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Balleste AF, Sangadi A, Titus DJ, Johnstone T, Hogenkamp D, Gee KW, Atkins CM. Enhancing cognitive recovery in chronic traumatic brain injury through simultaneous allosteric modulation of α7 nicotinic acetylcholine and α5 GABA A receptors. Exp Neurol 2024; 379:114879. [PMID: 38942266 PMCID: PMC11283977 DOI: 10.1016/j.expneurol.2024.114879] [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: 03/11/2024] [Revised: 05/20/2024] [Accepted: 06/25/2024] [Indexed: 06/30/2024]
Abstract
Traumatic brain injury (TBI) leads to changes in the neural circuitry of the hippocampus that result in chronic learning and memory deficits. However, effective therapeutic strategies to ameliorate these chronic learning and memory impairments after TBI are limited. Two pharmacological targets for enhancing cognition are nicotinic acetylcholine receptors (nAChRs) and GABAA receptors (GABAARs), both of which regulate hippocampal network activity to form declarative memories. A promising compound, 522-054, both allosterically enhances α7 nAChRs and inhibits α5 subunit-containing GABAARs. Administration of 522-054 enhances long-term potentiation (LTP) and cognitive functioning in non-injured animals. In this study, we assessed the effects of 522-054 on hippocampal synaptic plasticity and learning and memory deficits in the chronic post-TBI recovery period. Adult male Sprague Dawley rats received moderate parasagittal fluid-percussion brain injury or sham surgery. At 12 wk after injury, we assessed basal synaptic transmission and LTP at the Schaffer collateral-CA1 synapse of the hippocampus. Bath application of 522-054 to hippocampal slices reduced deficits in basal synaptic transmission and recovered TBI-induced impairments in LTP. Moreover, treatment of animals with 522-054 at 12 wk post-TBI improved cue and contextual fear memory and water maze acquisition and retention without a measurable effect on cortical or hippocampal atrophy. These results suggest that dual allosteric modulation of α7 nAChR and α5 GABAAR signaling may be a potential therapy for treating cognitive deficits during chronic recovery from TBI.
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Affiliation(s)
- Alyssa F Balleste
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Akhila Sangadi
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - David J Titus
- Department of Psychiatry & Behavioral Sciences, University of Minnesota, Minneapolis, MN, USA
| | | | - Derk Hogenkamp
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, USA
| | - Kelvin W Gee
- Department of Pharmaceutical Sciences, University of California Irvine, Irvine, USA
| | - Coleen M Atkins
- The Miami Project to Cure Paralysis, Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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Kniffin A, Bangasser DA, Parikh V. Septohippocampal cholinergic system at the intersection of stress and cognition: Current trends and translational implications. Eur J Neurosci 2024; 59:2155-2180. [PMID: 37118907 PMCID: PMC10875782 DOI: 10.1111/ejn.15999] [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: 09/27/2022] [Revised: 04/21/2023] [Accepted: 04/22/2023] [Indexed: 04/30/2023]
Abstract
Deficits in hippocampus-dependent memory processes are common across psychiatric and neurodegenerative disorders such as depression, anxiety and Alzheimer's disease. Moreover, stress is a major environmental risk factor for these pathologies and it exerts detrimental effects on hippocampal functioning via the activation of hypothalamic-pituitary-adrenal (HPA) axis. The medial septum cholinergic neurons extensively innervate the hippocampus. Although, the cholinergic septohippocampal pathway (SHP) has long been implicated in learning and memory, its involvement in mediating the adaptive and maladaptive impact of stress on mnemonic processes remains less clear. Here, we discuss current research highlighting the contributions of cholinergic SHP in modulating memory encoding, consolidation and retrieval. Then, we present evidence supporting the view that neurobiological interactions between HPA axis stress response and cholinergic signalling impact hippocampal computations. Finally, we critically discuss potential challenges and opportunities to target cholinergic SHP as a therapeutic strategy to improve cognitive impairments in stress-related disorders. We argue that such efforts should consider recent conceptualisations on the dynamic nature of cholinergic signalling in modulating distinct subcomponents of memory and its interactions with cellular substrates that regulate the adaptive stress response.
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Affiliation(s)
- Alyssa Kniffin
- Department of Psychology and Neuroscience, Temple University, Philadelphia, PA 19122
| | - Debra A. Bangasser
- Neuroscience Institute and Center for Behavioral Neuroscience, Georgia State University, Atlanta, GA
| | - Vinay Parikh
- Department of Psychology and Neuroscience, Temple University, Philadelphia, PA 19122
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3
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Vallés AS, Barrantes FJ. Nicotinic Acetylcholine Receptor Dysfunction in Addiction and in Some Neurodegenerative and Neuropsychiatric Diseases. Cells 2023; 12:2051. [PMID: 37626860 PMCID: PMC10453526 DOI: 10.3390/cells12162051] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/20/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
The cholinergic system plays an essential role in brain development, physiology, and pathophysiology. Herein, we review how specific alterations in this system, through genetic mutations or abnormal receptor function, can lead to aberrant neural circuitry that triggers disease. The review focuses on the nicotinic acetylcholine receptor (nAChR) and its role in addiction and in neurodegenerative and neuropsychiatric diseases and epilepsy. Cholinergic dysfunction is associated with inflammatory processes mainly through the involvement of α7 nAChRs expressed in brain and in peripheral immune cells. Evidence suggests that these neuroinflammatory processes trigger and aggravate pathological states. We discuss the preclinical evidence demonstrating the therapeutic potential of nAChR ligands in Alzheimer disease, Parkinson disease, schizophrenia spectrum disorders, and in autosomal dominant sleep-related hypermotor epilepsy. PubMed and Google Scholar bibliographic databases were searched with the keywords indicated below.
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Affiliation(s)
- Ana Sofía Vallés
- Bahía Blanca Institute of Biochemical Research (UNS-CONICET), Bahía Blanca 8000, Argentina;
| | - Francisco J. Barrantes
- Biomedical Research Institute (BIOMED), Faculty of Medical Sciences, Pontifical Catholic University of Argentina—National Scientific and Technical Research Council, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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4
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Sugisaki E, Fukushima Y, Nakajima N, Aihara T. The dependence of acetylcholine on dynamic changes in the membrane potential and an action potential during spike timing-dependent plasticity induction in the hippocampus. Eur J Neurosci 2022; 56:5972-5986. [PMID: 36164804 DOI: 10.1111/ejn.15832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/01/2022] [Accepted: 09/16/2022] [Indexed: 12/29/2022]
Abstract
The hippocampus is an important area for memory encoding and retrieval and is the location of spike timing-dependent plasticity (STDP), a basic phenomenon of learning and memory. STDP is facilitated if acetylcholine (ACh) is released from cholinergic neurons during attentional processes. However, it is unclear how ACh influences postsynaptic changes during STDP induction and determines the STDP magnitude. To address these issues, we obtained patch clamp recordings from CA1 pyramidal neurons to evaluate the postsynaptic changes during stimuli injection in Schaffer collaterals by quantifying baseline amplitudes (i.e., the lowest values elicited by paired pulses comprising STDP stimuli) and action potentials. The results showed that baseline amplitudes were elevated if eserine was applied in the presence of picrotoxin. In addition, muscarinic ACh receptors (mAChRs) contributed more to the baseline amplitude elevation than nicotinic AChRs (nAChRs). Moreover, the magnitude of the STDP depended on the magnitude of the baseline amplitude. However, in the absence of picrotoxin, baseline amplitudes were balanced, regardless of the ACh concentration, resulting in a similar magnitude of the STDP, except under the nAChR alone-activated condition, which showed a larger STDP and lower baseline amplitude induction. This was due to broadened widths of action potentials. These results suggest that activation of mAChRs and nAChRs, which are effective for baseline amplitudes and action potentials, respectively, plays an important role in postsynaptic changes during memory consolidation.
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Affiliation(s)
- Eriko Sugisaki
- Brain Science Institute, Tamagawa University, Tokyo, Japan
| | - Yasuhiro Fukushima
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,Kawasaki University of Medical Welfare, Okayama, Japan
| | - Naoki Nakajima
- Graduated School of Engineering, Tamagawa University, Tokyo, Japan
| | - Takeshi Aihara
- Brain Science Institute, Tamagawa University, Tokyo, Japan
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5
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Vallés AS, Barrantes FJ. Interactions between the Nicotinic and Endocannabinoid Receptors at the Plasma Membrane. MEMBRANES 2022; 12:812. [PMID: 36005727 PMCID: PMC9414690 DOI: 10.3390/membranes12080812] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Compartmentalization, together with transbilayer and lateral asymmetries, provide the structural foundation for functional specializations at the cell surface, including the active role of the lipid microenvironment in the modulation of membrane-bound proteins. The chemical synapse, the site where neurotransmitter-coded signals are decoded by neurotransmitter receptors, adds another layer of complexity to the plasma membrane architectural intricacy, mainly due to the need to accommodate a sizeable number of molecules in a minute subcellular compartment with dimensions barely reaching the micrometer. In this review, we discuss how nature has developed suitable adjustments to accommodate different types of membrane-bound receptors and scaffolding proteins via membrane microdomains, and how this "effort-sharing" mechanism has evolved to optimize crosstalk, separation, or coupling, where/when appropriate. We focus on a fast ligand-gated neurotransmitter receptor, the nicotinic acetylcholine receptor, and a second-messenger G-protein coupled receptor, the cannabinoid receptor, as a paradigmatic example.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca 8000, Argentina
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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6
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Eniwaye BP, Booth V, Hudetz AG, Zochowski M. Modeling cortical synaptic effects of anesthesia and their cholinergic reversal. PLoS Comput Biol 2022; 18:e1009743. [PMID: 35737717 PMCID: PMC9258872 DOI: 10.1371/journal.pcbi.1009743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 07/06/2022] [Accepted: 05/31/2022] [Indexed: 01/07/2023] Open
Abstract
General anesthetics work through a variety of molecular mechanisms while resulting in the common end point of sedation and loss of consciousness. Generally, the administration of common anesthetics induces reduction in synaptic excitation while promoting synaptic inhibition. Exogenous modulation of the anesthetics' synaptic effects can help determine the neuronal pathways involved in anesthesia. For example, both animal and human studies have shown that exogenously induced increases in acetylcholine in the brain can elicit wakeful-like behavior despite the continued presence of the anesthetic. However, the underlying mechanisms of anesthesia reversal at the cellular level have not been investigated. Here we apply a computational model of a network of excitatory and inhibitory neurons to simulate the network-wide effects of anesthesia, due to changes in synaptic inhibition and excitation, and their reversal by cholinergic activation through muscarinic receptors. We use a differential evolution algorithm to fit model parameters to match measures of spiking activity, neuronal connectivity, and network dynamics recorded in the visual cortex of rodents during anesthesia with desflurane in vivo. We find that facilitating muscarinic receptor effects of acetylcholine on top of anesthetic-induced synaptic changes predicts the reversal of anesthetic suppression of neurons' spiking activity, functional connectivity, as well as pairwise and population interactions. Thus, our model predicts a specific neuronal mechanism for the cholinergic reversal of anesthesia consistent with experimental behavioral observations.
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Affiliation(s)
- Bolaji P. Eniwaye
- Department of Applied Physics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Victoria Booth
- Department of Mathematics and Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (VB); (AGH); (MZ)
| | - Anthony G. Hudetz
- Department of Applied Physics, University of Michigan, Ann Arbor, Michigan, United States of America
- Center for Consciousness Science, Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (VB); (AGH); (MZ)
| | - Michal Zochowski
- Department of Applied Physics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Physics and Biophysics Program, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail: (VB); (AGH); (MZ)
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7
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Fuchsberger T, Paulsen O. Modulation of hippocampal plasticity in learning and memory. Curr Opin Neurobiol 2022; 75:102558. [PMID: 35660989 DOI: 10.1016/j.conb.2022.102558] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/15/2022] [Accepted: 04/25/2022] [Indexed: 11/17/2022]
Abstract
Synaptic plasticity plays a central role in the study of neural mechanisms of learning and memory. Plasticity rules are not invariant over time but are under neuromodulatory control, enabling behavioral states to influence memory formation. Neuromodulation controls synaptic plasticity at network level by directing information flow, at circuit level through changes in excitation/inhibition balance, and at synaptic level through modulation of intracellular signaling cascades. Although most research has focused on modulation of principal neurons, recent progress has uncovered important roles for interneurons in not only routing information, but also setting conditions for synaptic plasticity. Moreover, astrocytes have been shown to both gate and mediate plasticity. These additional mechanisms must be considered for a comprehensive mechanistic understanding of learning and memory.
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Affiliation(s)
- Tanja Fuchsberger
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Ole Paulsen
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
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8
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Vallés AS, Barrantes FJ. Dysregulation of Neuronal Nicotinic Acetylcholine Receptor-Cholesterol Crosstalk in Autism Spectrum Disorder. Front Mol Neurosci 2021; 14:744597. [PMID: 34803605 PMCID: PMC8604044 DOI: 10.3389/fnmol.2021.744597] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/21/2021] [Indexed: 12/27/2022] Open
Abstract
Autism spectrum disorder (ASD) is a set of complex neurodevelopmental diseases that include impaired social interaction, delayed and disordered language, repetitive or stereotypic behavior, restricted range of interests, and altered sensory processing. The underlying causes of the core symptoms remain unclear, as are the factors that trigger their onset. Given the complexity and heterogeneity of the clinical phenotypes, a constellation of genetic, epigenetic, environmental, and immunological factors may be involved. The lack of appropriate biomarkers for the evaluation of neurodevelopmental disorders makes it difficult to assess the contribution of early alterations in neurochemical processes and neuroanatomical and neurodevelopmental factors to ASD. Abnormalities in the cholinergic system in various regions of the brain and cerebellum are observed in ASD, and recently altered cholesterol metabolism has been implicated at the initial stages of the disease. Given the multiple effects of the neutral lipid cholesterol on the paradigm rapid ligand-gated ion channel, the nicotinic acetylcholine receptor, we explore in this review the possibility that the dysregulation of nicotinic receptor-cholesterol crosstalk plays a role in some of the neurological alterations observed in ASD.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Buenos Aires, Argentina
| | - Francisco J Barrantes
- Instituto de Investigaciones Biomédicas (BIOMED), UCA-CONICET, Buenos Aires, Argentina
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9
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Vallés AS, Barrantes FJ. Nanoscale Sub-Compartmentalization of the Dendritic Spine Compartment. Biomolecules 2021; 11:1697. [PMID: 34827695 PMCID: PMC8615865 DOI: 10.3390/biom11111697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 01/04/2023] Open
Abstract
Compartmentalization of the membrane is essential for cells to perform highly specific tasks and spatially constrained biochemical functions in topographically defined areas. These membrane lateral heterogeneities range from nanoscopic dimensions, often involving only a few molecular constituents, to micron-sized mesoscopic domains resulting from the coalescence of nanodomains. Short-lived domains lasting for a few milliseconds coexist with more stable platforms lasting from minutes to days. This panoply of lateral domains subserves the great variety of demands of cell physiology, particularly high for those implicated in signaling. The dendritic spine, a subcellular structure of neurons at the receiving (postsynaptic) end of central nervous system excitatory synapses, exploits this compartmentalization principle. In its most frequent adult morphology, the mushroom-shaped spine harbors neurotransmitter receptors, enzymes, and scaffolding proteins tightly packed in a volume of a few femtoliters. In addition to constituting a mesoscopic lateral heterogeneity of the dendritic arborization, the dendritic spine postsynaptic membrane is further compartmentalized into spatially delimited nanodomains that execute separate functions in the synapse. This review discusses the functional relevance of compartmentalization and nanodomain organization in synaptic transmission and plasticity and exemplifies the importance of this parcelization in various neurotransmitter signaling systems operating at dendritic spines, using two fast ligand-gated ionotropic receptors, the nicotinic acetylcholine receptor and the glutamatergic receptor, and a second-messenger G-protein coupled receptor, the cannabinoid receptor, as paradigmatic examples.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca 8000, Argentina;
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Institute of Biomedical Research (BIOMED), UCA-CONICET, Av. Alicia Moreau de Justo 1600, Buenos Aires C1107AFF, Argentina
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10
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Vallés AS, Barrantes FJ. Dendritic spine membrane proteome and its alterations in autistic spectrum disorder. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 128:435-474. [PMID: 35034726 DOI: 10.1016/bs.apcsb.2021.09.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Dendritic spines are small protrusions stemming from the dendritic shaft that constitute the primary specialization for receiving and processing excitatory neurotransmission in brain synapses. The disruption of dendritic spine function in several neurological and neuropsychiatric diseases leads to severe information-processing deficits with impairments in neuronal connectivity and plasticity. Spine dysregulation is usually accompanied by morphological alterations to spine shape, size and/or number that may occur at early pathophysiological stages and not necessarily be reflected in clinical manifestations. Autism spectrum disorder (ASD) is one such group of diseases involving changes in neuronal connectivity and abnormal morphology of dendritic spines on postsynaptic neurons. These alterations at the subcellular level correlate with molecular changes in the spine proteome, with alterations in the copy number, topography, or in severe cases in the phenotype of the molecular components, predominantly of those proteins involved in spine recognition and adhesion, reflected in abnormally short lifetimes of the synapse and compensatory increases in synaptic connections. Since cholinergic neurotransmission participates in the regulation of cognitive function (attention, memory, learning processes, cognitive flexibility, social interactions) brain acetylcholine receptors are likely to play an important role in the dysfunctional synapses in ASD, either directly or indirectly via the modulatory functions exerted on other neurotransmitter receptor proteins and spine-resident proteins.
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Affiliation(s)
- Ana Sofía Vallés
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca, Argentina
| | - Francisco J Barrantes
- Instituto de Investigaciones Biomédicas (BIOMED), UCA-CONICET, Buenos Aires, Argentina.
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11
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Skilling QM, Eniwaye B, Clawson BC, Shaver J, Ognjanovski N, Aton SJ, Zochowski M. Acetylcholine-gated current translates wake neuronal firing rate information into a spike timing-based code in Non-REM sleep, stabilizing neural network dynamics during memory consolidation. PLoS Comput Biol 2021; 17:e1009424. [PMID: 34543284 PMCID: PMC8483332 DOI: 10.1371/journal.pcbi.1009424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 09/30/2021] [Accepted: 09/06/2021] [Indexed: 11/19/2022] Open
Abstract
Sleep is critical for memory consolidation, although the exact mechanisms mediating this process are unknown. Combining reduced network models and analysis of in vivo recordings, we tested the hypothesis that neuromodulatory changes in acetylcholine (ACh) levels during non-rapid eye movement (NREM) sleep mediate stabilization of network-wide firing patterns, with temporal order of neurons’ firing dependent on their mean firing rate during wake. In both reduced models and in vivo recordings from mouse hippocampus, we find that the relative order of firing among neurons during NREM sleep reflects their relative firing rates during prior wake. Our modeling results show that this remapping of wake-associated, firing frequency-based representations is based on NREM-associated changes in neuronal excitability mediated by ACh-gated potassium current. We also show that learning-dependent reordering of sequential firing during NREM sleep, together with spike timing-dependent plasticity (STDP), reconfigures neuronal firing rates across the network. This rescaling of firing rates has been reported in multiple brain circuits across periods of sleep. Our model and experimental data both suggest that this effect is amplified in neural circuits following learning. Together our data suggest that sleep may bias neural networks from firing rate-based towards phase-based information encoding to consolidate memories. We show that neuromodulatory changes during non-rapid eye movement (NREM) sleep generate stable spike timing relationships between neurons, the ordering of which reflects the neurons’ relative firing rates during wake. Learning-dependent ordering of firing in the hippocampus during NREM, acting in tandem with spike timing-dependent plasticity, reconfigures neuronal firing rates across the hippocampal network. This “rescaling” of neuronal firing rates has recently been reported in multiple brain circuits across periods of sleep. Together, our results suggest that the brain is remapping frequency-biased representations of information formed during wake into timing biased-representations during NREM sleep.
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Affiliation(s)
- Quinton M Skilling
- Biophysics Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Bolaji Eniwaye
- Applied Physics Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Brittany C Clawson
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - James Shaver
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Nicolette Ognjanovski
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sara J Aton
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michal Zochowski
- Biophysics Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Physics, University of Michigan, Ann Arbor, Michigan, United States of America
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12
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Robert V, Therreau L, Davatolhagh MF, Bernardo-Garcia FJ, Clements KN, Chevaleyre V, Piskorowski RA. The mechanisms shaping CA2 pyramidal neuron action potential bursting induced by muscarinic acetylcholine receptor activation. J Gen Physiol 2021; 152:133812. [PMID: 32069351 PMCID: PMC7141590 DOI: 10.1085/jgp.201912462] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 12/18/2019] [Accepted: 01/13/2020] [Indexed: 01/04/2023] Open
Abstract
Recent studies have revealed that hippocampal area CA2 plays an important role in hippocampal network function. Disruption of this region has been implicated in neuropsychiatric disorders. It is well appreciated that cholinergic input to the hippocampus plays an important role in learning and memory. While the effect of elevated cholinergic tone has been well studied in areas CA1 and CA3, it remains unclear how changes in cholinergic tone impact synaptic transmission and the intrinsic properties of neurons in area CA2. In this study, we applied the cholinergic agonist carbachol and performed on-cell, whole-cell, and extracellular recordings in area CA2. We observed that under conditions of high cholinergic tone, CA2 pyramidal neurons depolarized and rhythmically fired bursts of action potentials. This depolarization depended on the activation of M1 and M3 cholinergic receptors. Furthermore, we examined how the intrinsic properties and action-potential firing were altered in CA2 pyramidal neurons treated with 10 µM carbachol. While this intrinsic burst firing persisted in the absence of synaptic transmission, bursts were shaped by synaptic inputs in the intact network. We found that both excitatory and inhibitory synaptic transmission were reduced upon carbachol treatment. Finally, we examined the contribution of different channels to the cholinergic-induced changes in neuronal properties. We found that a conductance from Kv7 channels partially contributed to carbachol-induced changes in resting membrane potential and membrane resistance. We also found that D-type potassium currents contributed to controlling several properties of the bursts, including firing rate and burst kinetics. Furthermore, we determined that T-type calcium channels and small conductance calcium-activated potassium channels play a role in regulating bursting activity.
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Affiliation(s)
- Vincent Robert
- Université Paris Descartes, Inserm UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Paris, France
| | - Ludivine Therreau
- Université Paris Descartes, Inserm UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Paris, France
| | - M Felicia Davatolhagh
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - F Javier Bernardo-Garcia
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA
| | | | - Vivien Chevaleyre
- Université Paris Descartes, Inserm UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Paris, France
| | - Rebecca A Piskorowski
- Université Paris Descartes, Inserm UMR1266, Institute of Psychiatry and Neuroscience of Paris, Team Synaptic Plasticity and Neural Networks, Paris, France
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13
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Kang YJ, Clement EM, Park IH, Greenfield LJ, Smith BN, Lee SH. Vulnerability of cholecystokinin-expressing GABAergic interneurons in the unilateral intrahippocampal kainate mouse model of temporal lobe epilepsy. Exp Neurol 2021; 342:113724. [PMID: 33915166 DOI: 10.1016/j.expneurol.2021.113724] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/26/2021] [Accepted: 04/22/2021] [Indexed: 10/21/2022]
Abstract
Temporal lobe epilepsy (TLE) is characterized by recurrent spontaneous seizures and behavioral comorbidities. Reduced hippocampal theta oscillations and hyperexcitability that contribute to cognitive deficits and spontaneous seizures are present beyond the sclerotic hippocampus in TLE. However, the mechanisms underlying compromised network oscillations and hyperexcitability observed in circuits remote from the sclerotic hippocampus are largely unknown. Cholecystokinin (CCK)-expressing basket cells (CCKBCs) critically participate in hippocampal theta rhythmogenesis, and regulate neuronal excitability. Thus, we examined whether CCKBCs were vulnerable in nonsclerotic regions of the ventral hippocampus remote from dorsal sclerotic hippocampus using the intrahippocampal kainate (IHK) mouse model of TLE, targeting unilateral dorsal hippocampus. We found a decrease in the number of CCK+ interneurons in ipsilateral ventral CA1 regions from epileptic mice compared to those from sham controls. We also found that the number of boutons from CCK+ interneurons was reduced in the stratum pyramidale, but not in other CA1 layers, of ipsilateral hippocampus in epileptic mice, suggesting that CCKBCs are vulnerable. Electrical recordings showed that synaptic connectivity and strength from surviving CCKBCs to CA1 pyramidal cells (PCs) were similar between epileptic mice and sham controls. In agreement with reduced CCKBC number in TLE, electrical recordings revealed a significant reduction in amplitude and frequency of IPSCs in CA1 PCs evoked by carbachol (commonly used to excite CCK+ interneurons) in ventral CA1 regions from epileptic mice versus sham controls. These findings suggest that loss of CCKBCs beyond the hippocampal lesion may contribute to hyperexcitability and compromised network oscillations in TLE.
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Affiliation(s)
- Young-Jin Kang
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA; Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Ethan M Clement
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Yale Child Study Center, Yale School of Medicine, New Haven, CT 06520, USA
| | - Lazar John Greenfield
- Department of Neurology, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Bret N Smith
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
| | - Sang-Hun Lee
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA; Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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14
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Wang Y, Tan B, Wang Y, Chen Z. Cholinergic Signaling, Neural Excitability, and Epilepsy. Molecules 2021; 26:molecules26082258. [PMID: 33924731 PMCID: PMC8070422 DOI: 10.3390/molecules26082258] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 11/16/2022] Open
Abstract
Epilepsy is a common brain disorder characterized by recurrent epileptic seizures with neuronal hyperexcitability. Apart from the classical imbalance between excitatory glutamatergic transmission and inhibitory γ-aminobutyric acidergic transmission, cumulative evidence suggest that cholinergic signaling is crucially involved in the modulation of neural excitability and epilepsy. In this review, we briefly describe the distribution of cholinergic neurons, muscarinic, and nicotinic receptors in the central nervous system and their relationship with neural excitability. Then, we summarize the findings from experimental and clinical research on the role of cholinergic signaling in epilepsy. Furthermore, we provide some perspectives on future investigation to reveal the precise role of the cholinergic system in epilepsy.
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Affiliation(s)
- Yu Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
| | - Bei Tan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
| | - Yi Wang
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
- Correspondence: (Y.W.); (Z.C.); Tel.: +86-5718-661-8660 (Z.C.)
| | - Zhong Chen
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou 310053, China; (Y.W.); (B.T.)
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310058, China
- Correspondence: (Y.W.); (Z.C.); Tel.: +86-5718-661-8660 (Z.C.)
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15
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Ruby NF. Suppression of Circadian Timing and Its Impact on the Hippocampus. Front Neurosci 2021; 15:642376. [PMID: 33897354 PMCID: PMC8060574 DOI: 10.3389/fnins.2021.642376] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/17/2021] [Indexed: 01/02/2023] Open
Abstract
In this article, I describe the development of the disruptive phase shift (DPS) protocol and its utility for studying how circadian dysfunction impacts memory processing in the hippocampus. The suprachiasmatic nucleus (SCN) of the Siberian hamster is a labile circadian pacemaker that is easily rendered arrhythmic (ARR) by a simple manipulation of ambient lighting. The DPS protocol uses room lighting to administer a phase-advancing signal followed by a phase-delaying signal within one circadian cycle to suppress clock gene rhythms in the SCN. The main advantage of this model for inducing arrhythmia is that the DPS protocol is non-invasive; circadian rhythms are eliminated while leaving the animals neurologically and genetically intact. In the area of learning and memory, DPS arrhythmia produces much different results than arrhythmia by surgical ablation of the SCN. As I show, SCN ablation has little to no effect on memory. By contrast, DPS hamsters have an intact, but arrhythmic, SCN which produces severe deficits in memory tasks that are accompanied by fragmentation of electroencephalographic theta oscillations, increased synaptic inhibition in hippocampal circuits, and diminished responsiveness to cholinergic signaling in the dentate gyrus of the hippocampus. The studies reviewed here show that DPS hamsters are a promising model for translational studies of adult onset circadian dysfunction in humans.
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Affiliation(s)
- Norman F. Ruby
- Biology Department, Stanford University, Stanford, CA, United States
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16
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McMartin L, Kiraly M, Heller HC, Madison DV, Ruby NF. Disruption of circadian timing increases synaptic inhibition and reduces cholinergic responsiveness in the dentate gyrus. Hippocampus 2021; 31:422-434. [PMID: 33439521 PMCID: PMC8048473 DOI: 10.1002/hipo.23301] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 12/28/2020] [Accepted: 01/02/2021] [Indexed: 12/11/2022]
Abstract
We investigated synaptic mechanisms in the hippocampus that could explain how loss of circadian timing leads to impairments in spatial and recognition memory. Experiments were performed in hippocampal slices from Siberian hamsters (Phodopus sungorus) because, unlike mice and rats, their circadian rhythms are easily eliminated without modifications to their genome and without surgical manipulations, thereby leaving neuronal circuits intact. Recordings of excitatory postsynaptic field potentials and population spikes in area CA1 and dentate gyrus granule cells revealed no effect of circadian arrhythmia on basic functions of synaptic circuitry, including long-term potentiation. However, dentate granule cells from circadian-arrhythmic animals maintained a more depolarized resting membrane potential than cells from circadian-intact animals; a significantly greater proportion of these cells depolarized in response to the cholinergic agonist carbachol (10 μM), and did so by increasing their membrane potential three-fold greater than cells from the control (entrained) group. Dentate granule cells from arrhythmic animals also exhibited higher levels of tonic inhibition, as measured by the frequency of spontaneous inhibitory postsynaptic potentials. Carbachol also decreased stimulus-evoked synaptic excitation in dentate granule cells from both intact and arrhythmic animals as expected, but reduced stimulus-evoked synaptic inhibition only in cells from control hamsters. These findings show that loss of circadian timing is accompanied by greater tonic inhibition, and increased synaptic inhibition in response to muscarinic receptor activation in dentate granule cells. Increased inhibition would likely attenuate excitation in dentate-CA3 microcircuits, which in turn might explain the spatial memory deficits previously observed in circadian-arrhythmic hamsters.
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Affiliation(s)
- Laura McMartin
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
| | - Marianna Kiraly
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
| | - H Craig Heller
- Biology Department, Stanford University, Stanford, California, USA
| | - Daniel V Madison
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California, USA
| | - Norman F Ruby
- Biology Department, Stanford University, Stanford, California, USA
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17
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Mergenthal A, Bouteiller JMC, Yu GJ, Berger TW. A Computational Model of the Cholinergic Modulation of CA1 Pyramidal Cell Activity. Front Comput Neurosci 2020; 14:75. [PMID: 33013341 PMCID: PMC7509450 DOI: 10.3389/fncom.2020.00075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 07/17/2020] [Indexed: 01/02/2023] Open
Abstract
Dysfunction in cholinergic modulation has been linked to a variety of cognitive disorders including Alzheimer's disease. The important role of this neurotransmitter has been explored in a variety of experiments, yet many questions remain unanswered about the contribution of cholinergic modulation to healthy hippocampal function. To address this question, we have developed a model of CA1 pyramidal neuron that takes into consideration muscarinic receptor activation in response to changes in extracellular concentration of acetylcholine and its effects on cellular excitability and downstream intracellular calcium dynamics. This model incorporates a variety of molecular agents to accurately simulate several processes heretofore ignored in computational modeling of CA1 pyramidal neurons. These processes include the inhibition of ionic channels by phospholipid depletion along with the release of calcium from intracellular stores (i.e., the endoplasmic reticulum). This paper describes the model and the methods used to calibrate its behavior to match experimental results. The result of this work is a compartmental model with calibrated mechanisms for simulating the intracellular calcium dynamics of CA1 pyramidal cells with a focus on those related to release from calcium stores in the endoplasmic reticulum. From this model we also make various predictions for how the inhibitory and excitatory responses to cholinergic modulation vary with agonist concentration. This model expands the capabilities of CA1 pyramidal cell models through the explicit modeling of molecular interactions involved in healthy cognitive function and disease. Through this expanded model we come closer to simulating these diseases and gaining the knowledge required to develop novel treatments.
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Affiliation(s)
- Adam Mergenthal
- Biomedical Engineering Department, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | - Jean-Marie C Bouteiller
- Biomedical Engineering Department, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | - Gene J Yu
- Biomedical Engineering Department, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
| | - Theodore W Berger
- Biomedical Engineering Department, Center for Neural Engineering, University of Southern California, Los Angeles, CA, United States
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18
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Vidal B, Droguerre M, Valdebenito M, Zimmer L, Hamon M, Mouthon F, Charvériat M. Pharmaco-fUS for Characterizing Drugs for Alzheimer's Disease - The Case of THN201, a Drug Combination of Donepezil Plus Mefloquine. Front Neurosci 2020; 14:835. [PMID: 32903470 PMCID: PMC7437134 DOI: 10.3389/fnins.2020.00835] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 07/17/2020] [Indexed: 01/29/2023] Open
Abstract
Donepezil is a potent acetylcholinesterase inhibitor, largely used worldwide to alleviate cognitive symptoms in Alzheimer’s disease (AD). Beyond the widely described neuronal impact of donepezil, it was recently shown that targeting connexins, the proteins involved in astrocyte network organization, potentiates donepezil efficacy profile using behavioral tests in AD rodent models. We herein present data demonstrating the potential of functional ultrasound imaging to monitor cerebral activity changes after pharmacological challenge in mice. As an example, we showed that although administration of donepezil or mefloquine alone at low dose had only very limited effects on the signal compared to the baseline, their combination produced marked hemodynamic effects in the hippocampus, in line with previously published behavioral data demonstrating a synergic interaction between both drugs. Thus, the present study provides new perspectives, (i) through the use of pharmaco-fUS, a new non-clinical imaging modality, to move forward drug discovery in AD and (ii) by the profiling of two drug treatments on brain dynamics, one used in AD: donepezil, and the other in development: donepezil combined with mefloquine (THN201) as a modulator of astrocyte network.
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Affiliation(s)
- Benjamin Vidal
- Theranexus, Lyon, France.,Lyon Neuroscience Research Center, Université de Lyon, INSERM, CNRS, Bron, France
| | | | | | - Luc Zimmer
- Lyon Neuroscience Research Center, Université de Lyon, INSERM, CNRS, Bron, France.,CERMEP-Imagerie du Vivant, Bron, France.,Hospices Civils de Lyon, Lyon, France
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19
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Positive allosteric modulation of the α7 nicotinic acetylcholine receptor as a treatment for cognitive deficits after traumatic brain injury. PLoS One 2019; 14:e0223180. [PMID: 31581202 PMCID: PMC6776323 DOI: 10.1371/journal.pone.0223180] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/16/2019] [Indexed: 11/19/2022] Open
Abstract
Cognitive impairments are a common consequence of traumatic brain injury (TBI). The hippocampus is a subcortical structure that plays a key role in the formation of declarative memories and is highly vulnerable to TBI. The α7 nicotinic acetylcholine receptor (nAChR) is highly expressed in the hippocampus and reduced expression and function of this receptor are linked with cognitive impairments in Alzheimer's disease and schizophrenia. Positive allosteric modulation of α7 nAChRs with AVL-3288 enhances receptor currents and improves cognitive functioning in naïve animals and healthy human subjects. Therefore, we hypothesized that targeting the α7 nAChR with the positive allosteric modulator AVL-3288 would enhance cognitive functioning in the chronic recovery period of TBI. To test this hypothesis, adult male Sprague Dawley rats received moderate parasagittal fluid-percussion brain injury or sham surgery. At 3 months after recovery, animals were treated with vehicle or AVL-3288 at 30 min prior to cue and contextual fear conditioning and the water maze task. Treatment of TBI animals with AVL-3288 rescued learning and memory deficits in water maze retention and working memory. AVL-3288 treatment also improved cue and contextual fear memory when tested at 24 hr and 1 month after training, when TBI animals were treated acutely just during fear conditioning at 3 months post-TBI. Hippocampal atrophy but not cortical atrophy was reduced with AVL-3288 treatment in the chronic recovery phase of TBI. AVL-3288 application to acute hippocampal slices from animals at 3 months after TBI rescued basal synaptic transmission deficits and long-term potentiation (LTP) in area CA1. Our results demonstrate that AVL-3288 improves hippocampal synaptic plasticity, and learning and memory performance after TBI in the chronic recovery period. Enhancing cholinergic transmission through positive allosteric modulation of the α7 nAChR may be a novel therapeutic to improve cognition after TBI.
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20
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Faiq MA, Wollstein G, Schuman JS, Chan KC. Cholinergic nervous system and glaucoma: From basic science to clinical applications. Prog Retin Eye Res 2019; 72:100767. [PMID: 31242454 PMCID: PMC6739176 DOI: 10.1016/j.preteyeres.2019.06.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 02/08/2023]
Abstract
The cholinergic system has a crucial role to play in visual function. Although cholinergic drugs have been a focus of attention as glaucoma medications for reducing eye pressure, little is known about the potential modality for neuronal survival and/or enhancement in visual impairments. Citicoline, a naturally occurring compound and FDA approved dietary supplement, is a nootropic agent that is recently demonstrated to be effective in ameliorating ischemic stroke, traumatic brain injury, Parkinson's disease, Alzheimer's disease, cerebrovascular diseases, memory disorders and attention-deficit/hyperactivity disorder in both humans and animal models. The mechanisms of its action appear to be multifarious including (i) preservation of cardiolipin, sphingomyelin, and arachidonic acid contents of phosphatidylcholine and phosphatidylethanolamine, (ii) restoration of phosphatidylcholine, (iii) stimulation of glutathione synthesis, (iv) lowering glutamate concentrations and preventing glutamate excitotoxicity, (v) rescuing mitochondrial function thereby preventing oxidative damage and onset of neuronal apoptosis, (vi) synthesis of myelin leading to improvement in neuronal membrane integrity, (vii) improving acetylcholine synthesis and thereby reducing the effects of mental stress and (viii) preventing endothelial dysfunction. Such effects have vouched for citicoline as a neuroprotective, neurorestorative and neuroregenerative agent. Retinal ganglion cells are neurons with long myelinated axons which provide a strong rationale for citicoline use in visual pathway disorders. Since glaucoma is a form of neurodegeneration involving retinal ganglion cells, citicoline may help ameliorate glaucomatous damages in multiple facets. Additionally, trans-synaptic degeneration has been identified in humans and experimental models of glaucoma suggesting the cholinergic system as a new brain target for glaucoma management and therapy.
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Affiliation(s)
- Muneeb A Faiq
- Department of Ophthalmology, New York University (NYU) School of Medicine, NYU Langone Health, New York, NY, United States
| | - Gadi Wollstein
- Department of Ophthalmology, New York University (NYU) School of Medicine, NYU Langone Health, New York, NY, United States
| | - Joel S Schuman
- Department of Ophthalmology, New York University (NYU) School of Medicine, NYU Langone Health, New York, NY, United States
| | - Kevin C Chan
- Department of Ophthalmology, New York University (NYU) School of Medicine, NYU Langone Health, New York, NY, United States; Department of Radiology, New York University (NYU) School of Medicine, NYU Langone Health, New York, NY, United States; Center for Neural Science, Faculty of Arts and Science, New York University, New York, NY, United States.
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21
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Sil’kis IG. Possible Mechanisms of the Complex Effects of Acetylcholine on Theta Activity, Learning, and Memory. NEUROCHEM J+ 2019. [DOI: 10.1134/s1819712419020119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Pretreatment Cancer-Related Cognitive Impairment-Mechanisms and Outlook. Cancers (Basel) 2019; 11:cancers11050687. [PMID: 31100985 PMCID: PMC6562730 DOI: 10.3390/cancers11050687] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/06/2019] [Accepted: 05/14/2019] [Indexed: 12/25/2022] Open
Abstract
Cognitive changes are common in patients with active cancer and during its remission. This has largely been blamed on therapy-related toxicities and diagnosis-related stress, with little attention paid to the biological impact of cancer itself. A plethora of clinical studies demonstrates that cancer patients experience cognitive impairment during and after treatment. However, recent studies show that a significant portion of patients with non-central nervous system (CNS) tumors experience cognitive decline prior to treatment, suggesting a role for tumor-derived factors in modulating cognition and behavior. Cancer-related cognitive impairment (CRCI) negatively impacts a patient’s quality of life, reduces occupational and social functioning, and increases morbidity and mortality. Furthermore, patients with cancer cachexia frequently experience a stark neurocognitive decline, suggesting peripheral tumors exert an enduring toll on the brain during this chronic paraneoplastic syndrome. However, the scarcity of research on cognitive impairment in non-CNS cancers makes it difficult to isolate psychosocial, genetic, behavioral, and pathophysiological factors in CRCI. Furthermore, clinical models of CRCI are frequently confounded by complicated drug regimens that inherently affect neurocognitive processes. The severity of CRCI varies considerably amongst patients and highlights its multifactorial nature. Untangling the biological aspects of CRCI from genetic, psychosocial, and behavioral factors is non-trivial, yet vital in understanding the pathogenesis of CRCI and discovering means for therapeutic intervention. Recent evidence demonstrating the ability of peripheral tumors to alter CNS pathways in murine models is compelling, and it allows researchers to isolate the underlying biological mechanisms from the confounding psychosocial stressors found in the clinic. This review summarizes the state of the science of CRCI independent of treatment and focuses on biological mechanisms in which peripheral cancers modulate the CNS.
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23
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Sukumaran NP, Amalraj A, Gopi S. Neuropharmacological and cognitive effects of Bacopa monnieri (L.) Wettst - A review on its mechanistic aspects. Complement Ther Med 2019; 44:68-82. [PMID: 31126578 DOI: 10.1016/j.ctim.2019.03.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 03/23/2019] [Accepted: 03/25/2019] [Indexed: 12/14/2022] Open
Abstract
Bacopa monnieri (L.) - (BM) is a perennial, creeping herb which is widely used in traditional ayurvedic medicine as a neural tonic to improve intelligence and memory. Research into the biological effects of this plant has burgeoned in recent years, promising its neuroprotective and memory boosting ability among others. In this context, an extensive literature survey allows an insight into the participation of numerous signaling pathways and oxidative mechanism involved in the mitigation of oxidative stress, along with other indirect mechanisms modulated by bioactive molecules of BM to improve the cognitive action by their synergistic potential and cellular multiplicity mechanism. This multi-faceted review describes the novel mechanisms that underlie the unfounded but long flaunted promises of BM and thereby direct a way to harness this acquired knowledge to develop innovative approaches to manipulate its intracellular pathways.
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Affiliation(s)
| | - Augustine Amalraj
- R&D Centre, Aurea Biolabs (P) Ltd, Kolenchery, Cochin 682 311, Kerala, India
| | - Sreeraj Gopi
- R&D Centre, Aurea Biolabs (P) Ltd, Kolenchery, Cochin 682 311, Kerala, India.
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24
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Chronic treatment with galantamine rescues reversal learning in an attentional set-shifting test after experimental brain trauma. Exp Neurol 2019; 315:32-41. [PMID: 30711647 DOI: 10.1016/j.expneurol.2019.01.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/12/2019] [Accepted: 01/30/2019] [Indexed: 12/19/2022]
Abstract
Approximately 10 million new cases of traumatic brain injury (TBI) are reported each year worldwide with many of these injuries resulting in higher order cognitive impairments. Galantamine (GAL), an acetylcholine esterase inhibitor (AChEI) and positive allosteric modulator of nicotinic acetylcholine receptors (nAChRs), has been reported to ameliorate cognitive deficits after clinical TBI. Previously, we demonstrated that controlled cortical impact (CCI) injury to rats resulted in significant executive function impairments as measured by the attentional set-shifting test (AST), a complex cognitive task analogous to the Wisconsin Card Sorting Test (WCST). We hypothesized that chronic administration of GAL would normalize performance on the AST post-TBI. Isoflurane-anesthetized adult male rats were subjected to moderate CCI (2.8 mm tissue deformation at 4 m/s) or sham injury. Rats were then randomized into one of three treatment groups (i.e., 1 mg/kg GAL, 2 mg/kg GAL, or 1 mL/kg saline vehicle; VEH) or their respective sham controls. GAL or VEH was administered intraperitoneally daily commencing 24 hours post-surgery and until AST testing at 4 weeks post-injury. The AST data revealed significant impairments in the first reversal stage after TBI, seen as increased trials to reach criterion and elevated total errors (p < 0.05). These behavioral flexibility deficits were equally normalized by the administration of both doses of GAL (p < 0.05). Additionally, the higher dose of GAL (2 mg/kg) also significantly reduced cortical lesion volume compared to TBI + VEH controls (p < 0.05). In summary, daily GAL administration provides an efficacious treatment for cognitive deficits and histological recovery after experimental brain trauma. Clinically, these findings are promising considering robust results were attained using a pharmacotherapy already used in the clinic to treat mild dementia.
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25
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Chung BYT, Bailey CDC. Sex differences in the nicotinic excitation of principal neurons within the developing hippocampal formation. Dev Neurobiol 2018; 79:110-130. [PMID: 30354016 DOI: 10.1002/dneu.22646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 10/15/2018] [Accepted: 10/17/2018] [Indexed: 12/21/2022]
Abstract
The hippocampal formation (HF) plays an important role to facilitate higher order cognitive functions. Cholinergic activation of heteromeric nicotinic acetylcholine receptors (nAChRs) within the HF is critical for the normal development of principal neurons within this brain region. However, previous research investigating the expression and function of heteromeric nAChRs in principal neurons of the HF is limited to males or does not differentiate between the sexes. We used whole-cell electrophysiology to show that principal neurons in the CA1 region of the female mouse HF are excited by heteromeric nAChRs throughout postnatal development, with the greatest response occurring during the first two weeks of postnatal life. Excitability responses to heteromeric nAChR stimulation were also found in principal neurons in the CA3, dentate gyrus, subiculum, and entorhinal cortex layer VI (ECVI) of young postnatal female HF. A direct comparison between male and female mice found that principal neurons in ECVI display greater heteromeric nicotinic passive and active excitability responses in females. This sex difference is likely influenced by the generally more excitable nature of ECVI neurons from female mice, which display a higher resting membrane potential, greater input resistance, and smaller afterhyperpolarization potential of medium duration (mAHP). These findings demonstrate that heteromeric nicotinic excitation of ECVI neurons differs between male and female mice during a period of major circuitry development within the HF, which may have mechanistic implications for known sex differences in the development and function of this cognitive brain region.
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Affiliation(s)
- Beryl Y T Chung
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
| | - Craig D C Bailey
- Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada, N1G 2W1
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26
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Hinman JR, Dannenberg H, Alexander AS, Hasselmo ME. Neural mechanisms of navigation involving interactions of cortical and subcortical structures. J Neurophysiol 2018; 119:2007-2029. [PMID: 29442559 DOI: 10.1152/jn.00498.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Animals must perform spatial navigation for a range of different behaviors, including selection of trajectories toward goal locations and foraging for food sources. To serve this function, a number of different brain regions play a role in coding different dimensions of sensory input important for spatial behavior, including the entorhinal cortex, the retrosplenial cortex, the hippocampus, and the medial septum. This article will review data concerning the coding of the spatial aspects of animal behavior, including location of the animal within an environment, the speed of movement, the trajectory of movement, the direction of the head in the environment, and the position of barriers and objects both relative to the animal's head direction (egocentric) and relative to the layout of the environment (allocentric). The mechanisms for coding these important spatial representations are not yet fully understood but could involve mechanisms including integration of self-motion information or coding of location based on the angle of sensory features in the environment. We will review available data and theories about the mechanisms for coding of spatial representations. The computation of different aspects of spatial representation from available sensory input requires complex cortical processing mechanisms for transformation from egocentric to allocentric coordinates that will only be understood through a combination of neurophysiological studies and computational modeling.
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Affiliation(s)
- James R Hinman
- Center for Systems Neuroscience, Boston University , Boston, Massachusetts
| | - Holger Dannenberg
- Center for Systems Neuroscience, Boston University , Boston, Massachusetts
| | - Andrew S Alexander
- Center for Systems Neuroscience, Boston University , Boston, Massachusetts
| | - Michael E Hasselmo
- Center for Systems Neuroscience, Boston University , Boston, Massachusetts
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27
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Abstract
The septo–hippocampal pathway adjusts CA1 network excitability to different behavioral states and is crucially involved in theta rhythmogenesis. In the medial septum, cholinergic, glutamatergic and GABAergic neurons form a highly interconnected local network. Neurons of these three classes project to glutamatergic pyramidal neurons and different subsets of GABAergic neurons in the hippocampal CA1 region. From there, GABAergic neurons project back to the medial septum and form a feedback loop between the two remote brain areas. In vivo, the firing of GABAergic medial septal neurons is theta modulated, while theta modulation is not observed in cholinergic neurons. One prominent feature of glutamatergic neurons is the correlation of their firing rates to the animals running speed. The cellular diversity, the high local interconnectivity and different activity patterns of medial septal neurons during different behaviors complicate the functional dissection of this network. New technical advances help to define specific functions of individual cell classes. In this review, we seek to highlight recent findings and elucidate functional implications of the septo-hippocampal connectivity on the microcircuit scale.
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Affiliation(s)
- Christina Müller
- Neuronal Networks Group, German Center for Neurodegenerative Diseases in the Helmholtz Association (DZNE e.V.), Bonn, Germany.
| | - Stefan Remy
- Neuronal Networks Group, German Center for Neurodegenerative Diseases in the Helmholtz Association (DZNE e.V.), Bonn, Germany.,Department of Epileptology, University of Bonn, Bonn, Germany
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28
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Dannenberg H, Young K, Hasselmo M. Modulation of Hippocampal Circuits by Muscarinic and Nicotinic Receptors. Front Neural Circuits 2017; 11:102. [PMID: 29321728 PMCID: PMC5733553 DOI: 10.3389/fncir.2017.00102] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/27/2017] [Indexed: 01/02/2023] Open
Abstract
This article provides a review of the effects of activation of muscarinic and nicotinic receptors on the physiological properties of circuits in the hippocampal formation. Previous articles have described detailed computational hypotheses about the role of cholinergic neuromodulation in enhancing the dynamics for encoding in cortical structures and the role of reduced cholinergic modulation in allowing consolidation of previously encoded information. This article will focus on addressing the broad scope of different modulatory effects observed within hippocampal circuits, highlighting the heterogeneity of cholinergic modulation in terms of the physiological effects of activation of muscarinic and nicotinic receptors and the heterogeneity of effects on different subclasses of neurons.
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Affiliation(s)
- Holger Dannenberg
- Center for Systems Neuroscience, Department of Psychological and Brain Sciences, Boston University, Boston, MA, United States
| | - Kimberly Young
- Center for Systems Neuroscience, Department of Psychological and Brain Sciences, Boston University, Boston, MA, United States
| | - Michael Hasselmo
- Center for Systems Neuroscience, Department of Psychological and Brain Sciences, Boston University, Boston, MA, United States
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Muscarinic receptor subtype distribution in the central nervous system and relevance to aging and Alzheimer's disease. Neuropharmacology 2017; 136:362-373. [PMID: 29138080 DOI: 10.1016/j.neuropharm.2017.11.018] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 11/04/2017] [Accepted: 11/10/2017] [Indexed: 12/14/2022]
Abstract
Muscarinic acetylcholine receptors (mAChRs) are G proteincoupled receptors (GPCRs) that mediate the metabotropic actions of acetylcholine (ACh). There are five subtypes of mAChR, M1 - M5, which are expressed throughout the central nervous system (CNS) on numerous cell types and represent promising treatment targets for a number of different diseases, disorders, and conditions of the CNS. Although the present review will focus on Alzheimer's disease (AD) and amnestic mild cognitive impairment (aMCI), a number of conditions such as Parkinson's disease (PD), schizophrenia, and others represent significant unmet medical needs for which selective muscarinic agents could offer therapeutic benefits. Numerous advances have been made regarding mAChR localization through the use of subtype-selective antibodies and radioligand binding studies and these efforts have helped propel a number of mAChR therapeutics into clinical trials. However, much of what we know about mAChR localization in the healthy and diseased brain has come from studies employing radioligand binding with relatively modest selectivity. The development of subtype-selective small molecule radioligands suitable for in vitro and in vivo use, as well as robust, commercially-available antibodies remains a critical need for the field. Additionally, novel genetic tools should be developed and leveraged to help move the field increasingly towards a systems-level understanding of mAChR subtype action. Finally, functional, proteomic, and genetic data from ongoing human studies hold great promise for optimizing the design and interpretation of studies examining receptor levels by enabling patient stratification. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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McKenzie S. Inhibition shapes the organization of hippocampal representations. Hippocampus 2017; 28:659-671. [PMID: 28921762 DOI: 10.1002/hipo.22803] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 09/11/2017] [Accepted: 09/13/2017] [Indexed: 01/12/2023]
Abstract
Hippocampal neurons become tuned to stimuli that predict behaviorally salient outcomes. This plasticity suggests that memory formation depends upon shifts in how different anatomical inputs can drive hippocampal activity. Here, I present evidence that inhibitory neurons can provide such a mechanism for learning-related changes in the tuning of pyramidal cells. Inhibitory currents arriving on the dendrites of pyramidal cells determine whether an excitatory input can drive action potential output. Specificity and plasticity of this dendritic modulation allows for precise, modifiable changes in how afferent inputs are integrated, a process that defines a neuron's receptive field. In addition, feedback inhibition plays a fundamental role in biasing which excitatory neurons may be co-active. By defining the rules of synchrony and the rules of input integration, interneurons likely play an important role in the organization of memory representation within the hippocampus.
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Affiliation(s)
- Sam McKenzie
- NYU Langone Medical Center, 450 E29th Street, 9th Floor, New York, New York 10016
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31
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Murakami M, Nagahama M, Maruyama T, Niikura T. Humanin ameliorates diazepam-induced memory deficit in mice. Neuropeptides 2017; 62:65-70. [PMID: 27814910 DOI: 10.1016/j.npep.2016.10.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 10/12/2016] [Accepted: 10/27/2016] [Indexed: 01/14/2023]
Abstract
Humanin (HN) is an endogenous 24-residue peptide. A highly potent HN derivative, S14G-HN, which has a substitution of serine 14 to glycine, reduced amyloid burden and suppressed cognitive impairment in a mouse model of Alzheimer's disease. S14G-HN also suppressed amnesia induced by a muscarinic receptor antagonist in rodents. To understand the effects of HN on brain function, we tested the effect of S14G-HN on diazepam (DZP)-induced memory impairment and anxiety in mice using the object recognition test and zero-maze test, respectively. Intraperitoneal injection of S14G-HN reversed the DZP-induced memory deficit, whereas no significant change was observed in behavioral markers of anxiety. S14G-HN had no effect on locomotor activity in either test, indicating that S14G-HN did not affect physical functioning or motivation. These results suggest that HN preferentially influences cognitive function but not emotional function in the central nervous system.
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Affiliation(s)
- Minetaka Murakami
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan
| | - Masatoshi Nagahama
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan
| | - Takuma Maruyama
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan
| | - Takako Niikura
- Department of Information and Communication Sciences, Faculty of Science and Technology, Sophia University, Japan.
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32
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Foley J, Blutstein T, Lee S, Erneux C, Halassa MM, Haydon P. Astrocytic IP 3/Ca 2+ Signaling Modulates Theta Rhythm and REM Sleep. Front Neural Circuits 2017; 11:3. [PMID: 28167901 PMCID: PMC5253379 DOI: 10.3389/fncir.2017.00003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 01/09/2017] [Indexed: 12/27/2022] Open
Abstract
Rapid eye movement (REM) sleep onset is triggered by disinhibition of cholinergic neurons in the pons. During REM sleep, the brain exhibits prominent activity in the 5–8 Hz (theta) frequency range. How REM sleep onset and theta waves are regulated is poorly understood. Astrocytes, a non-neuronal cell type in the brain, respond to cholinergic signals by elevating their intracellular Ca2+ concentration. The goal of this study was to assess the sleep architecture of mice with attenuated IP3 mediated Ca2+ signaling in astrocytes. Vigilance states and cortical electroencephalograph power were measured in wild type mice and mice with attenuated IP3/Ca2+ signaling. Attenuating IP3/Ca2+ signaling specifically in astrocytes caused mice to spend more time in REM sleep and enter this state more frequently during their inactive phase. These mice also exhibited greater power in the theta frequency range. These data suggest a role for astrocytic IP3/Ca2+ signaling in modulating REM sleep and the associated physiological state of the cortex.
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Affiliation(s)
- Jeannine Foley
- Department of Neuroscience, Tufts University, Boston MA, USA
| | | | - SoYoung Lee
- Department of Neuroscience, Tufts University, Boston MA, USA
| | - Christophe Erneux
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles Brussels, Belgium
| | - Michael M Halassa
- Departments of Psychiatry, Neuroscience and Physiology, Neuroscience Institute, New York University, New York NY, USA
| | - Philip Haydon
- Department of Neuroscience, Tufts University, Boston MA, USA
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33
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Dannenberg H, Hinman JR, Hasselmo ME. Potential roles of cholinergic modulation in the neural coding of location and movement speed. ACTA ACUST UNITED AC 2016; 110:52-64. [PMID: 27677935 DOI: 10.1016/j.jphysparis.2016.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Revised: 09/06/2016] [Accepted: 09/23/2016] [Indexed: 12/26/2022]
Abstract
Behavioral data suggest that cholinergic modulation may play a role in certain aspects of spatial memory, and neurophysiological data demonstrate neurons that fire in response to spatial dimensions, including grid cells and place cells that respond on the basis of location and running speed. These neurons show firing responses that depend upon the visual configuration of the environment, due to coding in visually-responsive regions of the neocortex. This review focuses on the physiological effects of acetylcholine that may influence the sensory coding of spatial dimensions relevant to behavior. In particular, the local circuit effects of acetylcholine within the cortex regulate the influence of sensory input relative to internal memory representations via presynaptic inhibition of excitatory and inhibitory synaptic transmission, and the modulation of intrinsic currents in cortical excitatory and inhibitory neurons. In addition, circuit effects of acetylcholine regulate the dynamics of cortical circuits including oscillations at theta and gamma frequencies. These effects of acetylcholine on local circuits and network dynamics could underlie the role of acetylcholine in coding of spatial information for the performance of spatial memory tasks.
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Affiliation(s)
- Holger Dannenberg
- Center for Systems Neuroscience, Department of Psychological and Brain Sciences, Center for Memory and Brain, Graduate Program for Neuroscience, Boston University, 2 Cummington Mall, Boston, MA 02215, USA.
| | - James R Hinman
- Center for Systems Neuroscience, Department of Psychological and Brain Sciences, Center for Memory and Brain, Graduate Program for Neuroscience, Boston University, 2 Cummington Mall, Boston, MA 02215, USA.
| | - Michael E Hasselmo
- Center for Systems Neuroscience, Department of Psychological and Brain Sciences, Center for Memory and Brain, Graduate Program for Neuroscience, Boston University, 2 Cummington Mall, Boston, MA 02215, USA.
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Sugisaki E, Fukushima Y, Fujii S, Yamazaki Y, Aihara T. The effect of coactivation of muscarinic and nicotinic acetylcholine receptors on LTD in the hippocampal CA1 network. Brain Res 2016; 1649:44-52. [PMID: 27545666 DOI: 10.1016/j.brainres.2016.08.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/14/2016] [Accepted: 08/18/2016] [Indexed: 11/30/2022]
Abstract
The neuromodulator acetylcholine (ACh) is considered to have a crucial effect on sensory inputs in the process of learning and memory, and ACh activates muscarinic (mAChR) and nicotinic (nAChR) acetylcholine receptors. Meanwhile in a hippocampal CA1 network including inhibitory connections, long-term potentiation (LTP) or long-term depression (LTD) is induced by the application of positive timing of the spike timing-dependent plasticity (STDP) protocol, while LTD is induced by negative timing protocol. In the previous study, the influence of ACh on LTD induced by the negative timing protocol application in the interneuron-blocked CA1 network was reported. However, the responsibility of mAChR and nAChR on pyramidal neuron and interneuron on STDP induction is still unclear. In order to clarify the role of AChRs in LTD, positive or negative timing protocol was applied in the interneuron-activated CA1 network in the presence of eserine. Consequently, the LTD induced by the positive timing protocol was switched to LTP, and the LTD by negative timing protocol was shifted toward potentiation when ACh was effective. The STDP facilitation was more effectively brought by mAChR activation on pyramidal neuron than nAChR, while mAChR on interneuron had a potential to down regulate the facilitation. These findings suggest that the direction (LTD/LTP) of STDP is determined by the activation of mAChR not only on pyramidal neuron but also on interneuron, and the magnitude of STDP is sensitively fine-tuned by nAChR. Therefore, the modulation of synaptic plasticity induced by the coactivation of mAChR and nAChR might be an important stage in integrating ACh and sensory inputs in the hippocampal CA1 network.
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Affiliation(s)
- Eriko Sugisaki
- College of Engineering, Tamagawa University, 6-1-1 Tamagawagakuen, Machida, Tokyo 194-8610, Japan; Brain Science Institute, Tamagawa University School of Medicine, 6-1-1 Tamagawagakuen, Machida, Tokyo 194-8610, Japan.
| | - Yasuhiro Fukushima
- Brain Science Institute, Tamagawa University School of Medicine, 6-1-1 Tamagawagakuen, Machida, Tokyo 194-8610, Japan; Kawasaki University of Medical Welfare, 288 Matsushima, Kurashiki, Okayama 701-0193, Japan.
| | - Satoshi Fujii
- Department of Physiology, Yamagata University of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan.
| | - Yoshihiko Yamazaki
- Department of Physiology, Yamagata University of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan.
| | - Takeshi Aihara
- College of Engineering, Tamagawa University, 6-1-1 Tamagawagakuen, Machida, Tokyo 194-8610, Japan; Brain Science Institute, Tamagawa University School of Medicine, 6-1-1 Tamagawagakuen, Machida, Tokyo 194-8610, Japan.
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35
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Chung BYT, Bignell W, Jacklin DL, Winters BD, Bailey CDC. Postsynaptic nicotinic acetylcholine receptors facilitate excitation of developing CA1 pyramidal neurons. J Neurophysiol 2016; 116:2043-2055. [PMID: 27489367 DOI: 10.1152/jn.00370.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/01/2016] [Indexed: 11/22/2022] Open
Abstract
The hippocampus plays a key role in learning and memory. The normal development and mature function of hippocampal networks supporting these cognitive functions depends on afferent cholinergic neurotransmission mediated by nicotinic acetylcholine receptors. Whereas it is well-established that nicotinic receptors are present on GABAergic interneurons and on glutamatergic presynaptic terminals within the hippocampus, the ability of these receptors to mediate postsynaptic signaling in pyramidal neurons is not well understood. We use whole cell electrophysiology to show that heteromeric nicotinic receptors mediate direct inward currents, depolarization from rest and enhanced excitability in hippocampus CA1 pyramidal neurons of male mice. Measurements made throughout postnatal development provide a thorough developmental profile for these heteromeric nicotinic responses, which are greatest during the first 2 wk of postnatal life and decrease to low adult levels shortly thereafter. Pharmacological experiments show that responses are blocked by a competitive antagonist of α4β2* nicotinic receptors and augmented by a positive allosteric modulator of α5 subunit-containing receptors, which is consistent with expression studies suggesting the presence of α4β2 and α4β2α5 nicotinic receptors within the developing CA1 pyramidal cell layer. These findings demonstrate that functional heteromeric nicotinic receptors are present on CA1 pyramidal neurons during a period of major hippocampal development, placing these receptors in a prime position to play an important role in the establishment of hippocampal cognitive networks.
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Affiliation(s)
- Beryl Y T Chung
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada; and
| | - Warren Bignell
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada; and
| | - Derek L Jacklin
- Department of Psychology, College of Social and Applied Human Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Boyer D Winters
- Department of Psychology, College of Social and Applied Human Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Craig D C Bailey
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada; and
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36
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Neske GT, Connors BW. Synchronized gamma-frequency inhibition in neocortex depends on excitatory-inhibitory interactions but not electrical synapses. J Neurophysiol 2016; 116:351-68. [PMID: 27121576 PMCID: PMC4969394 DOI: 10.1152/jn.00071.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/23/2016] [Indexed: 11/22/2022] Open
Abstract
Synaptic inhibition plays a crucial role in the precise timing of spiking activity in the cerebral cortex. Synchronized, rhythmic inhibitory activity in the gamma (30-80 Hz) range is thought to be especially important for the active, information-processing neocortex, but the circuit mechanisms that give rise to synchronized inhibition are uncertain. In particular, the relative contributions of reciprocal inhibitory connections, excitatory-inhibitory interactions, and electrical synapses to precise spike synchrony among inhibitory interneurons are not well understood. Here we describe experiments on mouse barrel cortex in vitro as it spontaneously generates slow (<1 Hz) oscillations (Up and Down states). During Up states, inhibitory postsynaptic currents (IPSCs) are generated at gamma frequencies and are more synchronized than excitatory postsynaptic currents (EPSCs) among neighboring pyramidal cells. Furthermore, spikes in homotypic pairs of interneurons are more synchronized than in pairs of pyramidal cells. Comparing connexin36 knockout and wild-type animals, we found that electrical synapses make a minimal contribution to synchronized inhibition during Up states. Estimations of the delays between EPSCs and IPSCs in single pyramidal cells showed that excitation often preceded inhibition by a few milliseconds. Finally, tonic optogenetic activation of different interneuron subtypes in the absence of excitation led to only weak synchrony of IPSCs in pairs of pyramidal neurons. Our results suggest that phasic excitatory inputs are indispensable for synchronized spiking in inhibitory interneurons during Up states and that electrical synapses play a minimal role.
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Affiliation(s)
- Garrett T Neske
- Department of Neuroscience, Brown University, Providence, Rhode Island
| | - Barry W Connors
- Department of Neuroscience, Brown University, Providence, Rhode Island
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37
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Bjorefeldt A, Wasling P, Zetterberg H, Hanse E. Neuromodulation of fast-spiking and non-fast-spiking hippocampal CA1 interneurons by human cerebrospinal fluid. J Physiol 2016; 594:937-52. [PMID: 26634295 DOI: 10.1113/jp271553] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/30/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS How the brain extracellular fluid influences the activity of GABAergic interneurons in vivo is not known. This issue is examined in the hippocampal brain slice by comparing GABAergic interneuron activity in human versus artificial cerebrospinal fluid. Human cerebrospinal fluid (hCSF) substantially increases the excitability of fast-spiking and non-fast-spiking CA1 interneurons. CA1 pyramidal cells are even more strongly excited by hCSF. The tonic excitation of pyramidal cells, in combination with an increased responsiveness of interneurons to excitatory input, is likely to promote the generation of synchronized network activity in the hippocampus. ABSTRACT GABAergic interneurons intricately regulate the activity of hippocampal and neocortical networks. Their function in vivo is likely to be tuned by neuromodulatory substances in the brain extracellular fluid. However, in vitro investigations of GABAergic interneuron function do not account for such effects, as neurons are kept in artificial extracellular fluid. To examine the neuromodulatory influence of brain extracellular fluid on GABAergic activity, we recorded from fast-spiking and non-fast-spiking CA1 interneurons, as well as from pyramidal cells, in the presence of human cerebrospinal fluid (hCSF), using a matched artificial cerebrospinal fluid (aCSF) as control. We found that hCSF increased the frequency of spontaneous firing more than twofold in the two groups of interneurons, and more than fourfold in CA1 pyramidal cells. hCSF did not affect the resting membrane potential of CA1 interneurons but caused depolarization in pyramidal cells. The increased excitability of interneurons and pyramidal cells was accompanied by reductions in after-hyperpolarization amplitudes and a left-shift in the frequency-current relationships. Our results suggest that ambient concentrations of neuromodulators in the brain extracellular fluid powerfully influence the excitability of neuronal networks.
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Affiliation(s)
- Andreas Bjorefeldt
- Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, 405 30 Gothenburg, Sweden
| | - Pontus Wasling
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, University of Gothenburg, 413 45 Gothenburg, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, University of Gothenburg, 431 80 Molndal, Sweden.,Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Eric Hanse
- Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, 405 30 Gothenburg, Sweden
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38
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Brisch R, Bernstein HG, Dobrowolny H, Krzyżanowska M, Jankowski Z, Bogerts B, Gos T. Volumetric analysis of the diagonal band of Broca in patients with schizophrenia and affective disorders: A post-mortem study. Clin Anat 2015; 29:466-72. [PMID: 26457806 DOI: 10.1002/ca.22656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 10/05/2015] [Accepted: 10/09/2015] [Indexed: 11/09/2022]
Abstract
The human diagonal band of Broca is connected to other parts of the limbic system, such as the hippocampus, that are involved in the pathology of schizophrenia. This study aimed to characterize the volume and anterior-to-posterior distance of the human diagonal band of Broca (vertical limb) from post-mortem brains obtained from three groups: healthy control subjects (N = 17), patients with schizophrenia (N = 26), and patients with affective disorders (N = 12). There were no significant differences in the volume or anterior-to-posterior distance in the patients with schizophrenia or affective disorders compared with the healthy control subjects. To date, this is the first post-mortem investigation measuring the volume and the anterior-to-posterior distance of the diagonal band of Broca (vertical limb) in patients with schizophrenia or affective disorders compared with healthy control subjects.
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Affiliation(s)
- Ralf Brisch
- Department of Forensic Medicine, Ul. Dębowa 23, Medical University of Gdańsk, Gdańsk, Poland
| | - Hans-Gert Bernstein
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany
| | - Henrik Dobrowolny
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany
| | - Marta Krzyżanowska
- Department of Forensic Medicine, Ul. Dębowa 23, Medical University of Gdańsk, Gdańsk, Poland
| | - Zbigniew Jankowski
- Department of Forensic Medicine, Ul. Dębowa 23, Medical University of Gdańsk, Gdańsk, Poland
| | - Bernhard Bogerts
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Tomasz Gos
- Department of Forensic Medicine, Ul. Dębowa 23, Medical University of Gdańsk, Gdańsk, Poland
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39
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Stankiewicz AM, Goscik J, Dyr W, Juszczak GR, Ryglewicz D, Swiergiel AH, Wieczorek M, Stefanski R. Novel candidate genes for alcoholism--transcriptomic analysis of prefrontal medial cortex, hippocampus and nucleus accumbens of Warsaw alcohol-preferring and non-preferring rats. Pharmacol Biochem Behav 2015; 139:27-38. [PMID: 26455281 DOI: 10.1016/j.pbb.2015.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 10/06/2015] [Accepted: 10/06/2015] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Animal models provide opportunity to study neurobiological aspects of human alcoholism. Changes in gene expression have been implicated in mediating brain functions, including reward system and addiction. The current study aimed to identify genes that may underlie differential ethanol preference in Warsaw High Preferring (WHP) and Warsaw Low Preferring (WLP) rats. METHODS Microarray analysis comparing gene expression in nucleus accumbens (NAc), hippocampus (HP) and medial prefrontal cortex (mPFC) was performed in male WHP and WLP rats bred for differences in ethanol preference. RESULTS Differential and stable between biological repeats expression of 345, 254 and 129 transcripts in NAc, HP and mPFC was detected. Identified genes and processes included known mediators of ethanol response (Mx2, Fam111a, Itpr1, Gabra4, Agtr1a, LTP/LTD, renin-angiotensin signaling pathway), toxicity (Sult1c2a, Ces1, inflammatory response), as well as genes involved in regulation of important addiction-related brain systems such as dopamine, tachykinin or acetylcholine (Gng7, Tac4, Slc5a7). CONCLUSIONS The identified candidate genes may underlie differential ethanol preference in an animal model of alcoholism. COMMENT Names of genes are written in italics, while names of proteins are written in standard font. Names of human genes/proteins are written in all capital letters. Names of rodent genes/proteins are written in capital letter followed by small letters.
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Affiliation(s)
- Adrian M Stankiewicz
- Department of Animal Behaviour, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, 05-552 Jastrzebiec, Poland
| | - Joanna Goscik
- Software Department, Faculty of Computer Science, Bialystok University of Technology, 15-351 Bialystok, Poland
| | - Wanda Dyr
- Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
| | - Grzegorz R Juszczak
- Department of Animal Behaviour, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, 05-552 Jastrzebiec, Poland
| | - Danuta Ryglewicz
- First Department of Neurology, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
| | - Artur H Swiergiel
- Department of Animal and Human Physiology, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland; Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center, Shreveport, LA71130, USA.
| | - Marek Wieczorek
- Department of Neurobiology, Faculty of Biology and Environmental Protection, University of Lodz, 90-236 Lodz, Poland
| | - Roman Stefanski
- Department of Pharmacology and Physiology of the Nervous System, Institute of Psychiatry and Neurology, 02-957 Warsaw, Poland
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40
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Vijayaraghavan S, Sharma G. Editorial: Brain cholinergic mechanisms. Front Synaptic Neurosci 2015; 7:14. [PMID: 26441630 PMCID: PMC4569963 DOI: 10.3389/fnsyn.2015.00014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/31/2015] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sukumar Vijayaraghavan
- Department of Physiology and Biophysics and the Neuroscience Program, School of Medicine, University of Colorado Aurora, CO, USA
| | - Geeta Sharma
- Department of Physiology and Biophysics and the Neuroscience Program, School of Medicine, University of Colorado Aurora, CO, USA
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