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Gulledge AT. Cholinergic Activation of Corticofugal Circuits in the Adult Mouse Prefrontal Cortex. J Neurosci 2024; 44:e1388232023. [PMID: 38050146 PMCID: PMC10860659 DOI: 10.1523/jneurosci.1388-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/10/2023] [Accepted: 11/08/2023] [Indexed: 12/06/2023] Open
Abstract
Acetylcholine (ACh) promotes neocortical output to the thalamus and brainstem by preferentially enhancing the postsynaptic excitability of layer 5 pyramidal tract (PT) neurons relative to neighboring intratelencephalic (IT) neurons. Less is known about how ACh regulates the excitatory synaptic drive of IT and PT neurons. To address this question, spontaneous excitatory postsynaptic potentials (sEPSPs) were recorded in dual recordings of IT and PT neurons in slices of prelimbic cortex from adult female and male mice. ACh (20 µM) enhanced sEPSP amplitudes, frequencies, rise-times, and half-widths preferentially in PT neurons. These effects were blocked by the muscarinic receptor antagonist atropine (1 µM). When challenged with pirenzepine (1 µM), an antagonist selective for M1-type muscarinic receptors, ACh instead reduced sEPSP frequencies, suggesting that ACh may generally suppress synaptic transmission in the cortex via non-M1 receptors. Cholinergic enhancement of sEPSPs in PT neurons was not sensitive to antagonism of GABA receptors with gabazine (10 µM) and CGP52432 (2.5 µM) but was blocked by tetrodotoxin (1 µM), suggesting that ACh enhances action-potential-dependent excitatory synaptic transmission in PT neurons. ACh also preferentially promoted the occurrence of synchronous sEPSPs in dual recordings of PT neurons relative to IT-PT and IT-IT parings. Finally, selective chemogenetic silencing of hM4Di-expressing PT, but not commissural IT, neurons blocked cholinergic enhancement of sEPSP amplitudes and frequencies in PT neurons. These data suggest that, in addition to selectively enhancing the postsynaptic excitability of PT neurons, M1 receptor activation promotes corticofugal output by amplifying recurrent excitation within networks of PT neurons.
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Affiliation(s)
- Allan T Gulledge
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth College, Hanover 03755, New Hampshire
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2
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Gulledge AT. Cholinergic activation of corticofugal circuits in the adult mouse prefrontal cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.28.538437. [PMID: 37163128 PMCID: PMC10168390 DOI: 10.1101/2023.04.28.538437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In layer 5 of the neocortex, ACh promotes cortical output to the thalamus and brainstem by preferentially enhancing the postsynaptic excitability of pyramidal tract (PT) neurons relative to neighboring intratelencephalic (IT) neurons. Less is known about how ACh regulates the excitatory synaptic drive of IT and PT neurons. To address this question, spontaneous excitatory postsynaptic potentials (sEPSPs) were recorded in pairs of IT and PT neurons in slices of prelimbic cortex from adult female and male mice. ACh (20 µM) enhanced sEPSP amplitudes, frequencies, rise-times, and half-widths preferentially in PT neurons. These effects were blocked by the muscarinic acetylcholine receptor antagonist atropine (1 µM). When challenged with pirenzepine (1 µM), an antagonist selective for M1-type muscarinic receptors, ACh instead reduced sEPSP frequencies. The cholinergic increase in sEPSP amplitudes and frequencies in PT neurons was not sensitive to blockade of GABAergic receptors with gabazine (10 µM) and CGP52432 (2.5 µM), but was blocked by tetrodotoxin (1 µM), suggesting that ACh enhances action-potential-dependent excitatory synaptic transmission in PT neurons. ACh also preferentially promoted the occurrence of synchronous sEPSPs in pairs of PT neurons relative to IT-PT and IT-IT pairs. Finally, selective chemogenetic silencing of hM4Di-expressing PT, but not IT, neurons with clozapine-N-oxide (5 µM) blocked cholinergic enhancement of sEPSP amplitudes and frequencies in PT neurons. These data suggest that, in addition to enhancing the postsynaptic excitability of PT neurons, M1 receptor activation promotes corticofugal output by preferentially amplifying recurrent excitation within networks of PT neurons.
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Affiliation(s)
- Allan T Gulledge
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth College 74 College Street, Vail 601, Hanover, New Hampshire 03755, USA
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3
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Ledneczki I, Tapolcsányi P, Gábor E, Visegrády A, Vass M, Éles J, Holm P, Horváth A, Pocsai A, Mahó S, Greiner I, Krámos B, Béni Z, Kóti J, Káncz AE, Thán M, Kolok S, Laszy J, Balázs O, Bugovits G, Nagy J, Vastag M, Szájli Á, Bozó É, Lévay G, Lendvai B, Némethy Z. Discovery of novel positive allosteric modulators of the α7 nicotinic acetylcholine receptor: Scaffold hopping approach. Eur J Med Chem 2021; 214:113189. [PMID: 33540354 DOI: 10.1016/j.ejmech.2021.113189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 01/08/2021] [Accepted: 01/08/2021] [Indexed: 11/26/2022]
Abstract
The paper focuses on the scaffold hopping-based discovery and characterization of novel nicotinic alpha 7 receptor positive modulator (α7 nAChR PAM) ligands around the reference molecule (A-867744). First, substantial efforts were carried out to assess the importance of the various pharmacophoric elements on the in vitro potency (SAR evaluation) by chemical modifications. Subsequently, several new derivatives with versatile, heteroaromatic central cores were synthesized and characterized. A promising, pyrazole-containing new chemotype with good physicochemical and in vitro parameters was identified. Retrospective analysis based on homology modeling was also carried out. Besides its favorable in vitro characteristics, the most advanced derivative 69 also showed in vivo efficacy in a rodent model of cognition (scopolamine-induced amnesia in the mouse place recognition test) and acceptable pharmacokinetic properties. Based on the in vivo data, the resulting molecule with advanced drug-like characteristics has the possibility to improve cognitive performance in a biologically relevant dose range, further strengthening the view of the supportive role of α7 nACh receptors in the cognitive processes.
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Affiliation(s)
- István Ledneczki
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary.
| | - Pál Tapolcsányi
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Eszter Gábor
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - András Visegrády
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary; Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Márton Vass
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - János Éles
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | | | - Anita Horváth
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Anikó Pocsai
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Sándor Mahó
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - István Greiner
- Research Management, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Krámos
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - Zoltán Béni
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - János Kóti
- Spectroscopic Research Department, Gedeon Richter Plc., Budapest, Hungary
| | - Anna E Káncz
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Márta Thán
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Sándor Kolok
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Judit Laszy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Ottilia Balázs
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Gyula Bugovits
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - József Nagy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Mónika Vastag
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Ágota Szájli
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - Éva Bozó
- Department of Chemistry, Gedeon Richter Plc., Budapest, Hungary
| | - György Lévay
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Balázs Lendvai
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
| | - Zsolt Némethy
- Pharmacological and Drug Safety Research, Gedeon Richter Plc., Budapest, Hungary
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Yang D, Ding C, Qi G, Feldmeyer D. Cholinergic and Adenosinergic Modulation of Synaptic Release. Neuroscience 2020; 456:114-130. [PMID: 32540364 DOI: 10.1016/j.neuroscience.2020.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/29/2020] [Accepted: 06/01/2020] [Indexed: 01/14/2023]
Abstract
In this review we will discuss the effect of two neuromodulatory transmitters, acetylcholine (ACh) and adenosine, on the synaptic release probability and short-term synaptic plasticity. ACh and adenosine differ fundamentally in the way they are released into the extracellular space. ACh is released mostly from synaptic terminals and axonal bouton of cholinergic neurons in the basal forebrain (BF). Its mode of action on synaptic release probability is complex because it activate both ligand-gated ion channels, so-called nicotinic ACh receptors and G-protein coupled muscarinic ACh receptors. In contrast, adenosine is released from both neurons and glia via nucleoside transporters or diffusion over the cell membrane in a non-vesicular, non-synaptic fashion; its receptors are exclusively G-protein coupled receptors. We show that ACh and adenosine effects are highly specific for an identified synaptic connection and depend mostly on the presynaptic but also on the postsynaptic receptor type and discuss the functional implications of these differences.
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Affiliation(s)
- Danqing Yang
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany
| | - Chao Ding
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany
| | - Guanxiao Qi
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany
| | - Dirk Feldmeyer
- Research Centre Juelich, Institute of Neuroscience and Medicine 10, Leo-Brandt-Strasse, Juelich, Germany; RWTH Aachen University Hospital, Pauwelsstrasse 30, Aachen, Germany; Jülich-Aachen Research Alliance Brain - JARA Brain, Germany.
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5
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Urban-Ciecko J, Jouhanneau JS, Myal SE, Poulet JFA, Barth AL. Precisely Timed Nicotinic Activation Drives SST Inhibition in Neocortical Circuits. Neuron 2019; 97:611-625.e5. [PMID: 29420933 DOI: 10.1016/j.neuron.2018.01.037] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 10/30/2017] [Accepted: 01/12/2018] [Indexed: 11/13/2022]
Abstract
Sleep, waking, locomotion, and attention are associated with cell-type-specific changes in neocortical activity. The effect of brain state on circuit output requires understanding of how neuromodulators influence specific neuronal classes and their synapses, with normal patterns of neuromodulator release from endogenous sources. We investigated the state-dependent modulation of a ubiquitous feedforward inhibitory motif in mouse sensory cortex, local pyramidal (Pyr) inputs onto somatostatin (SST)-expressing interneurons. Paired whole-cell recordings in acute brain slices and in vivo showed that Pyr-to-SST synapses are remarkably weak, with failure rates approaching 80%. Pharmacological screening revealed that cholinergic agonists uniquely enhance synaptic efficacy. Brief, optogenetically gated acetylcholine release dramatically enhanced Pyr-to-SST input, via nicotinic receptors and presynaptic PKA signaling. Importantly, endogenous acetylcholine release preferentially activated nicotinic, not muscarinic, receptors, thus differentiating drug effects from endogenous neurotransmission. Brain state- and synapse-specific unmasking of synapses may be a powerful way to functionally rewire cortical circuits dependent on behavioral demands.
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Affiliation(s)
- Joanna Urban-Ciecko
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Department of Molecular and Cellular Neurobiology, Nencki Institute of Experimental Biology, Pasteur str. 3, 02-093 Warsaw, Poland
| | - Jean-Sebastien Jouhanneau
- Department of Neuroscience, Max Delbrück Center for Molecular Medicine (MDC), Berlin-Buch, Robert-Rössle-Str. 10, 13092 Berlin, Germany; Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Stephanie E Myal
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - James F A Poulet
- Department of Neuroscience, Max Delbrück Center for Molecular Medicine (MDC), Berlin-Buch, Robert-Rössle-Str. 10, 13092 Berlin, Germany; Cluster of Excellence NeuroCure, Neuroscience Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Alison L Barth
- Department of Biological Sciences and Center for the Neural Basis of Cognition, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
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Colangelo C, Shichkova P, Keller D, Markram H, Ramaswamy S. Cellular, Synaptic and Network Effects of Acetylcholine in the Neocortex. Front Neural Circuits 2019; 13:24. [PMID: 31031601 PMCID: PMC6473068 DOI: 10.3389/fncir.2019.00024] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 03/22/2019] [Indexed: 12/17/2022] Open
Abstract
The neocortex is densely innervated by basal forebrain (BF) cholinergic neurons. Long-range axons of cholinergic neurons regulate higher-order cognitive function and dysfunction in the neocortex by releasing acetylcholine (ACh). ACh release dynamically reconfigures neocortical microcircuitry through differential spatiotemporal actions on cell-types and their synaptic connections. At the cellular level, ACh release controls neuronal excitability and firing rate, by hyperpolarizing or depolarizing target neurons. At the synaptic level, ACh impacts transmission dynamics not only by altering the presynaptic probability of release, but also the magnitude of the postsynaptic response. Despite the crucial role of ACh release in physiology and pathophysiology, a comprehensive understanding of the way it regulates the activity of diverse neocortical cell-types and synaptic connections has remained elusive. This review aims to summarize the state-of-the-art anatomical and physiological data to develop a functional map of the cellular, synaptic and microcircuit effects of ACh in the neocortex of rodents and non-human primates, and to serve as a quantitative reference for those intending to build data-driven computational models on the role of ACh in governing brain states.
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Affiliation(s)
- Cristina Colangelo
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | | | | | | | - Srikanth Ramaswamy
- Blue Brain Project, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
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Villa C, Colombo G, Meneghini S, Gotti C, Moretti M, Ferini-Strambi L, Chisci E, Giovannoni R, Becchetti A, Combi R. CHRNA2 and Nocturnal Frontal Lobe Epilepsy: Identification and Characterization of a Novel Loss of Function Mutation. Front Mol Neurosci 2019; 12:17. [PMID: 30809122 PMCID: PMC6379349 DOI: 10.3389/fnmol.2019.00017] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/17/2019] [Indexed: 12/21/2022] Open
Abstract
Mutations in genes coding for subunits of the neuronal nicotinic acetylcholine receptor (nAChR) have been involved in familial sleep-related hypermotor epilepsy (also named autosomal dominant nocturnal frontal lobe epilepsy, ADNFLE). Most of these mutations reside in CHRNA4 and CHRNB2 genes, coding for the α4 and β2 nAChR subunits, respectively. Two mutations with contrasting functional effects were also identified in the CHRNA2 gene coding for the α2 subunit. Here, we report the third mutation in the CHRNA2, found in a patient showing ADNFLE. The patient was examined by scalp EEG, contrast-enhanced brain magnetic resonance imaging (MRI), and nocturnal video-polysomnographic recording. All exons and the exon-intron boundaries of CHRNA2, CHRNA4, CHRNB2, CRH, KCNT1 were amplified and Sanger sequenced. In the proband, we found a c.754T>C (p.Tyr252His) missense mutation located in the N-terminal ligand-binding domain and inherited from the mother. Functional studies were performed by transient co-expression of α2 and α2Tyr252His, with either β2 or β4, in human embryonic kidney (HEK293) cells. Equimolar amounts of subunits expression were obtained by using F2A-based multi-cistronic constructs encoding for the genes relative to the nAChR subunits of interest and for the enhanced green fluorescent protein. The mutation reduced the maximal currents by approximately 80% in response to saturating concentrations of nicotine in homo- and heterozygous form, in both the α2β4 and α2β2 nAChR subtypes. The effect was accompanied by a strong right-shift of the concentration-response to nicotine. Similar effects were observed using ACh. Negligible effects were produced by α2Tyr252His on the current reversal potential. Moreover, binding of (±)-[3H]Epibatidine revealed an approximately 10-fold decrease of both Kd and Bmax (bound ligand in saturating conditions), in cells expressing α2Tyr252His. The reduced Bmax and whole-cell currents were not caused by a decrease in mutant receptor expression, as minor effects were produced by α2Tyr252His on the level of transcripts and the membrane expression of α2β4 nAChR. Overall, these results suggest that α2Tyr252His strongly reduced the number of channels bound to the agonist, without significantly altering the overall channel expression. We conclude that mutations in CHRNA2 are more commonly linked to ADNFLE than previously thought, and may cause a loss-of-function phenotype.
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Affiliation(s)
- Chiara Villa
- School of Medicine and Surgery, University of Milano - Bicocca, Monza, Italy
| | - Giulia Colombo
- Department of Biotechnology and Biosciences, University of Milano - Bicocca, Milan, Italy
| | - Simone Meneghini
- Department of Biotechnology and Biosciences, University of Milano - Bicocca, Milan, Italy
| | | | - Milena Moretti
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Luigi Ferini-Strambi
- Department of Clinical Neurosciences, San Raffaele Scientific Institute, Sleep Disorders Center, Vita-Salute San Raffaele University, Milan, Italy
| | - Elisa Chisci
- School of Medicine and Surgery, University of Milano - Bicocca, Monza, Italy
| | - Roberto Giovannoni
- School of Medicine and Surgery, University of Milano - Bicocca, Monza, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano - Bicocca, Milan, Italy
| | - Romina Combi
- School of Medicine and Surgery, University of Milano - Bicocca, Monza, Italy
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Schmidt HD, Rupprecht LE, Addy NA. Neurobiological and Neurophysiological Mechanisms Underlying Nicotine Seeking and Smoking Relapse. MOLECULAR NEUROPSYCHIATRY 2019; 4:169-189. [PMID: 30815453 PMCID: PMC6388439 DOI: 10.1159/000494799] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/23/2018] [Indexed: 12/19/2022]
Abstract
Tobacco-related morbidity and mortality continue to be a significant public health concern. Unfortunately, current FDA-approved smoking cessation pharmacotherapies have limited efficacy and are associated with high rates of relapse. Therefore, a better understanding of the neurobiological and neurophysiological mechanisms that promote smoking relapse is needed to develop novel smoking cessation medications. Here, we review preclinical studies focused on identifying the neurotransmitter and neuromodulator systems that mediate nicotine relapse, often modeled in laboratory animals using the reinstatement paradigm, as well as the plasticity-dependent neurophysiological mechanisms that facilitate nicotine reinstatement. Particular emphasis is placed on how these neuroadaptations relate to smoking relapse in humans. We also highlight a number of important gaps in our understanding of the neural mechanisms underlying nicotine reinstatement and critical future directions, which may lead toward the development of novel, target pharmacotherapies for smoking cessation.
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Affiliation(s)
- Heath D. Schmidt
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Laura E. Rupprecht
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
| | - Nii A. Addy
- Department of Psychiatry, Yale School of Medicine, New Haven, Connecticut, USA
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
- Interdepartmental Neuroscience Program, Yale Graduate School of Arts and Sciences, New Haven, Connecticut, USA
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Tricoire L, Drobac E, Tsuzuki K, Gallopin T, Picaud S, Cauli B, Rossier J, Lambolez B. Bioluminescence calcium imaging of network dynamics and their cholinergic modulation in slices of cerebral cortex from male rats. J Neurosci Res 2019; 97:414-432. [PMID: 30604494 DOI: 10.1002/jnr.24380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 11/27/2018] [Accepted: 12/11/2018] [Indexed: 12/12/2022]
Abstract
The activity of neuronal ensembles was monitored in neocortical slices from male rats using wide-field bioluminescence imaging of a calcium sensor formed with the fusion of green fluorescent protein and aequorin (GA) and expressed through viral transfer. GA expression was restricted to pyramidal neurons and did not conspicuously alter neuronal morphology or neocortical cytoarchitecture. Removal of extracellular magnesium or addition of GABA receptor antagonists triggered epileptiform flashes of variable amplitude and spatial extent, indicating that the excitatory and inhibitory networks were functionally preserved in GA-expressing slices. We found that agonists of muscarinic acetylcholine receptors largely increased the peak bioluminescence response to local electrical stimulation in layer I or white matter, and gave rise to a slowly decaying response persisting for tens of seconds. The peak increase involved layers II/III and V and did not result in marked alteration of response spatial properties. The persistent response involved essentially layer V and followed the time course of the muscarinic afterdischarge depolarizing plateau in layer V pyramidal cells. This plateau potential triggered spike firing in layer V, but not layer II/III pyramidal cells, and was accompanied by recurrent synaptic excitation in layer V. Our results indicate that wide-field imaging of GA bioluminescence is well suited to monitor local and global network activity patterns, involving different mechanisms of intracellular calcium increase, and occurring on various timescales.
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Affiliation(s)
- Ludovic Tricoire
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Estelle Drobac
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Keisuke Tsuzuki
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Thierry Gallopin
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Sandrine Picaud
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Bruno Cauli
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Jean Rossier
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
| | - Bertrand Lambolez
- Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), INSERM, CNRS, Sorbonne Universités, Paris, France
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Rajji TK. Impaired brain plasticity as a potential therapeutic target for treatment and prevention of dementia. Expert Opin Ther Targets 2018; 23:21-28. [DOI: 10.1080/14728222.2019.1550074] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Tarek K. Rajji
- Centre for Addiction and Mental Health and Department of Psychiatry, University of Toronto, Toronto, ON, Canada
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11
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Záborszky L, Gombkoto P, Varsanyi P, Gielow MR, Poe G, Role LW, Ananth M, Rajebhosale P, Talmage DA, Hasselmo ME, Dannenberg H, Minces VH, Chiba AA. Specific Basal Forebrain-Cortical Cholinergic Circuits Coordinate Cognitive Operations. J Neurosci 2018; 38:9446-9458. [PMID: 30381436 PMCID: PMC6209837 DOI: 10.1523/jneurosci.1676-18.2018] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 11/21/2022] Open
Abstract
Based on recent molecular genetics, as well as functional and quantitative anatomical studies, the basal forebrain (BF) cholinergic projections, once viewed as a diffuse system, are emerging as being remarkably specific in connectivity. Acetylcholine (ACh) can rapidly and selectively modulate activity of specific circuits and ACh release can be coordinated in multiple areas that are related to particular aspects of cognitive processing. This review discusses how a combination of multiple new approaches with more established techniques are being used to finally reveal how cholinergic neurons, together with other BF neurons, provide temporal structure for behavior, contribute to local cortical state regulation, and coordinate activity between different functionally related cortical circuits. ACh selectively modulates dynamics for encoding and attention within individual cortical circuits, allows for important transitions during sleep, and shapes the fidelity of sensory processing by changing the correlation structure of neural firing. The importance of this system for integrated and fluid behavioral function is underscored by its disease-modifying role; the demise of BF cholinergic neurons has long been established in Alzheimer's disease and recent studies have revealed the involvement of the cholinergic system in modulation of anxiety-related circuits. Therefore, the BF cholinergic system plays a pivotal role in modulating the dynamics of the brain during sleep and behavior, as foretold by the intricacies of its anatomical map.
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Affiliation(s)
- Laszlo Záborszky
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark 07102,
| | - Peter Gombkoto
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark 07102
| | - Peter Varsanyi
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark 07102
| | - Matthew R Gielow
- Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark 07102
| | - Gina Poe
- Department of Integrative Biology and Physiology, University of California, Los Angeles 90095
| | - Lorna W Role
- Department of Neurobiology and Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York 11794
| | - Mala Ananth
- Program in Neuroscience and Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York 11794
| | - Prithviraj Rajebhosale
- Program in Neuroscience and Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York 11794
| | - David A Talmage
- Department of Pharmacological Sciences and Center for Nervous System Disorders, Stony Brook University, Stony Brook, New York 11794
| | - Michael E Hasselmo
- Center for Systems Neuroscience and Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts 02215, and
| | - Holger Dannenberg
- Center for Systems Neuroscience and Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts 02215, and
| | - Victor H Minces
- Department of Cognitive Science, University of California, San Diego 92093
| | - Andrea A Chiba
- Department of Cognitive Science, University of California, San Diego 92093
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12
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Ramaswamy S, Colangelo C, Markram H. Data-Driven Modeling of Cholinergic Modulation of Neural Microcircuits: Bridging Neurons, Synapses and Network Activity. Front Neural Circuits 2018; 12:77. [PMID: 30356701 PMCID: PMC6189313 DOI: 10.3389/fncir.2018.00077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/10/2018] [Indexed: 01/26/2023] Open
Abstract
Neuromodulators, such as acetylcholine (ACh), control information processing in neural microcircuits by regulating neuronal and synaptic physiology. Computational models and simulations enable predictions on the potential role of ACh in reconfiguring network activity. As a prelude into investigating how the cellular and synaptic effects of ACh collectively influence emergent network dynamics, we developed a data-driven framework incorporating phenomenological models of the physiology of cholinergic modulation of neocortical cells and synapses. The first-draft models were integrated into a biologically detailed tissue model of neocortical microcircuitry to investigate the effects of levels of ACh on diverse neuron types and synapses, and consequently on emergent network activity. Preliminary simulations from the framework, which was not tuned to reproduce any specific ACh-induced network effects, not only corroborate the long-standing notion that ACh desynchronizes spontaneous network activity, but also predict that a dose-dependent activation of ACh gives rise to a spectrum of neocortical network activity. We show that low levels of ACh, such as during non-rapid eye movement (nREM) sleep, drive microcircuit activity into slow oscillations and network synchrony, whereas high ACh concentrations, such as during wakefulness and REM sleep, govern fast oscillations and network asynchrony. In addition, spontaneous network activity modulated by ACh levels shape spike-time cross-correlations across distinct neuronal populations in strikingly different ways. These effects are likely due to the regulation of neurons and synapses caused by increasing levels of ACh, which enhances cellular excitability and decreases the efficacy of local synaptic transmission. We conclude by discussing future directions to refine the biological accuracy of the framework, which will extend its utility and foster the development of hypotheses to investigate the role of neuromodulators in neural information processing.
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Affiliation(s)
- Srikanth Ramaswamy
- Blue Brain Project (BBP), École Polytechnique Fédérale de Lausanne (EPFL) Biotech Campus, Geneva, Switzerland
| | - Cristina Colangelo
- Blue Brain Project (BBP), École Polytechnique Fédérale de Lausanne (EPFL) Biotech Campus, Geneva, Switzerland
| | - Henry Markram
- Blue Brain Project (BBP), École Polytechnique Fédérale de Lausanne (EPFL) Biotech Campus, Geneva, Switzerland
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13
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Salavati B, Daskalakis ZJ, Zomorrodi R, Blumberger DM, Chen R, Pollock BG, Rajji TK. Pharmacological Modulation of Long-Term Potentiation-Like Activity in the Dorsolateral Prefrontal Cortex. Front Hum Neurosci 2018; 12:155. [PMID: 29740299 PMCID: PMC5928132 DOI: 10.3389/fnhum.2018.00155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/05/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Long-term potentiation (LTP) depends on glutamatergic neurotransmission and is modulated by cholinergic, dopaminergic and GABAergic inputs. Paired associative stimulation (PAS) is a neurostimulation paradigm that, when combined with electroencephalography (EEG), assesses LTP-like activity (PAS-induced LTP) in the dorsolateral prefrontal cortex (DLPFC). Thus, we conducted a study to assess the role of cholinergic, dopaminergic, GABAergic and glutamatergic neurotransmission on PAS-induced LTP in the DLPFC. We hypothesized that increasing the dopaminergic tone with L-DOPA and the cholinergic tone with rivastigmine will enhance PAS-induced LTP, while increasing the GABAergic tone with baclofen and inhibiting glutamatergic neurotransmission with dextromethorphan will reduce it compared to placebo. Methods: In this randomized controlled, double-blind cross-over within-subject study, 12 healthy participants received five sessions of PAS to the DLPFC in a random order, each preceded by the administration of placebo or one of the four active drugs. PAS-induced LTP was assessed after each drug administration and compared to PAS-induced LTP after placebo. Results: As predicted, L-DOPA and rivastigmine resulted in enhanced PAS-induced LTP in the DLPFC and dextromethorphan inhibited it compared to placebo. In contrast, baclofen did not significantly suppress PAS-induced LTP compared to placebo. Conclusions: This study provides a novel approach to study DLPFC neuroplasticity and its modulation in patients with brain disorders that are associated with abnormalities in these neurochemical systems. This study was based on a single dose administration of each drug. Given that these drugs are typically administered chronically, future studies should assess the effects of chronic administration.
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Affiliation(s)
- Bahar Salavati
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Zafiris J Daskalakis
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Reza Zomorrodi
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Daniel M Blumberger
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Robert Chen
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Bruce G Pollock
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Tarek K Rajji
- Geriatric Psychiatry Division, Centre for Addiction and Mental Health, Toronto, ON, Canada.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
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14
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Al-Onaizi MA, Parfitt GM, Kolisnyk B, Law CSH, Guzman MS, Barros DM, Leung LS, Prado MAM, Prado VF. Regulation of Cognitive Processing by Hippocampal Cholinergic Tone. Cereb Cortex 2018; 27:1615-1628. [PMID: 26803167 DOI: 10.1093/cercor/bhv349] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cholinergic dysfunction has been associated with cognitive abnormalities in a variety of neurodegenerative and neuropsychiatric diseases. Here we tested how information processing is regulated by cholinergic tone in genetically modified mice targeting the vesicular acetylcholine transporter (VAChT), a protein required for acetylcholine release. We measured long-term potentiation of Schaffer collateral-CA1 synapses in vivo and assessed information processing by using a mouse touchscreen version of paired associates learning task (PAL). Acquisition of information in the mouse PAL task correlated to levels of hippocampal VAChT, suggesting a critical role for cholinergic tone. Accordingly, synaptic plasticity in the hippocampus in vivo was disturbed, but not completely abolished, by decreased hippocampal cholinergic signaling. Disrupted forebrain cholinergic signaling also affected working memory, a result reproduced by selectively decreasing VAChT in the hippocampus. In contrast, spatial memory was relatively preserved, whereas reversal spatial memory was sensitive to decreased hippocampal cholinergic signaling. This work provides a refined roadmap of how synaptically secreted acetylcholine influences distinct behaviors and suggests that distinct forms of cognitive processing may be regulated in different ways by cholinergic activity.
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Affiliation(s)
| | - Gustavo M Parfitt
- Robarts Research Institute.,Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Neurociências (FURG), Brazil
| | | | - Clayton S H Law
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, CanadaN6A5K8
| | - Monica S Guzman
- Robarts Research Institute.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A5K8
| | - Daniela Martí Barros
- Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Laboratório de Neurociências (FURG), Brazil
| | - L Stan Leung
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, CanadaN6A5K8
| | - Marco A M Prado
- Robarts Research Institute.,Department of Anatomy and Cell Biology.,Graduate Program in Neuroscience and.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A5K8
| | - Vania F Prado
- Robarts Research Institute.,Department of Anatomy and Cell Biology.,Graduate Program in Neuroscience and.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A5K8
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15
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Pharmacological Manipulation of Cortical Inhibition in the Dorsolateral Prefrontal Cortex. Neuropsychopharmacology 2018; 43:354-361. [PMID: 28553835 PMCID: PMC5729552 DOI: 10.1038/npp.2017.104] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Revised: 05/03/2017] [Accepted: 05/22/2017] [Indexed: 12/20/2022]
Abstract
Cortical inhibition (CI) occurs largely through GABA receptor-mediated inhibitory neurotransmission, which can be modulated by cholinergic, dopaminergic, and glutamatergic inputs. Transcranial magnetic stimulation (TMS) can be used to index CI through a paradigm known as long-interval CI (LICI). When TMS is combined with electroencephalography (EEG), LICI can index GABA receptor-mediated inhibitory neurotransmission in the dorsolateral prefrontal cortex (DLPFC). We conducted a hypothesis-driven pharmacological study to assess the role of cholinergic, dopaminergic, GABAergic, and glutamatergic neurotransmission on LICI from the DLPFC using TMS-EEG. In this randomized controlled, double-blind crossover within-subject study, 12 healthy participants received five sessions of LICI to the DLPFC in a random order, each preceded by the administration of placebo or one of the four active drugs. LICI was assessed after each drug administration and compared to LICI after placebo. Relative to placebo, baclofen resulted in a significant increase in LICI, while rivastigmine resulted in a significant decrease in LICI. Dextromethorphan and L-DOPA did not result in a significant change in LICI relative to placebo. Our study confirms that LICI in the DLPFC is largely mediated by GABAB receptor-mediated inhibitory neurotransmission and also suggests that cholinergic modulation decreases LICI in the DLPFC. Such findings may help guide future work examining the neurophysiological impact of these neurotransmitters in healthy and diseased states.
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16
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Radzicki D, Pollema-Mays SL, Sanz-Clemente A, Martina M. Loss of M1 Receptor Dependent Cholinergic Excitation Contributes to mPFC Deactivation in Neuropathic Pain. J Neurosci 2017; 37:2292-2304. [PMID: 28137966 PMCID: PMC5354343 DOI: 10.1523/jneurosci.1553-16.2017] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 12/01/2016] [Accepted: 01/05/2017] [Indexed: 11/21/2022] Open
Abstract
In chronic pain, the medial prefrontal cortex (mPFC) is deactivated and mPFC-dependent tasks such as attention and working memory are impaired. We investigated the mechanisms of mPFC deactivation in the rat spared nerve injury (SNI) model of neuropathic pain. Patch-clamp recordings in acute slices showed that, 1 week after the nerve injury, cholinergic modulation of layer 5 (L5) pyramidal neurons was severely impaired. In cells from sham-operated animals, focal application of acetylcholine induced a left shift of the input/output curve and persistent firing. Both of these effects were almost completely abolished in cells from SNI-operated rats. The cause of this impairment was an ∼60% reduction of an M1-coupled, pirenzepine-sensitive depolarizing current, which appeared to be, at least in part, the consequence of M1 receptor internalization. Although no changes were detected in total M1 protein or transcript, both the fraction of the M1 receptor in the synaptic plasma membrane and the biotinylated M1 protein associated with the total plasma membrane were decreased in L5 mPFC of SNI rats. The loss of excitatory cholinergic modulation may play a critical role in mPFC deactivation in neuropathic pain and underlie the mPFC-specific cognitive deficits that are comorbid with neuropathic pain.SIGNIFICANCE STATEMENT The medial prefrontal cortex (mPFC) undergoes major reorganization in chronic pain. Deactivation of mPFC output is causally correlated with both the cognitive and the sensory component of neuropathic pain. Here, we show that cholinergic excitation of commissural layer 5 mPFC pyramidal neurons is abolished in neuropathic pain rats due to a severe reduction of a muscarinic depolarizing current and M1 receptor internalization. Therefore, in neuropathic pain rats, the acetylcholine (ACh)-dependent increase in neuronal excitability is reduced dramatically and the ACh-induced persisting firing, which is critical for working memory, is abolished. We propose that the blunted cholinergic excitability contributes to the functional mPFC deactivation that is causal for the pain phenotype and represents a cellular mechanism for the attention and memory impairments comorbid with chronic pain.
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Affiliation(s)
| | | | - Antonio Sanz-Clemente
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611
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17
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Shimegi S, Kimura A, Sato A, Aoyama C, Mizuyama R, Tsunoda K, Ueda F, Araki S, Goya R, Sato H. Cholinergic and serotonergic modulation of visual information processing in monkey V1. ACTA ACUST UNITED AC 2016; 110:44-51. [PMID: 27619519 DOI: 10.1016/j.jphysparis.2016.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 08/24/2016] [Accepted: 09/08/2016] [Indexed: 11/30/2022]
Abstract
The brain dynamically changes its input-output relationship depending on the behavioral state and context in order to optimize information processing. At the molecular level, cholinergic/monoaminergic transmitters have been extensively studied as key players for the state/context-dependent modulation of brain function. In this paper, we review how cortical visual information processing in the primary visual cortex (V1) of macaque monkey, which has a highly differentiated laminar structure, is optimized by serotonergic and cholinergic systems by examining anatomical and in vivo electrophysiological aspects to highlight their similarities and distinctions. We show that these two systems have a similar layer bias for axonal fiber innervation and receptor distribution. The common target sites are the geniculorecipient layers and geniculocortical fibers, where the appropriate gain control is established through a geniculocortical signal transformation. Both systems exert activity-dependent response gain control across layers, but in a manner consistent with the receptor subtype. The serotonergic receptors 5-HT1B and 5HT2A modulate the contrast-response curve in a manner consistent with bi-directional response gain control, where the sign (facilitation/suppression) is switched according to the firing rate and is complementary to the other. On the other hand, cholinergic nicotinic/muscarinic receptors exert mono-directional response gain control without a sign reversal. Nicotinic receptors increase the response magnitude in a multiplicative manner, while muscarinic receptors exert both suppressive and facilitative effects. We discuss the implications of the two neuromodulator systems in hierarchical visual signal processing in V1 on the basis of the developed laminar structure.
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Affiliation(s)
- Satoshi Shimegi
- Graduate School of Medicine, Osaka University, Toyonaka, Osaka 560-0043, Japan; Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan.
| | - Akihiro Kimura
- Department of Healthcare, Osaka Health Science University, Toyonaka, Osaka 560-0043, Japan
| | - Akinori Sato
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Chisa Aoyama
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Ryo Mizuyama
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Keisuke Tsunoda
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Fuyuki Ueda
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Sera Araki
- Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Ryoma Goya
- Graduate School of Sports and Health Science, Fukuoka University, Fukuoka 814-0180, Japan
| | - Hiromichi Sato
- Graduate School of Medicine, Osaka University, Toyonaka, Osaka 560-0043, Japan; Graduate School of Frontier Biosciences, Osaka University, Toyonaka, Osaka 560-0043, Japan
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18
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Udakis M, Wright VL, Wonnacott S, Bailey CP. Integration of inhibitory and excitatory effects of α7 nicotinic acetylcholine receptor activation in the prelimbic cortex regulates network activity and plasticity. Neuropharmacology 2016; 105:618-629. [PMID: 26921769 PMCID: PMC4881417 DOI: 10.1016/j.neuropharm.2016.02.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 02/05/2016] [Accepted: 02/22/2016] [Indexed: 12/02/2022]
Abstract
Cognitive and attentional processes governed by the prefrontal cortex (PFC) are influenced by cholinergic innervation. Here we have explored the role of α7 nicotinic acetylcholine receptors (nAChRs) as mediators of cholinergic signalling in the dorsomedial (prelimbic) PFC, using mouse brain slice electrophysiology. Activation of α7 nAChRs located on glutamatergic terminals and cell soma of GABAergic interneurons increased excitation and inhibition, respectively, in layer V of the prelimbic cortex. These actions were distinguished by their differential dependence on local acetylcholine (ACh): potentiation of endogenous cholinergic signalling with the positive allosteric modulator, PNU-120596, enhanced spontaneous excitatory events, an effect that was further increased by inhibition of acetylcholinesterase. In contrast, α7 nicotinic modulation of inhibitory signalling required addition of exogenous agonist (PNU-282987) as well as PNU-120596, and was unaffected by acetylcholinesterase inhibition. Thus α7 nAChRs can bi-directionally regulate network activity in the prelimbic cortex, depending on the magnitude and localisation of cholinergic signalling. This bidirectional influence is manifest in dual effects of α7 nAChRs on theta-burst-induced long-term potentiation (LTP) in layer V of the prelimbic cortex. Antagonism of α7 nAChRs significantly decreased LTP implicating a contribution from endogenous ACh, consistent with the ability of local ACh to enhance glutamatergic signalling. Exogenous agonist plus potentiator also decreased LTP, indicative of the influence of this drug combination on inhibitory signalling. Thus α7 nAChRs make a complex contribution to network activity and synaptic plasticity in the prelimbic cortex. α7 nAChRs exist at glutamatergic nerve terminals in the prelimbic cortex. α7 nAChRs exist at GABAergic cell bodies in the prelimbic cortex. Tonic ACh preferentially activates α7 nAChRs at glutamatergic nerve terminals. α7 nAChRs exert bidirectional control of LTP in the prelimbic cortex.
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Affiliation(s)
- Matthew Udakis
- Department of Pharmacy & Pharmacology, University of Bath, Bath BA2 7AY, UK
| | | | - Susan Wonnacott
- Department of Biology & Biochemistry, University of Bath, Bath BA2 7AY, UK
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19
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Brusco S, Ambrosi P, Meneghini S, Becchetti A. Agonist and antagonist effects of tobacco-related nitrosamines on human α4β2 nicotinic acetylcholine receptors. Front Pharmacol 2015; 6:201. [PMID: 26441658 PMCID: PMC4585029 DOI: 10.3389/fphar.2015.00201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 09/01/2015] [Indexed: 01/03/2023] Open
Abstract
Regulation of the “neuronal” nicotinic acetylcholine receptors (nAChRs) is implicated in both tobacco addiction and smoking-dependent tumor promotion. Some of these effects are caused by the tobacco-derived N-nitrosamines, which are carcinogenic compounds that avidly bind to nAChRs. However, the functional effects of these drugs on specific nAChR subtypes are largely unknown. By using patch-clamp methods, we tested 4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) on human α4β2 nAChRs. These latter are widely distributed in the mammalian brain and are also frequently expressed outside the nervous system. NNK behaved as a partial agonist, with an apparent EC50 of 16.7 μM. At 100 μM, it activated 16% of the maximal current activated by nicotine. When NNK was co-applied with nicotine, it potentiated the currents elicited by nicotine concentrations ≤ 100 nM. At higher concentrations of nicotine, NNK always inhibited the α4β2 nAChR. In contrast, NNN was a pure inhibitor of this nAChR subtype, with IC50 of approximately 1 nM in the presence of 10 μM nicotine. The effects of both NNK and NNN were mainly competitive and largely independent of Vm. The different actions of NNN and NNK must be taken into account when interpreting their biological effects in vitro and in vivo.
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Affiliation(s)
- Simone Brusco
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Paola Ambrosi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Simone Meneghini
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca Milano, Italy
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20
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Gao PP, Zhang JW, Fan SJ, Sanes DH, Wu EX. Auditory midbrain processing is differentially modulated by auditory and visual cortices: An auditory fMRI study. Neuroimage 2015; 123:22-32. [PMID: 26306991 DOI: 10.1016/j.neuroimage.2015.08.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 08/15/2015] [Accepted: 08/18/2015] [Indexed: 11/19/2022] Open
Abstract
The cortex contains extensive descending projections, yet the impact of cortical input on brainstem processing remains poorly understood. In the central auditory system, the auditory cortex contains direct and indirect pathways (via brainstem cholinergic cells) to nuclei of the auditory midbrain, called the inferior colliculus (IC). While these projections modulate auditory processing throughout the IC, single neuron recordings have samples from only a small fraction of cells during stimulation of the corticofugal pathway. Furthermore, assessments of cortical feedback have not been extended to sensory modalities other than audition. To address these issues, we devised blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) paradigms to measure the sound-evoked responses throughout the rat IC and investigated the effects of bilateral ablation of either auditory or visual cortices. Auditory cortex ablation increased the gain of IC responses to noise stimuli (primarily in the central nucleus of the IC) and decreased response selectivity to forward species-specific vocalizations (versus temporally reversed ones, most prominently in the external cortex of the IC). In contrast, visual cortex ablation decreased the gain and induced a much smaller effect on response selectivity. The results suggest that auditory cortical projections normally exert a large-scale and net suppressive influence on specific IC subnuclei, while visual cortical projections provide a facilitatory influence. Meanwhile, auditory cortical projections enhance the midbrain response selectivity to species-specific vocalizations. We also probed the role of the indirect cholinergic projections in the auditory system in the descending modulation process by pharmacologically blocking muscarinic cholinergic receptors. This manipulation did not affect the gain of IC responses but significantly reduced the response selectivity to vocalizations. The results imply that auditory cortical gain modulation is mediated primarily through direct projections and they point to future investigations of the differential roles of the direct and indirect projections in corticofugal modulation. In summary, our imaging findings demonstrate the large-scale descending influences, from both the auditory and visual cortices, on sound processing in different IC subdivisions. They can guide future studies on the coordinated activity across multiple regions of the auditory network, and its dysfunctions.
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Affiliation(s)
- Patrick P Gao
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Jevin W Zhang
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Shu-Juan Fan
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Dan H Sanes
- Center for Neural Science, New York University, New York, NY 10003, United States
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong SAR, China; Department of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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21
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Koukouli F, Maskos U. The multiple roles of the α7 nicotinic acetylcholine receptor in modulating glutamatergic systems in the normal and diseased nervous system. Biochem Pharmacol 2015. [PMID: 26206184 DOI: 10.1016/j.bcp.2015.07.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Neuronal nicotinic acetylcholine receptors (nAChRs) play an important role in a variety of modulatory and regulatory processes including neurotransmitter release and synaptic transmission in various brain regions of the central nervous system (CNS). Glutamate is the principal excitatory neurotransmitter in the brain and the glutamatergic system participates in the pathophysiology of several neuropsychiatric disorders. Underpinning the importance of nAChRs, many studies demonstrated that nAChRs containing the α7 subunit facilitate glutamate release. Here, we review the currently available body of experimental evidence pertaining to α7 subunit containing nAChRs in their contribution to the modulation of glutamatergic neurotransmission, and we highlight the role of α7 in synaptic plasticity, the morphological and functional maturation of the glutamatergic system and therefore its important contribution in the modulation of neural circuits of the CNS.
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Affiliation(s)
- Fani Koukouli
- Institut Pasteur, Neurobiologie intégrative des systèmes cholinergiques, CNRS UMR 3571, Paris, France.
| | - Uwe Maskos
- Institut Pasteur, Neurobiologie intégrative des systèmes cholinergiques, CNRS UMR 3571, Paris, France.
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22
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Yang YC, Hu CC, Lai YC. Non-additive modulation of synaptic transmission by serotonin, adenosine, and cholinergic modulators in the sensory thalamus. Front Cell Neurosci 2015; 9:60. [PMID: 25852468 PMCID: PMC4360759 DOI: 10.3389/fncel.2015.00060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/09/2015] [Indexed: 11/13/2022] Open
Abstract
The thalamus relays sensory information to the cortex. Oscillatory activities of the thalamocortical network are modulated by monoamines, acetylcholine, and adenosine, and could be the key features characteristic of different vigilance states. Although the thalamus is almost always subject to the actions of more than just one neuromodulators, reports on the modulatory effect of coexisting neuromodulators on thalamic synaptic transmission are unexpectedly scarce. We found that, if present alone, monoamine or adenosine decreases retinothalamic synaptic strength and short-term depression, whereas cholinergic modulators generally enhance postsynaptic response to presynaptic activity. However, coexistence of different modulators tends to produce non-additive effect, not predictable based on the action of individual modulators. Acetylcholine, acting via nicotinic receptors, can interact with either serotonin or adenosine to abolish most short-term synaptic depression. Moreover, the coexistence of adenosine and monoamine, with or without acetylcholine, results in robustly decreased synaptic strength and transforms short-term synaptic depression to facilitation. These findings are consistent with a view that acetylcholine is essential for an "enriched" sensory flow through the thalamus, and the flow is trimmed down by concomitant monoamine or adenosine (presumably for the wakefulness and rapid-eye movement, or REM, sleep states, respectively). In contrast, concomitant adenosine and monoamine would lead to a markedly "deprived" (and high-pass filtered) sensory flow, and thus the dramatic decrease of monoamine may constitute the basic demarcation between non-REM and REM sleep. The collective actions of different neuromodulators on thalamic synaptic transmission thus could be indispensable for the understanding of network responsiveness in different vigilance states.
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Affiliation(s)
- Ya-Chin Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan ; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan
| | - Chun-Chang Hu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan ; Department of Neurosurgery, Chang-Gung Memorial Hospital Linkou, Taiwan
| | - Yi-Chen Lai
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University Tao-Yuan, Taiwan
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Jiang L, López-Hernández GY, Lederman J, Talmage DA, Role LW. Optogenetic studies of nicotinic contributions to cholinergic signaling in the central nervous system. Rev Neurosci 2015; 25:755-71. [PMID: 25051276 DOI: 10.1515/revneuro-2014-0032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/27/2014] [Indexed: 11/15/2022]
Abstract
Molecular manipulations and targeted pharmacological studies provide a compelling picture of which nicotinic receptor subtypes are where in the central nervous system (CNS) and what happens if one activates or deletes them. However, understanding the physiological contribution of nicotinic receptors to endogenous acetylcholine (ACh) signaling in the CNS has proven a more difficult problem to solve. In this review, we provide a synopsis of the literature on the use of optogenetic approaches to control the excitability of cholinergic neurons and to examine the role of CNS nicotinic ACh receptors (nAChRs). As is often the case, this relatively new technology has answered some questions and raised others. Overall, we believe that optogenetic manipulation of cholinergic excitability in combination with some rigorous pharmacology will ultimately advance our understanding of the many functions of nAChRs in the brain.
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Becchetti A, Aracri P, Meneghini S, Brusco S, Amadeo A. The role of nicotinic acetylcholine receptors in autosomal dominant nocturnal frontal lobe epilepsy. Front Physiol 2015; 6:22. [PMID: 25717303 PMCID: PMC4324070 DOI: 10.3389/fphys.2015.00022] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 01/14/2015] [Indexed: 11/22/2022] Open
Abstract
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is a focal epilepsy with attacks typically arising in the frontal lobe during non-rapid eye movement (NREM) sleep. It is characterized by clusters of complex and stereotyped hypermotor seizures, frequently accompanied by sudden arousals. Cognitive and psychiatric symptoms may be also observed. Approximately 12% of the ADNFLE families carry mutations on genes coding for subunits of the heteromeric neuronal nicotinic receptors (nAChRs). This is consistent with the widespread expression of these receptors, particularly the α4β2* subtype, in the neocortex and thalamus. However, understanding how mutant nAChRs lead to partial frontal epilepsy is far from being straightforward because of the complexity of the cholinergic regulation in both developing and mature brains. The relation with the sleep-waking cycle must be also explained. We discuss some possible pathogenetic mechanisms in the light of recent advances about the nAChR role in prefrontal regions as well as the studies carried out in murine models of ADNFLE. Functional evidence points to alterations in prefrontal GABA release, and the synaptic unbalance probably arises during the cortical circuit maturation. Although most of the available functional evidence concerns mutations on nAChR subunit genes, other genes have been recently implicated in the disease, such as KCNT1 (coding for a Na+-dependent K+ channel), DEPD5 (Disheveled, Egl-10 and Pleckstrin Domain-containing protein 5), and CRH (Corticotropin-Releasing Hormone). Overall, the uncertainties about both the etiology and the pathogenesis of ADNFLE point to the current gaps in our knowledge the regulation of neuronal networks in the cerebral cortex.
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Affiliation(s)
- Andrea Becchetti
- Department of Biotechnology and Biosciences and NeuroMi-Milan Center for Neuroscience, University of Milano-Bicocca Milano, Italy
| | - Patrizia Aracri
- Department of Biotechnology and Biosciences and NeuroMi-Milan Center for Neuroscience, University of Milano-Bicocca Milano, Italy
| | - Simone Meneghini
- Department of Biotechnology and Biosciences and NeuroMi-Milan Center for Neuroscience, University of Milano-Bicocca Milano, Italy
| | - Simone Brusco
- Department of Biotechnology and Biosciences and NeuroMi-Milan Center for Neuroscience, University of Milano-Bicocca Milano, Italy
| | - Alida Amadeo
- Department of Biosciences, University of Milano Milano, Italy
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Bali ZK, Inkeller J, Csurgyók R, Bruszt N, Horváth H, Hernádi I. Differential effects of α7 nicotinic receptor agonist PHA-543613 on spatial memory performance of rats in two distinct pharmacological dementia models. Behav Brain Res 2015; 278:404-10. [DOI: 10.1016/j.bbr.2014.10.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 10/16/2014] [Accepted: 10/20/2014] [Indexed: 12/18/2022]
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Hedrick T, Waters J. Acetylcholine excites neocortical pyramidal neurons via nicotinic receptors. J Neurophysiol 2015; 113:2195-209. [PMID: 25589590 DOI: 10.1152/jn.00716.2014] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 01/13/2015] [Indexed: 11/22/2022] Open
Abstract
The neuromodulator acetylcholine (ACh) shapes neocortical function during sensory perception, motor control, arousal, attention, learning, and memory. Here we investigate the mechanisms by which ACh affects neocortical pyramidal neurons in adult mice. Stimulation of cholinergic axons activated muscarinic and nicotinic ACh receptors on pyramidal neurons in all cortical layers and in multiple cortical areas. Nicotinic receptor activation evoked short-latency, depolarizing postsynaptic potentials (PSPs) in many pyramidal neurons. Nicotinic receptor-mediated PSPs promoted spiking of pyramidal neurons. The duration of the increase in spiking was membrane potential dependent, with nicotinic receptor activation triggering persistent spiking lasting many seconds in neurons close to threshold. Persistent spiking was blocked by intracellular BAPTA, indicating that nicotinic ACh receptor activation evoked persistent spiking via a long-lasting calcium-activated depolarizing current. We compared nicotinic PSPs in primary motor cortex (M1), prefrontal cortex (PFC), and visual cortex. The laminar pattern of nicotinic excitation was not uniform but was broadly similar across areas, with stronger modulation in deep than superficial layers. Superimposed on this broad pattern were local differences, with nicotinic PSPs being particularly large and common in layer 5 of M1 but not layer 5 of PFC or primary visual cortex (V1). Hence, in addition to modulating the excitability of pyramidal neurons in all layers via muscarinic receptors, synaptically released ACh preferentially increases the activity of deep-layer neocortical pyramidal neurons via nicotinic receptors, thereby adding laminar selectivity to the widespread enhancement of excitability mediated by muscarinic ACh receptors.
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Affiliation(s)
- Tristan Hedrick
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Jack Waters
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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Martin-Cortecero J, Nuñez A. Tactile response adaptation to whisker stimulation in the lemniscal somatosensory pathway of rats. Brain Res 2014; 1591:27-37. [DOI: 10.1016/j.brainres.2014.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/17/2014] [Accepted: 10/01/2014] [Indexed: 11/29/2022]
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Pollard M, Bartolome JM, Conn PJ, Steckler T, Shaban H. Modulation of neuronal microcircuit activities within the medial prefrontal cortex by mGluR5 positive allosteric modulator. J Psychopharmacol 2014; 28:935-46. [PMID: 25031220 PMCID: PMC4356529 DOI: 10.1177/0269881114542856] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Suppressing anxiety and fear memory relies on bidirectional projections between the medial prefrontal cortex and the amygdala. Positive allosteric modulators of mGluR5 improve cognition in animal models of schizophrenia and retrieval of newly formed associations such as extinction of fear-conditioned behaviour. The increase in neuronal network activities of the medial prefrontal cortex is influenced by both mGluR1 and mGluR5; however, it is not well understood how they modulate network activities and downstream information processing. To map mGluR5-mediated network activity in relation to its emergence as a viable cognitive enhancer, we tested group I mGluR compounds on medial prefrontal cortex network activity via multi-electrode array neuronal spiking and whole-cell patch clamp recordings. Results indicate that mGluR5 activation promotes feed-forward inhibition that depends on recruitment of neuronal activity by carbachol-evoked up states. The rate of neuronal spiking activity under the influence of carbachol was reduced by the mGluR5 positive allosteric modulator, N-(1,3-Diphenyl-1H-pyrazolo-5-yl)-4-nitrobenzamide (VU-29), and enhanced by the mGluR5 negative allosteric modulator, 3-((2-methyl-1,3-thiazol-4-yl)ethynyl)pyridine hydrochloride (MTEP). Spontaneous inhibitory post-synaptic currents were increased upon application of carbachol and in combination with VU-29. These results emphasize a bias towards tonic mGluR5-mediated inhibition that might serve as a signal-to-noise enhancer of sensory inputs projected from associated limbic areas onto the medial prefrontal cortex neuronal microcircuit.
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Affiliation(s)
| | | | - P Jeffrey Conn
- Department of Pharmacology, and the Vanderbilt Center for Neuroscience Drug Discovery 2, Vanderbilt University Medical School, Nashville, TN, USA
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Nicotinic acetylcholine receptors in attention circuitry: the role of layer VI neurons of prefrontal cortex. Cell Mol Life Sci 2014; 71:1225-44. [PMID: 24122021 PMCID: PMC3949016 DOI: 10.1007/s00018-013-1481-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 09/03/2013] [Accepted: 09/16/2013] [Indexed: 12/15/2022]
Abstract
Cholinergic modulation of prefrontal cortex is essential for attention. In essence, it focuses the mind on relevant, transient stimuli in support of goal-directed behavior. The excitation of prefrontal layer VI neurons through nicotinic acetylcholine receptors optimizes local and top-down control of attention. Layer VI of prefrontal cortex is the origin of a dense feedback projection to the thalamus and is one of only a handful of brain regions that express the α5 nicotinic receptor subunit, encoded by the gene chrna5. This accessory nicotinic receptor subunit alters the properties of high-affinity nicotinic receptors in layer VI pyramidal neurons in both development and adulthood. Studies investigating the consequences of genetic deletion of α5, as well as other disruptions to nicotinic receptors, find attention deficits together with altered cholinergic excitation of layer VI neurons and aberrant neuronal morphology. Nicotinic receptors in prefrontal layer VI neurons play an essential role in focusing attention under challenging circumstances. In this regard, they do not act in isolation, but rather in concert with cholinergic receptors in other parts of prefrontal circuitry. This review urges an intensification of focus on the cellular mechanisms and plasticity of prefrontal attention circuitry. Disruptions in attention are one of the greatest contributing factors to disease burden in psychiatric and neurological disorders, and enhancing attention may require different approaches in the normal and disordered prefrontal cortex.
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Bloem B, Poorthuis RB, Mansvelder HD. Cholinergic modulation of the medial prefrontal cortex: the role of nicotinic receptors in attention and regulation of neuronal activity. Front Neural Circuits 2014; 8:17. [PMID: 24653678 PMCID: PMC3949318 DOI: 10.3389/fncir.2014.00017] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 02/20/2014] [Indexed: 11/27/2022] Open
Abstract
Acetylcholine (ACh) release in the medial prefrontal cortex (mPFC) is crucial for normal cognitive performance. Despite the fact that many have studied how ACh affects neuronal processing in the mPFC and thereby influences attention behavior, there is still a lot unknown about how this occurs. Here we will review the evidence that cholinergic modulation of the mPFC plays a role in attention and we will summarize the current knowledge about the role between ACh receptors (AChRs) and behavior and how ACh receptor activation changes processing in the cortical microcircuitry. Recent evidence implicates fast phasic release of ACh in cue detection and attention. This review will focus mainly on the fast ionotropic nicotinic receptors and less on the metabotropic muscarinic receptors. Finally, we will review limitations of the existing studies and address how innovative technologies might push the field forward in order to gain understanding into the relation between ACh, neuronal activity and behavior.
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Affiliation(s)
- Bernard Bloem
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije UniversiteitAmsterdam, Netherlands
- McGovern Institute for Brain Research, Massachusetts Institute of TechnologyCambridge, MA, USA
| | | | - Huibert D. Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, Vrije UniversiteitAmsterdam, Netherlands
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Rowe DL, Hermens DF. Attention-deficit/hyperactivity disorder: neurophysiology, information processing, arousal and drug development. Expert Rev Neurother 2014; 6:1721-34. [PMID: 17144785 DOI: 10.1586/14737175.6.11.1721] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In this review, we draw on literature from both animal and human neurophysiological studies to consider the neurochemical mechanisms underlying attention-deficit/ hyperactivity disorder (ADHD). Psychophysiological and neuropsychological research is used to propose possible etiological endophenotypes of ADHD. These are conceptualized as patients with distinct cortical-arousal, information-processing or maturational abnormalities, or a combination thereof, and how the endophenotypes can be used to help drug development and optimize treatment and management. To illustrate, the paper focuses on neuro- and psychophysiological evidence that suggests cholinergic mechanisms may underlie specific information-processing abnormalities that occur in ADHD. The clinical implications for a cholinergic hypothesis of ADHD are considered, along with its possible implications for treatment and pharmacological development.
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Affiliation(s)
- Donald L Rowe
- The Brain Dynamics Centre and Department of Psychological Medicine, Westmead Hospital and University of Sydney, NSW, Australia.
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32
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Portero-Tresserra M, Cristóbal-Narváez P, Martí-Nicolovius M, Guillazo-Blanch G, Vale-Martínez A. D-cycloserine in prelimbic cortex reverses scopolamine-induced deficits in olfactory memory in rats. PLoS One 2013; 8:e70584. [PMID: 23936452 PMCID: PMC3732227 DOI: 10.1371/journal.pone.0070584] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 06/19/2013] [Indexed: 12/02/2022] Open
Abstract
A significant interaction between N-methyl-D-aspartate (NMDA) and muscarinic receptors has been suggested in the modulation of learning and memory processes. The present study further investigates this issue and explores whether d-cycloserine (DCS), a partial agonist at the glycine binding site of the NMDA receptors that has been regarded as a cognitive enhancer, would reverse scopolamine (SCOP)-induced amnesia in two olfactory learning tasks when administered into the prelimbic cortex (PLC). Thus, in experiment 1, DCS (10 µg/site) was infused prior to acquisition of odor discrimination (ODT) and social transmission of food preference (STFP), which have been previously characterized as paradigms sensitive to PLC muscarinic blockade. Immediately after learning such tasks, SCOP was injected (20 µg/site) and the effects of both drugs (alone and combined) were tested in 24-h retention tests. To assess whether DCS effects may depend on the difficulty of the task, in the STFP the rats expressed their food preference either in a standard two-choice test (experiment 1) or a more challenging three-choice test (experiment 2). The results showed that bilateral intra-PLC infusions of SCOP markedly disrupted the ODT and STFP memory tests. Additionally, infusions of DCS alone into the PLC enhanced ODT but not STFP retention. However, the DCS treatment reversed SCOP-induced memory deficits in both tasks, and this effect seemed more apparent in ODT and 3-choice STFP. Such results support the interaction between the glutamatergic and the cholinergic systems in the PLC in such a way that positive modulation of the NMDA receptor/channel, through activation of the glycine binding site, may compensate dysfunction of muscarinic neurotransmission involved in stimulus-reward and relational learning tasks.
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Affiliation(s)
- Marta Portero-Tresserra
- Departament de Psicobiologia i Metodologia de les Ciencies de la Salut, Institut de Neurociencies, Universitat Autonoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Paula Cristóbal-Narváez
- Departament de Psicobiologia i Metodologia de les Ciencies de la Salut, Institut de Neurociencies, Universitat Autonoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Margarita Martí-Nicolovius
- Departament de Psicobiologia i Metodologia de les Ciencies de la Salut, Institut de Neurociencies, Universitat Autonoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Gemma Guillazo-Blanch
- Departament de Psicobiologia i Metodologia de les Ciencies de la Salut, Institut de Neurociencies, Universitat Autonoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Anna Vale-Martínez
- Departament de Psicobiologia i Metodologia de les Ciencies de la Salut, Institut de Neurociencies, Universitat Autonoma de Barcelona, Bellaterra, Barcelona, Spain
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Aracri P, Amadeo A, Pasini ME, Fascio U, Becchetti A. Regulation of glutamate release by heteromeric nicotinic receptors in layer V of the secondary motor region (Fr2) in the dorsomedial shoulder of prefrontal cortex in mouse. Synapse 2013; 67:338-57. [PMID: 23424068 DOI: 10.1002/syn.21655] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 02/15/2013] [Indexed: 12/24/2022]
Abstract
We studied how nicotinic acetylcholine receptors (nAChRs) regulate glutamate release in the secondary motor area (Fr2) of the dorsomedial murine prefrontal cortex, in the presence of steady agonist levels. Fr2 mediates response to behavioral situations that require immediate attention and is a candidate for generating seizures in the frontal epilepsies caused by mutant nAChRs. Morphological analysis showed a peculiar chemoarchitecture and laminar distribution of pyramidal cells and interneurons. Tonic application of 5 µM nicotine on Layer V pyramidal neurons strongly increased the frequency of spontaneous glutamatergic excitatory postsynaptic currents. The effect was inhibited by 1 µM dihydro-β-erythroidine (which blocks α4-containing nAChRs) but not by 10 nM methyllicaconitine (which blocks α7-containing receptors). Excitatory postsynaptic currents s were also stimulated by 5-iodo-3-[2(S)-azetidinylmethoxy]pyridine, selective for β2-containing receptors, in a dihydro-β-erythroidine -sensitive way. We next studied the association of α4 with different populations of glutamatergic terminals, by using as markers the vesicular glutamate transporter type (VGLUT) 1 for corticocortical synapses and VGLUT2 for thalamocortical projecting fibers. Immunoblots showed higher expression of α4 in Fr2, as compared with the somatosensory cortex. Immunofluorescence showed intense VGLUT1 staining throughout the cortical layers, whereas VGLUT2 immunoreactivity displayed a more distinct laminar distribution. In Layer V, colocalization of α4 nAChR subunit with both VGLUT1 and VGLUT2 was considerably stronger in Fr2 than in somatosensory cortex. Thus, in Fr2, α4β2 nAChRs are expressed in both intrinsic and extrinsic glutamatergic terminals and give a major contribution to control glutamate release in Layer V, in the presence of tonic agonist levels.
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Affiliation(s)
- Patrizia Aracri
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano 20126, Italy
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Acetylcholine as a neuromodulator: cholinergic signaling shapes nervous system function and behavior. Neuron 2012; 76:116-29. [PMID: 23040810 DOI: 10.1016/j.neuron.2012.08.036] [Citation(s) in RCA: 783] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2012] [Indexed: 11/22/2022]
Abstract
Acetylcholine in the brain alters neuronal excitability, influences synaptic transmission, induces synaptic plasticity, and coordinates firing of groups of neurons. As a result, it changes the state of neuronal networks throughout the brain and modifies their response to internal and external inputs: the classical role of a neuromodulator. Here, we identify actions of cholinergic signaling on cellular and synaptic properties of neurons in several brain areas and discuss consequences of this signaling on behaviors related to drug abuse, attention, food intake, and affect. The diverse effects of acetylcholine depend on site of release, receptor subtypes, and target neuronal population; however, a common theme is that acetylcholine potentiates behaviors that are adaptive to environmental stimuli and decreases responses to ongoing stimuli that do not require immediate action. The ability of acetylcholine to coordinate the response of neuronal networks in many brain areas makes cholinergic modulation an essential mechanism underlying complex behaviors.
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Becchetti A. Neuronal nicotinic receptors in sleep-related epilepsy: studies in integrative biology. ISRN BIOCHEMISTRY 2012; 2012:262941. [PMID: 25969754 PMCID: PMC4392997 DOI: 10.5402/2012/262941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 10/21/2012] [Indexed: 11/23/2022]
Abstract
Although Mendelian diseases are rare, when considered one by one, overall they constitute a significant social burden. Besides the medical aspects, they propose us one of the most general biological problems. Given the simplest physiological perturbation of an organism, that is, a single gene mutation, how do its effects percolate through the hierarchical biological levels to determine the pathogenesis? And how robust is the physiological system to this perturbation? To solve these problems, the study of genetic epilepsies caused by mutant ion channels presents special advantages, as it can exploit the full range of modern experimental methods. These allow to extend the functional analysis from single channels to whole brains. An instructive example is autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), which can be caused by mutations in neuronal nicotinic acetylcholine receptors. In vitro, such mutations often produce hyperfunctional receptors, at least in heterozygous condition. However, understanding how this leads to sleep-related frontal epilepsy is all but straightforward. Several available animal models are helping us to determine the effects of ADNFLE mutations on the mammalian brain. Because of the complexity of the cholinergic regulation in both developing and mature brains, several pathogenic mechanisms are possible, which also present different therapeutic implications.
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Affiliation(s)
- Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
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36
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Nicotine improves performance in an attentional set shifting task in rats. Neuropharmacology 2012; 64:314-20. [PMID: 22776507 DOI: 10.1016/j.neuropharm.2012.06.055] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 06/23/2012] [Accepted: 06/26/2012] [Indexed: 11/23/2022]
Abstract
A large number of studies in both humans and experimental animals have demonstrated nicotine-induced improvements in various aspects of cognitive function, including attention and memory. The prefrontal cortex (PFC) is thought to be critically involved in the modulation of executive function and these attentional processes are enhanced by nicotine acting at nicotinic acetylcholine receptors. The involvement of nicotinic processes on cognitive flexibility in particular has not been specifically investigated. The effects of nicotine on attentional flexibility were therefore evaluated using the rodent attentional set shifting task in rats. Nicotine injected both acutely and following repeated pre-exposure significantly improved both intradimensional and extradimensional set shifting performance in the task. Further investigation of the acute effects of nicotine demonstrated this improvement in attentional flexibility to be dose-dependent. These results implicate the nicotinic receptor system in the mediation of processes underlying cognitive flexibility and suggest that nicotine improves attentional flexibility in rats, both within and between perceptual dimensions of a compound stimulus. Nicotine-induced alterations in prefrontal circuitry may underlie these effects on cognitive flexibility. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
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37
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Broussard JI. Posterior parietal cortex dynamically ranks topographic signals via cholinergic influence. Front Integr Neurosci 2012; 6:32. [PMID: 22712008 PMCID: PMC3375019 DOI: 10.3389/fnint.2012.00032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Accepted: 05/28/2012] [Indexed: 01/08/2023] Open
Abstract
The hypothesis to be discussed in this review is that posterior parietal cortex (PPC) is directly involved in selecting relevant stimuli and filtering irrelevant distractors. The PPC receives input from several sensory modalities and integrates them in part to direct the allocation of resources to optimize gains. In conjunction with prefrontal cortex, nucleus accumbens, and basal forebrain cholinergic nuclei, it comprises a network mediating sustained attentional performance. Numerous anatomical, neurophysiological, and lesion studies have substantiated the notion that the basic functions of the PPC are conserved from rodents to humans. One such function is the detection and selection of relevant stimuli necessary for making optimal choices or responses. The issues to be addressed here are how behaviorally relevant targets recruit oscillatory potentials and spiking activity of posterior parietal neurons compared to similar yet irrelevant stimuli. Further, the influence of cortical cholinergic input to PPC in learning and decision-making is also discussed. I propose that these neurophysiological correlates of attention are transmitted to frontal cortical areas contributing to the top-down selection of stimuli in a timely manner.
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Affiliation(s)
- John I Broussard
- Department of Neuroscience, Center on Addiction, Learning, Memory, Baylor College of Medicine, Houston TX, USA
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Alexander KS, Wu HQ, Schwarcz R, Bruno JP. Acute elevations of brain kynurenic acid impair cognitive flexibility: normalization by the alpha7 positive modulator galantamine. Psychopharmacology (Berl) 2012; 220:627-37. [PMID: 22038535 PMCID: PMC3666324 DOI: 10.1007/s00213-011-2539-2] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 10/04/2011] [Indexed: 12/28/2022]
Abstract
RATIONALE Cognitive deficits represent a core symptom cluster in schizophrenia (SZ) that is predictive of outcome but not effectively treated by current antipsychotics. Thus, there is a need for validated animal models for testing potential pro-cognitive drugs. OBJECTIVE As kynurenic acid levels are increased in prefrontal cortex (PFC) of individuals with SZ, we acutely increased brain levels of this astrocyte-derived, negative modulator of alpha7 nicotinic acetylcholine receptors (α7nAChRs) by administration of its bioprecursor kynurenine and measured the effects on extracellular kynurenic acid and glutamate levels in PFC and also performance in a set-shifting task. RESULTS Injections of kynurenine (100 mg/kg, i.p.) increased extracellular kynurenic acid (1,500%) and decreased glutamate levels (30%) in PFC. Kynurenine also produced selective deficits in set-shifting. Saline- and kynurenine-treated rats similarly acquired the compound discrimination and intra-dimensional shift (saline, 7.0 and 6.3 trials, respectively; kynurenine, 8.0 and 6.7). Both groups required more trials to acquire the initial reversal (saline, 15.3; kynurenine, 22.2). Only kynurenine-treated rats were impaired in acquiring the extra-dimensional shift (saline, 8.2; kynurenine, 21.3). These deficits were normalized by administering the α7nAChR positive allosteric modulator galantamine (3.0 mg/kg, i.p) prior to kynurenine, as trials were comparable between galantamine + kynurenine (7.8) and controls (8.2). Bilateral local perfusion of the PFC with galantamine (5.0 μM) also attenuated kynurenine-induced deficits. CONCLUSIONS These results validate the use of animals with elevated brain kynurenic acid levels in SZ research and support studies of drugs that normalize brain kynurenic acid levels and/or positively modulate α7nAChRs as pro-cognitive treatments for SZ.
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Affiliation(s)
- Kathleen S Alexander
- Department of Psychology and Neuroscience, The Ohio State University, 1835 Neil Ave., Columbus, OH 43210, USA
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α4* Nicotinic acetylcholine receptors modulate experience-based cortical depression in the adult mouse somatosensory cortex. J Neurosci 2012; 32:1207-19. [PMID: 22279206 DOI: 10.1523/jneurosci.4568-11.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The molecular mechanisms that mediate experience-based changes in the function of the cerebral cortex, particularly in the adult animal, are poorly understood. Here we show using in vivo voltage-sensitive dye imaging, that whisker trimming leads to depression of whisker-evoked sensory responses in primary, secondary and associative somatosensory cortical regions. Given the importance of cholinergic neurotransmission in cognitive and sensory functions, we examined whether α4-containing (α4*) nicotinic acetylcholine receptors (nAChRs) mediate cortical depression. Using knock-in mice that express YFP-tagged α4 nAChRs subunits, we show that whisker trimming selectively increased the number α4*-YFP nAChRs in layer 4 of deprived barrel columns within 24 h, which persisted until whiskers regrew. Confocal and electron microscopy revealed that these receptors were preferentially increased on the cell bodies of GABAergic neurons. To directly link these receptors with functional cortical depression, we show that depression could be induced in normal mice by topical application or micro-injection of α4* nAChR agonist in the somatosensory cortex. Furthermore, cortical depression could be blocked after whisker trimming with chronic infusions of an α4* nAChR antagonist. Collectively, these results uncover a new role for α4* nAChRs in regulating rapid changes in the functional responsiveness of the adult somatosensory cortex.
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Barr MS, Farzan F, Wing VC, George TP, Fitzgerald PB, Daskalakis ZJ. Repetitive transcranial magnetic stimulation and drug addiction. Int Rev Psychiatry 2011; 23:454-66. [PMID: 22200135 DOI: 10.3109/09540261.2011.618827] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation technique that is now being tested for its ability to treat addiction. This review discusses current research approaches and results of studies which measured the therapeutic use of rTMS to treat tobacco, alcohol and illicit drug addiction. The research in this area is limited and therefore all studies evaluating the therapeutic use of rTMS in tobacco, alcohol or illicit drug addiction were retained including case studies through NCBI PubMed ( http://www.ncbi.nlm.nih.gov ) and manual searches. A total of eight studies were identified that examined the ability of rTMS to treat tobacco, alcohol and cocaine addiction. The results of this review indicate that rTMS is effective in reducing the level of cravings for smoking, alcohol, and cocaine when applied at high frequencies to the dorsolateral prefrontal cortex (DLPFC). Furthermore, these studies suggest that repeated sessions of high frequency rTMS over the DLPFC may be most effective in reducing the level of smoking and alcohol consumption. Although work in this area is limited, this review indicates that rTMS is a promising modality for treating drug addiction.
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Affiliation(s)
- Mera S Barr
- Schizophrenia Program, Centre for Addiction and Mental Health, Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
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Changeux JP, Lou HC. Emergent pharmacology of conscious experience: new perspectives in substance addiction. FASEB J 2011; 25:2098-108. [PMID: 21719514 DOI: 10.1096/fj.11-0702ufm] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We here review experimental findings relevant for the pharmacology of conscious experience, an issue largely neglected in pharmacological research. First, we focus on self-awareness, a pivotal component of conscious experience and its integration within the global neuronal network (GNW), a theoretical concept that unifies convergent approaches on the neural bases of conscious processing. We report recent evidence to show that self-awareness mobilizes a paralimbic circuitry of γ synchrony, and that such synchrony is, in particular, regulated by GABA interneurons under the control of acetylcholine and dopamine. Recent data illustrate that these neurotransmitters establish a causal relationship with the control of self-awareness. The hypothesis is presented that not only is self-awareness chemically regulated, but the reverse may be true. Long-term deficit in self-control of drug intake would result in compulsive substance use, accompanied, in particular, with lesions of the paralimbic circuitry of self-awareness, leading to aggravation of substance abuse, resulting in addiction in a vicious circle. Finally, we propose that the emergent pharmacology of conscious experience may provide new perspectives, not only in substance addiction but also in the many other pathological conditions with deficient self-awareness.
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Verhoog MB, Mansvelder HD. Presynaptic ionotropic receptors controlling and modulating the rules for spike timing-dependent plasticity. Neural Plast 2011; 2011:870763. [PMID: 21941664 PMCID: PMC3173883 DOI: 10.1155/2011/870763] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 07/15/2011] [Indexed: 11/18/2022] Open
Abstract
Throughout life, activity-dependent changes in neuronal connection strength enable the brain to refine neural circuits and learn based on experience. In line with predictions made by Hebb, synapse strength can be modified depending on the millisecond timing of action potential firing (STDP). The sign of synaptic plasticity depends on the spike order of presynaptic and postsynaptic neurons. Ionotropic neurotransmitter receptors, such as NMDA receptors and nicotinic acetylcholine receptors, are intimately involved in setting the rules for synaptic strengthening and weakening. In addition, timing rules for STDP within synapses are not fixed. They can be altered by activation of ionotropic receptors located at, or close to, synapses. Here, we will highlight studies that uncovered how network actions control and modulate timing rules for STDP by activating presynaptic ionotropic receptors. Furthermore, we will discuss how interaction between different types of ionotropic receptors may create "timing" windows during which particular timing rules lead to synaptic changes.
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Affiliation(s)
- Matthijs B. Verhoog
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam, VU University Amsterdam, Room C-440, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Huibert D. Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research (CNCR), Neuroscience Campus Amsterdam, VU University Amsterdam, Room C-440, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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Cholinergic modulation of cognition: insights from human pharmacological functional neuroimaging. Prog Neurobiol 2011; 94:360-88. [PMID: 21708219 PMCID: PMC3382716 DOI: 10.1016/j.pneurobio.2011.06.002] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 06/02/2011] [Accepted: 06/07/2011] [Indexed: 11/22/2022]
Abstract
Evidence from lesion and cortical-slice studies implicate the neocortical cholinergic system in the modulation of sensory, attentional and memory processing. In this review we consider findings from sixty-three healthy human cholinergic functional neuroimaging studies that probe interactions of cholinergic drugs with brain activation profiles, and relate these to contemporary neurobiological models. Consistent patterns that emerge are: (1) the direction of cholinergic modulation of sensory cortex activations depends upon top-down influences; (2) cholinergic hyperstimulation reduces top-down selective modulation of sensory cortices; (3) cholinergic hyperstimulation interacts with task-specific frontoparietal activations according to one of several patterns, including: suppression of parietal-mediated reorienting; decreasing ‘effort’-associated activations in prefrontal regions; and deactivation of a ‘resting-state network’ in medial cortex, with reciprocal recruitment of dorsolateral frontoparietal regions during performance-challenging conditions; (4) encoding-related activations in both neocortical and hippocampal regions are disrupted by cholinergic blockade, or enhanced with cholinergic stimulation, while the opposite profile is observed during retrieval; (5) many examples exist of an ‘inverted-U shaped’ pattern of cholinergic influences by which the direction of functional neural activation (and performance) depends upon both task (e.g. relative difficulty) and subject (e.g. age) factors. Overall, human cholinergic functional neuroimaging studies both corroborate and extend physiological accounts of cholinergic function arising from other experimental contexts, while providing mechanistic insights into cholinergic-acting drugs and their potential clinical applications.
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Dasari S, Gulledge AT. M1 and M4 receptors modulate hippocampal pyramidal neurons. J Neurophysiol 2010; 105:779-92. [PMID: 21160001 DOI: 10.1152/jn.00686.2010] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acetylcholine (ACh), acting at muscarinic ACh receptors (mAChRs), modulates the excitability and synaptic connectivity of hippocampal pyramidal neurons. CA1 pyramidal neurons respond to transient ("phasic") mAChR activation with biphasic responses in which inhibition is followed by excitation, whereas prolonged ("tonic") mAChR activation increases CA1 neuron excitability. Both phasic and tonic mAChR activation excites pyramidal neurons in the CA3 region, yet ACh suppresses glutamate release at the CA3-to-CA1 synapse (the Schaffer-collateral pathway). Using mice genetically lacking specific mAChRs (mAChR knockout mice), we identified the mAChR subtypes responsible for cholinergic modulation of hippocampal pyramidal neuron excitability and synaptic transmission. Knockout of M1 receptors significantly reduced, or eliminated, most phasic and tonic cholinergic responses in CA1 and CA3 pyramidal neurons. On the other hand, in the absence of other G(q)-linked mAChRs (M3 and M5), M1 receptors proved sufficient for all postsynaptic cholinergic effects on CA1 and CA3 pyramidal neuron excitability. M3 receptors were able to participate in tonic depolarization of CA1 neurons, but otherwise contributed little to cholinergic responses. At the Schaffer-collateral synapse, bath application of the cholinergic agonist carbachol suppressed stratum radiatum-evoked excitatory postsynaptic potentials (EPSPs) in wild-type CA1 neurons and in CA1 neurons from mice lacking M1 or M2 receptors. However, Schaffer-collateral EPSPs were not significantly suppressed by carbachol in neurons lacking M4 receptors. We therefore conclude that M1 and M4 receptors are the major mAChR subtypes responsible for direct cholinergic modulation of the excitatory hippocampal circuit.
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Affiliation(s)
- Sameera Dasari
- Dartmouth Medical School, Department of Physiology and Neurobiology, One Medical Center Drive, Lebanon, NH 03756-0001, USA
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Konradsson-Geuken A, Wu HQ, Gash CR, Alexander KS, Campbell A, Sozeri Y, Pellicciari R, Schwarcz R, Bruno JP. Cortical kynurenic acid bi-directionally modulates prefrontal glutamate levels as assessed by microdialysis and rapid electrochemistry. Neuroscience 2010; 169:1848-59. [PMID: 20600676 PMCID: PMC2918728 DOI: 10.1016/j.neuroscience.2010.05.052] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 05/21/2010] [Accepted: 05/24/2010] [Indexed: 12/23/2022]
Abstract
Using two in vivo methods, microdialysis and rapid in situ electrochemistry, this study examined the modulation of extracellular glutamate levels by endogenously produced kynurenic acid (KYNA) in the prefrontal cortex (PFC) of awake rats. Measured by microdialysis, i.p. administration of KYNA's bioprecursor L-kynurenine dose-dependently elevated extracellular KYNA and reduced extracellular glutamate (nadir after 50 mg/kg kynurenine: 60% decrease from baseline values). This dose-dependent decrease in glutamate levels was also seen using a glutamate-sensitive microelectrode array (MEA) (31% decrease following 50 mg/kg kynurenine). The kynurenine-induced reduction in glutamate was blocked (microdialysis) or attenuated (MEA) by co-administration of galantamine (3 mg/kg i.p.), a drug that competes with KYNA at an allosteric potentiating site of the alpha 7 nicotinic acetylcholine receptor. In separate experiments, extracellular glutamate levels were measured by MEA following the local perfusion (45 min) of the PFC with kynurenine (2.5 microM) or the selective KYNA biosynthesis inhibitor S-ethylsulfonylbenzoylalanine (S-ESBA; 5 mM). In agreement with previous microdialysis studies, local kynurenine application produced a reversible reduction in glutamate (nadir: -29%), whereas perfusion with S-ESBA increased glutamate levels reversibly (maximum: +38%). Collectively, these results demonstrate that fluctuations in the biosynthesis of KYNA in the PFC bi-directionally modulate extracellular glutamate levels, and that qualitatively very similar data are obtained by microdialysis and MEA. Since KYNA levels are elevated in the PFC of individuals with schizophrenia, and since prefrontal glutamatergic and nicotinic transmission mediate cognitive flexibility, normalization of KYNA levels in the PFC may constitute an effective treatment strategy for alleviating cognitive deficits in schizophrenia.
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Affiliation(s)
- A Konradsson-Geuken
- Department of Psychology, The Ohio State University, Columbus, OH 43210, USA
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Blockade of different muscarinic receptor subtypes changes the equilibrium between excitation and inhibition in rat visual cortex. Neuroscience 2010; 169:1610-20. [PMID: 20600670 DOI: 10.1016/j.neuroscience.2010.06.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 06/09/2010] [Accepted: 06/10/2010] [Indexed: 11/22/2022]
Abstract
We have shown that cortical acetylcholine modulates the balance between excitation and inhibition evoked in layer 5 pyramidal neurons of rat visual cortex [Lucas-Meunier E, Monier C, Amar M, Baux G, Frégnac Y, Fossier P (2009) Cereb Cortex 19:2411-2427]. Our aim is now to establish a functional basis for the role of the different types of muscarinic receptors (MRs) on glutamate fibers and on GABAergic interneurons and to analyse their contribution to the modulation of excitation-inhibition balance in the rat visual cortex. To ascertain that there was a basis for our functional study, we first checked for the presence of the various MR subtypes by single cell RT-PCR and immunolabeling experiments. Then, recording the composite responses in layer 5 pyramidal neurons to layer 1-2 stimulation (which also recruits cholinergic fibers) in the presence of specific antagonists of the different types of MR allowed us to determine their modulatory role. We show that the specific blockade of the widely distributed M1R (with the mamba toxin, MT7) induced a significant increase in the excitatory conductance without modifying the inhibitory conductance, pointing to a localization of M1R on glutamatergic neurons where their activation would decrease the release of glutamate. From our functional results, M2/M4Rs appear to be located on glutamatergic neurons afferent to the recorded layer 5 pyramidal neuron and they decrease glutamate release. The extended distribution of M4Rs in the cortex compared to the restricted distribution of M2R (layers 3-5) is in favour of a major role as a modulator of M4R. The selective antagonist of M3Rs, 4-DAMP, decreased the inhibitory conductance, showing that activated M3Rs increase the release of GABA and thus are located on GABAergic interneurons. The activation of the different types of MRs located either on glutamatergic neurons or on GABAergic interneurons converges to reinforce the dominance of inhibitory inputs thus decreasing the excitability of layer 5 pyramidal neurons.
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Zhang ZW, Burke MW, Calakos N, Beaulieu JM, Vaucher E. Confocal Analysis of Cholinergic and Dopaminergic Inputs onto Pyramidal Cells in the Prefrontal Cortex of Rodents. Front Neuroanat 2010; 4:21. [PMID: 20589096 PMCID: PMC2893003 DOI: 10.3389/fnana.2010.00021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 05/05/2010] [Indexed: 11/13/2022] Open
Abstract
Cholinergic and dopaminergic projections to the rat medial prefrontal cortex (mPFC) are both involved in cognitive functions including attention. These neuronal systems modulate mPFC neuronal activity mainly through diffuse transmission. In order to better understand the anatomical level of influence of these systems, confocal microscopy with triple-fluorescent immunolabeling was used in three subregions of the mPFC of rats and Drd1a-tdTomato/Drd2-EGFP transgenic mice. The zone of interaction was defined as a reciprocal microproximity between dopaminergic and cholinergic axonal segments as well as pyramidal neurons. The density of varicosities, along these segments was considered as a possible activity-dependant morphological feature. The percentage of cholinergic and dopaminergic fibers in microproximity ranged from 12 to 40% depending on the layer and mPFC subregion. The cholinergic system appeared to have more influence on dopaminergic fibers since a larger proportion of the dopaminergic fibers were within microproximity to cholinergic fibers. The density of both cholinergic and dopaminergic varicosities was significantly elevated within microproximities. The main results indicate that the cholinergic and dopaminergic systems converge on pyramidal cells in mPFC particularly in the layer V. In transgenic mice 93% of the pyramidal cells expressed the transgenic marker for Drd2 expression, but only 22% expressed the maker for Drd1ar expression. Data presented here suggest that the modulation of mPFC by dopaminergic fibers would be mostly inhibitory and localized at the output level whereas the cholinergic modulation would be exerted at the input and output level both through direct interaction with pyramidal cells and dopaminergic fibers.
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Affiliation(s)
- Zi-Wei Zhang
- School of Optometry, Université de Montréal Montréal, QC, Canada
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Changeux JP. Nicotine addiction and nicotinic receptors: lessons from genetically modified mice. Nat Rev Neurosci 2010; 11:389-401. [PMID: 20485364 DOI: 10.1038/nrn2849] [Citation(s) in RCA: 333] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The past decades have seen a revolution in our understanding of brain diseases and in particular of drug addiction. This has been largely due to the identification of neurotransmitter receptors and the development of animal models, which together have enabled the investigation of brain functions from the molecular to the cognitive level. Tobacco smoking, the principal - yet avoidable - cause of lung cancer is associated with nicotine addiction. Recent studies in mice involving deletion and replacement of nicotinic acetylcholine receptor subunits have begun to identify the molecular mechanisms underlying nicotine addiction and might offer new therapeutic strategies to treat this addiction.
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Affiliation(s)
- Jean-Pierre Changeux
- Collge de France and the Institut Pasteur CNRS URA 2182, 25 rue du Dr Roux, 75015 Paris, France.
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Petrovsky N, Quednow BB, Ettinger U, Schmechtig A, Mössner R, Collier DA, Kühn KU, Maier W, Wagner M, Kumari V. Sensorimotor gating is associated with CHRNA3 polymorphisms in schizophrenia and healthy volunteers. Neuropsychopharmacology 2010; 35:1429-39. [PMID: 20393456 PMCID: PMC3055462 DOI: 10.1038/npp.2010.12] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Attentional gating deficits, commonly measured by prepulse inhibition (PPI) of the acoustic startle response (ASR), have been established as an endophenotype of schizophrenia. Prepulse inhibition is heritable and has been associated with polymorphisms in serotonin and dopamine system genes. Prepulse inhibition can be enhanced by nicotine, and therefore it has been proposed that schizophrenia patients smoke to ameliorate their early attentional deficits. The PPI-enhancing effects of nicotine in rodents are strain dependent, suggesting a genetic contribution to PPI within the nicotinic acetylcholine receptor (nAChR) system. Recent human genetic studies also imply that tobacco dependence is affected by polymorphisms in the alpha3/alpha5 subunits of the nAChR (CHRNA3/CHRNA5) gene cluster. We, therefore, investigated the impact of two common CHRNA3 polymorphisms (rs1051730/rs1317286) on PPI, startle reactivity, and habituation of the ASR in two independent samples of 107 healthy British volunteers and 73 schizophrenia patients hailing from Germany. In both samples, PPI was influenced by both CHRNA3 polymorphisms (combined p-value=0.0027), which were strongly linked. Moreover, CHRNA3 genotype was associated with chronicity, treatment, and negative symptoms in the schizophrenia sample. These results suggest that sensorimotor gating is influenced by variations of the CHRNA3 gene, which might also have an impact on the course and severity of schizophrenia.
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Affiliation(s)
- Nadine Petrovsky
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Boris B Quednow
- Division of Experimental and Clinical Pharmacopsychology, University Hospital of Psychiatry, University of Zurich, Zurich, Switzerland,Division of Experimental and Clinical Pharmacopsychology, University Hospital of Psychiatry, Lenggstrasse 31, CH-8032 Zurich, Switzerland, Tel: +41 44 384 2777, Fax: +41 44 384 2499, E-mail:
| | - Ulrich Ettinger
- Department of Psychiatry and Department of Psychology, Ludwig-Maximilians University Munich, Munich, Germany
| | - Anne Schmechtig
- Department of Psychology, Institute of Psychiatry, King's College London, London, UK
| | - Rainald Mössner
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - David A Collier
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK
| | - Kai-Uwe Kühn
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Wolfgang Maier
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Michael Wagner
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Veena Kumari
- Department of Psychology, Institute of Psychiatry, King's College London, London, UK
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