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Barr HJ, Wall EM, Woolley SC. Dopamine in the songbird auditory cortex shapes auditory preference. Curr Biol 2021; 31:4547-4559.e5. [PMID: 34450091 DOI: 10.1016/j.cub.2021.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 06/22/2021] [Accepted: 08/02/2021] [Indexed: 01/10/2023]
Abstract
Vocal communication signals can provide listeners with information about the signaler and elicit motivated responses. Auditory cortical and mesolimbic reward circuits are often considered to have distinct roles in these processes, with auditory cortical circuits responsible for detecting and discriminating sounds and mesolimbic circuits responsible for ascribing salience and modulating preference for those sounds. Here, we investigated whether dopamine within auditory cortical circuits themselves can shape the incentive salience of a vocal signal. Female zebra finches demonstrate natural preferences for vocal signals produced by males ("songs"), and we found that brief pairing of passive song playback with pharmacological dopamine manipulations in the secondary auditory cortex significantly altered song preferences. In particular, pairing passive song playback with retrodialysis of dopamine agonists into the auditory cortex enhanced preferences for less-preferred songs. Plasticity of song preferences by dopamine persisted for at least 1 week and was mediated by D1 receptors. In contrast, song preferences were not shaped by norepinephrine. In line with this, while we found that the ventral tegmental area, substantia nigra pars compacta, and locus coeruleus all project to the secondary auditory cortex, only dopamine-producing neurons in the ventral tegmental area differentially responded to preferred versus less-preferred songs. In contrast, norepinephrine neurons in the locus coeruleus increased expression of activity-dependent neural markers for both preferred and less-preferred songs. These data suggest that dopamine acting directly in sensory-processing areas can shape the incentive salience of communication signals.
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Affiliation(s)
- Helena J Barr
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada; Center for Research on Brain, Language, and Music, McGill University, Montreal, QC, Canada
| | - Erin M Wall
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada; Center for Research on Brain, Language, and Music, McGill University, Montreal, QC, Canada
| | - Sarah C Woolley
- Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada; Center for Research on Brain, Language, and Music, McGill University, Montreal, QC, Canada; Department of Biology, McGill University, Montreal, QC, Canada.
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2
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Macedo-Lima M, Boyd HM, Remage-Healey L. Dopamine D1 Receptor Activation Drives Plasticity in the Songbird Auditory Pallium. J Neurosci 2021; 41:6050-6069. [PMID: 34083251 PMCID: PMC8276744 DOI: 10.1523/jneurosci.2823-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 03/09/2021] [Accepted: 04/21/2021] [Indexed: 12/24/2022] Open
Abstract
Vocal learning species must form and extensively hone associations between sounds and social contingencies. In songbirds, dopamine signaling guides song motor production, variability, and motivation, but it is unclear how dopamine regulates fundamental auditory associations for learning new sounds. We hypothesized that dopamine regulates learning in the auditory pallium, in part by interacting with local neuroestradiol signaling. Here, we show that zebra finch auditory neurons frequently coexpress D1 receptor (D1R) protein, neuroestradiol-synthase, GABA, and parvalbumin (PV). Auditory classical conditioning increased neuroplasticity gene induction in D1R-positive neurons. In vitro, D1R pharmacological activation reduced the amplitude of GABAergic and glutamatergic currents and increased the latter's frequency. In vivo, D1R activation reduced the firing of putative interneurons, increased the firing of putative excitatory neurons, and made both neuronal types unable to adapt to novel stimuli. Together, these findings support the hypothesis that dopamine acting via D1Rs modulates auditory association in the songbird sensory pallium.SIGNIFICANCE STATEMENT Our key finding is that auditory forebrain D1 receptors (D1Rs) modulate auditory plasticity, in support of the hypothesis that dopamine modulates the formation of associations between sounds and outcomes. Recent work in songbirds has identified roles for dopamine in driving reinforcement learning and motor variability in song production. This leaves open whether dopamine shapes the initial events that are critical for learning vocalizations, e.g., auditory learning. Our study begins to address this question in the songbird caudomedial nidopallium (NCM), an analog of the mammalian secondary auditory cortex. Our findings indicate that dopamine receptors are important modulators of excitatory/inhibitory balance and sound association learning mechanisms in the NCM, a system that could be a fundamental feature of vertebrate ascending auditory pathways.
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Affiliation(s)
- Matheus Macedo-Lima
- Neuroscience and Behavior Program
- Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, Massachusetts 01003
- CAPES Foundation, Ministry of Education of Brazil, Brasília, DF 70040-020, Brazil
| | - Hannah M Boyd
- Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, Massachusetts 01003
| | - Luke Remage-Healey
- Neuroscience and Behavior Program
- Center for Neuroendocrine Studies, University of Massachusetts Amherst, Amherst, Massachusetts 01003
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3
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Costanzi M, Cianfanelli B, Santirocchi A, Lasaponara S, Spataro P, Rossi-Arnaud C, Cestari V. Forgetting Unwanted Memories: Active Forgetting and Implications for the Development of Psychological Disorders. J Pers Med 2021; 11:jpm11040241. [PMID: 33810436 PMCID: PMC8066077 DOI: 10.3390/jpm11040241] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
Intrusive memories are a common feature of many psychopathologies, and suppression-induced forgetting of unwanted memories appears as a critical ability to preserve mental health. In recent years, biological and cognitive studies converged in revealing that forgetting is due to active processes. Recent neurobiological studies provide evidence on the active role of main neurotransmitter systems in forgetting, suggesting that the brain actively works to suppress retrieval of unwanted memories. On the cognitive side, there is evidence that voluntary and involuntary processes (here termed "intentional" and "incidental" forgetting, respectively) contribute to active forgetting. In intentional forgetting, an inhibitory control mechanism suppresses awareness of unwanted memories at encoding or retrieval. In incidental forgetting, retrieval practice of some memories involuntarily suppresses the retrieval of other related memories. In this review we describe recent findings on deficits in active forgetting observed in psychopathologies, like post-traumatic stress disorder, depression, schizophrenia, and obsessive-compulsive disorder. Moreover, we report studies in which the role of neurotransmitter systems, known to be involved in the pathogenesis of mental disorders, has been investigated in active forgetting paradigms. The possibility that biological and cognitive mechanisms of active forgetting could be considered as hallmarks of the early onset of psychopathologies is also discussed.
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Affiliation(s)
- Marco Costanzi
- Department of Human Sciences, Lumsa University, 00193 Rome, Italy; (B.C.); (S.L.)
- Correspondence:
| | - Beatrice Cianfanelli
- Department of Human Sciences, Lumsa University, 00193 Rome, Italy; (B.C.); (S.L.)
| | - Alessandro Santirocchi
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
| | - Stefano Lasaponara
- Department of Human Sciences, Lumsa University, 00193 Rome, Italy; (B.C.); (S.L.)
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
| | - Pietro Spataro
- Department of Economy, Universitas Mercatorum, 00100 Rome, Italy;
| | - Clelia Rossi-Arnaud
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
| | - Vincenzo Cestari
- Department of Psychology, Sapienza University, 00185 Rome, Italy; (A.S.); (C.R.-A.); (V.C.)
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4
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Schicknick H, Henschke JU, Budinger E, Ohl FW, Gundelfinger ED, Tischmeyer W. β-adrenergic modulation of discrimination learning and memory in the auditory cortex. Eur J Neurosci 2019; 50:3141-3163. [PMID: 31162753 PMCID: PMC6900137 DOI: 10.1111/ejn.14480] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 05/27/2019] [Accepted: 05/31/2019] [Indexed: 01/11/2023]
Abstract
Despite vast literature on catecholaminergic neuromodulation of auditory cortex functioning in general, knowledge about its role for long‐term memory formation is scarce. Our previous pharmacological studies on cortex‐dependent frequency‐modulated tone‐sweep discrimination learning of Mongolian gerbils showed that auditory‐cortical D1/5‐dopamine receptor activity facilitates memory consolidation and anterograde memory formation. Considering overlapping functions of D1/5‐dopamine receptors and β‐adrenoceptors, we hypothesised a role of β‐adrenergic signalling in the auditory cortex for sweep discrimination learning and memory. Supporting this hypothesis, the β1/2‐adrenoceptor antagonist propranolol bilaterally applied to the gerbil auditory cortex after task acquisition prevented the discrimination increment that was normally monitored 1 day later. The increment in the total number of hurdle crossings performed in response to the sweeps per se was normal. Propranolol infusion after the seventh training session suppressed the previously established sweep discrimination. The suppressive effect required antagonist injection in a narrow post‐session time window. When applied to the auditory cortex 1 day before initial conditioning, β1‐adrenoceptor‐antagonising and β1‐adrenoceptor‐stimulating agents retarded and facilitated, respectively, sweep discrimination learning, whereas β2‐selective drugs were ineffective. In contrast, single‐sweep detection learning was normal after propranolol infusion. By immunohistochemistry, β1‐ and β2‐adrenoceptors were identified on the neuropil and somata of pyramidal and non‐pyramidal neurons of the gerbil auditory cortex. The present findings suggest that β‐adrenergic signalling in the auditory cortex has task‐related importance for discrimination learning of complex sounds: as previously shown for D1/5‐dopamine receptor signalling, β‐adrenoceptor activity supports long‐term memory consolidation and reconsolidation; additionally, tonic input through β1‐adrenoceptors may control mechanisms permissive for memory acquisition.
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Affiliation(s)
- Horst Schicknick
- Special Lab Molecular Biological Techniques, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Julia U Henschke
- Department Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Institute of Cognitive Neurology and Dementia Research, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Eike Budinger
- Department Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Frank W Ohl
- Department Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Institute of Biology, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Center for Behavioral Brain Sciences, Magdeburg, Germany.,Department Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Molecular Neurobiology, Medical Faculty, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Wolfgang Tischmeyer
- Special Lab Molecular Biological Techniques, Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
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5
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Learning Induces Transient Upregulation of Brevican in the Auditory Cortex during Consolidation of Long-Term Memories. J Neurosci 2019; 39:7049-7060. [PMID: 31217331 DOI: 10.1523/jneurosci.2499-18.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 12/25/2022] Open
Abstract
It is a daily challenge for our brains to establish new memories via learning while providing stable storage of remote memories. In the adult vertebrate brain, bimodal regulation of the extracellular matrix (ECM) may regulate the delicate balance of learning-dependent plasticity and stable memory formation. Here, we trained adult male mice in a cortex-dependent auditory discrimination task and measured the abundance of ECM proteins brevican (BCN) and tenascin-R over the course of acquisition learning, consolidation, and long-term recall in two learning-relevant brain regions; the auditory cortex and hippocampus. Although early training led to a general downregulation of total ECM proteins, successful retrieval correlated with a region-specific and transient upregulation of BCN levels in the auditory cortex. No other parameter such as arousal or stress could account for the transient and region-specific BCN upregulation. This performance-dependent biphasic regulation of the ECM may assist transient plasticity to facilitate initial learning and subsequently promote the long-term consolidation of memory.SIGNIFICANCE STATEMENT The capacity to learn throughout life and at the same time guarantee lifelong storage and remote recall of established memories is a daily challenge. Emerging evidence suggests an important function of the extracellular matrix (ECM), a conglomerate of secreted proteins and polysaccharides in the adult vertebrate brain. We trained mice in an auditory long-term memory task and measured learning-related dynamic changes of the ECM protein brevican. Specifically, in the auditory cortex brevican is downregulated during initial learning and subsequently upregulated in exclusively those animals that have learned the task, suggesting a performance-dependent regulation in the service of memory consolidation and storage. Our data may provide novel therapeutic implications for several neuropsychiatric diseases involving dysregulation of the ECM.
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6
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Blum K, Badgaiyan RD, Dunston GM, Baron D, Modestino EJ, McLaughlin T, Steinberg B, Gold MS, Gondré-Lewis MC. The DRD2 Taq1A A1 Allele May Magnify the Risk of Alzheimer's in Aging African-Americans. Mol Neurobiol 2018; 55:5526-5536. [PMID: 28965318 PMCID: PMC5878111 DOI: 10.1007/s12035-017-0758-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/27/2017] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease is an irreversible, progressive brain disorder that slowly destroys cognitive skills and the ability to perform the simplest tasks. More than 5 million Americans are afflicted with Alzheimer's; a disorder which ranks third, just behind heart disease and cancer, as a cause of death for older people. With no real cure and in spite of enormous efforts worldwide, the disease remains a mystery in terms of treatment. Importantly, African-Americans are two times as likely as Whites to develop late-onset Alzheimer's disease and less likely to receive timely diagnosis and treatment. Dopamine function is linked to normal cognition and memory and carriers of the DRD2 Taq1A A1 allele have significant loss of D2 receptor density in the brain. Recent research has shown that A1 carriers have worse memory performance during long-term memory (LTM) updating, compared to non-carriers or A2-carriers. A1carriers also show less blood oxygen level-dependent (BOLD) activation in the left caudate nucleus which is important for LTM updating. This latter effect was only seen in older adults, suggesting magnification of genetic effects on brain functioning in the elderly. Moreover, the frequency of the A1 allele is 0.40 in African-Americans, with an approximate prevalence of the DRD2 A1 allele in 50% of an African-American subset of individuals. This is higher than what is found in a non-screened American population (≤ 28%) for reward deficiency syndrome (RDS) behaviors. Based on DRD2 known genetic polymorphisms, we hypothesize that the DRD2 Taq1A A1 allele magnifies the risk of Alzheimer's in aging African-Americans. Research linking this high risk for Alzheimer's in the African-American population, with DRD2/ANKK1-TaqIA polymorphism and neurocognitive deficits related to LTM, could pave the way for novel, targeted pro-dopamine homeostatic treatment.
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Affiliation(s)
- Kenneth Blum
- Department of Psychiatry & McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, USA
- Department of Psychiatry and Behavioral Sciences, Keck Medicine University of Southern California, Los Angeles, CA, USA
- Division of Applied Clinical Research & Education, Dominion Diagnostics, LLC, North Kingstown, RI, USA
- Department of Neurogenetics, Igene, LLC, Austin, TX, USA
- Division of Reward Deficiency Syndrome and Addiction Therapy, Nupathways, Inc., Innsbrook, MO, USA
- Department of Clinical Neurology, Path Foundation, New York, NY, USA
- Division of Neuroscience Based Addiction Therapy, The Shores Treatment & Recovery Center, Port Saint Lucie, FL, USA
- Eötvös Loránd University, Institute of Psychology, Budapest, Hungary
- Department of Psychiatry and Behavioral Health, Richmond University Medical Center, 355 Bard Avenue, Staten Island, NY, 10310, USA
- NeuroPsychoSocial Genomics Core, National Human Genome Center, Howard University, Washington, DC, USA
| | - Rajendra D Badgaiyan
- Department of Psychiatry and Behavioral Health, Richmond University Medical Center, 355 Bard Avenue, Staten Island, NY, 10310, USA
| | - Georgia M Dunston
- NeuroPsychoSocial Genomics Core, National Human Genome Center, Howard University, Washington, DC, USA
| | - David Baron
- Department of Psychiatry and Behavioral Sciences, Keck Medicine University of Southern California, Los Angeles, CA, USA
| | | | | | | | - Mark S Gold
- Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
| | - Marjorie C Gondré-Lewis
- NeuroPsychoSocial Genomics Core, National Human Genome Center, Howard University, Washington, DC, USA.
- Developmental Neuropsychopharmacology Laboratory, Department of Anatomy, Howard University College of Medicine, Washington, DC, USA.
- Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC, USA.
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7
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Characterization of Behavioral, Signaling and Cytokine Alterations in a Rat Neurodevelopmental Model for Schizophrenia, and Their Reversal by the 5-HT 6 Receptor Antagonist SB-399885. Mol Neurobiol 2018; 55:7413-7430. [PMID: 29423817 PMCID: PMC6096968 DOI: 10.1007/s12035-018-0940-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/28/2018] [Indexed: 12/15/2022]
Abstract
Post-weaning social isolation of rats produces neuroanatomical, neurochemical and behavioral alterations resembling some core features of schizophrenia. This study examined the ability of the 5-HT6 receptor antagonist SB-399885 to reverse isolation-induced cognitive deficits, then investigated alterations in hippocampal cell proliferation and hippocampal and frontal cortical expression of selected intracellular signaling molecules and cytokines. Male Lister hooded rats (weaned on post-natal days 21-24 and housed individually or in groups of 3-4) received six i.p. injections of vehicle (1% Tween 80, 1 mL/kg) or SB-399885 (5 or 10 mg/kg) over a 2-week period starting 40 days post-weaning, on the days that locomotor activity, novel object discrimination (NOD), pre-pulse inhibition of acoustic startle and acquisition, retention and extinction of a conditioned freezing response (CFR) were assessed. Tissue was collected 24 h after the final injection for immunohistochemistry, reverse-phase protein microarray and western blotting. Isolation rearing impaired NOD and cue-mediated CFR, decreased cell proliferation within the dentate gyrus, and elevated hippocampal TNFα levels and Cdc42 expression. SB-399885 reversed the NOD deficit and partially normalized CFR and cell proliferation. These effects were accompanied by altered expression of several members of the c-Jun N-terminal Kinase (JNK) and p38 MAPK signaling pathways (including TAK1, MKK4 and STAT3). Although JNK and p38 themselves were unaltered at this time point hippocampal TAK1 expression and phosphorylation correlated with visual recognition memory in the NOD task. Continued use of this neurodevelopmental model could further elucidate the neurobiology of schizophrenia and aid assessment of novel therapies for drug-resistant cognitive symptoms.
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8
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Helbing C, Tischmeyer W, Angenstein F. Late effect of dopamine D 1/5 receptor activation on stimulus-induced BOLD responses in the hippocampus and its target regions depends on the history of previous stimulations. Neuroimage 2017; 152:119-129. [DOI: 10.1016/j.neuroimage.2017.02.077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/23/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022] Open
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9
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Kolodziej A, Smalla KH, Richter S, Engler A, Pielot R, Dieterich DC, Tischmeyer W, Naumann M, Kähne T. High Resolution Quantitative Synaptic Proteome Profiling of Mouse Brain Regions After Auditory Discrimination Learning. J Vis Exp 2016. [PMID: 28060347 PMCID: PMC5226410 DOI: 10.3791/54992] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The molecular synaptic mechanisms underlying auditory learning and memory remain largely unknown. Here, the workflow of a proteomic study on auditory discrimination learning in mice is described. In this learning paradigm, mice are trained in a shuttle box Go/NoGo-task to discriminate between rising and falling frequency-modulated tones in order to avoid a mild electric foot-shock. The protocol involves the enrichment of synaptosomes from four brain areas, namely the auditory cortex, frontal cortex, hippocampus, and striatum, at different stages of training. Synaptic protein expression patterns obtained from trained mice are compared to naïve controls using a proteomic approach. To achieve sufficient analytical depth, samples are fractionated in three different ways prior to mass spectrometry, namely 1D SDS-PAGE/in-gel digestion, in-solution digestion and phospho-peptide enrichment. High-resolution proteomic analysis on a mass spectrometer and label-free quantification are used to examine synaptic protein profiles in phospho-peptide-depleted and phospho-peptide-enriched fractions of synaptosomal protein samples. A commercial software package is utilized to reveal proteins and phospho-peptides with significantly regulated relative synaptic abundance levels (trained/naïve controls). Common and differential regulation modes for the synaptic proteome in the investigated brain regions of mice after training were observed. Subsequently, meta-analyses utilizing several databases are employed to identify underlying cellular functions and biological pathways.
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Affiliation(s)
| | | | - Sandra Richter
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University Magdeburg
| | | | - Rainer Pielot
- Leibniz Institute for Neurobiology (LIN); Institute of Pharmacology and Toxicology, Medical School, Otto von Guericke University
| | - Daniela C Dieterich
- Institute of Pharmacology and Toxicology, Medical School, Otto von Guericke University
| | | | - Michael Naumann
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University Magdeburg
| | - Thilo Kähne
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University Magdeburg;
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10
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Immunoproteasome induction is suppressed in hepatitis C virus-infected cells in a protein kinase R-dependent manner. Exp Mol Med 2016; 48:e270. [PMID: 27833096 PMCID: PMC5133375 DOI: 10.1038/emm.2016.98] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/11/2016] [Indexed: 02/08/2023] Open
Abstract
By changing the relative abundance of generated antigenic peptides through alterations in the proteolytic activity, interferon (IFN)-γ-induced immunoproteasomes influence the outcome of CD8+ cytotoxic T lymphocyte responses. In the present study, we investigated the effects of hepatitis C virus (HCV) infection on IFN-γ-induced immunoproteasome expression using a HCV infection cell culture system. We found that, although IFN-γ induced the transcriptional expression of mRNAs encoding the β1i/LMP2, β2i/MECL-1 and β5i/LMP7 immunoproteasome subunits, the formation of immunoproteasomes was significantly suppressed in HCV-infected cells. This finding indicated that immunoproteasome induction was impaired at the translational or posttranslational level by HCV infection. Gene silencing studies showed that the suppression of immunoproteasome induction is essentially dependent on protein kinase R (PKR). Indeed, the generation of a strictly immunoproteasome-dependent cytotoxic T lymphocyte epitope was impaired in in vitro processing experiments using isolated 20S proteasomes from HCV-infected cells and was restored by the silencing of PKR expression. In conclusion, our data point to a novel mechanism of immune regulation by HCV that affects the antigen-processing machinery through the PKR-mediated suppression of immunoproteasome induction in infected cells.
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11
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Garza-Lombó C, Gonsebatt ME. Mammalian Target of Rapamycin: Its Role in Early Neural Development and in Adult and Aged Brain Function. Front Cell Neurosci 2016; 10:157. [PMID: 27378854 PMCID: PMC4910040 DOI: 10.3389/fncel.2016.00157] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/30/2016] [Indexed: 01/14/2023] Open
Abstract
The kinase mammalian target of rapamycin (mTOR) integrates signals triggered by energy, stress, oxygen levels, and growth factors. It regulates ribosome biogenesis, mRNA translation, nutrient metabolism, and autophagy. mTOR participates in various functions of the brain, such as synaptic plasticity, adult neurogenesis, memory, and learning. mTOR is present during early neural development and participates in axon and dendrite development, neuron differentiation, and gliogenesis, among other processes. Furthermore, mTOR has been shown to modulate lifespan in multiple organisms. This protein is an important energy sensor that is present throughout our lifetime its role must be precisely described in order to develop therapeutic strategies and prevent diseases of the central nervous system. The aim of this review is to present our current understanding of the functions of mTOR in neural development, the adult brain and aging.
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Affiliation(s)
- Carla Garza-Lombó
- Departamento de Medicina Genómica, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México México
| | - María E Gonsebatt
- Departamento de Medicina Genómica, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México México
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12
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Kähne T, Richter S, Kolodziej A, Smalla KH, Pielot R, Engler A, Ohl FW, Dieterich DC, Seidenbecher C, Tischmeyer W, Naumann M, Gundelfinger ED. Proteome rearrangements after auditory learning: high-resolution profiling of synapse-enriched protein fractions from mouse brain. J Neurochem 2016; 138:124-38. [PMID: 27062398 PMCID: PMC5089584 DOI: 10.1111/jnc.13636] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 03/23/2016] [Accepted: 04/01/2016] [Indexed: 01/09/2023]
Abstract
Learning and memory processes are accompanied by rearrangements of synaptic protein networks. While various studies have demonstrated the regulation of individual synaptic proteins during these processes, much less is known about the complex regulation of synaptic proteomes. Recently, we reported that auditory discrimination learning in mice is associated with a relative down-regulation of proteins involved in the structural organization of synapses in various brain regions. Aiming at the identification of biological processes and signaling pathways involved in auditory memory formation, here, a label-free quantification approach was utilized to identify regulated synaptic junctional proteins and phosphoproteins in the auditory cortex, frontal cortex, hippocampus, and striatum of mice 24 h after the learning experiment. Twenty proteins, including postsynaptic scaffolds, actin-remodeling proteins, and RNA-binding proteins, were regulated in at least three brain regions pointing to common, cross-regional mechanisms. Most of the detected synaptic proteome changes were, however, restricted to individual brain regions. For example, several members of the Septin family of cytoskeletal proteins were up-regulated only in the hippocampus, while Septin-9 was down-regulated in the hippocampus, the frontal cortex, and the striatum. Meta analyses utilizing several databases were employed to identify underlying cellular functions and biological pathways. Data are available via ProteomeExchange with identifier PXD003089. How does the protein composition of synapses change in different brain areas upon auditory learning? We unravel discrete proteome changes in mouse auditory cortex, frontal cortex, hippocampus, and striatum functionally implicated in the learning process. We identify not only common but also area-specific biological pathways and cellular processes modulated 24 h after training, indicating individual contributions of the regions to memory processing.
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Affiliation(s)
- Thilo Kähne
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University, Magdeburg, Germany
| | - Sandra Richter
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University, Magdeburg, Germany
| | - Angela Kolodziej
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.,Institute of Biology, Otto von Guericke University, Magdeburg, Germany
| | - Karl-Heinz Smalla
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Rainer Pielot
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany
| | | | - Frank W Ohl
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.,Institute of Biology, Otto von Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Daniela C Dieterich
- Center for Behavioral Brain Sciences, Magdeburg, Germany.,Institute of Pharmacology and Toxicology, Medical School, Otto von Guericke University, Magdeburg, Germany
| | - Constanze Seidenbecher
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Wolfgang Tischmeyer
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Michael Naumann
- Institute of Experimental Internal Medicine, Medical School, Otto von Guericke University, Magdeburg, Germany
| | - Eckart D Gundelfinger
- Leibniz Institute for Neurobiology (LIN), Magdeburg, Germany.,Center for Behavioral Brain Sciences, Magdeburg, Germany.,Molecular Neuroscience, Medical School, Otto von Guericke University, Magdeburg, Germany.,German Center for Neurodegenerative Diseases, Magdeburg, Germany
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Happel MFK. Dopaminergic impact on local and global cortical circuit processing during learning. Behav Brain Res 2015; 299:32-41. [PMID: 26608540 DOI: 10.1016/j.bbr.2015.11.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/10/2015] [Accepted: 11/15/2015] [Indexed: 11/17/2022]
Abstract
We have learned to detect, predict and behaviorally respond to important changes in our environment on short and longer time scales. Therefore, brains of humans and higher animals build upon a perceptual and semantic salience stored in their memories mainly generated by associative reinforcement learning. Functionally, the brain needs to extract and amplify a small number of features of sensory input with behavioral relevance to a particular situation in order to guide behavior. In this review, I argue that dopamine action, particularly in sensory cortex, orchestrates layer-dependent local and long-range cortical circuits integrating sensory associated bottom-up and semantically relevant top-down information, respectively. Available evidence reveals that dopamine thereby controls both the selection of perceptually or semantically salient signals as well as feedback processing from higher-order areas in the brain. Sensory cortical dopamine thereby governs the integration of selected sensory information within a behavioral context. This review proposes that dopamine enfolds this function by temporally distinct actions on particular layer-dependent local and global cortical circuits underlying the integration of sensory, and non-sensory cognitive and behavioral variables.
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Affiliation(s)
- Max F K Happel
- Leibniz Institute for Neurobiology, D-39118 Magdeburg, Germany; Institute of Biology, Otto-von-Guericke-University, D-39120 Magdeburg, Germany.
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