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Zhao R. Can exercise benefits be harnessed with drugs? A new way to combat neurodegenerative diseases by boosting neurogenesis. Transl Neurodegener 2024; 13:36. [PMID: 39049102 PMCID: PMC11271207 DOI: 10.1186/s40035-024-00428-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 07/01/2024] [Indexed: 07/27/2024] Open
Abstract
Adult hippocampal neurogenesis (AHN) is affected by multiple factors, such as enriched environment, exercise, ageing, and neurodegenerative disorders. Neurodegenerative disorders can impair AHN, leading to progressive neuronal loss and cognitive decline. Compelling evidence suggests that individuals engaged in regular exercise exhibit higher production of proteins that are essential for AHN and memory. Interestingly, specific molecules that mediate the effects of exercise have shown effectiveness in promoting AHN and cognition in different transgenic animal models. Despite these advancements, the precise mechanisms by which exercise mimetics induce AHN remain partially understood. Recently, some novel exercise molecules have been tested and the underlying mechanisms have been proposed, involving intercommunications between multiple organs such as muscle-brain crosstalk, liver-brain crosstalk, and gut-brain crosstalk. In this review, we will discuss the current evidence regarding the effects and potential mechanisms of exercise mimetics on AHN and cognition in various neurological disorders. Opportunities, challenges, and future directions in this research field are also discussed.
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Affiliation(s)
- Renqing Zhao
- College of Physical Education, Yangzhou University, 88 South Daxue Road, Yangzhou, 225009, China.
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2
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Matsushita MT, Xia Z. Cadmium inhibits calcium activity in hippocampal CA1 neurons of freely moving mice. Toxicol Sci 2024; 200:199-212. [PMID: 38579196 PMCID: PMC11199909 DOI: 10.1093/toxsci/kfae048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2024] Open
Abstract
Cadmium (Cd) is a ubiquitous toxic heavy metal and a potential neurotoxicant due to its wide use in industrial manufacturing processes and commercial products, including fertilizers. The general population is exposed to Cd through food and smoking due to high transfer rates of Cd from contaminated soil. Cd has been shown to mimic calcium ions (Ca2+) and interfere with intracellular Ca2+ levels and Ca2+ signaling in in vitro studies. However, nothing is known about Cd's effects on Ca2+ activity in neurons in live animals. This study aimed to determine if Cd disrupts Ca2+ transients of neurons in CA1 region of the hippocampus during an associative learning paradigm. We utilized in vivo Ca2+ imaging in awake, freely moving C57BL/6 mice to measure Ca2+ activity in CA1 excitatory neurons expressing genetically encoded Ca2+ sensor GCaMP6 during an associative learning paradigm. We found that a smaller proportion of neurons are activated in Cd-treated groups compared with control during fear conditioning, suggesting that Cd may contribute to learning and memory deficit by reducing the activity of neurons. We observed these effects at Cd exposure levels that result in blood Cd levels comparable with the general U.S. population levels. This provides a possible molecular mechanism for Cd interference of learning and memory at exposure levels relevant to U.S. adults. To our knowledge, our study is the first to describe Cd effects on brain Ca2+ activity in vivo in freely behaving mice. This study provides evidence for impairment of neuronal calcium activity in hippocampal CA1 excitatory neurons in freely moving mice following cadmium exposure.
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Affiliation(s)
- Megumi T Matsushita
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98105, USA
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, Washington 98105, USA
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3
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Maheshwari M, Singla A, Rawat A, Banerjee T, Pati S, Shah S, Maiti S, Vaidya VA. Chronic chemogenetic activation of hippocampal progenitors enhances adult neurogenesis and modulates anxiety-like behavior and fear extinction learning. IBRO Neurosci Rep 2024; 16:168-181. [PMID: 39007086 PMCID: PMC11240292 DOI: 10.1016/j.ibneur.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 01/18/2024] [Indexed: 07/16/2024] Open
Abstract
Adult hippocampal neurogenesis is a lifelong process that involves the integration of newborn neurons into the hippocampal network, and plays a role in cognitive function and the modulation of mood-related behavior. Here, we sought to address the impact of chemogenetic activation of adult hippocampal progenitors on distinct stages of progenitor development, including quiescent stem cell activation, progenitor turnover, differentiation and morphological maturation. We find that hM3Dq-DREADD-mediated activation of nestin-positive adult hippocampal progenitors recruits quiescent stem cells, enhances progenitor proliferation, increases doublecortin-positive newborn neuron number, accompanied by an acceleration of differentiation and morphological maturation, associated with increased dendritic complexity. Behavioral analysis indicated anxiolytic behavioral responses in transgenic mice subjected to chemogenetic activation of adult hippocampal progenitors at timepoints when newborn neurons are predicted to integrate into the mature hippocampal network. Furthermore, we noted an enhanced fear memory extinction on a contextual fear memory learning task in transgenic mice subjected to chemogenetic activation of adult hippocampal progenitors. Our findings indicate that hM3Dq-DREAD-mediated chemogenetic activation of adult hippocampal progenitors impacts distinct aspects of hippocampal neurogenesis, associated with the regulation of anxiety-like behavior and fear memory extinction.
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Affiliation(s)
| | | | - Anoop Rawat
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Toshali Banerjee
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Sthitapranjya Pati
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Sneha Shah
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Sudipta Maiti
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
| | - Vidita A. Vaidya
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra 400005, India
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4
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Nguyen JH, Curtis MA, Imami AS, Ryan WG, Alganem K, Neifer KL, Saferin N, Nawor CN, Kistler BP, Miller GW, Shukla R, McCullumsmith RE, Burkett JP. Developmental pyrethroid exposure disrupts molecular pathways for MAP kinase and circadian rhythms in mouse brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.28.555113. [PMID: 37745438 PMCID: PMC10515776 DOI: 10.1101/2023.08.28.555113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Neurodevelopmental disorders (NDDs) are a category of pervasive disorders of the developing nervous system with few or no recognized biomarkers. A significant portion of the risk for NDDs, including attention deficit hyperactivity disorder (ADHD), is contributed by the environment, and exposure to pyrethroid pesticides during pregnancy has been identified as a potential risk factor for NDD in the unborn child. We recently showed that low-dose developmental exposure to the pyrethroid pesticide deltamethrin in mice causes male-biased changes to ADHD- and NDD-relevant behaviors as well as the striatal dopamine system. Here, we used an integrated multiomics approach to determine the broadest possible set of biological changes in the mouse brain caused by developmental pyrethroid exposure (DPE). Using a litter-based, split-sample design, we exposed mouse dams during pregnancy and lactation to deltamethrin (3 mg/kg or vehicle every 3 days) at a concentration well below the EPA-determined benchmark dose used for regulatory guidance. We raised male offspring to adulthood, euthanized them, and pulverized and divided whole brain samples for split-sample transcriptomics, kinomics and multiomics integration. Transcriptome analysis revealed alterations to multiple canonical clock genes, and kinome analysis revealed changes in the activity of multiple kinases involved in synaptic plasticity, including the mitogen-activated protein (MAP) kinase ERK. Multiomics integration revealed a dysregulated protein-protein interaction network containing primary clusters for MAP kinase cascades, regulation of apoptosis, and synaptic function. These results demonstrate that DPE causes a multi-modal biophenotype in the brain relevant to ADHD and identifies new potential mechanisms of action. NEW & NOTEWORTHY Here, we provide the first evidence that low-dose developmental exposure to the pyrethroid pesticide, deltamethrin, results in molecular disruptions in the adult mouse brain in pathways regulating circadian rhythms and neuronal growth (MAP kinase). This same exposure causes a neurodevelopmental disorder (NDD) relevant behavioral changes in adult mice, making these findings relevant to the prevention of NDDs.
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Martínez-Canabal A, López-Oropeza G, Sotres-Bayón F. Hippocampal neurogenesis facilitates cognitive flexibility in a fear discrimination task. Front Behav Neurosci 2024; 17:1331928. [PMID: 38282713 PMCID: PMC10813213 DOI: 10.3389/fnbeh.2023.1331928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 12/18/2023] [Indexed: 01/30/2024] Open
Abstract
Hippocampal neurogenesis, the continuous creation of new neurons in the adult brain, influences memory, regulates the expression of defensive responses to threat (fear), and cognitive processes like pattern separation and behavioral flexibility. One hypothesis proposes that neurogenesis promotes cognitive flexibility by degrading established memories and promoting relearning. Yet, empirical evidence on its role in fear discrimination tasks is scarce. In this study, male rats were initially trained to differentiate between two similar environments, one associated with a threat. Subsequently, we enhanced neurogenesis through environmental enrichment and memantine treatments. We then reversed the emotional valence of these contexts. In both cases, neurogenesis improved the rats' ability to relearn the aversive context. Interestingly, we observed increased hippocampal activity, and decreased activity in the prelimbic cortex and lateral habenula, while the infralimbic cortex remained unchanged, suggesting neurogenesis-induced plasticity changes in this brain network. Moreover, when we pharmacologically inhibited the increased neurogenesis with Methotrexate, rats struggled to relearn context discrimination, confirming the crucial role of neurogenesis in this cognitive process. Overall, our findings highlight neurogenesis's capacity to facilitate changes in fear discrimination and emphasize the involvement of a prefrontal-hippocampal-habenula mechanism in this process. This study emphasizes the intricate relationship between hippocampal neurogenesis, cognitive flexibility, and the modulation of fear-related memories.
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Affiliation(s)
- Alonso Martínez-Canabal
- Department of Cell Biology, Faculty of Sciences, National Autonomous University of Mexico (UNAM), México City, Mexico
- Cell Physiology Institute - Neuroscience, National Autonomous University of Mexico (UNAM), México City, Mexico
| | - Grecia López-Oropeza
- Department of Cell Biology, Faculty of Sciences, National Autonomous University of Mexico (UNAM), México City, Mexico
- Cell Physiology Institute - Neuroscience, National Autonomous University of Mexico (UNAM), México City, Mexico
- Graduate Program in Biological Sciences, National Autonomous University of Mexico (UNAM), México City, Mexico
| | - Francisco Sotres-Bayón
- Cell Physiology Institute - Neuroscience, National Autonomous University of Mexico (UNAM), México City, Mexico
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Berdugo‐Vega G, Dhingra S, Calegari F. Sharpening the blades of the dentate gyrus: how adult-born neurons differentially modulate diverse aspects of hippocampal learning and memory. EMBO J 2023; 42:e113524. [PMID: 37743770 PMCID: PMC11059975 DOI: 10.15252/embj.2023113524] [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: 01/16/2023] [Revised: 06/19/2023] [Accepted: 08/18/2023] [Indexed: 09/26/2023] Open
Abstract
For decades, the mammalian hippocampus has been the focus of cellular, anatomical, behavioral, and computational studies aimed at understanding the fundamental mechanisms underlying cognition. Long recognized as the brain's seat for learning and memory, a wealth of knowledge has been accumulated on how the hippocampus processes sensory input, builds complex associations between objects, events, and space, and stores this information in the form of memories to be retrieved later in life. However, despite major efforts, our understanding of hippocampal cognitive function remains fragmentary, and models trying to explain it are continually revisited. Here, we review the literature across all above-mentioned domains and offer a new perspective by bringing attention to the most distinctive, and generally neglected, feature of the mammalian hippocampal formation, namely, the structural separability of the two blades of the dentate gyrus into "supra-pyramidal" and "infra-pyramidal". Next, we discuss recent reports supporting differential effects of adult neurogenesis in the regulation of mature granule cell activity in these two blades. We propose a model for how differences in connectivity and adult neurogenesis in the two blades can potentially provide a substrate for subtly different cognitive functions.
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Affiliation(s)
- Gabriel Berdugo‐Vega
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
- Present address:
Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale Lausanne (EPFL)LausanneSwitzerland
| | - Shonali Dhingra
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Federico Calegari
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
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7
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Wang W, Wang Z, Cao J, Dong Y, Chen Y. Roles of Rac1-Dependent Intrinsic Forgetting in Memory-Related Brain Disorders: Demon or Angel. Int J Mol Sci 2023; 24:10736. [PMID: 37445914 DOI: 10.3390/ijms241310736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Animals are required to handle daily massive amounts of information in an ever-changing environment, and the resulting memories and experiences determine their survival and development, which is critical for adaptive evolution. However, intrinsic forgetting, which actively deletes irrelevant information, is equally important for memory acquisition and consolidation. Recently, it has been shown that Rac1 activity plays a key role in intrinsic forgetting, maintaining the balance of the brain's memory management system in a controlled manner. In addition, dysfunctions of Rac1-dependent intrinsic forgetting may contribute to memory deficits in neurological and neurodegenerative diseases. Here, these new findings will provide insights into the neurobiology of memory and forgetting, pathological mechanisms and potential therapies for brain disorders that alter intrinsic forgetting mechanisms.
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Affiliation(s)
- Wei Wang
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zixu Wang
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Jing Cao
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yulan Dong
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yaoxing Chen
- Neurobiology Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
- Key Laboratory of Precision Nutrition and Food Quality, Key Laboratory of Functional Dairy, Ministry of Education, Beijing Laboratory of Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing 100083, China
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8
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Matsushita MT, Wang H, Abel GM, Xia Z. Inducible and Conditional Activation of Adult Neurogenesis Rescues Cadmium-Induced Hippocampus-Dependent Memory Deficits in ApoE4-KI Mice. Int J Mol Sci 2023; 24:9118. [PMID: 37298071 PMCID: PMC10253189 DOI: 10.3390/ijms24119118] [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: 04/19/2023] [Revised: 05/17/2023] [Accepted: 05/19/2023] [Indexed: 06/12/2023] Open
Abstract
The apolipoprotein E (ApoE) gene is a genetic risk factor for late-onset Alzheimer's disease, in which ε4 allele carriers have increased risk compared to the common ε3 carriers. Cadmium (Cd) is a toxic heavy metal and a potential neurotoxicant. We previously reported a gene-environment interaction (GxE) effect between ApoE4 and Cd that accelerates or increases the severity of the cognitive decline in ApoE4-knockin (ApoE4-KI) mice exposed to 0.6 mg/L CdCl2 through drinking water compared to control ApoE3-KI mice. However, the mechanisms underlying this GxE effect are not yet defined. Because Cd impairs adult neurogenesis, we investigated whether genetic and conditional stimulation of adult neurogenesis can functionally rescue Cd-induced cognitive impairment in ApoE4-KI mice. We crossed either ApoE4-KI or ApoE3-KI to an inducible Cre mouse strain, Nestin-CreERTM:caMEK5-eGFPloxP/loxP (designated as caMEK5), to generate ApoE4-KI:caMEK5 and ApoE3-KI:caMEK5. Tamoxifen administration in these mice genetically and conditionally induces the expression of caMEK5 in adult neural stem/progenitor cells, enabling the stimulation of adult neurogenesis in the brain. Male ApoE4-KI:caMEK5 and ApoE3-KI:caMEK5 mice were exposed to 0.6 mg/L CdCl2 throughout the experiment, and tamoxifen was administered once Cd-induced impairment in spatial working memory was consistently observed. Cd exposure impaired spatial working memory earlier in ApoE4-KI:caMEK5 than in ApoE3-KI:caMEK5 mice. In both strains, these deficits were rescued after tamoxifen treatment. Consistent with these behavioral findings, tamoxifen treatment enhanced adult neurogenesis by increasing the morphological complexity of adult-born immature neurons. These results provide evidence for a direct link between impaired spatial memory and adult neurogenesis in this GxE model.
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Affiliation(s)
| | | | | | - Zhengui Xia
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA 98105, USA
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9
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Inoue R, Ni X, Mori H. Blockade of D-serine signaling and adult hippocampal neurogenesis attenuates remote contextual fear memory following multiple memory retrievals in male mice. Front Neurosci 2023; 16:1030702. [PMID: 36685240 PMCID: PMC9845639 DOI: 10.3389/fnins.2022.1030702] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
The retrieval of fear memories induces two opposing processes, reconsolidation, and extinction. The memory reconsolidation is an active process that involves gene expression and updates an existing memory. It is hypothesized that blockade of reconsolidation by manipulating the neurobiological factors, which are mechanistically involved in the process, could weaken or disrupt the original fear memory. The N-methyl-D-aspartate (NMDA) receptor and hippocampal neurogenesis play crucial roles in hippocampus-dependent memory processes, including reconsolidation. Using contextual fear conditioning paradigm with multiple retrievals, we attempted to weaken the original contextual fear memory by repeatedly disrupting retrieval-induced reconsolidation via downregulation of NMDA receptor signaling and inhibition of neurogenesis. In the first experiment, prior to fear conditioning, NMDA receptor signaling was downregulated by the genetic reduction of its co-agonist, D-serine, and the neurogenesis was dampened by focal X-ray irradiation on the hippocampus. We found that simultaneous D-serine reduction and neurogenesis dampening resulted in a progressive decrease in freezing following each retrieval, leading to an attenuation of remote contextual fear memory on day 28. In the second experiment using the same behavioral protocols, after conditioning, pharmacological approaches were conducted to simultaneously block D-serine signaling and neurogenesis, resulting in a similar suppressive effect on the remote fear memory. The present findings provide insights for understanding the role of D-serine-mediated NMDA receptor signaling and neurogenesis in memory retrieval and the maintenance of remote fear memory, and improving the efficacy of exposure-based therapy for the treatment of post-traumatic stress disorder (PTSD).
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Affiliation(s)
- Ran Inoue
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Xiance Ni
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan,Graduate School of Innovative Life Science, University of Toyama, Toyama, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan,*Correspondence: Hisashi Mori,
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Reich N, Hölscher C. Beyond Appetite: Acylated Ghrelin As A Learning, Memory and Fear Behavior-modulating Hormone. Neurosci Biobehav Rev 2022; 143:104952. [DOI: 10.1016/j.neubiorev.2022.104952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 04/27/2022] [Accepted: 11/05/2022] [Indexed: 11/10/2022]
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11
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Simonova NA, Volgushev MA, Malyshev AY. Enhanced Non-Associative Long-Term Potentiation in Immature Granule Cells in the Dentate Gyrus of Adult Rats. Front Synaptic Neurosci 2022; 14:889947. [PMID: 35711669 PMCID: PMC9192440 DOI: 10.3389/fnsyn.2022.889947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/15/2022] [Indexed: 11/20/2022] Open
Abstract
The dentate gyrus is one of the few sites of neurogenesis in the adult brain. Integration of new-generated granule cells into the hippocampal circuitry provides a substrate for structural plasticity, fundamental for normal function of adult hippocampus. However, mechanisms of synaptic plasticity that mediate integration of new-generated granule cells into the existing circuitry remain poorly understood. Especially mechanisms of plasticity at GABA-ergic synapses remain elusive. Here, we show that postsynaptic spiking without presynaptic activation can induce heterosynaptic, non-associative plasticity at GABA-ergic inputs to both immature and mature granule cells. In both immature and mature neurons, plastic changes were bidirectional and individual inputs could express long-term potentiation (LTP) or long-term depression (LTD), or do not change. However, properties of non-associative plasticity dramatically change with maturation of newly generated granule cells: while in immature cells there was a clear predominance of non-associative LTP and net potentiation across the inputs, in mature neurons, potentiation and depression were balanced with no net change on average. We conclude that GABA-ergic inputs to granule cells are plastic, and that the rules for induction of non-associative plasticity change with maturation. We propose that potentiation-biased non-associative plasticity of GABA-ergic transmission might help to counter-balance an increase of excitatory drive that is facilitated by enhanced LTP at glutamatergic synapses in maturating granule cells. Such mechanism might help to build a strong GABA-ergic input to surviving active new cells, necessary for normal function of mature granule cells, which operate under a tight inhibitory control and generate sparse spiking activity.
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Affiliation(s)
- Natalia A. Simonova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
| | - Maxim A. Volgushev
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
- *Correspondence: Maxim A. Volgushev
| | - Alexey Y. Malyshev
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
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Wang H, Abel GM, Storm DR, Xia Z. Adolescent cadmium exposure impairs cognition and hippocampal neurogenesis in C57BL/6 mice. ENVIRONMENTAL TOXICOLOGY 2022; 37:335-348. [PMID: 34741586 PMCID: PMC10942748 DOI: 10.1002/tox.23402] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Cadmium (Cd) is a toxic heavy metal and a significant public health concern. Epidemiological studies suggest that Cd is a potential neurotoxicant, and its exposure is associated with cognitive deficits in children, adults, and seniors. Our previous study has found that adulthood-only Cd exposure can impair cognition in mice. However, few studies have addressed the effects of Cd exposure during adolescence on cognitive behavior in animals later in life. In the present study, we exposed 4-week-old male C57BL/6 mice to 3 mg/L Cd via drinking water for 28 weeks and assessed their hippocampus-dependent learning and memory. Cd did not affect anxiety or locomotor activity in the open field test. However, Cd exposure impaired short-term spatial memory and contextual fear memory in mice. A separate cohort of 4-week-old mice was similarly exposed to Cd for 13 weeks to investigate the potential mechanism of Cd neurotoxicity on cognition. We observed that Cd-treated mice had fewer adult-born cells, adult-born neurons, and a reduced proportion of adult-born cells that differentiated into mature neurons in the subgranular zone of the dentate gyrus. These results suggest that Cd exposure from adolescence to adulthood is sufficient to cause cognitive deficits and impair key processes of hippocampal neurogenesis in mice.
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Affiliation(s)
- Hao Wang
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Glen M. Abel
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - Daniel R. Storm
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
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13
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Hernández-Mercado K, Zepeda A. Morris Water Maze and Contextual Fear Conditioning Tasks to Evaluate Cognitive Functions Associated With Adult Hippocampal Neurogenesis. Front Neurosci 2022; 15:782947. [PMID: 35046769 PMCID: PMC8761726 DOI: 10.3389/fnins.2021.782947] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 11/29/2021] [Indexed: 12/12/2022] Open
Abstract
New neurons are continuously generated and functionally integrated into the dentate gyrus (DG) network during the adult lifespan of most mammals. The hippocampus is a crucial structure for spatial learning and memory, and the addition of new neurons into the DG circuitry of rodents seems to be a key element for these processes to occur. The Morris water maze (MWM) and contextual fear conditioning (CFC) are among the most commonly used hippocampus-dependent behavioral tasks to study episodic-like learning and memory in rodents. While the functional contribution of adult hippocampal neurogenesis (AHN) through these paradigms has been widely addressed, results have generated controversial findings. In this review, we analyze and discuss possible factors in the experimental methods that could explain the inconsistent results among AHN studies; moreover, we provide specific suggestions for the design of more sensitive protocols to assess AHN-mediated learning and memory functions.
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Affiliation(s)
- Karina Hernández-Mercado
- Departamento de Medicina Genómica y Toxicológia Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Angélica Zepeda
- Departamento de Medicina Genómica y Toxicológia Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
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Che X, Bai Y, Cai J, Liu Y, Li Y, Yin M, Xu T, Wu C, Yang J. Hippocampal neurogenesis interferes with extinction and reinstatement of methamphetamine-associated reward memory in mice. Neuropharmacology 2021; 196:108717. [PMID: 34273388 DOI: 10.1016/j.neuropharm.2021.108717] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 06/30/2021] [Accepted: 07/11/2021] [Indexed: 12/16/2022]
Abstract
Drugs of abuse, including morphine and cocaine, can reduce hippocampal neurogenesis (HN). Whereas promotion of HN is being increasingly recognized as a promising strategy for treating morphine and cocaine addiction. The present study is focused on exploring the changes of HN during methamphetamine (METH) administration and further clarify if HN is involved in METH-associated reward memory. After successfully establishing the conditioned place preference (CPP) paradigm to simulate the METH-associated reward memory in C57BL/6 mice, we observed that HN was significantly inhibited during METH (2 mg/kg, i. p.) administration and returned to normal after the extinction of METH CPP, as indicated by the immunostaining of bromodeoxyuridine (BrdU) and doublecortin (DCX) in the hippocampus. To promote/inhibit HN levels, 7,8-dihydroxyflavone (DHF), a small tyrosine kinase receptor B (TrkB) agonist and temozolomide (TMZ), an alkylating agent, were administered intraperitoneally (i.p.), respectively. The data showed that either DHF (5 mg/kg, i. p.) or TMZ (25 mg/kg, i. p.) pre-treatment before METH administration could significantly prolong extinction and enhance reinstatement of the reward memory. Notably, DHF treatment after METH administration significantly facilitated extinction and inhibited METH reinstatement, while TMZ treatment resulted in opposite effects. The present study indicated that METH administration could induce a temporal inhibitory effect on HN. More importantly, promotion of HN after the acquisition of METH-associated reward memory, but not inhibition of HN or promotion of HN before the acquisition of reward memory, could facilitate METH extinction and inhibit METH reinstatement, indicating the beneficial effect of HN on METH addiction by erasing the according reward memory.
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Affiliation(s)
- Xiaohang Che
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Yijun Bai
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Jialing Cai
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Yueyang Liu
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Yuting Li
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Meixue Yin
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Tianyu Xu
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China
| | - Chunfu Wu
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China.
| | - Jingyu Yang
- Department of Pharmacology, Shenyang Pharmaceutical University, Shenyang, 110016, PR China.
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15
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Sevoflurane Postconditioning Ameliorates Neuronal Migration Disorder Through Reelin/Dab1 and Improves Long-term Cognition in Neonatal Rats After Hypoxic-Ischemic Injury. Neurotox Res 2021; 39:1524-1542. [PMID: 34224102 DOI: 10.1007/s12640-021-00377-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/09/2021] [Accepted: 05/17/2021] [Indexed: 10/20/2022]
Abstract
Sevoflurane postconditioning (SPC) has been widely reported to attenuate brain injury after hypoxia-ischemia encephalopathy (HIE) by inhibiting neural necrosis and autophagy. Moreover, recent reports revealed that sevoflurane facilitated hippocampal reconstruction via regulating migration. Yet, it remains unclear whether the promotion of neural migration by SPC repairs the hippocampal injury after HIE. Here, we hypothesize that SPC exerts a neuroprotective effect by ameliorating neuronal migration disorder after HIE and regulating Reelin expression. Furthermore, the downstream Reelin/Dab1 pathway may be involved. The classical Rice-Vannucci model of hypoxia-ischemia was performed on postnatal day 7 rat pups, which was followed by SPC at 1 minimum alveolar concentration (MAC 2.5%) for 30 min. Piceatannol, causing Reelin aggregation in vivo, was used to detect whether Reelin/Dab1 was involved in the neuroprotection effect of SPC. Hippocampal-dependent learning ability tests were conducted to assess the long-term effects on locomotor activity and spatial learning ability. Our findings suggest that hypoxia-ischemia injury inhibited neurons migrated outward from the basal zone of dentate gyrus, disrupted cytoarchitecture of the dentate gyrus (DG), and led to long-term cognition deficits. However, SPC could relieve the restricted hippocampal neurons and repair the hippocampal-dependent memory function damaged after HIE by attenuating the overactivation of the Reelin/Dab1 pathway. These results demonstrate that SPC plays a pivotal role in ameliorating neuronal migration disorder and maintaining normal cytoarchitecture of the DG via inhibiting overactivated Reelin expression. This process may involve overactivated Reelin/Dab1 signaling pathway and spatial learning ability by regulating the Reelin expression which may associate with its neuroprotection.
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16
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Zhang L, Wang H, Abel GM, Storm DR, Xia Z. The Effects of Gene-Environment Interactions Between Cadmium Exposure and Apolipoprotein E4 on Memory in a Mouse Model of Alzheimer's Disease. Toxicol Sci 2021; 173:189-201. [PMID: 31626305 DOI: 10.1093/toxsci/kfz218] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Cadmium (Cd) is a heavy metal of great public health concern. Recent studies suggested a link between Cd exposure and cognitive decline in humans. The ε4 allele, compared with the common ε3 allele, of the human apolipoprotein E gene (ApoE) is associated with accelerated cognitive decline and increased risks for Alzheimer's disease (AD). To investigate the gene-environment interactions (GxE) between ApoE-ε4 and Cd exposure on cognition, we used a mouse model of AD that expresses human ApoE-ε3 (ApoE3-KI [knock-in]) or ApoE-ε4 (ApoE4-KI). Mice were exposed to 0.6 mg/l CdCl2 through drinking water for 14 weeks and assessed for hippocampus-dependent memory. A separate cohort was sacrificed immediately after exposure and used for Cd measurements and immunostaining. The peak blood Cd was 0.3-0.4 µg/l, within levels found in the U.S. general population. All Cd-treated animals exhibited spatial working memory deficits in the novel object location test. This deficit manifested earlier in ApoE4-KI mice than in ApoE3-KI within the same sex and earlier in males than females within the same genotype. ApoE4-KI but not ApoE3-KI mice exhibited reduced spontaneous alternation later in life in the T-maze test. Finally, Cd exposure impaired neuronal differentiation of adult-born neurons in the hippocampus of male ApoE4-KI mice. These data suggest that a GxE between ApoE4 and Cd exposure leads to accelerated cognitive impairment and that impaired adult hippocampal neurogenesis may be one of the underlying mechanisms. Furthermore, male mice were more susceptible than female mice to this GxE effect when animals were young.
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Affiliation(s)
- Liang Zhang
- Department of Environmental and Occupational Health Sciences
| | - Hao Wang
- Department of Environmental and Occupational Health Sciences
| | - Glen M Abel
- Department of Environmental and Occupational Health Sciences
| | - Daniel R Storm
- Department of Pharmacology, University of Washington, Seattle, Washington 98195
| | - Zhengui Xia
- Department of Environmental and Occupational Health Sciences
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17
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Wang C, Wan H, Li M, Zhang C. Celastrol attenuates ischemia/reperfusion-mediated memory dysfunction by downregulating AK005401/MAP3K12. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2021; 82:153441. [PMID: 33387968 DOI: 10.1016/j.phymed.2020.153441] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 11/11/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Oxidative stress induces mitochondrial dysfunction, causing memory loss. Long noncoding RNAs influence mitochondrial function and suppress oxidative stress by regulating target protein expression and gene transcription. Celastrol, a natural antioxidant extracted from Tripterygium wilfordii Hook F. ("Thunder of God Vine"), effectively alleviates oxidative stress-mediated tissue injury. In the present study, we examined the effects of celastrol on memory dysfunction induced by ischemia/reperfusion (I/R) and elucidated the mechanisms underlying these effects. METHODS C57BL/6 mice were used to mimic I/R using the bilateral common carotid clip reperfusion method, and a hippocampal cell line (HT-22) cells were used to establish a model of oxygen-glucose deprivation/reoxygenation (OGD/R). We observed changes in behavior and mitochondrial structure. Cell activity, cell respiration, and antioxidant capacity were measured. MAP3K12, p-JNK, p-c-Jun, p-Akt/Akt, PI3K, Bcl-2, and Bax expression were evaluated. RESULTS I/R or OGD/R significantly increased AK005401 and MAP3K12 expression, further attenuating PI3K/Akt activation, promoting reactive oxygen species generation and causing mitochondrial dysfunction and cell apoptosis, thereby resulting in memory dysfunction. Celastrol increased antioxidant capacity, inhibited cell apoptosis, and improved mitochondrial function, effectively improving learning and memory by downregulating AK005401 and MAP3K12 and activating PI3K/Akt. CONCLUSIONS The AK005401/MAP3K12 signaling pathway has an important role in I/R-mediated hippocampal injury, and celastrol can potentially reduce or possibly prevent I/R-induced neuronal injury by downregulating AK005401/MAP3K12 signaling.
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Affiliation(s)
- Chaoyun Wang
- Basic Medical School, Binzhou Medical University, Yantai, P. R. China.
| | - Hongzhi Wan
- School of Pharmacy, Binzhou Medical University, Yantai, P. R. China
| | - Miao Li
- School of Pharmacy, Binzhou Medical University, Yantai, P. R. China
| | - Chunxiang Zhang
- Department of Biomedical Engineering, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
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18
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Wang H, Matsushita MT, Zhang L, Abel GM, Mommer BC, Huddy TF, Storm DR, Xia Z. Inducible and Conditional Stimulation of Adult Hippocampal Neurogenesis Rescues Cadmium-Induced Impairments of Adult Hippocampal Neurogenesis and Hippocampus-Dependent Memory in Mice. Toxicol Sci 2020; 177:263-280. [PMID: 32617577 PMCID: PMC7553705 DOI: 10.1093/toxsci/kfaa104] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cadmium (Cd) is a heavy metal and an environmental pollutant. However, the full spectrum of its neurotoxicity and the underlying mechanisms are not completely understood. Our previous studies demonstrated that Cd exposure impairs adult hippocampal neurogenesis and hippocampus-dependent memory in mice. This study aims to determine if these adverse effects of Cd exposure can be mitigated by genetically and conditionally enhancing adult neurogenesis. To address this issue, we utilized the transgenic constitutive active MEK5 (caMEK5) mouse strain we previously developed and characterized. This mouse strain enables us to genetically and conditionally activate adult neurogenesis by administering tamoxifen to induce expression of a caMEK5 in adult neural stem/progenitor cells, which stimulates adult neurogenesis through activation of the endogenous extracellular signal-regulated kinase 5 mitogen-activated protein kinase pathway. The caMEK5 mice were exposed to 0.6 mg/l Cd through drinking water for 38 weeks. Once impairment of memory was confirmed, tamoxifen was administered to induce caMEK5 expression and to activate adult neurogenesis. Behavior tests were conducted at various time points to monitor hippocampus-dependent memory. Upon completion of the behavior tests, brain tissues were collected for cellular studies of adult hippocampal neurogenesis. We report here that Cd impaired hippocampus-dependent spatial memory and contextual fear memory in mice. These deficits were rescued by the tamoxifen induction of caMEK5 expression. Furthermore, Cd inhibition of adult hippocampal neurogenesis was also reversed. This rescue experiment provides strong evidence for a direct link between Cd-induced impairments of adult hippocampal neurogenesis and hippocampus-dependent memory.
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Affiliation(s)
- Hao Wang
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Megumi T Matsushita
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Liang Zhang
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Glen M Abel
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Brett C Mommer
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | | | - Daniel R Storm
- Department of Pharmacology, University of Washington, Seattle, Washington 98195
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences
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19
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Sun KH, Jin Y, Mei ZG, Feng ZT, Liu JR, Cao MQ, Wu ZZ. Antidepressant-Like Effects of Chaihu Shugan Powder () on Rats Exposed to Chronic Unpredictable Mild Stress through Inhibition of Endoplasmic Reticulum Stress-Induced Apoptosis. Chin J Integr Med 2020; 27:353-360. [PMID: 32572775 DOI: 10.1007/s11655-020-3228-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2019] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To investigate the antidepressant-like effects of Chaihu Shugan Powder (CSP, ) and to explore its underlying mechanisms. METHODS Thirty-two Sprague-Dawley rats were randomly divided into control (CON), chronic unpredictable mild stress (CUMS), fluoxetine (FLU), and CSP groups, 8 rats in each group. All of the rats except for those in the control group were subjected to 3 consecutive weeks of CUMS to establish the depression model. The open field test (OFT), forced swimming test (FST), and sucrose preference test were used to assess the anti-anxiety and antidepressant effects of CSP. Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling was used to determine the apoptosis rate in the hippocampal tissues. The mRNA and protein levels of glucose-regulated protein (GRP) 78, spliced X-box-binding protein (XBP)-1, CCAAT/enhancer-binding protein homologous protein (CHOP), caspase-12, and c-Jun N-terminal kinase (JNK) in the hippocampus of rats were evaluated by real-time PCR and Western blot analysis, respectively. RESULTS Administration of CSP alleviated anxiety and depression-like behavior in CUMS rats, as revealed by enhanced time and distance in the center of the OFT (P<0.05), an increased preference for sucrose, and longer swimming time and shorter immobility time during the FST (all P<0.05). In addition, CSP treatment significantly reduced the rate of apoptosis in rat hippocampal neurons (P<0.05). The mRNA and protein expression levels of GRP78, spliced XBP-1, and CHOP were down-regulated along with the expression of caspase-12 and cleaved caspase-12 proteins (all P<0.05), whereas total and phosphorylated JNK1 protein levels did not differ significantly between control and CSP-treated rats. CONCLUSION CSP can improve depression-like behavior in rats exposed to CUMS, possibly by suppressing CHOP and caspase-12 mediated apoptosis in the rat hippocampus.
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Affiliation(s)
- Ke-Huan Sun
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518020, China
| | - Yu Jin
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518020, China
| | - Zhi-Gang Mei
- Third- Grade Pharmacological Laboratory on Chinese Medicine Approved by State Administration of Traditional Chinese Medicine, Medical College of China Three Gorges University, Yichang, Hubei Province, 443002, China
| | - Zhi-Tao Feng
- Third- Grade Pharmacological Laboratory on Chinese Medicine Approved by State Administration of Traditional Chinese Medicine, Medical College of China Three Gorges University, Yichang, Hubei Province, 443002, China
| | - Jie-Ren Liu
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518020, China
| | - Mei-Qun Cao
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518020, China
| | - Zheng-Zhi Wu
- Shenzhen Second People's Hospital, The First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong Province, 518020, China.
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20
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Wang S, Wang T, Liu T, Xie RG, Zhao XH, Wang L, Yang Q, Jia LT, Han J. Ermin is a p116 RIP -interacting protein promoting oligodendroglial differentiation and myelin maintenance. Glia 2020; 68:2264-2276. [PMID: 32530539 DOI: 10.1002/glia.23838] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 04/17/2020] [Accepted: 04/21/2020] [Indexed: 12/21/2022]
Abstract
Myelin sheaths, which insulate the axons and ensure saltatory conduction of the nerve impulse, are generated and maintained via largely uncharacterized mechanisms. Ermin is an oligodendrocyte-specific protein associated with the cytoskeleton, but how it regulates cytoskeletal remodeling during oligodendrocyte differentiation and its role in myelin maintenance are not clear. To address this, we generated mice constitutively deficient for Ermn, the Ermin-coding gene. We found that aged Ermn-knockout mice exhibit an aberrant myelin architecture, with splitting of myelin layers, peeling of the myelin sheath from axons, and breakdown of myelinated fibers. As a result, these mice had remarkably impaired motor coordination. Ermn knockout also accelerated cuprizone-induced demyelination and exacerbated the associated movement disorders. Ermin was found to contribute to oligodendrocyte morphogenesis by associating with the myosin phosphatase Rho interacting protein (Mprip/p116RIP ) and inactivating RhoA, a GTPase that controls cytoskeletal rearrangement in differentiating cells. These findings provide novel insights into the mechanisms regulating oligodendroglial differentiation, the maintenance of the myelin sheaths, and remyelination.
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Affiliation(s)
- Shan Wang
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China
| | - Tao Wang
- Department of Neurology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Tao Liu
- Key Laboratory of Modern Teaching Technology, Shaanxi Normal University, Xi'an, China
| | - Rou-Gang Xie
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, China
| | - Xiang-Hui Zhao
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, China
| | - Lei Wang
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China
| | - Qian Yang
- Department of Neurology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Lin-Tao Jia
- Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, China
| | - Jing Han
- Key Laboratory of Modern Teaching Technology, Shaanxi Normal University, Xi'an, China
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21
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Tripathi S, Verma A, Jha SK. Training on an Appetitive Trace-Conditioning Task Increases Adult Hippocampal Neurogenesis and the Expression of Arc, Erk and CREB Proteins in the Dorsal Hippocampus. Front Cell Neurosci 2020; 14:89. [PMID: 32362814 PMCID: PMC7181388 DOI: 10.3389/fncel.2020.00089] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 03/26/2020] [Indexed: 12/11/2022] Open
Abstract
Adult hippocampal neurogenesis (AHN) plays an essential role in hippocampal-dependent memory consolidation. Increased neurogenesis enhances learning, whereas its ablation causes memory impairment. In contrast, few reports suggest that neurogenesis reduces after learning. Although the interest in exploring the role of adult neurogenesis in learning has been growing, the evidence is still limited. The role of the trace- and delay-appetitive-conditioning on AHN and its underlying mechanism are not known. The consolidation of trace-conditioned memory requires the hippocampus, but delay-conditioning does not. Moreover, the dorsal hippocampus (DH) and ventral hippocampus (VH) may have a differential role in these two conditioning paradigms. Here, we have investigated the changes in: (A) hippocampal cell proliferation and their progression towards neuronal lineage; and (B) expression of Arc, Erk1, Erk2, and CREB proteins in the DH and VH after trace- and delay-conditioning in the rat. The number of newly generated cells significantly increased in the trace-conditioned but did not change in the delay-conditioned animals compared to the control group. Similarly, the expression of Arc protein significantly increased in the DH but not in the VH after trace-conditioning. Nonetheless, it remains unaltered in the delay-conditioned group. The expression of pErk1, pErk2, and pCREB also increased in the DH after trace-conditioning. Whereas, the expression of only pErk1 pErk2 and pCREB proteins increased in the VH after delay-conditioning. Our results suggest that appetitive trace-conditioning enhances AHN. The increased DH neuronal activation and pErk1, pErk2, and pCREB in the DH may be playing an essential role in learning-induced cell-proliferation after appetitive trace-conditioning.
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Affiliation(s)
- Shweta Tripathi
- School of Life Science, Jawaharlal Nehru University, New Delhi, India
| | - Anita Verma
- School of Life Science, Jawaharlal Nehru University, New Delhi, India
| | - Sushil K Jha
- School of Life Science, Jawaharlal Nehru University, New Delhi, India
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22
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Eid RS, Lieblich SE, Duarte-Guterman P, Chaiton JA, Mah AG, Wong SJ, Wen Y, Galea LAM. Selective activation of estrogen receptors α and β: Implications for depressive-like phenotypes in female mice exposed to chronic unpredictable stress. Horm Behav 2020; 119:104651. [PMID: 31790664 DOI: 10.1016/j.yhbeh.2019.104651] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 11/06/2019] [Accepted: 11/26/2019] [Indexed: 01/19/2023]
Abstract
The estrogen receptor (ER) mechanisms by which 17β-estradiol influences depressive-like behaviour have primarily been investigated acutely and not within an animal model of depression. Therefore, the current study aimed to dissect the contribution of ERα and ERβ to the effects of 17β-estradiol under non-stress and chronic stress conditions. Ovariectomized (OVX) or sham-operated mice were treated chronically (47 days) with 17β-estradiol (E2), the ERβ agonist diarylpropionitrile (DPN), the ERα agonist propylpyrazole-triol (PPT), or vehicle. On day 15 of treatment, mice from each group were assigned to chronic unpredictable stress (CUS; 28 days) or non-CUS conditions. Mice were assessed for anxiety- and depressive-like behaviour and hypothalamic-pituitary-adrenal (HPA) axis function. Cytokine and chemokine levels, and postsynaptic density protein 95 were measured in the hippocampus and frontal cortex, and adult hippocampal neurogenesis was assessed. Overall, the effects of CUS were more robust that those of estrogenic treatments, as seen by increased immobility in the tail suspension test (TST), reduced PSD-95 expression, reduced neurogenesis in the ventral hippocampus, and HPA axis negative feedback dysregulation. However, we also observe CUS-dependent and -independent effects of ovarian status and estrogenic treatments. The effects of CUS on PSD-95 expression, the cytokine milieu, and in TST were largely driven by PPT and DPN, indicating that these treatments were not protective. Independent of CUS, estradiol increased neurogenesis in the dorsal hippocampus, blunted the corticosterone response to an acute stressor, and increased anxiety-like behaviour. These findings provide insights into the complexities of estrogen signaling in modulating depressive-like phenotypes under non-stress and chronic stress conditions.
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Affiliation(s)
- Rand S Eid
- Graduate program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Stephanie E Lieblich
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Paula Duarte-Guterman
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jessica A Chaiton
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Amanda G Mah
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Sarah J Wong
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Yanhua Wen
- Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Liisa A M Galea
- Graduate program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Department of Psychology, University of British Columbia, Vancouver, BC, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
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23
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Takehara‐Nishiuchi K. Neurobiology of systems memory consolidation. Eur J Neurosci 2020; 54:6850-6863. [DOI: 10.1111/ejn.14694] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 01/17/2020] [Accepted: 01/30/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Kaori Takehara‐Nishiuchi
- Department of Psychology University of Toronto Toronto ON Canada
- Department of Cell and Systems Biology University of Toronto Toronto ON Canada
- Neuroscience Program University of Toronto Toronto ON Canada
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24
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Daun KA, Fuchigami T, Koyama N, Maruta N, Ikenaka K, Hitoshi S. Early Maternal and Social Deprivation Expands Neural Stem Cell Population Size and Reduces Hippocampus/Amygdala-Dependent Fear Memory. Front Neurosci 2020; 14:22. [PMID: 32063832 PMCID: PMC7000530 DOI: 10.3389/fnins.2020.00022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 01/10/2020] [Indexed: 11/13/2022] Open
Abstract
Early life stress can exert detrimental or beneficial effects on neural development and postnatal behavior depending on the timing, duration, strength, and ability to control the stressors. In this study, we utilized a maternal and social deprivation (MSD) model to investigate the effects of early life stress on neural stem cells (NSCs) and neurogenesis in the adult brain. We found that MSD during the stress-hyporesponsive period (SHRP) (early-MSD), when corticosterone secretion is suppressed, increased the size of the NSC population, whereas the same stress beyond the SHRP abrogated these effects. Early-MSD enhanced neurogenesis not only in the dentate gyrus of the hippocampus, one of the classic neurogenic regions, but also in the amygdala. In addition, mice exposed to early-MSD exhibited a reduction in amygdala/hippocampus-dependent fear memory. These results suggest that animals exposed to early life stress during the SHRP have reinforced stress resilience to cope with perceived stressors to maintain a normal homeostatic state.
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Affiliation(s)
- Kenny Anak Daun
- Department of Integrative Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Takahiro Fuchigami
- Department of Integrative Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Natsu Koyama
- Department of Integrative Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Noriko Maruta
- Department of Psychiatry, Health Center, Hitotsubashi University, Tokyo, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Sciences, The Graduate University for Advanced Studies, Okazaki, Japan
| | - Seiji Hitoshi
- Department of Integrative Physiology, Shiga University of Medical Science, Otsu, Japan.,Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Physiological Sciences, School of Life Sciences, The Graduate University for Advanced Studies, Okazaki, Japan
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25
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Horie T, Park G, Inaba Y, Hashiuchi E, Iezaki T, Tokumura K, Fukasawa K, Yamada T, Hiraiwa M, Kitaguchi Y, Kamada H, Kaneda K, Tanaka T, Inoue H, Hinoi E. MAPK Erk5 in Leptin Receptor‒Expressing Neurons Controls Body Weight and Systemic Energy Homeostasis in Female Mice. Endocrinology 2019; 160:2837-2848. [PMID: 31555819 DOI: 10.1210/en.2019-00090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 09/11/2019] [Indexed: 01/06/2023]
Abstract
Extracellular signal-regulated kinase 5 (Erk5), a member of the MAPK family, is specifically phosphorylated and activated by MAPK/Erk kinase-5. Although it has been implicated in odor discrimination and long-term memory via its expression in the central nervous system, little is known regarding the physiological importance of neuronal Erk5 in body weight and energy homeostasis. In the current study, systemic insulin injection significantly induced phosphorylation of Erk5 in the hypothalamus. Moreover, Erk5 deficiency in leptin receptor (LepR)‒expressing neurons led to an obesity phenotype, with increased white adipose tissue mass due to increased adipocyte size, only in female mice fed a normal chow diet. Furthermore, Erk5 deficiency in LepR-expressing neurons showed impaired glucose tolerance along with decreased physical activity, food intake, and energy expenditure. These results suggest that Erk5 controls body weight and systemic energy homeostasis probably via its expression in hypothalamic neurons in female mice, thereby providing a target for metabolic diseases such as obesity and type 2 diabetes mellitus.
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Affiliation(s)
- Tetsuhiro Horie
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
| | - Gyujin Park
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
| | - Yuka Inaba
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Emi Hashiuchi
- Department of Physiology and Metabolism, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Takashi Iezaki
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Venture Business Laboratory, Organization of Frontier Science and Innovation, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Kazuya Tokumura
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
| | - Kazuya Fukasawa
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
| | - Takanori Yamada
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
| | - Manami Hiraiwa
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
| | - Yuka Kitaguchi
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
| | - Hikari Kamada
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
| | - Katsuyuki Kaneda
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
| | - Tomohiro Tanaka
- Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiroshi Inoue
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
- Department of Physiology and Metabolism, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Eiichi Hinoi
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School, Kanazawa, Ishikawa, Japan
- Laboratory of Pharmacology, Department of Bioactive Molecules, Gifu Pharmaceutical University, Gifu, Japan
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26
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Gulinello M, Mitchell HA, Chang Q, Timothy O'Brien W, Zhou Z, Abel T, Wang L, Corbin JG, Veeraragavan S, Samaco RC, Andrews NA, Fagiolini M, Cole TB, Burbacher TM, Crawley JN. Rigor and reproducibility in rodent behavioral research. Neurobiol Learn Mem 2019; 165:106780. [PMID: 29307548 PMCID: PMC6034984 DOI: 10.1016/j.nlm.2018.01.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 12/22/2017] [Accepted: 01/03/2018] [Indexed: 01/08/2023]
Abstract
Behavioral neuroscience research incorporates the identical high level of meticulous methodologies and exacting attention to detail as all other scientific disciplines. To achieve maximal rigor and reproducibility of findings, well-trained investigators employ a variety of established best practices. Here we explicate some of the requirements for rigorous experimental design and accurate data analysis in conducting mouse and rat behavioral tests. Novel object recognition is used as an example of a cognitive assay which has been conducted successfully with a range of methods, all based on common principles of appropriate procedures, controls, and statistics. Directors of Rodent Core facilities within Intellectual and Developmental Disabilities Research Centers contribute key aspects of their own novel object recognition protocols, offering insights into essential similarities and less-critical differences. Literature cited in this review article will lead the interested reader to source papers that provide step-by-step protocols which illustrate optimized methods for many standard rodent behavioral assays. Adhering to best practices in behavioral neuroscience will enhance the value of animal models for the multiple goals of understanding biological mechanisms, evaluating consequences of genetic mutations, and discovering efficacious therapeutics.
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Affiliation(s)
- Maria Gulinello
- IDDRC Behavioral Core Facility, Neuroscience Department, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Heather A Mitchell
- IDD Models Core, Waisman Center, University of Wisconsin Madison, Madison, WI 53705, USA
| | - Qiang Chang
- IDD Models Core, Waisman Center, University of Wisconsin Madison, Madison, WI 53705, USA
| | - W Timothy O'Brien
- IDDRC Preclinical Models Core, Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Zhaolan Zhou
- IDDRC Preclinical Models Core, Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ted Abel
- IDDRC Preclinical Models Core, Children's Hospital of Philadelphia and University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Current affiliation: Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA
| | - Li Wang
- IDDRC Neurobehavioral Core, Center for Neuroscience Research, Children's National Health System, Washington, DC 20010, USA
| | - Joshua G Corbin
- IDDRC Neurobehavioral Core, Center for Neuroscience Research, Children's National Health System, Washington, DC 20010, USA
| | - Surabi Veeraragavan
- IDDRC Neurobehavioral Core, Baylor College of Medicine, Houston, TX 77030, USA
| | - Rodney C Samaco
- IDDRC Neurobehavioral Core, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nick A Andrews
- IDDRC Neurodevelopmental Behavior Core, Boston Children's Hospital, Boston, MA 02115, USA
| | - Michela Fagiolini
- IDDRC Neurodevelopmental Behavior Core, Boston Children's Hospital, Boston, MA 02115, USA
| | - Toby B Cole
- IDDRC Rodent Behavior Laboratory, Center on Human Development and Disability, University of Washington, Seattle, WA 98195, USA
| | - Thomas M Burbacher
- IDDRC Rodent Behavior Laboratory, Center on Human Development and Disability, University of Washington, Seattle, WA 98195, USA
| | - Jacqueline N Crawley
- IDDRC Rodent Behavior Core, MIND Institute, University of California Davis School of Medicine, Sacramento, CA 95817, USA.
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27
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Chen J, Huang Z, Wu X, Kang J, Ren Y, Gao W, Lu X, Wang J, Ding W, Nakabeppu Y, Fan Y, Wang Y. Oxidative stress induces different tissue dependent effects on Mutyh-deficient mice. Free Radic Biol Med 2019; 143:482-493. [PMID: 31505270 DOI: 10.1016/j.freeradbiomed.2019.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/06/2019] [Accepted: 09/06/2019] [Indexed: 11/17/2022]
Abstract
8-oxoguanine (8-oxoG) is one of the most prevalent genotoxic lesions, and it is generated in DNA attacked by reactive oxygen species (ROS). Adenine misincorporated opposite to 8-oxoG during replication is excised by MutY homolog (MUTYH), an important protein of the base excision repair (BER) system. Mutyh plays an important role in the maintenance of genomic integrity, but the functional consequences of Mutyh deficiency are not fully understood. In the current study, we investigated the histological and functional changes of five tissues (hippocampus, heart, liver, kidney and lung) and their molecular basis in Mutyh-/- and wild-type mice exposed to D-galactose (D-gal). Our data indicated that Mutyh deficiency hindered the weight gain of experimental mice and induced substantial alterations of 8-oxoG content and superoxide dismutase (SOD) activity, but no significant histological and functional impairment appeared in the investigated tissues of Mutyh- deficient mice without D-gal exposure. Under low-dose D-gal exposure, Mutyh deficiency altered expression of genes involved in mitochondrial unfolded protein response (UPRmt) in the heart, liver and lung, and caused an enhanced expression of mitochondrial dynamics proteins (MDPs) in hippocampus and liver. The stress responses could maintain mitochondrial proteostasis and function. However, such responses were not noted when experiencing excessive damage burden induced by high-dose D-gal exposure, in which Mutyh deficiency increased accumulation of 8-oxoG and aggravated mitonuclear protein imbalance, as well as histological lesions in heart, liver and kidney. A higher sensitivity to ROS-induced cardiotoxicity with high-dose D-gal exposure was noticed in Mutyh-/- mice. However, no differences in learning and memory impairments were observed between Mutyh-/- and wild-type mice with high-dose D-gal exposure. In conclusion, our data demonstrated that Mutyh deficiency has different impacts on various tissues based on the degree of oxidative stress.
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Affiliation(s)
- Jingwen Chen
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China
| | - Zhenqian Huang
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China
| | - Xin Wu
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China
| | - Jiaqi Kang
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China
| | - Yan Ren
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China
| | - Wei Gao
- Department of Geriatrics, Sir Run Run Hospital of Nanjing Medical University, Nanjing, 211166, China
| | - Xiang Lu
- Department of Geriatrics, Sir Run Run Hospital of Nanjing Medical University, Nanjing, 211166, China
| | - Jingmei Wang
- Department of Pathology, Affiliated Drum Tower Hospital of Nanjing University School of Medicine, Nanjing, 210008, China
| | - Weidong Ding
- Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China; Department of Pathology, Nanjing University School of Medicine, Nanjing, 210093, China
| | - Yusaku Nakabeppu
- Division of Neurofunctional Genomics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Yimei Fan
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China.
| | - Yaping Wang
- Department of Medical Genetics, Nanjing University School of Medicine, Nanjing, 210093, China; Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, 210093, China.
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28
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Miller SM, Sahay A. Functions of adult-born neurons in hippocampal memory interference and indexing. Nat Neurosci 2019; 22:1565-1575. [PMID: 31477897 PMCID: PMC7397477 DOI: 10.1038/s41593-019-0484-2] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/30/2019] [Indexed: 12/22/2022]
Abstract
The dentate gyrus-CA3 circuit of the hippocampus is continuously modified by the integration of adult-born dentate granule cells (abDGCs). All abDGCs undergo a prolonged period of maturation, during which they exhibit heightened synaptic plasticity and refinement of electrophysiological properties and connectivity. Consistent with theoretical models and the known functions of the dentate gyrus-CA3 circuit, acute or chronic manipulations of abDGCs support a role for abDGCs in the regulation of memory interference. In this Review, we integrate insights from studies that examine the maturation of abDGCs and their integration into the circuit with network mechanisms that support memory discrimination, consolidation and clearance. We propose that adult hippocampal neurogenesis enables the generation of a library of experiences, each registered in mature abDGC physiology and connectivity. Mature abDGCs recruit inhibitory microcircuits to support pattern separation and memory indexing.
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Affiliation(s)
- Samara M Miller
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA.
- Harvard Stem Cell Institute, Cambridge, Massachusetts, USA.
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.
- BROAD Institute of Harvard and MIT, Cambridge, Massachusetts, USA.
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29
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Wang H, Abel GM, Storm DR, Xia Z. Cadmium Exposure Impairs Adult Hippocampal Neurogenesis. Toxicol Sci 2019; 171:501-514. [PMID: 31271426 DOI: 10.1093/toxsci/kfz152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/07/2019] [Accepted: 06/29/2019] [Indexed: 01/30/2023] Open
Abstract
Cadmium (Cd) is an environmental pollutant of considerable interest throughout the world and potentially a neurotoxicant. Our recent data indicate that Cd exposure induces impairment of hippocampus-dependent learning and memory in mice. However, the underlying mechanisms for this defect are not known. The goal of this study was to determine if Cd inhibits adult neurogenesis and to identify underlying signaling pathways responsible for this impairment. Adult hippocampal neurogenesis is a process in which adult neural progenitor/stem cells (aNPCs) in the subgranular zone (SGZ) of the dentate gyrus (DG) generate functional new neurons in the hippocampus which contributes to hippocampus-dependent learning and memory. However, studies concerning the effects of neurotoxicants on adult hippocampal neurogenesis and the underlying signaling mechanisms are limited. Here, we report that Cd significantly induces apoptosis, inhibits proliferation, and impairs neuronal differentiation in primary cultured aNPCs derived from the SGZ. In addition, the c-jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein (MAP) kinase signaling pathways are activated by Cd and contribute to its toxicity. Furthermore, we exposed 8-week-old male C57BL/6 mice to Cd through drinking water for 13 weeks to assess the effects of Cd on adult hippocampal neurogenesis in vivo. Cd treatment reduced the number of 5-week old adult-born cells in the DG and impaired the differentiation of adult-born hippocampal neurons. These results suggest that Cd exposure impairs adult hippocampal neurogenesis both in vitro and in vivo. This may contribute to Cd-mediated inhibition of hippocampus-dependent learning and memory.
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Affiliation(s)
- Hao Wang
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Glen M Abel
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Daniel R Storm
- Department of Pharmacology, University of Washington, Seattle, WA, USA
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences
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30
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Fujisaki Y, Matsuo R. Context-Dependent Passive Avoidance Learning in the Terrestrial Slug Limax. Zoolog Sci 2019; 34:532-537. [PMID: 29219042 DOI: 10.2108/zs170071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The terrestrial slug Limax has been used as a model animal for studying the neural mechanisms underlying associative olfactory learning. The slug also innately exhibits negative phototactic behavior using its eyes. In the present study, we developed an experimental paradigm for quantification of slug's negative phototaxis behavior, and investigated whether the nature of the negative phototaxis can be modified by learning experience. The experimental set-up consists of light and dark compartments, between which the slug can move freely. During conditioning, the slug was placed in the light compartment, and an aversive stimulus (quinidine sulfate solution) was applied when it reached the dark compartment. After a single conditioning session, the time to reach the dark compartment significantly increased when it was tested following 24 hr or one week. Protein synthesis inhibition immediately following the conditioning impaired the memory retention at one week but not at 24 hr. The retrieval of the memory was context-dependent, as the time to reach the dark compartment did not significantly increase if the slug was placed on a floor with a different texture in the memory retention test. If the aversive stimulus was applied when the slug was in the light compartment, the time to reach the dark compartment did not increase after 24 hr. This is the first report demonstrating the capability of the slug to form context-dependent passive avoidance memory that can be established in a single conditioning session.
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Affiliation(s)
- Yuko Fujisaki
- International College of Arts and Sciences, Fukuoka Women's University, 1-1-1 Kasumigaoka, Higashi-ku, Fukuoka 813-8529, Japan
| | - Ryota Matsuo
- International College of Arts and Sciences, Fukuoka Women's University, 1-1-1 Kasumigaoka, Higashi-ku, Fukuoka 813-8529, Japan
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31
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Ryu T, Park HJ, Kim H, Cho YC, Kim BC, Jo J, Seo YW, Choi WS, Kim K. Improved memory and reduced anxiety in δ-catenin transgenic mice. Exp Neurol 2019; 318:22-31. [PMID: 30981806 DOI: 10.1016/j.expneurol.2019.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 03/13/2019] [Accepted: 04/10/2019] [Indexed: 10/27/2022]
Abstract
δ-Catenin is abundant in the brain and affects its synaptic plasticity. Furthermore, loss of δ-catenin is related to the deficits of learning and memory, mental retardation (cri-du-chat syndrome), and autism. A few studies about δ-catenin deficiency mice were performed. However, the effect of δ-catenin overexpression in the brain has not been investigated as yet. Therefore we generated a δ-catenin overexpressing mouse model. To generate a transgenic mouse model overexpressing δ-catenin in the brain, δ-catenin plasmid having a Thy-1 promotor was microinjected in C57BL/6 mice. Our results showed δ-catenin transgenic mice expressed higher levels of N-cadherin, β-catenin, and p120-catenin than did wild type mice. Furthermore, δ-catenin transgenic mice exhibited better object recognition, better sociability, and lower anxiety than wild type mice. However, both mice groups showed a similar pattern in locomotion tests. Although δ-catenin transgenic mice show similar locomotion, they show improved sociability and reduced anxiety. These characteristics are opposite to the symptoms of autism or mental retardation, which are caused when δ-catenin is deficient. These results suggest that δ-catenin may alleviate symptoms of autism, Alzheimer's disease and mental retardation.
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Affiliation(s)
- Taeyong Ryu
- College of Pharmacy and Research Institute for Drug Development, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Hyung Joon Park
- School of Biological Sciences and Technology, College of Natural Sciences, College of Medicine, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Hangun Kim
- College of Pharmacy and Research Institute of Life and Pharmaceutical Sciences, Sunchon National University, Sunchon 57922, Republic of Korea
| | - Young-Chang Cho
- College of Pharmacy and Research Institute for Drug Development, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Byeong C Kim
- Department of Neurology, Chonnam National University Medical School, Gwnagju 61469, Republic of Korea
| | - Jihoon Jo
- Department of Neurology, Chonnam National University Medical School, Gwnagju 61469, Republic of Korea
| | - Young-Woo Seo
- Korea Basic Science Institute, Gwangju Center, Gwangju 61186, Republic of Korea
| | - Won-Seok Choi
- School of Biological Sciences and Technology, College of Natural Sciences, College of Medicine, Chonnam National University, Gwangju 61186, Republic of Korea.
| | - Kwonseop Kim
- College of Pharmacy and Research Institute for Drug Development, Chonnam National University, Gwangju 61186, Republic of Korea.
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32
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Martínez-Canabal A, López-Oropeza G, Gaona-Gamboa A, Ballesteros-Zebadua P, de la Cruz OG, Moreno-Jimenez S, Sotres-Bayon F. Hippocampal neurogenesis regulates recovery of defensive responses by recruiting threat- and extinction-signalling brain networks. Sci Rep 2019; 9:2939. [PMID: 30814555 PMCID: PMC6393575 DOI: 10.1038/s41598-019-39136-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 01/18/2019] [Indexed: 12/26/2022] Open
Abstract
Safe exposure to a context that was previously associated with threat leads to extinction of defensive responses. Such contextual fear extinction involves the formation of a new memory that inhibits a previously acquired contextual fear memory. However, fear-related responses often return with the simple passage of time (spontaneous fear recovery). Given that contextual fear and extinction memories are hippocampus-dependent and hippocampal neurogenesis has been reported to modify preexisting memories, we hypothesized that neurogenesis-mediated modification of preexisting extinction memory would modify spontaneous fear recovery. To test this, rats underwent contextual fear conditioning followed by extinction. Subsequently, we exposed rats to an enriched environment or focal X-irradiation to enhance or ablate hippocampal neurogenesis, respectively. Over a month later, rats were tested to evaluate spontaneous fear recovery. We found that enhancing neurogenesis after, but not before, extinction prevented fear recovery. In contrast, neurogenesis ablation after, but not before, extinction promoted fear recovery. Using the neuronal activity marker c-Fos, we identified brain regions recruited in these opposing neurogenesis-mediated changes during fear recovery. Together, our findings indicate that neurogenesis manipulation after extinction learning modifies fear recovery by recruiting brain network activity that mediates the expression of preexisting contextual fear and extinction memories.
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Affiliation(s)
- Alonso Martínez-Canabal
- Instituto de Fisiología Celular - Neurociencias, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Grecia López-Oropeza
- Instituto de Fisiología Celular - Neurociencias, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | - Abril Gaona-Gamboa
- Instituto de Fisiología Celular - Neurociencias, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico
| | | | | | - Sergio Moreno-Jimenez
- Instituto Nacional de Neurología y Neurocirugía - Radioneurocirugía, Ciudad de México, Mexico
| | - Francisco Sotres-Bayon
- Instituto de Fisiología Celular - Neurociencias, Universidad Nacional Autónoma de México, 04510, Ciudad de México, Mexico.
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33
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Wang H, Zhang L, Abel GM, Storm DR, Xia Z. Cadmium Exposure Impairs Cognition and Olfactory Memory in Male C57BL/6 Mice. Toxicol Sci 2019; 161:87-102. [PMID: 29029324 DOI: 10.1093/toxsci/kfx202] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cadmium (Cd) is a heavy metal of high interest to the superfund initiative. Recent epidemiology studies have suggested a possible association between Cd exposure and cognitive as well as olfactory impairments in humans. However, studies in animal models are needed to establish a direct causal relationship between Cd exposure and impairments in cognition and olfaction. This study aims to investigate the toxic effect of Cd on cognition and olfactory function in mice. One group of 8-week-old C57BL/6 male mice was exposed to 3 mg/l Cd (in the form of CdCl2) through drinking water for 20 weeks for behavior tests and final blood Cd concentration analysis. The behavior tests were conducted before, during, and after Cd exposure to analyze the effects of Cd on cognition and olfactory function. Upon completion of behavior tests, blood was collected to measure final blood Cd concentration. Two additional groups of mice were similarly exposed to Cd for 5 or 13 weeks for peak blood Cd concentration measurement. The peak blood Cd concentration was 2.125-2.25 μg/l whereas the final blood Cd concentration was 0.18 μg/l. At this exposure level, Cd impaired hippocampus-dependent learning and memory in novel object location test, T-maze test, and contextual fear memory test. It also caused deficits in short-term olfactory memory and odor-cued olfactory learning and memory. Results in this study demonstrate a direct relationship between Cd exposure and cognitive as well as olfactory impairments in an animal model.
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Affiliation(s)
- Hao Wang
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Liang Zhang
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Glen M Abel
- Toxicology Program, Department of Environmental and Occupational Health Sciences
| | - Daniel R Storm
- Department of Pharmacology, University of Washington, Seattle, Washington 98195
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences
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34
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Chen C, Wu S, Hong Z, Chen X, Shan X, Fischbach S, Xiao X. Chronic hyperglycemia regulates microglia polarization through ERK5. Aging (Albany NY) 2019; 11:697-706. [PMID: 30684443 PMCID: PMC6366978 DOI: 10.18632/aging.101770] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 01/07/2019] [Indexed: 05/01/2023]
Abstract
Diabetic patients are prone to developing Alzheimer's disease (AD), in which microglia play a critical role. However, the direct effect of high glucose (HG) on microglia and the role of extracellular-signal-regulated kinase 5 (ERK5) signaling in this interaction have not been examined before. Here, these questions were addressed in microglia cultured in HG versus normal glucose (NG) conditions. Initially, HG induced microglial differentiation into the M2a phenotype with concomitant ERK5 activation. However, longer exposure to HG further induced differentiation of microglia into the M2b-like phenotype, followed by the M1-like subtype, concomitant with a gradual loss of ERK5 activation. BIX021895, a specific inhibitor of ERK5 activation, prevented M2a- differentiation of microglia, but induced earlier M2b-like polarization followed by M1-like polarization. Transfection of microglia with a sustained activated form of MEK5 (MEK5DD) prolonged the duration of the M2a phenotype, and prevented later differentiation into the M2b/M1 subtype. Conditioned media from the M2a-polarized microglia reduced neuronal cell apoptosis in hypoxic condition, while media from M2b-like or M1-like microglia enhanced apoptosis. Together, our data suggest that chronic hyperglycemia may induce a gradual alteration of microglia polarization into an increasingly proinflammatory subtype, which could be suppressed by sustained activation of ERK5 signaling.
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Affiliation(s)
- Congde Chen
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou
Medical University, Wenzhou 325000, China
| | - Suichun Wu
- Reproductive Medicine Centre, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Zipu Hong
- Department of Pediatric Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Xiaoming Chen
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou
Medical University, Wenzhou 325000, China
- Department of Pediatric Endocrinology and Metabolism, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University , Wenzhou 325000, China
| | - Xiaoou Shan
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou
Medical University, Wenzhou 325000, China
- Department of Pediatric Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, China
| | - Shane Fischbach
- Department of Surgery, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
| | - Xiangwei Xiao
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou
Medical University, Wenzhou 325000, China
- Department of Surgery, Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, PA 15224, USA
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35
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Otto SL, Yakel JL. The α7 nicotinic acetylcholine receptors regulate hippocampal adult-neurogenesis in a sexually dimorphic fashion. Brain Struct Funct 2018; 224:829-846. [PMID: 30515567 DOI: 10.1007/s00429-018-1799-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/16/2018] [Indexed: 12/17/2022]
Abstract
Disruption in cholinergic signaling has been linked to many environmental and/or pathological conditions known to modify adult neurogenesis. The α7 nAChRs are in the family of cys-loop receptor channels which have been shown to be neuroprotective in adult neurons and are thought to be critical for survival and integration of immature neurons. However, in developing neurons, poor calcium buffering may cause α7 nAChR activation to be neurotoxic. To investigate whether the α7 nAChR regulates neurogenesis in the hippocampus, we used a combination of mouse genetics and imaging to quantify neural stem cell (NSC) densities located in the dentate gyrus of adult mice. In addition, we considered whether the loss of α7 nAChRs had functional consequences on a spatial discrimination task that is thought to rely on pattern separation mechanisms. We found that the loss of α7 nAChRs resulted in increased neurogenesis in male mice only, while female mice showed increased cell divisions and intermediate progenitors but no change in neurogenesis. Knocking out the α7 nAChR from nestin+ NSCs and their progeny showed signaling in these cells contributes to regulating neurogenesis. In addition, male, but not female, mice lacking α7 nAChRs performed significantly worse in the spatial discrimination task. This task was sexually dimorphic in wild-type mice, but not in the absence of α7 nAChRs. We conclude that α7 nAChRs regulate adult neurogenesis and impact spatial discrimination function in male, but not female mice, via a mechanism involving nestin+ NSCs and their progeny.
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Affiliation(s)
- Simone L Otto
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, P.O. box 12233, Mail Drop F2-08, Research Triangle Park, NC, 27709, USA
| | - Jerrel L Yakel
- Neurobiology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, P.O. box 12233, Mail Drop F2-08, Research Triangle Park, NC, 27709, USA.
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Kashino Y, Obara Y, Okamoto Y, Saneyoshi T, Hayashi Y, Ishii K. ERK5 Phosphorylates K v4.2 and Inhibits Inactivation of the A-Type Current in PC12 Cells. Int J Mol Sci 2018; 19:ijms19072008. [PMID: 29996472 PMCID: PMC6073465 DOI: 10.3390/ijms19072008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 06/28/2018] [Accepted: 06/28/2018] [Indexed: 12/31/2022] Open
Abstract
Extracellular signal-regulated kinase 5 (ERK5) regulates diverse physiological responses such as proliferation, differentiation, and gene expression. Previously, we demonstrated that ERK5 is essential for neurite outgrowth and catecholamine biosynthesis in PC12 cells and sympathetic neurons. However, it remains unclear how ERK5 regulates the activity of ion channels, which are important for membrane excitability. Thus, we examined the effect of ERK5 on the ion channel activity in the PC12 cells that overexpress both ERK5 and the constitutively active MEK5 mutant. The gene and protein expression levels of voltage-dependent Ca2+ and K+ channels were determined by RT-qPCR or Western blotting. The A-type K+ current was recorded using the whole-cell patch clamp method. In these ERK5-activated cells, the gene expression levels of voltage-dependent L- and P/Q-type Ca2+ channels did not alter, but the N-type Ca2+ channel was slightly reduced. In contrast, those of Kv4.2 and Kv4.3, which are components of the A-type current, were significantly enhanced. Unexpectedly, the protein levels of Kv4.2 were not elevated by ERK5 activation, but the phosphorylation levels were increased by ERK5 activation. By electrophysiological analysis, the inactivation time constant of the A-type current was prolonged by ERK5 activation, without changes in the peak current. Taken together, ERK5 inhibits an inactivation of the A-type current by phosphorylation of Kv4.2, which may contribute to the neuronal differentiation process.
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Affiliation(s)
- Yurina Kashino
- Department of Pharmacology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | - Yutaro Obara
- Department of Pharmacology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | - Yosuke Okamoto
- Department of Pharmacology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
| | - Takeo Saneyoshi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
| | - Yasunori Hayashi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
| | - Kuniaki Ishii
- Department of Pharmacology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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Increased Microglial Activity, Impaired Adult Hippocampal Neurogenesis, and Depressive-like Behavior in Microglial VPS35-Depleted Mice. J Neurosci 2018; 38:5949-5968. [PMID: 29853629 DOI: 10.1523/jneurosci.3621-17.2018] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 05/15/2018] [Accepted: 05/21/2018] [Indexed: 12/21/2022] Open
Abstract
Vacuolar sorting protein 35 (VPS35) is a critical component of retromer, which is essential for selective endosome-to-Golgi retrieval of membrane proteins. VPS35 deficiency is implicated in neurodegenerative disease pathology, including Alzheimer's disease (AD). However, exactly how VPS35 loss promotes AD pathogenesis remains largely unclear. VPS35 is expressed in various types of cells in the brain, including neurons and microglia. Whereas neuronal VPS35 plays a critical role in preventing neurodegeneration, the role of microglial VPS35 is largely unknown. Here we provide evidence for microglial VPS35's function in preventing microglial activation and promoting adult hippocampal neurogenesis. VPS35 is expressed in microglia in various regions of the mouse brain, with a unique distribution pattern in a brain region-dependent manner. Conditional knocking out of VPS35 in microglia of male mice results in regionally increased microglial density and activity in the subgranular zone of the hippocampal dentate gyrus (DG), accompanied by elevated neural progenitor proliferation, but decreased neuronal differentiation. Additionally, newborn neurons in the mutant DG show impaired dendritic morphology and reduced dendritic spine density. When examining the behavioral phenotypes of these animals, microglial VPS3S-depleted mice display depression-like behavior and impairment in long-term recognition memory. At the cellular level, VPS35-depleted microglia have grossly enlarged vacuolar structures with increased phagocytic activity toward postsynaptic marker PSD95, which may underlie the loss of dendritic spines observed in the mutant DG. Together, these findings identify an important role of microglial VPS35 in suppressing microglial activation and promoting hippocampal neurogenesis, which are both processes involved in AD pathogenesis.SIGNIFICANCE STATEMENT The findings presented here provide the first in vivo evidence that Vacuolar sorting protein 35 (VPS35)/retromer is essential for regulating microglial function and that when microglial retromer mechanics are disrupted, the surrounding brain tissue can be affected in a neurodegenerative manner. These findings present a novel, microglial-specific role of VPS35 and raise multiple questions regarding the mechanisms underlying our observations. These findings also have myriad implications for the field of retromer research and the role of retromer dysfunction in neurodegenerative pathophysiology. Furthermore, they implicate a pivotal role of microglia in the regulation of adult hippocampal neurogenesis and the survival/integration of newborn neurons in the adult hippocampus.
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Beyond good and evil: A putative continuum-sorting hypothesis for the functional role of proBDNF/BDNF-propeptide/mBDNF in antidepressant treatment. Neurosci Biobehav Rev 2018; 90:70-83. [PMID: 29626490 DOI: 10.1016/j.neubiorev.2018.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/13/2018] [Accepted: 04/03/2018] [Indexed: 02/07/2023]
Abstract
Depression and posttraumatic stress disorder are assumed to be maladaptive responses to stress and antidepressants are thought to counteract such responses by increasing BDNF (brain-derived neurotrophic factor) levels. BDNF acts through TrkB (tropomyosin-related receptor kinase B) and plays a central role in neuroplasticity. In contrast, both precursor proBDNF and BDNF propeptide (another metabolic product from proBDNF cleavage) have a high affinity to p75 receptor (p75R) and usually convey apoptosis and neuronal shrinkage. Although BDNF and proBDNF/propeptide apparently act in opposite ways, neuronal turnover and remodeling might be a final common way that both act to promote more effective neuronal networking, avoiding neuronal redundancy and the misleading effects of environmental contingencies. This review aims to provide a brief overview about the BDNF functional role in antidepressant action and about p75R and TrkB signaling to introduce the "continuum-sorting hypothesis." The resulting hypothesis suggests that both BDNF/proBDNF and BDNF/propeptide act as protagonists to fine-tune antidepressant-dependent neuroplasticity in crucial brain structures to modulate behavioral responses to stress.
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Medina JH. Neural, Cellular and Molecular Mechanisms of Active Forgetting. Front Syst Neurosci 2018; 12:3. [PMID: 29467630 PMCID: PMC5808127 DOI: 10.3389/fnsys.2018.00003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/18/2018] [Indexed: 11/16/2022] Open
Abstract
The neurobiology of memory formation attracts much attention in the last five decades. Conversely, the rules that govern and the mechanisms underlying forgetting are less understood. In addition to retroactive interference, retrieval-induced forgetting and passive decay of time, it has been recently demonstrated that the nervous system has a diversity of active and inherent processes involved in forgetting. In Drosophila, some operate mainly at an early stage of memory formation and involves dopamine (DA) neurons, specific postsynaptic DA receptor subtypes, Rac1 activation and induces rapid active forgetting. In mammals, others regulate forgetting and persistence of seemingly consolidated memories and implicate the activity of DA receptor subtypes and AMPA receptors in the hippocampus (HP) and related structures to activate parallel signaling pathways controlling active time-dependent forgetting. Most of them may involve plastic changes in synaptic and extrasynaptic receptors including specific removal of GluA2 AMPA receptors. Forgetting at longer timescales might also include changes in adult neurogenesis in the dentate gyrus (DG) of the HP. Therefore, based on relevance or value considerations neuronal circuits may regulate in a time-dependent manner what is formed, stored, and maintained and what is forgotten.
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Affiliation(s)
- Jorge H Medina
- Laboratorio de Memoria, IBCN Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (UBA-CONICET), Buenos Aires, Argentina.,Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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40
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Castilla-Ortega E, Ladrón de Guevara-Miranda D, Serrano A, Pavón FJ, Suárez J, Rodríguez de Fonseca F, Santín LJ. The impact of cocaine on adult hippocampal neurogenesis: Potential neurobiological mechanisms and contributions to maladaptive cognition in cocaine addiction disorder. Biochem Pharmacol 2017; 141:100-117. [DOI: 10.1016/j.bcp.2017.05.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/03/2017] [Indexed: 12/14/2022]
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Engstrom AK, Xia Z. Lead exposure in late adolescence through adulthood impairs short-term spatial memory and the neuronal differentiation of adult-born cells in C57BL/6 male mice. Neurosci Lett 2017; 661:108-113. [PMID: 28970130 DOI: 10.1016/j.neulet.2017.09.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/06/2017] [Accepted: 09/28/2017] [Indexed: 11/27/2022]
Abstract
Lead is a neurotoxicant of immense public health importance. Epidemiology studies suggest that heavy metal exposure may be associated with an increased risk of cognitive decline, yet few studies to date have assessed the effect of adult lead exposure on cognitive behavior in animal models. Here, we exposed 6-week-old male C57BL/6 mice to 0.2% lead acetate via drinking water for 12 weeks starting at 6 weeks of age and then assessed for deficits in hippocampus-dependent spatial memory and impairment of adult hippocampal neurogenesis. Lead did not cause locomotor deficits or anxiety in the open field test. However, we found that adult, subchronic lead exposure was sufficient to cause deficits in spatial short-term memory and these deficits persisted through at least 2 months post-lead exposure. Furthermore, we observed that lead-treated mice had fewer adult-born, mature neurons in the dentate gyrus of the hippocampus compared to control animals, suggesting that lead exposure during adolescence and adulthood may impair the neuronal differentiation of adult-born cells. These data suggest that adult lead exposure is sufficient to cause persistent deficits in spatial short-term memory and impair key processes in adult hippocampal neurogenesis.
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Affiliation(s)
- Anna K Engstrom
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, 98195, USA.
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42
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Kim SH, Park YR, Lee B, Choi B, Kim H, Kim CH. Reduction of Cav1.3 channels in dorsal hippocampus impairs the development of dentate gyrus newborn neurons and hippocampal-dependent memory tasks. PLoS One 2017; 12:e0181138. [PMID: 28715454 PMCID: PMC5513490 DOI: 10.1371/journal.pone.0181138] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 06/27/2017] [Indexed: 12/12/2022] Open
Abstract
Cav1.3 has been suggested to mediate hippocampal neurogenesis of adult mice and contribute to hippocampal-dependent learning and memory processes. However, the mechanism of Cav1.3 contribution in these processes is unclear. Here, roles of Cav1.3 of mouse dorsal hippocampus during newborn cell development were examined. We find that knock-out (KO) of Cav1.3 resulted in the reduction of survival of newborn neurons at 28 days old after mitosis. The retroviral eGFP expression showed that both dendritic complexity and the number and length of mossy fiber bouton (MFB) filopodia of newborn neurons at ≥ 14 days old were significantly reduced in KO mice. Both contextual fear conditioning (CFC) and object-location recognition tasks were impaired in recent (1 day) memory test while passive avoidance task was impaired only in remote (≥ 20 days) memory in KO mice. Results using adeno-associated virus (AAV)-mediated Cav1.3 knock-down (KD) or retrovirus-mediated KD in dorsal hippocampal DG area showed that the recent memory of CFC was impaired in both KD mice but the remote memory was impaired only in AAV KD mice, suggesting that Cav1.3 of mature neurons play important roles in both recent and remote CFC memory while Cav1.3 in newborn neurons is selectively involved in the recent CFC memory process. Meanwhile, AAV KD of Cav1.3 in ventral hippocampal area has no effect on the recent CFC memory. In conclusion, the results suggest that Cav1.3 in newborn neurons of dorsal hippocampus is involved in the survival of newborn neurons while mediating developments of dendritic and axonal processes of newborn cells and plays a role in the memory process differentially depending on the stage of maturation and the type of learning task.
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Affiliation(s)
- Su-Hyun Kim
- Center for Neuroscience, Korea Institute of Science and Technology, Seoul, Korea
- Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
| | - Ye-Ryoung Park
- Center for Neuroscience, Korea Institute of Science and Technology, Seoul, Korea
- Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
| | - Boyoung Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, Korea
| | - Byungil Choi
- Department of Anatomy and Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Hyun Kim
- Department of Anatomy and Division of Brain Korea 21 Biomedical Science, College of Medicine, Korea University, Seoul, Korea
| | - Chong-Hyun Kim
- Center for Neuroscience, Korea Institute of Science and Technology, Seoul, Korea
- Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
- * E-mail:
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43
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Heisz JJ, Clark IB, Bonin K, Paolucci EM, Michalski B, Becker S, Fahnestock M. The Effects of Physical Exercise and Cognitive Training on Memory and Neurotrophic Factors. J Cogn Neurosci 2017; 29:1895-1907. [PMID: 28699808 DOI: 10.1162/jocn_a_01164] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
This study examined the combined effect of physical exercise and cognitive training on memory and neurotrophic factors in healthy, young adults. Ninety-five participants completed 6 weeks of exercise training, combined exercise and cognitive training, or no training (control). Both the exercise and combined training groups improved performance on a high-interference memory task, whereas the control group did not. In contrast, neither training group improved on general recognition performance, suggesting that exercise training selectively increases high-interference memory that may be linked to hippocampal function. Individuals who experienced greater fitness improvements from the exercise training (i.e., high responders to exercise) also had greater increases in the serum neurotrophic factors brain-derived neurotrophic factor and insulin-like growth factor-1. These high responders to exercise also had better high-interference memory performance as a result of the combined exercise and cognitive training compared with exercise alone, suggesting that potential synergistic effects might depend on the availability of neurotrophic factors. These findings are especially important, as memory benefits accrued from a relatively short intervention in high-functioning young adults.
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Bernier BE, Lacagnina AF, Ayoub A, Shue F, Zemelman BV, Krasne FB, Drew MR. Dentate Gyrus Contributes to Retrieval as well as Encoding: Evidence from Context Fear Conditioning, Recall, and Extinction. J Neurosci 2017; 37:6359-6371. [PMID: 28546308 PMCID: PMC5490069 DOI: 10.1523/jneurosci.3029-16.2017] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 04/10/2017] [Accepted: 05/20/2017] [Indexed: 11/21/2022] Open
Abstract
Dentate gyrus (DG) is widely thought to provide a teaching signal that enables hippocampal encoding of memories, but its role during retrieval is poorly understood. Some data and models suggest that DG plays no role in retrieval; others encourage the opposite conclusion. To resolve this controversy, we evaluated the effects of optogenetic inhibition of dorsal DG during context fear conditioning, recall, generalization, and extinction in male mice. We found that (1) inhibition during training impaired context fear acquisition; (2) inhibition during recall did not impair fear expression in the training context, unless mice had to distinguish between similar feared and neutral contexts; (3) inhibition increased generalization of fear to an unfamiliar context that was similar to a feared one and impaired fear expression in the conditioned context when it was similar to a neutral one; and (4) inhibition impaired fear extinction. These effects, as well as several seemingly contradictory published findings, could be reproduced by BACON (Bayesian Context Fear Algorithm), a physiologically realistic hippocampal model positing that acquisition and retrieval both involve coordinated activity in DG and CA3. Our findings thus suggest that DG contributes to retrieval and extinction, as well as to the initial establishment of context fear.SIGNIFICANCE STATEMENT Despite abundant evidence that the hippocampal dentate gyrus (DG) plays a critical role in memory, it remains unclear whether the role of DG relates to memory acquisition or retrieval. Using contextual fear conditioning and optogenetic inhibition, we show that DG contributes to both of these processes. Using computational simulations, we identify specific mechanisms through which the suppression of DG affects memory performance. Finally, we show that DG contributes to fear extinction learning, a process in which learned fear is attenuated through exposures to a fearful context in the absence of threat. Our data resolve a long-standing question about the role of DG in memory and provide insight into how disorders affecting DG, including aging, stress, and depression, influence cognitive processes.
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Affiliation(s)
- Brian E Bernier
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712, and
| | - Anthony F Lacagnina
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712, and
| | - Adam Ayoub
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712, and
| | - Francis Shue
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712, and
| | - Boris V Zemelman
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712, and
| | - Franklin B Krasne
- Department of Psychology, University of California at Los Angeles, Los Angeles, California 90095
| | - Michael R Drew
- Center for Learning and Memory, Department of Neuroscience, University of Texas at Austin, Austin, Texas 78712, and
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França TFA, Bitencourt AM, Maximilla NR, Barros DM, Monserrat JM. Hippocampal neurogenesis and pattern separation: A meta-analysis of behavioral data. Hippocampus 2017; 27:937-950. [PMID: 28597491 DOI: 10.1002/hipo.22746] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/09/2017] [Accepted: 05/26/2017] [Indexed: 12/16/2022]
Abstract
The generation of new neurons in the hippocampus of adult mammals has become a widely accepted phenomenon, but the functional significance of the adult neurogenesis in the hippocampus is not fully understood. One of the main hypotheses currently investigated suggests that neurogenesis contributes to pattern separation in the dentate gyrus. Many behavioral studies were conducted aiming to test this hypothesis using rodents as animal model. In those studies, researches ablated neurogenesis in the animals and subsequently evaluate them in tests of behavioral pattern separation, that is, behaviors that are thought to rely on the computational process of pattern separation. The results of these studies are varied, with most supporting a role for neurogenesis in pattern separation, but some others not. To address this controversy we performed a systematic review and meta-analysis of studies evaluating the effect of neurogenesis ablation on behavioral pattern separation. Analysis results indicated that most of the literature in the topic is surprisingly consistent and, although there are two studies with divergent results, the bulk of the literature supports an effect of hippocampal neurogenesis on behavioral pattern separation. We discuss those findings in light of other behavioral effects of hippocampal neurogenesis ablation, limitations of behavioral data and other lines of evidence about the effect of hippocampal neurogenesis in the dentate gyrus.
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Affiliation(s)
- Thiago F A França
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil
| | - Alexandre M Bitencourt
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil
| | - Naiana R Maximilla
- Curso de graduação em Ciências Biológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil
| | - Daniela M Barros
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil.,Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil
| | - José M Monserrat
- Programa de Pós-graduação em Ciências Fisiológicas, Universidade Federal do Rio Grande-FURG, Rio Grande, RS, Brazil.,Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil
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46
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Yin P, Xu H, Wang Q, Wang J, Yin L, Xu M, Xie Z, Liu W, Cao X. Overexpression of βCaMKII impairs behavioral flexibility and NMDAR-dependent long-term depression in the dentate gyrus. Neuropharmacology 2017; 116:270-287. [DOI: 10.1016/j.neuropharm.2016.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 11/17/2016] [Accepted: 12/15/2016] [Indexed: 12/13/2022]
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47
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Choi WS, Kim HW, Tronche F, Palmiter RD, Storm DR, Xia Z. Conditional deletion of Ndufs4 in dopaminergic neurons promotes Parkinson's disease-like non-motor symptoms without loss of dopamine neurons. Sci Rep 2017; 7:44989. [PMID: 28327638 PMCID: PMC5361188 DOI: 10.1038/srep44989] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 02/17/2017] [Indexed: 12/21/2022] Open
Abstract
Reduction of mitochondrial complex I activity is one of the major hypotheses for dopaminergic neuron death in Parkinson’s disease. However, reduction of complex I activity in all cells or selectively in dopaminergic neurons via conditional deletion of the Ndufs4 gene, a subunit of the mitochondrial complex I, does not cause dopaminergic neuron death or motor impairment. Here, we investigated the effect of reduced complex I activity on non-motor symptoms associated with Parkinson’s disease using conditional knockout (cKO) mice in which Ndufs4 was selectively deleted in dopaminergic neurons (Ndufs4 cKO). This conditional deletion of Ndufs4, which reduces complex I activity in dopamine neurons, did not cause a significant loss of dopaminergic neurons in substantia nigra pars compacta (SNpc), and there was no loss of dopaminergic neurites in striatum or amygdala. However, Ndufs4 cKO mice had a reduced amount of dopamine in the brain compared to control mice. Furthermore, even though motor behavior were not affected, Ndufs4 cKO mice showed non-motor symptoms experienced by many Parkinson’s disease patients including impaired cognitive function and increased anxiety-like behavior. These data suggest that mitochondrial complex I dysfunction in dopaminergic neurons promotes non-motor symptoms of Parkinson’s disease and reduces dopamine content in the absence of dopamine neuron loss.
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Affiliation(s)
- Won-Seok Choi
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.,School of Biological Sciences and Technology, College of Natural Sciences, College of Medicine, Chonnam National University, Gwangju 61186, Korea
| | - Hyung-Wook Kim
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.,College of Life Sciences, Sejong University, Seoul 05006, Korea
| | - François Tronche
- Sorbonne Universités, Université Pierre et Marie Curie, UMR_CR18, Neuroscience, Paris-Seine, F-75005, Paris
| | - Richard D Palmiter
- Howard Hughes Medical Institute and Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Daniel R Storm
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Zhengui Xia
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA
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48
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Engstrom AK, Snyder JM, Maeda N, Xia Z. Gene-environment interaction between lead and Apolipoprotein E4 causes cognitive behavior deficits in mice. Mol Neurodegener 2017; 12:14. [PMID: 28173832 PMCID: PMC5297175 DOI: 10.1186/s13024-017-0155-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 01/18/2017] [Indexed: 01/10/2023] Open
Abstract
Background Alzheimer’s disease (AD) is characterized by progressive cognitive decline and memory loss. Environmental factors and gene-environment interactions (GXE) may increase AD risk, accelerate cognitive decline, and impair learning and memory. However, there is currently little direct evidence supporting this hypothesis. Methods In this study, we assessed for a GXE between lead and ApoE4 on cognitive behavior using transgenic knock-in (KI) mice that express the human Apolipoprotein E4 allele (ApoE4-KI) or Apolipoprotein E3 allele (ApoE3-KI). We exposed 8-week-old male and female ApoE3-KI and ApoE4-KI mice to 0.2% lead acetate via drinking water for 12 weeks and assessed for cognitive behavior deficits during and after the lead exposure. In addition, we exposed a second (cellular) cohort of animals to lead and assessed for changes in adult hippocampal neurogenesis as a potential underlying mechanism for lead-induced learning and memory deficits. Results In the behavior cohort, we found that lead reduced contextual fear memory in all animals; however, this decrease was greatest and statistically significant only in lead-treated ApoE4-KI females. Similarly, only lead-treated ApoE4-KI females exhibited a significant decrease in spontaneous alternation in the T-maze. Furthermore, all lead-treated animals developed persistent spatial working memory deficits in the novel object location test, and this deficit manifested earlier in ApoE4-KI mice, with female ApoE4-KI mice exhibiting the earliest deficit onset. In the cellular cohort, we observed that the maturation, differentiation, and dendritic development of adult-born neurons in the hippocampus was selectively impaired in lead-treated female ApoE4-KI mice. Conclusions These data suggest that GXE between ApoE4 and lead exposure may contribute to cognitive impairment and that impaired adult hippocampal neurogenesis may contribute to these deficits in cognitive behavior. Together, these data suggest a role for GXE and sex differences in AD risk.
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Affiliation(s)
- Anna K Engstrom
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Box 357234, Seattle, WA, 98195, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, School of Medicine, University of Washington, Seattle, WA, 98195, USA
| | - Nobuyo Maeda
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Zhengui Xia
- Toxicology Program, Department of Environmental and Occupational Health Sciences, University of Washington, Box 357234, Seattle, WA, 98195, USA.
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49
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Becker S. Neurogenesis and pattern separation: time for a divorce. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2016; 8. [PMID: 28026915 DOI: 10.1002/wcs.1427] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 09/09/2016] [Accepted: 09/30/2016] [Indexed: 01/08/2023]
Abstract
The generation of new neurons in the adult mammalian brain has led to numerous theories as to their functional significance. One of the most widely held views is that adult neurogenesis promotes pattern separation, a process by which overlapping patterns of neural activation are mapped to less overlapping representations. While a large body of evidence supports a role for neurogenesis in high interference memory tasks, it does not support the proposed function of neurogenesis in mediating pattern separation. Instead, the adult-generated neurons seem to generate highly overlapping and yet distinct distributed representations for similar events. One way in which these immature, highly plastic, hyperactive neurons may contribute to novel memory formation while avoiding interference is by virtue of their extremely sparse connectivity with incoming perforant path fibers. Another intriguing proposal, awaiting empirical confirmation, is that the young neurons' recruitment into memory formation is gated by a novelty/mismatch mechanism mediated by CA3 or hilar back-projections. Ongoing research into the intriguing link between neurogenesis, stress-related mood disorders, and age-related neurodegeneration may lead to promising neurogenesis-based treatments for this wide range of clinical disorders. WIREs Cogn Sci 2017, 8:e1427. doi: 10.1002/wcs.1427 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Suzanna Becker
- Department of Psychology Neuroscience and Behaviour, McMaster University, Hamilton, Canada
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50
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Yan X, Zhang B, Lu W, Peng L, Yang Q, Cao W, Lin S, Yu W, Li X, Ke Y, Li S, Yang W, Luo J. Increased Src Family Kinase Activity Disrupts Excitatory Synaptic Transmission and Impairs Remote Fear Memory in Forebrain Shp2-Deficient Mice. Mol Neurobiol 2016; 54:7235-7250. [PMID: 27796759 DOI: 10.1007/s12035-016-0222-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/13/2016] [Indexed: 11/29/2022]
Abstract
Src homolog domain-containing phosphatase 2 (Shp2) signals a variety of cellular and physiological functions including learning and memory. Dysregulation of ERK signaling is known to be responsible for the cognitive deficits associated with gain-of-function mutated Shp2 mimicking Noonan syndrome. However, here, we report that CaMKIIα-cre induced knockout (CaSKO) of Shp2 in hippocampal pyramidal neurons resulted in increased Src activity, upregulated phosphorylation of N-methyl-D-aspartate receptors (NMDARs) at Y1325 of GluN2A and at Y1472 of GluN2B, disrupted the balance of synaptic transmission, and impaired long-term potentiation and remote contextual fear memory. Administration of PP2, a specific Src family kinase inhibitor, reversed the tyrosine phosphorylation of NMDARs, restored basal synaptic transmission, and rescued the contextual fear memory deficit in CaSKO mice without altering the phospho-ERK level. Taken together, our results reveal a novel role of Shp2 in NMDAR-dependent synaptic function and fear memory via the Src signaling pathway rather than the ERK pathway, and suggest a complicated mechanism for Shp2-associated cognitive deficits.
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Affiliation(s)
- Xunyi Yan
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Bin Zhang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Wen Lu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Lin Peng
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Qian Yang
- BIO-X Institute, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Wei Cao
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Shen Lin
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Wenyue Yu
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Xiaoming Li
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Yuehai Ke
- Department of Pathology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Shengtian Li
- BIO-X Institute, Shanghai Jiaotong University, Shanghai, 200240, China
| | - Wei Yang
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Jianhong Luo
- Department of Neurobiology, Key Laboratory of Medical Neurobiology (Ministry of Health of China), Collaborative Innovation Center for Brain Science, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
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