together with prominent neuroinflammatory activation of astrocytes and microglia. Robust deficits in hippocampus-dependent memory tasks were observed in APP/PS1 female mice as early as 3 months of age. We then studied the functional properties of the lateral perforant path (LPP) to DG granule cells. Remarkably DG granule cells displayed higher intrinsic excitability in APP/PS1 female mice. We showed that the long term potentiation of population spike amplitude induced by high frequency stimulation (HFS) at LPP-DG granule cells synapse is impaired in APP/PS1 female mice. HFS induced plasticity of intrinsic excitability in DG granule cells without inducing noticeable modification of synaptic strength. Furthermore, the enhanced intrinsic excitability was potentiated to a greater extent in APP/PS1 as compared to control mice following HFS. Our study shows that changes in the intrinsic excitability of DG granule cells in AD contribute to the dysfunctional transfer of information from the entorhinal cortex to the hippocampus.
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Affiliation(s)
- Nan Jiang
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Dario Cupolillo
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Noelle Grosjean
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Emeline Muller
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Séverine Deforges
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Christophe Mulle
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Thierry Amédée
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France.
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15
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Gulmez Karaca K, Kupke J, Oliveira AMM. Molecular and cellular mechanisms of engram allocation and maintenance. Brain Res Bull 2021; 170:274-82. [PMID: 33647419 DOI: 10.1016/j.brainresbull.2021.02.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/29/2021] [Accepted: 02/18/2021] [Indexed: 01/19/2023]
Abstract
Understanding how we learn and remember has been a long-standing question in neuroscience. Technological developments of the past 15 years have allowed for dramatically increased access to the neurons that hold the physical representation of memory, also known as a memory trace or engram. Such developments have tremendously facilitated advancement of the memory field, since they made possible interrogation of the cellular and molecular mechanisms underlying memory formation with unprecedented cellular specificity. Here, we discuss the studies that have investigated rules governing neuronal recruitment to a particular memory engram. Furthermore, we provide an overview of the evidence that functional and structural changes associated with memory consolidation occur in engram neurons. Moreover, we summarize the expanding literature showing that transcriptional regulatory factors such as transcription factors and epigenetic mechanisms play an important role in the maintained allocation of behaviorally-selected neurons to an engram. Together, these studies have begun elucidating how neuronal networks are selected and modified in order to support memory formation and storage.
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16
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Binda F, Valente P, Marte A, Baldelli P, Benfenati F. Increased responsiveness at the cerebellar input stage in the PRRT2 knockout model of paroxysmal kinesigenic dyskinesia. Neurobiol Dis 2021; 152:105275. [PMID: 33515674 DOI: 10.1016/j.nbd.2021.105275] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/24/2021] [Accepted: 01/24/2021] [Indexed: 02/07/2023] Open
Abstract
PRoline-Rich Transmembrane protein-2 (PRRT2) is a recently described neuron-specific type-2 integral membrane protein with a large cytosolic N-terminal domain that distributes in presynaptic and axonal domains where it interacts with several presynaptic proteins and voltage-gated Na+ channels. Several PRRT2 mutations are the main cause of a wide and heterogeneous spectrum of paroxysmal disorders with a loss-of-function pathomechanism. The highest expression levels of PRRT2 in brain occurs in cerebellar granule cells (GCs) and cerebellar dysfunctions participate in the dyskinetic phenotype of PRRT2 knockout (KO) mice. We have investigated the effects of PRRT2 deficiency on the intrinsic excitability of GCs and the input-output relationships at the mossy fiber-GC synapses. We show that PRRT2 KO primary GCs display increased expression of Na+ channels, increased amplitude of Na+ currents and increased length of the axon initial segment, leading to an overall enhancement of intrinsic excitability. In acute PRRT2 KO cerebellar slices, GCs were more prone to action potential discharge in response to mossy fiber activation and exhibited an enhancement of transient and persistent Na+ currents, in the absence of changes at the mossy fiber-GC synapses. The results support a key role of PRRT2 expressed in GCs in the physiological regulation of the excitatory input to the cerebellum and are consistent with a major role of a cerebellar dysfunction in the pathogenesis of the PRRT2-linked paroxysmal pathologies.
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Affiliation(s)
- Francesca Binda
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy.
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17
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Clennell B, Steward TGJ, Elley M, Shin E, Weston M, Drinkwater BW, Whitcomb DJ. Transient ultrasound stimulation has lasting effects on neuronal excitability. Brain Stimul 2021; 14:217-225. [PMID: 33444809 PMCID: PMC7973721 DOI: 10.1016/j.brs.2021.01.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/23/2022] Open
Abstract
Background Transcranial ultrasound stimulation can acutely modulate brain activity, but the lasting effects on neurons are unknown. Objective To assess the excitability profile of neurons in the hours following transient ultrasound stimulation. Methods Primary rat cortical neurons were stimulated with a 40 s, 200 kHz pulsed ultrasound stimulation or sham-stimulation. Intrinsic firing properties were investigated through whole-cell patch-clamp recording by evoking action potentials in response to somatic current injection. Recordings were taken at set timepoints following ultrasound stimulation: 0–2 h, 6–8 h, 12–14 h and 24–26 h. Transmission electron microscopy was used to assess synaptic ultrastructure at the same timepoints. Results In the 0–2 h window, neurons stimulated with ultrasound displayed an increase in the mean frequency of evoked action potentials of 32% above control cell levels (p = 0.023). After 4–6 h this increase was measured as 44% (p = 0.0043). By 12–14 h this effect was eliminated and remained absent 24–26 h post-stimulation. These changes to action potential firing occurred in conjunction with statistically significant differences between control and ultrasound-stimulated neurons in action potential half-width, depolarisation rate, and repolarisation rate, that were similarly eliminated by 24 h following stimulation. These effects occurred in the absence of alterations to intrinsic membrane properties or synaptic ultrastructure. Conclusion We report that stimulating neurons with 40 s of ultrasound enhances their excitability for up to 8 h in conjunction with modifications to action potential kinetics. This occurs in the absence of major ultrastructural change or modification of intrinsic membrane properties. These results can inform the application of transcranial ultrasound in experimental and therapeutic settings. 40 s of ultrasound stimulation enhances intrinsic excitability of cultured rat neurons. Enhanced excitability lasts for up to 8 h. Ultrasound has no effects on neuronal ultrastructure.
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Affiliation(s)
- Benjamin Clennell
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, BS1 3NY, UK
| | - Tom G J Steward
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, BS1 3NY, UK
| | - Meg Elley
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, BS1 3NY, UK
| | - Eunju Shin
- Neuroscience and Mental Health Research Institute, Cardiff University, Cardiff, CF24 4HQ, UK
| | - Miles Weston
- TWI Technology Centre, Port Talbot, SA13 1SB, UK
| | | | - Daniel J Whitcomb
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, BS1 3NY, UK.
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18
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Galaj E, Guo C, Huang D, Ranaldi R, Ma YY. Contrasting effects of adolescent and early-adult ethanol exposure on prelimbic cortical pyramidal neurons. Drug Alcohol Depend 2020; 216:108309. [PMID: 32998090 PMCID: PMC7814343 DOI: 10.1016/j.drugalcdep.2020.108309] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Adolescence and early-adulthood are vulnerable developmental periods during which binge drinking can have long-lasting effects on brain function. However, little is known about the effects of binge drinking on the pyramidal cells of the prelimbic cortex (PrL) during early and protracted withdrawal periods. METHODS In the present study, we performed whole-cell patch clamp recordings and dendritic spine staining to examine the intrinsic excitability, spontaneous excitatory post-synaptic currents (sEPSCs), and spine morphology of pyramidal cells in the PrL from rats exposed to chronic intermittent ethanol (CIE) during adolescence or early-adulthood. RESULTS Compared to chronic intermittent water (CIW)-treated controls, the excitability of PrL-L5 pyramidal neurons was significantly increased 21 days after adolescent CIE but decreased 21 days after early-adult CIE. No changes of excitability in PrL Layer (L) 5 were detected 2 days after either adolescent or early-adulthood CIE. Interestingly, decreases in sEPSC amplitude and increases in thin spines ratio were detected 2 days after adolescent CIE. Furthermore, decreased frequency and amplitude of sEPSCs, accompanied by a decrease in the density of total spines and non-thin spines were observed 21 days after adolescent CIE. In contrast, increased frequency and amplitude of sEPSCs, accompanied by increased densities of total spines and non-thin spines were found 21 days after early adult CIE. CONCLUSION CIE produced prolonged neuronal and synaptic alterations in PrL-L5, and the developmental stage, i.e., adolescence vs. early-adulthood when subjects receive CIE, is a key factor in determining the direction of these changes.
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Affiliation(s)
- Ewa Galaj
- Department of Psychology, Behavioral Neuroscience Program, State University of New York, Binghamton, NY, 13902, USA
| | - Changyong Guo
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Donald Huang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Robert Ranaldi
- Department of Psychology, Queens College, City University of New York, Flushing, NY, 11367, USA
| | - Yao-Ying Ma
- Department of Psychology, Behavioral Neuroscience Program, State University of New York, Binghamton, NY, 13902, USA; Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA; Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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19
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Popescu IR, Le KQ, Ducote AL, Li JE, Leland AE, Mostany R. Increased intrinsic excitability and decreased synaptic inhibition in aged somatosensory cortex pyramidal neurons. Neurobiol Aging 2020; 98:88-98. [PMID: 33249377 DOI: 10.1016/j.neurobiolaging.2020.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/02/2020] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
Abstract
Sensorimotor performance declines during advanced age, partially due to deficits in somatosensory acuity. Cortical receptive field expansion contributes to somatosensory deficits, suggesting increased excitability or decreased inhibition in primary somatosensory cortex (S1) pyramidal neurons. To ascertain changes in excitability and inhibition, we measured both properties in neurons from vibrissal S1 in brain slices from young and aged mice. Because adapting and non-adapting neurons-the principal pyramidal types in layer 5 (L5)-differ in intrinsic properties and inhibitory inputs, we determined age-dependent changes according to neuron type. We found an age-dependent increase in intrinsic excitability in adapting neurons, caused by a decrease in action potential threshold. Surprisingly, in non-adapting neurons we found both an increase in excitability caused by increased input resistance, and a decrease in synaptic inhibition. Spike frequency adaptation, already small in non-adapting neurons, was further reduced by aging, whereas sag, a manifestation of Ih, was increased. Therefore, aging caused both decreased inhibition and increased intrinsic excitability, but these effects were specific to pyramidal neuron type.
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Affiliation(s)
- Ion R Popescu
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA.
| | - Kathy Q Le
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Alexis L Ducote
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Jennifer E Li
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | | | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
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20
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Kim YG, Kim SJ. Decreased intrinsic excitability of cerebellar Purkinje cells following optokinetic learning in mice. Mol Brain 2020; 13:136. [PMID: 33028375 DOI: 10.1186/s13041-020-00678-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 09/25/2020] [Indexed: 01/28/2023] Open
Abstract
The optokinetic response (OKR), a reflexive eye movement evoked by a motion of the visual field, is known to adapt its strength to cope with an environmental change throughout life, which is a type of cerebellum-dependent learning. Previous studies suggested that OKR learning induces changes in in-vivo spiking activity and synaptic transmission of the cerebellar Purkinje cell (PC). Despite the recent emphasis on the importance of the intrinsic excitability related to learning and memory, the direct correlation between the intrinsic excitability of PCs and OKR learning has not been tested. In the present study, by utilizing the whole-cell patch-clamp recording, we compared the responses of cerebellar PCs to somatic current injection between the control and learned groups. We found that the neurons from the learned group showed a significant reduction in mean firing rate compared with neurons in the control group. In the analysis of single action potential (AP), we revealed that the rheobase current for the generation of single AP was increased by OKR learning, while AP threshold, AP amplitude, and afterhyperpolarization amplitude were not altered. Taken together, our result suggests that the decrease in the intrinsic excitability was induced in the cerebellar PC of learned group by an increase in the current threshold for generating AP.
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21
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Severin D, Gallagher M, Kirkwood A. Afterhyperpolarization amplitude in CA1 pyramidal cells of aged Long-Evans rats characterized for individual differences. Neurobiol Aging 2020; 96:43-48. [PMID: 32932137 DOI: 10.1016/j.neurobiolaging.2020.07.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 07/06/2020] [Accepted: 07/25/2020] [Indexed: 11/18/2022]
Abstract
Altered neural excitability is considered a prominent contributing factor to cognitive decline during aging. A clear example is the excess neural activity observed in several temporal lobe structures of cognitively impaired older individuals in rodents and humans. At a cellular level, aging-related changes in mechanisms regulating intrinsic excitability have been well examined in pyramidal cells of the CA1 hippocampal subfield. Studies in the inbred Fisher 344 rat strain document an age-related increase in the slow afterhyperpolarization (AHP) that normally occurs after a burst of action potentials, and serves to reduce subsequent firing. We evaluated the status of the AHP in the outbred Long-Evans rat, a well-established model for studying individual differences in neurocognitive aging. In contrast to the findings reported in the Fisher 344 rats, in the Long-Evan rats we detected a selective reduction in AHP in cognitively impaired aged individuals. We discuss plausible scenarios to account for these differences and also discuss possible implications of these differences.
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Affiliation(s)
- Daniel Severin
- Department of Neurosciences, Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Alfredo Kirkwood
- Department of Neurosciences, Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA.
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22
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Chen L, Cummings KA, Mau W, Zaki Y, Dong Z, Rabinowitz S, Clem RL, Shuman T, Cai DJ. The role of intrinsic excitability in the evolution of memory: Significance in memory allocation, consolidation, and updating. Neurobiol Learn Mem 2020; 173:107266. [PMID: 32512183 PMCID: PMC7429265 DOI: 10.1016/j.nlm.2020.107266] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 05/28/2020] [Accepted: 05/31/2020] [Indexed: 11/30/2022]
Abstract
Memory is a dynamic process that is continuously regulated by both synaptic and intrinsic neural mechanisms. While numerous studies have shown that synaptic plasticity is important in various types and phases of learning and memory, neuronal intrinsic excitability has received relatively less attention, especially regarding the dynamic nature of memory. In this review, we present evidence demonstrating the importance of intrinsic excitability in memory allocation, consolidation, and updating. We also consider the intricate interaction between intrinsic excitability and synaptic plasticity in shaping memory, supporting both memory stability and flexibility.
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Affiliation(s)
- Lingxuan Chen
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Kirstie A Cummings
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - William Mau
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Yosif Zaki
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Zhe Dong
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Sima Rabinowitz
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Roger L Clem
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Tristan Shuman
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Denise J Cai
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States.
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23
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Porter JT, Sepulveda-Orengo MT. Learning-induced intrinsic and synaptic plasticity in the rodent medial prefrontal cortex. Neurobiol Learn Mem 2019; 169:107117. [PMID: 31765801 DOI: 10.1016/j.nlm.2019.107117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 11/06/2019] [Accepted: 11/14/2019] [Indexed: 01/12/2023]
Abstract
In rodents, the anterior cingulate (ACC), prelimbic (PL), and infralimbic cortex (IL) comprise the medial prefrontal cortex (mPFC). Through extensive connections with cortical and subcortical structures, the mPFC plays a key modulatory role in the neuronal circuits underlying associative fear and reward learning. In this article, we have compiled the evidence that associative learning induces plasticity in both the intrinsic and synaptic excitability of mPFC neurons to modulate conditioned fear and cocaine seeking behavior. The literature highlights the accumulating evidence that plasticity in the intrinsic excitability of mPFC neurons represents a major cellular mechanism that interacts with synaptic changes to alter the impact of the mPFC on fear and reward circuits.
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Affiliation(s)
- James T Porter
- Dept of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, PR 00732, United States.
| | - Marian T Sepulveda-Orengo
- Dept of Basic Sciences, Ponce Research Institute, Ponce Health Sciences University, Ponce, PR 00732, United States
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24
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Dunn AR, Kaczorowski CC. Regulation of intrinsic excitability: Roles for learning and memory, aging and Alzheimer's disease, and genetic diversity. Neurobiol Learn Mem 2019; 164:107069. [PMID: 31442579 DOI: 10.1016/j.nlm.2019.107069] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/09/2019] [Accepted: 08/17/2019] [Indexed: 12/28/2022]
Abstract
Plasticity of intrinsic neuronal excitability facilitates learning and memory across multiple species, with aberrant modulation of this process being linked to the development of neurological symptoms in models of cognitive aging and Alzheimer's disease. Learning-related increases in intrinsic excitability of neurons occurs in a variety of brain regions, and is generally thought to promote information processing and storage through enhancement of synaptic throughput and induction of synaptic plasticity. Experience-dependent changes in intrinsic neuronal excitability rely on activity-dependent gene expression patterns, which can be influenced by genetic and environmental factors, aging, and disease. Reductions in baseline intrinsic excitability, as well as aberrant plasticity of intrinsic neuronal excitability and in some cases pathological hyperexcitability, have been associated with cognitive deficits in animal models of both normal cognitive aging and Alzheimer's disease. Genetic factors that modulate plasticity of intrinsic excitability likely underlie individual differences in cognitive function and susceptibility to cognitive decline. Thus, targeting molecular mediators that either control baseline intrinsic neuronal excitability, subserve learning-related intrinsic neuronal plasticity, and/or promote resilience may be a promising therapeutic strategy for maintaining cognitive function in aging and disease. In this review, we discuss the complementary relationship between intrinsic excitability and learning, with a particular focus on how this relationship varies as a function of age, disease state, and genetic make-up, and how targeting these factors may help to further elucidate our understanding of the role of intrinsic excitability in cognitive function and cognitive decline.
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Affiliation(s)
- Amy R Dunn
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
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25
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Francis TC, Gaynor A, Chandra R, Fox ME, Lobo MK. The Selective RhoA Inhibitor Rhosin Promotes Stress Resiliency Through Enhancing D1-Medium Spiny Neuron Plasticity and Reducing Hyperexcitability. Biol Psychiatry 2019; 85:1001-10. [PMID: 30955841 DOI: 10.1016/j.biopsych.2019.02.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/22/2019] [Accepted: 02/05/2019] [Indexed: 12/11/2022]
Abstract
BACKGROUND Nucleus accumbens dopamine 1 receptor medium spiny neurons (D1-MSNs) play a critical role in the development of depression-like behavior in mice. Social defeat stress causes dendritic morphological changes on this MSN subtype through expression and activation of early growth response 3 (EGR3) and the Rho guanosine triphosphatase RhoA. However, it is unknown how RhoA inhibition affects electrophysiological properties underlying stress-induced susceptibility. METHODS A novel RhoA-specific inhibitor, Rhosin, was used to inhibit RhoA activity following chronic social defeat stress. Whole-cell electrophysiological recordings of D1-MSNs were performed to assess synaptic and intrinsic consequences of Rhosin treatment on stressed mice. Additionally, recorded cells were filled and analyzed for their morphological properties. RESULTS We found that RhoA inhibition prevents both D1-MSN hyperexcitability and reduced excitatory input to D1-MSNs caused by social defeat stress. Nucleus accumbens-specific RhoA inhibition is capable of blocking susceptibility caused by D1-MSN EGR3 expression. Lastly, we found that Rhosin enhances spine density, which correlates with D1-MSN excitability, without affecting overall dendritic branching. CONCLUSIONS These findings demonstrate that pharmacological inhibition of RhoA during stress drives an enhancement of total spine number in a subset of nucleus accumbens neurons that prevents stress-related electrophysiological deficits and promotes stress resiliency.
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26
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Anderson EM, Gomez D, Caccamise A, McPhail D, Hearing M. Chronic unpredictable stress promotes cell-specific plasticity in prefrontal cortex D1 and D2 pyramidal neurons. Neurobiol Stress 2019; 10:100152. [PMID: 30937357 DOI: 10.1016/j.ynstr.2019.100152] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 03/04/2019] [Accepted: 03/04/2019] [Indexed: 11/24/2022] Open
Abstract
Exposure to unpredictable environmental stress is widely recognized as a major determinant for risk and severity in neuropsychiatric disorders such as major depressive disorder, anxiety, schizophrenia, and PTSD. The ability of ostensibly unrelated disorders to give rise to seemingly similar psychiatric phenotypes highlights a need to identify circuit-level concepts that could unify diverse factors under a common pathophysiology. Although difficult to disentangle a causative effect of stress from other factors on medial prefrontal cortex (PFC) dysfunction, a wealth of data from humans and rodents demonstrates that the PFC is a key target of stress. The present study sought to identify a model of chronic unpredictable stress (CUS) which induces affective behaviors in C57BL6J mice and once established, measure stress-related alterations in intrinsic excitability and synaptic regulation of mPFC layer 5/6 pyramidal neurons. Adult male mice received 2 weeks of 'less intense' stress or 2 or 4 weeks of 'more intense' CUS followed by sucrose preference for assessment of anhedonia, elevated plus maze for assessment of anxiety and forced swim test for assessment of depressive-like behaviors. Our findings indicate that more intense CUS exposure results in increased anhedonia, anxiety, and depressive behaviors, while the less intense stress results in no measured behavioral phenotypes. Once a behavioral model was established, mice were euthanized approximately 21 days post-stress for whole-cell patch clamp recordings from layer 5/6 pyramidal neurons in the prelimbic (PrL) and infralimbic (IL) cortices. No significant differences were initially observed in intrinsic cell excitability in either region. However, post-hoc analysis and subsequent confirmation using transgenic mice expressing tdtomato or eGFP under control of dopamine D1-or D2-type receptor showed that D1-expressing pyramidal neurons (D1-PYR) in the PrL exhibit reduced thresholds to fire an action potential (increased excitability) but impaired firing capacity at more depolarized potentials, whereas D2-expressing pyramidal neurons (D2-PYR) showed an overall reduction in excitability and spike firing frequency. Examination of synaptic transmission showed that D1-and D2-PYR exhibit differences in basal excitatory and inhibitory signaling under naïve conditions. In CUS mice, D1-PYR showed increased frequency of both miniature excitatory and inhibitory postsynaptic currents, whereas D2-PYR only showed a reduction in excitatory currents. These findings demonstrate that D1-and D2-PYR subpopulations differentially undergo stress-induced intrinsic and synaptic plasticity that may have functional implications for stress-related pathology, and that these adaptations may reflect unique differences in basal properties regulating output of these cells.
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27
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Curran JA, Buhl E, Tsaneva-Atanasova K, Hodge JJL. Age-dependent changes in clock neuron structural plasticity and excitability are associated with a decrease in circadian output behavior and sleep. Neurobiol Aging 2019; 77:158-168. [PMID: 30825692 PMCID: PMC6491500 DOI: 10.1016/j.neurobiolaging.2019.01.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/19/2018] [Accepted: 01/25/2019] [Indexed: 12/16/2022]
Abstract
Aging has significant effects on circadian behavior across a wide variety of species, but the underlying mechanisms are poorly understood. Previous work has demonstrated the age-dependent decline in behavioral output in the model organism Drosophila. We demonstrate that this age-dependent decline in circadian output is combined with changes in daily activity of Drosophila. Aging also has a large impact on sleep behavior, significantly increasing sleep duration while reducing latency. We used electrophysiology to record from large ventral lateral neurons of the Drosophila circadian clock, finding a significant decrease in input resistance with age but no significant changes in spontaneous electrical activity or membrane potential. We propose this change contributes to observed behavioral and sleep changes in light-dark conditions. We also demonstrate a reduction in the daily plasticity of the architecture of the small ventral lateral neurons, likely underlying the reduction in circadian rhythmicity during aging. These results provide further insights into the effect of aging on circadian biology, demonstrating age-related changes in electrical activity in conjunction with the decline in behavioral outputs.
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Affiliation(s)
- Jack A Curran
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Edgar Buhl
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Krasimira Tsaneva-Atanasova
- Department of Mathematics and Living Systems Institute, University of Exeter, Exeter, UK; EPSRC Centre for Predictive Modelling in Healthcare, University of Exeter, Exeter, UK
| | - James J L Hodge
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
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28
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Yu W, Sohn JW, Kwon J, Lee SH, Kim S, Ho WK. Enhancement of dendritic persistent Na + currents by mGluR5 leads to an advancement of spike timing with an increase in temporal precision. Mol Brain 2018; 11:67. [PMID: 30413218 PMCID: PMC6230299 DOI: 10.1186/s13041-018-0410-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 10/23/2018] [Indexed: 11/10/2022] Open
Abstract
Timing and temporal precision of action potential generation are thought to be important for encoding of information in the brain. The ability of single neurons to transform their input into output action potential is primarily determined by intrinsic excitability. Particularly, plastic changes in intrinsic excitability represent the cellular substrate for spatial memory formation in CA1 pyramidal neurons (CA1-PNs). Here, we report that synaptically activated mGluR5-signaling can modulate the intrinsic excitability of CA1-PNs. Specifically, high-frequency stimulation at CA3-CA1 synapses increased firing rate and advanced spike onset with an improvement of temporal precision. These changes are mediated by mGluR5 activation that induces cADPR/RyR-dependent Ca2+ release in the dendrites of CA1-PNs, which in turn causes an increase in persistent Na+ currents (INa,P) in the dendrites. When group I mGluRs in CA1-PNs are globally activated pharmacologically, afterdepolarization (ADP) generation as well as increased firing rate are observed. These effects are abolished by inhibiting mGluR5/cADPR/RyR-dependent Ca2+ release. However, the increase in firing rate, but not the generation of ADP is affected by inhibiting INa,P. The differences between local and global activation of mGluR5-signaling in CA1-PNs indicates that mGluR5-dependent modulation of intrinsic excitability is highly compartmentalized and a variety of ion channels are recruited upon their differential subcellular localizations. As mGluR5 activation is induced by physiologically plausible brief high-frequency stimulation at CA3-CA1 synapses, our results suggest that mGluR5-induced enhancement of dendritic INa,P in CA1-PNs may provide important implications for our understanding about place field formation in the hippocampus.
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Affiliation(s)
- Weonjin Yu
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea
| | - Jong-Woo Sohn
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea
| | - Jaehan Kwon
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea
| | - Suk-Ho Lee
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea
| | - Sooyun Kim
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea.
| | - Won-Kyung Ho
- Department of Physiology, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea. .,Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 110-799, Republic of Korea.
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29
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Ransdell JL, Nerbonne JM. Voltage-gated sodium currents in cerebellar Purkinje neurons: functional and molecular diversity. Cell Mol Life Sci 2018; 75:3495-3505. [PMID: 29982847 PMCID: PMC6123253 DOI: 10.1007/s00018-018-2868-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 06/28/2018] [Accepted: 07/03/2018] [Indexed: 01/09/2023]
Abstract
Purkinje neurons, the sole output of the cerebellar cortex, deliver GABA-mediated inhibition to the deep cerebellar nuclei. To subserve this critical function, Purkinje neurons fire repetitively, and at high frequencies, features that have been linked to the unique properties of the voltage-gated sodium (Nav) channels expressed. In addition to the rapidly activating and inactivating, or transient, component of the Nav current (INaT) present in many types of central and peripheral neurons, Purkinje neurons, also expresses persistent (INaP) and resurgent (INaR) Nav currents. Considerable progress has been made in detailing the biophysical properties and identifying the molecular determinants of these discrete Nav current components, as well as defining their roles in the regulation of Purkinje neuron excitability. Here, we review this important work and highlight the remaining questions about the molecular mechanisms controlling the expression and the functioning of Nav currents in Purkinje neurons. We also discuss the impact of the dynamic regulation of Nav currents on the functioning of individual Purkinje neurons and cerebellar circuits.
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Affiliation(s)
- Joseph L Ransdell
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Department of Medicine, Washington University School of Medicine, Box 8086, 660 South Euclid Avenue, St. Louis, MO, 63110, USA
| | - Jeanne M Nerbonne
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA.
- Department of Medicine, Washington University School of Medicine, Box 8086, 660 South Euclid Avenue, St. Louis, MO, 63110, USA.
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30
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Xiao K, Sun Z, Jin X, Ma W, Song Y, Lai S, Chen Q, Fan M, Zhang J, Yue W, Huang Z. ERG3 potassium channel-mediated suppression of neuronal intrinsic excitability and prevention of seizure generation in mice. J Physiol 2018; 596:4729-4752. [PMID: 30016551 DOI: 10.1113/jp275970] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 07/05/2018] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS ERG3 channels have a high expression level in the central nervous system. Knockdown of ERG3 channels enhances neuronal intrinsic excitability (caused by decreased fast afterhyperpolarization, shortened delay time to the generation of an action potential and enhanced summation of somatic excitatory postsynaptic potentials) in hippocampal CA1 pyramidal neurons and dentate gyrus granule cells. The expression of ERG3 protein is reduced in human and mouse hippocampal epileptogenic foci. Knockdown of ERG3 channels in hippocampus enhanced seizure susceptibility, while mice treated with the ERG channel activator NS-1643 were less prone to epileptogenesis. The results provide strong evidence that ERG3 channels have a crucial role in the regulation of neuronal intrinsic excitability in hippocampal CA1 pyramidal neurons and dentate gyrus granule cells and are critically involved in the onset and development of epilepsy. ABSTRACT The input-output relationship of neuronal networks depends heavily on the intrinsic properties of their neuronal elements. Profound changes in intrinsic properties have been observed in various physiological and pathological processes, such as learning, memory and epilepsy. However, the cellular and molecular mechanisms underlying acquired changes in intrinsic excitability are still not fully understood. Here, we demonstrate that ERG3 channels are critically involved in the regulation of intrinsic excitability in hippocampal CA1 pyramidal neurons and dentate gyrus granule cells. Knock-down of ERG3 channels significantly increases neuronal intrinsic excitability, which is mainly caused by decreased fast afterhyperpolarization, shortened delay time to the generation of an action potential and enhanced summation of somatic excitatory postsynaptic potentials. Interestingly, the expression level of ERG3 protein is significantly reduced in human and mouse brain tissues with temporal lobe epilepsy. Moreover, ERG3 channel knockdown in hippocampus significantly enhanced seizure susceptibility, while mice treated with the ERG channel activator NS-1643 were less prone to epileptogenesis. Taken together, our results suggest ERG3 channels play an important role in determining the excitability of hippocampal neurons and dysregulation of these channels may be involved in the generation of epilepsy. ERG3 channels may thus be a novel therapeutic target for the prevention of epilepsy.
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Affiliation(s)
- Kuo Xiao
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Zhiming Sun
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Xueqin Jin
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Weining Ma
- Department of Neurology, Shengjing Hospital affiliated to China Medical University, Shenyang, 110000, China
| | - Yan Song
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Shirong Lai
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Qian Chen
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Minghua Fan
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Jingliang Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China
| | - Weihua Yue
- Peking University Sixth Hospital (Institute of Mental Health), Beijing, 100191, China.,National Clinical Research Center for Mental Disorders & Key Laboratory of Mental Health, Ministry of Health (Peking University), Beijing, 100191, China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, 100191, China.,Key Laboratory for Neuroscience, Ministry of Education, Beijing, 100191, China
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31
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Evans MC, Dougherty KA. Carbamazepine-induced suppression of repetitive firing in CA1 pyramidal neurons is greater in the dorsal hippocampus than the ventral hippocampus. Epilepsy Res 2018; 145:63-72. [PMID: 29913405 DOI: 10.1016/j.eplepsyres.2018.05.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/11/2018] [Accepted: 05/29/2018] [Indexed: 10/14/2022]
Abstract
Medial temporal lobe epilepsy (mTLE)-the most common form of focal epilepsy-is defined by recurrent partial seizures originating within the medial temporal lobe. Such seizures are commonly associated with the anterior hippocampus (as opposed to the posterior hippocampus), and refractory to the currently available anti-epileptic drugs (AED) for about one third of patients. Unfortunately, the mechanisms driving seizure generation and AED efficacy along the longitudinal hippocampal axis remain poorly understood. Recently, several groups investigating differences in excitability along the rodent longitudinal hippocampal axis have demonstrated that CA1 pyramidal neurons from the rodent ventral hippocampus (the rodent homolog of the human anterior hippocampus) are intrinsically more excitable than their dorsal counterparts (the rodent homolog of the human posterior hippocampus). This phenotypic difference is accompanied by significant differences in gene expression along the longitudinal hippocampal axis, which include gene products-such as voltage-gated sodium channel β-subunits-known to influence AED efficacy. Given this phenotypic heterogeneity, and the differential expression of gene products known to influence anti-epileptic drug efficacy, we sought to investigate the efficacy of the classical use-dependent sodium channel blocker, carbamazepine, in CA1 pyramidal neurons across the longitudinal hippocampal axis. Accordingly, we performed whole-cell current-clamp recordings on CA1 pyramidal neurons from acute hippocampal slices prepared from the dorsal and ventral hippocampus, and found that acute exposure to 100 μM carbamazepine induced a significantly greater suppression of repetitive firing for dorsal neurons relative to ventral neurons by inducing profound spike frequency adaptation (SFA). Moreover, we observed a small, but significant depolarization of resting membrane potential (RMP) for dorsal neurons (but not ventral neurons), following exposure to carbamazepine. Together, these observations demonstrate that carbamazepine's effect is concentrated in the dorsal hippocampus, which could provide meaningful insight into the side effect profile of carbamazepine (and related anti-epileptic drugs) in non-epileptic tissue, and inform future work investigating the mechanisms of carbamazepine resistance in epileptic tissue.
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Affiliation(s)
| | - Kelly Ann Dougherty
- Department of Biology, Rhodes College, 2000 N Parkway, Memphis, TN, 38112, USA.
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32
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Abstract
Throughout life, neural circuits change their connectivity, especially during development, when neurons frequently extend and retract dendrites and axons, and form and eliminate synapses. In spite of their changing connectivity, neural circuits maintain relatively constant activity levels. Neural circuits achieve functional stability by homeostatic plasticity, which equipoises intrinsic excitability and synaptic strength, balances network excitation and inhibition, and coordinates changes in circuit connectivity. Here, we review how diverse mechanisms of homeostatic plasticity stabilize activity in developing neural circuits.
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Affiliation(s)
- Nai-Wen Tien
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, USA. .,Graduate Program in Neuroscience, Washington University School of Medicine, Saint Louis, USA.
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, USA. .,Department of Neuroscience, Washington University School of Medicine, Saint Louis, USA. .,Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, USA. .,Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, MO, 63110, USA.
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Nimitvilai S, Lopez MF, Woodward JJ. Effects of monoamines on the intrinsic excitability of lateral orbitofrontal cortex neurons in alcohol-dependent and non-dependent female mice. Neuropharmacology 2018; 137:1-12. [PMID: 29689260 DOI: 10.1016/j.neuropharm.2018.04.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 04/10/2018] [Accepted: 04/19/2018] [Indexed: 11/20/2022]
Abstract
Changes in brain reward and control systems of frontal cortical areas including the orbitofrontal cortex (OFC) are associated with alcohol use disorders (AUD). The OFC is extensively innervated by monoamines, and drugs that target monoamine receptors have been used to treat a number of neuropsychiatric diseases, including AUDs. Recent findings from this laboratory demonstrate that D2, α2-adrenergic and 5HT1A receptors all decrease the intrinsic excitability of lateral OFC (lOFC) neurons in naïve male mice and that this effect is lost in mice exposed to repeated cycles of chronic intermittent ethanol (CIE) vapor. As biological sex differences may influence an individual's response to alcohol and contribute to the propensity to engage in addictive behaviors, we examined whether monoamines have similar effects on lOFC neurons in control and CIE exposed female mice. Dopamine, norepinephrine and serotonin all decreased spiking of lOFC neurons in naïve females via activation of Giα-coupled D2, α2-adrenergic and 5HT1A receptors, respectively. Firing was also inhibited by the direct GIRK channel activator ML297, while blocking these channels with barium eliminated the inhibitory actions of monoamines. Following CIE treatment, evoked spiking of lOFC neurons from female mice was significantly enhanced and monoamines and ML297 no longer inhibited firing. Unlike in male mice, the enhanced firing of neurons from CIE exposed female mice was not associated with changes in the after-hyperpolarization and the small-conductance potassium channel blocker apamin had no effect on current-evoked tail currents from either control or CIE exposed female mice. These results suggest that while CIE exposure alters monoamine regulation of OFC neuron firing similarly in males and female mice, there are sex-dependent differences in processes that regulate the intrinsic excitability of these neurons.
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Sehgal M, Zhou M, Lavi A, Huang S, Zhou Y, Silva AJ. Memory allocation mechanisms underlie memory linking across time. Neurobiol Learn Mem 2018; 153:21-5. [PMID: 29496645 DOI: 10.1016/j.nlm.2018.02.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 02/14/2018] [Accepted: 02/19/2018] [Indexed: 11/22/2022]
Abstract
Memories are dynamic in nature. A cohesive representation of the world requires memories to be altered over time, linked with other memories and eventually integrated into a larger framework of sematic knowledge. Although there is a considerable literature on how single memories are encoded, retrieved and updated, little is known about the mechanisms that govern memory linking, e.g., linking and integration of various memories across hours or days. In this review, we present evidence that specific memory allocation mechanisms, such as changes in CREB and intrinsic excitability, ensure memory storage in ways that facilitate effective recall and linking at a later time. Beyond CREB and intrinsic excitability, we also review a number of other phenomena with potential roles in memory linking.
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35
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Cannady R, Rinker JA, Nimitvilai S, Woodward JJ, Mulholland PJ. Chronic Alcohol, Intrinsic Excitability, and Potassium Channels: Neuroadaptations and Drinking Behavior. Handb Exp Pharmacol 2018; 248:311-343. [PMID: 29374839 DOI: 10.1007/164_2017_90] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neural mechanisms underlying alcohol use disorder remain elusive, and this lack of understanding has slowed the development of efficacious treatment strategies for reducing relapse rates and prolonging abstinence. While synaptic adaptations produced by chronic alcohol exposure have been extensively characterized in a variety of brain regions, changes in intrinsic excitability of critical projection neurons are understudied. Accumulating evidence suggests that prolonged alcohol drinking and alcohol dependence produce plasticity of intrinsic excitability as measured by changes in evoked action potential firing and after-hyperpolarization amplitude. In this chapter, we describe functional changes in cell firing of projection neurons after long-term alcohol exposure that occur across species and in multiple brain regions. Adaptations in calcium-activated (KCa2), voltage-dependent (KV7), and G protein-coupled inwardly rectifying (Kir3 or GIRK) potassium channels that regulate the evoked firing and after-hyperpolarization parallel functional changes in intrinsic excitability induced by chronic alcohol. Moreover, there are strong genetic links between alcohol-related behaviors and genes encoding KCa2, KV7, and GIRK channels, and pharmacologically targeting these channels reduces alcohol consumption and alcohol-related behaviors. Together, these studies demonstrate that chronic alcohol drinking produces adaptations in KCa2, KV7, and GIRK channels leading to impaired regulation of the after-hyperpolarization and aberrant cell firing. Correcting the deficit in the after-hyperpolarization with positive modulators of KCa2 and KV7 channels and altering the GIRK channel binding pocket to block the access of alcohol represent a potentially highly effective pharmacological approach that can restore changes in intrinsic excitability and reduce alcohol consumption in affected individuals.
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Affiliation(s)
- Reginald Cannady
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Jennifer A Rinker
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Sudarat Nimitvilai
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - John J Woodward
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA
| | - Patrick J Mulholland
- Departments of Neuroscience and Psychiatry and Behavioral Sciences, Charleston Alcohol Research Center, Addiction Sciences Division, Medical University of South Carolina, Charleston, SC, USA.
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36
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Albiñana E, Luengo JG, Baraibar AM, Muñoz MD, Gandía L, Solís JM, Hernández-Guijo JM. Choline induces opposite changes in pyramidal neuron excitability and synaptic transmission through a nicotinic receptor-independent process in hippocampal slices. Pflugers Arch 2017; 469:779-795. [PMID: 28176016 DOI: 10.1007/s00424-017-1939-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 01/17/2017] [Accepted: 01/19/2017] [Indexed: 01/13/2023]
Abstract
Choline is present at cholinergic synapses as a product of acetylcholine degradation. In addition, it is considered a selective agonist for α5 and α7 nicotinic acetylcholine receptors (nAChRs). In this study, we determined how choline affects action potentials and excitatory synaptic transmission using extracellular and intracellular recording techniques in CA1 area of hippocampal slices obtained from both mice and rats. Choline caused a reversible depression of evoked field excitatory postsynaptic potentials (fEPSPs) in a concentration-dependent manner that was not affected by α7 nAChR antagonists. Moreover, this choline-induced effect was not mimicked by either selective agonists or allosteric modulators of α7 nAChRs. Additionally, this choline-mediated effect was not prevented by either selective antagonists of GABA receptors or hemicholinium, a choline uptake inhibitor. The paired pulse facilitation paradigm, which detects whether a substance affects presynaptic release of glutamate, was not modified by choline. On the other hand, choline induced a robust increase of population spike evoked by orthodromic stimulation but did not modify that evoked by antidromic stimulation. We also found that choline impaired recurrent inhibition recorded in the pyramidal cell layer through a mechanism independent of α7 nAChR activation. These choline-mediated effects on fEPSP and population spike observed in rat slices were completely reproduced in slices obtained from α7 nAChR knockout mice, which reinforces our conclusion that choline modulates synaptic transmission and neuronal excitability by a mechanism independent of nicotinic receptor activation.
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Affiliation(s)
- E Albiñana
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - J G Luengo
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - A M Baraibar
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - M D Muñoz
- Servicio de Neurología Experimental, Hospital Universitario Ramón y Cajal, IRYCIS, 28034, Madrid, Spain
| | - L Gandía
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain.,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain
| | - J M Solís
- Servicio de Neurobiología-Investigación, Hospital Universitario Ramón y Cajal, IRYCIS, 28034, Madrid, Spain
| | - J M Hernández-Guijo
- Department of Pharmacology and Therapeutic, University Autónoma de Madrid, Av. Arzobispo Morcillo 4, 28029, Madrid, Spain. .,Instituto Teófilo Hernando, Facultad de Medicina, University Autónoma de Madrid, 28029, Madrid, Spain.
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37
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Song C, Zhang WH, Wang XH, Zhang JY, Tian XL, Yin XP, Pan BX. Acute stress enhances the glutamatergic transmission onto basoamygdala neurons embedded in distinct microcircuits. Mol Brain 2017; 10:3. [PMID: 28069030 PMCID: PMC5223467 DOI: 10.1186/s13041-016-0283-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 12/25/2016] [Indexed: 02/03/2023] Open
Abstract
Amygdala activation is known to be critical for the processing of stressful events in brain. Recent studies have shown that the projection neurons (PNs) in amygdala, although architecturally intermingled, are integrated into distinct microcircuits and thus play divergent roles in amygdala-related behaviors. It remains unknown how stress regulates the individual amygdala PNs embedded in distinct microcircuits. Here, by using retrograde tracing and electrophysiological recording in in vitro slices, we explored the modulation of acute immobilization stress (AIS) on the basoamygdala (BA) PNs projecting either to medial prefrontal cortex (mPFC) or elsewhere, which we designated as BA-mPFC and non-BA-mPFC PNs respectively. The results showed that in the control mice, both the excitatory and inhibitory postsynaptic currents (sEPSCs/sIPSCs) were comparable between these two subsets of BA PNs. The influences of AIS on sEPSCs and sIPSCs were overall similar between the two neuronal populations. It markedly increased the sEPSCs amplitude but left unaltered their frequency as well as the sIPSCs amplitude and frequency. Despite this, several differences emerged between the effects of AIS on the distribution of sEPSCs/sIPSCs frequency in these two groups of BA PNs. Similar changes were also observed in the sEPSCs/sIPSCs of the two PN populations from mice experiencing forced swimming stress. Their intrinsic excitability, on the other hand, was nearly unaltered following AIS. Our results thus suggest that acute stress recruit both BA-mPFC and non-BA-mPFC PNs mainly through enhancing the glutamatergic transmission they receive.
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Affiliation(s)
- Chen Song
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, 330031, Nanchang, China.,College of Life Science, 330031, Nanchang, China
| | - Wen-Hua Zhang
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, 330031, Nanchang, China
| | - Xue-Hui Wang
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, 330031, Nanchang, China
| | - Jun-Yu Zhang
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, 330031, Nanchang, China
| | - Xiao-Li Tian
- College of Life Science, 330031, Nanchang, China
| | - Xiao-Ping Yin
- Department of Neurology, the 2nd affiliated Hospital, Nanchang University, 330031, Nanchang, China
| | - Bing-Xing Pan
- Laboratory of Fear and Anxiety Disorders, Institute of Life Science, 330031, Nanchang, China. .,College of Life Science, 330031, Nanchang, China. .,Department of Neurology, the 2nd affiliated Hospital, Nanchang University, 330031, Nanchang, China. .,Jiangxi Provincial Collaborative Innovation Center for Cardiovascular, Digestive and Neuropsychiatric diseases, 330031, Nanchang, China.
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38
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Abstract
The sigma-1 receptor (Sig-1R), via interaction with various proteins, including voltage-gated and ligand-gated ion channels (VGICs and LGICs), is involved in a plethora of neuronal functions. This capability to regulate a variety of ion channel targets endows the Sig-1R with a powerful capability to fine tune neuronal excitability, and thereby the transmission of information within brain circuits. This versatility may also explain why the Sig-1R is associated to numerous diseases at both peripheral and central levels. To date, how the Sig-1R chooses its targets and how the combinations of target modulations alter overall neuronal excitability is one of the challenges in the field of Sig-1R-dependent regulation of neuronal activity. Here, we will describe and discuss the latest findings on Sig-1R-dependent modulation of VGICs and LGICs, and provide hypotheses that may explain the diverse excitability outcomes that have been reported so far.
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Affiliation(s)
- Saïd Kourrich
- Department of Psychiatry, University of Texas Southwestern Medical Center, 2201 Inwood Road, Dallas, TX, 75390-9070, USA.
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39
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Soler-Cedeño O, Cruz E, Criado-Marrero M, Porter JT. Contextual fear conditioning depresses infralimbic excitability. Neurobiol Learn Mem 2016; 130:77-82. [PMID: 26860438 DOI: 10.1016/j.nlm.2016.01.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 01/28/2016] [Accepted: 01/31/2016] [Indexed: 01/14/2023]
Abstract
Patients with posttraumatic stress disorder (PTSD) show hypo-active ventromedial prefrontal cortices (vmPFC) that correlate with their impaired ability to discriminate between safe and dangerous contexts and cues. Previously, we found that auditory fear conditioning depresses the excitability of neurons populating the homologous structure in rodents, the infralimbic cortex (IL). However, it is undetermined if IL depression was mediated by the cued or contextual information. The objective of this study was to examine whether contextual information was sufficient to depress IL neuronal excitability. After exposing rats to context-alone, pseudoconditioning, or contextual fear conditioning, we used whole-cell current-clamp recordings to examine the excitability of IL neurons in prefrontal brain slices. We found that contextual fear conditioning reduced IL neuronal firing in response to depolarizing current steps. In addition, neurons from contextual fear conditioned animals showed increased slow afterhyperpolarization potentials (sAHPs). Moreover, the observed changes in IL excitability correlated with contextual fear expression, suggesting that IL depression may contribute to the encoding of contextual fear.
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Affiliation(s)
- Omar Soler-Cedeño
- Department of Basic Sciences, Ponce Health Sciences University-School of Medicine/Ponce Research Institute, Ponce 00732, Puerto Rico
| | - Emmanuel Cruz
- Department of Basic Sciences, Ponce Health Sciences University-School of Medicine/Ponce Research Institute, Ponce 00732, Puerto Rico
| | - Marangelie Criado-Marrero
- Department of Basic Sciences, Ponce Health Sciences University-School of Medicine/Ponce Research Institute, Ponce 00732, Puerto Rico
| | - James T Porter
- Department of Basic Sciences, Ponce Health Sciences University-School of Medicine/Ponce Research Institute, Ponce 00732, Puerto Rico.
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40
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Scala F, Fusco S, Ripoli C, Piacentini R, Li Puma DD, Spinelli M, Laezza F, Grassi C, D'Ascenzo M. Intraneuronal Aβ accumulation induces hippocampal neuron hyperexcitability through A-type K(+) current inhibition mediated by activation of caspases and GSK-3. Neurobiol Aging 2015; 36:886-900. [PMID: 25541422 PMCID: PMC4801354 DOI: 10.1016/j.neurobiolaging.2014.10.034] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 10/14/2014] [Accepted: 10/24/2014] [Indexed: 11/20/2022]
Abstract
Amyloid β-protein (Aβ) pathologies have been linked to dysfunction of excitability in neurons of the hippocampal circuit, but the molecular mechanisms underlying this process are still poorly understood. Here, we applied whole-cell patch-clamp electrophysiology to primary hippocampal neurons and show that intracellular Aβ42 delivery leads to increased spike discharge and action potential broadening through downregulation of A-type K(+) currents. Pharmacologic studies showed that caspases and glycogen synthase kinase 3 (GSK-3) activation are required for these Aβ42-induced effects. Extracellular perfusion and subsequent internalization of Aβ42 increase spike discharge and promote GSK-3-dependent phosphorylation of the Kv4.2 α-subunit, a molecular determinant of A-type K(+) currents, at Ser-616. In acute hippocampal slices derived from an adult triple-transgenic Alzheimer's mouse model, characterized by endogenous intracellular accumulation of Aβ42, CA1 pyramidal neurons exhibit hyperexcitability accompanied by increased phosphorylation of Kv4.2 at Ser-616. Collectively, these data suggest that intraneuronal Aβ42 accumulation leads to an intracellular cascade culminating into caspases activation and GSK-3-dependent phosphorylation of Kv4.2 channels. These findings provide new insights into the toxic mechanisms triggered by intracellular Aβ42 and offer potentially new therapeutic targets for Alzheimer's disease treatment.
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Affiliation(s)
- Federico Scala
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Salvatore Fusco
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Cristian Ripoli
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Roberto Piacentini
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | | | - Matteo Spinelli
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy
| | - Fernanda Laezza
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA
| | - Claudio Grassi
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy.
| | - Marcello D'Ascenzo
- Institute of Human Physiology, Medical School, Università Cattolica, Rome, Italy.
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Kang MS, Yang YS, Kim SH, Park JM, Eun SY, Jung SC. The Downregulation of Somatic A-Type K(+) Channels Requires the Activation of Synaptic NMDA Receptors in Young Hippocampal Neurons of Rats. Korean J Physiol Pharmacol 2014; 18:135-41. [PMID: 24757375 PMCID: PMC3994300 DOI: 10.4196/kjpp.2014.18.2.135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 11/24/2022]
Abstract
The downregulation of A-type K+ channels (IA channels) accompanying enhanced somatic excitability can mediate epileptogenic conditions in mammalian central nervous system. As IA channels are dominantly targeted by dendritic and postsynaptic processings during synaptic plasticity, it is presumable that they may act as cellular linkers between synaptic responses and somatic processings under various excitable conditions. In the present study, we electrophysiologically tested if the downregulation of somatic IA channels was sensitive to synaptic activities in young hippocampal neurons. In primarily cultured hippocampal neurons (DIV 6~9), the peak of IA recorded by a whole-cell patch was significantly reduced by high KCl or exogenous glutamate treatment to enhance synaptic activities. However, the pretreatment of MK801 to block synaptic NMDA receptors abolished the glutamate-induced reduction of the IA peak, indicating the necessity of synaptic activation for the reduction of somatic IA. This was again confirmed by glycine treatment, showing a significant reduction of the somatic IA peak. Additionally, the gating property of IA channels was also sensitive to the activation of synaptic NMDA receptors, showing the hyperpolarizing shift in inactivation kinetics. These results suggest that synaptic LTP possibly potentiates somatic excitability via downregulating IA channels in expression and gating kinetics. The consequential changes of somatic excitability following the activity-dependent modulation of synaptic responses may be a series of processings for neuronal functions to determine outputs in memory mechanisms or pathogenic conditions.
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Affiliation(s)
- Moon-Seok Kang
- Department of Physiology, School of Medicine, Jeju National University, Jeju 690-756, Korea
| | - Yoon-Sil Yang
- Department of Physiology, School of Medicine, Jeju National University, Jeju 690-756, Korea
| | - Seon-Hee Kim
- Department of Physiology, School of Medicine, Jeju National University, Jeju 690-756, Korea
| | - Joo-Min Park
- Department of Physiology, School of Medicine, Jeju National University, Jeju 690-756, Korea
| | - Su-Yong Eun
- Department of Physiology, School of Medicine, Jeju National University, Jeju 690-756, Korea
| | - Sung-Cherl Jung
- Department of Physiology, School of Medicine, Jeju National University, Jeju 690-756, Korea. ; Institute of Medical Science, Jeju National University, Jeju 690-756, Korea
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42
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Fransén E. Ionic mechanisms in peripheral pain. Prog Mol Biol Transl Sci 2014; 123:23-51. [PMID: 24560139 DOI: 10.1016/B978-0-12-397897-4.00010-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Chronic pain constitutes an important and growing problem in society with large unmet needs with respect to treatment and clear implications for quality of life. Computational modeling is used to complement experimental studies to elucidate mechanisms involved in pain states. Models representing the peripheral nerve ending often address questions related to sensitization or reduction in pain detection threshold. In models of the axon or the cell body of the unmyelinated C-fiber, a large body of work concerns the role of particular sodium channels and mutations of these. Furthermore, in central structures: spinal cord or higher structures, sensitization often refers not only to enhanced synaptic efficacy but also to elevated intrinsic neuronal excitability. One of the recent developments in computational neuroscience is the emergence of computational neuropharmacology. In this area, computational modeling is used to study mechanisms of pathology with the objective of finding the means of restoring healthy function. This research has received increased attention from the pharmaceutical industry as ion channels have gained increased interest as drug targets. Computational modeling has several advantages, notably the ability to provide mechanistic links between molecular and cellular levels on the one hand and functions at the systems level on the other hand. These characteristics make computational modeling an additional tool to be used in the process of selecting pharmaceutical targets. Furthermore, large-scale simulations can provide a framework to systematically study the effects of several interacting disease parameters or effects from combinations of drugs.
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Sehgal M, Song C, Ehlers VL, Moyer JR. Learning to learn - intrinsic plasticity as a metaplasticity mechanism for memory formation. Neurobiol Learn Mem 2013; 105:186-99. [PMID: 23871744 DOI: 10.1016/j.nlm.2013.07.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 07/09/2013] [Accepted: 07/11/2013] [Indexed: 10/26/2022]
Abstract
"Use it or lose it" is a popular adage often associated with use-dependent enhancement of cognitive abilities. Much research has focused on understanding exactly how the brain changes as a function of experience. Such experience-dependent plasticity involves both structural and functional alterations that contribute to adaptive behaviors, such as learning and memory, as well as maladaptive behaviors, including anxiety disorders, phobias, and posttraumatic stress disorder. With the advancing age of our population, understanding how use-dependent plasticity changes across the lifespan may also help to promote healthy brain aging. A common misconception is that such experience-dependent plasticity (e.g., associative learning) is synonymous with synaptic plasticity. Other forms of plasticity also play a critical role in shaping adaptive changes within the nervous system, including intrinsic plasticity - a change in the intrinsic excitability of a neuron. Intrinsic plasticity can result from a change in the number, distribution or activity of various ion channels located throughout the neuron. Here, we review evidence that intrinsic plasticity is an important and evolutionarily conserved neural correlate of learning. Intrinsic plasticity acts as a metaplasticity mechanism by lowering the threshold for synaptic changes. Thus, learning-related intrinsic changes can facilitate future synaptic plasticity and learning. Such intrinsic changes can impact the allocation of a memory trace within a brain structure, and when compromised, can contribute to cognitive decline during the aging process. This unique role of intrinsic excitability can provide insight into how memories are formed and, more interestingly, how neurons that participate in a memory trace are selected. Most importantly, modulation of intrinsic excitability can allow for regulation of learning ability - this can prevent or provide treatment for cognitive decline not only in patients with clinical disorders but also in the aging population.
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Affiliation(s)
- Megha Sehgal
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
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