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Kumar M, Mehan S, Kumar A, Sharma T, Khan Z, Tiwari A, Das Gupta G, Narula AS. Therapeutic efficacy of Genistein in activation of neuronal AC/cAMP/CREB/PKA and mitochondrial ETC-Complex pathways in experimental model of autism: Evidence from CSF, blood plasma and brain analysis. Brain Res 2024:149251. [PMID: 39384128 DOI: 10.1016/j.brainres.2024.149251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 09/10/2024] [Accepted: 09/22/2024] [Indexed: 10/11/2024]
Abstract
Autism is a complex neurodevelopmental condition characterized by repetitive behaviors, impaired social communication, and various associated conditions such as depression and anxiety. Its multifactorial etiology includes genetic, environmental, dietary, and gastrointestinal contributions. Pathologically, Autism is linked to mitochondrial dysfunction, oxidative stress, neuroinflammation, and neurotransmitter imbalances involving GABA, glutamate, dopamine, and oxytocin. Propionic acid (PRPA) is a short-chain fatty acid produced by gut bacteria, influencing central nervous system functions. Elevated PRPA levels can exacerbate Autism-related symptoms by disrupting metabolic processes and crossing the blood-brain barrier. Our research investigates the neuroprotective potential of Genistein (GNT), an isoflavone compound with known benefits in neuropsychiatric and neurodegenerative disorders, through modulation of the AC/cAMP/CREB/PKA signaling pathway and mitochondrial ETC complex (I-IV) function. In silico analyses revealed GNT's high affinity for these targets. Subsequent in vitro and in vivo experiments using a PRPA-induced rat model of autism demonstrated that GNT (40 and 80 mg/kg., orally) significantly improves locomotion, neuromuscular coordination, and cognitive functions in PRPA-treated rodents. Behavioral assessments showed reduced immobility in the forced swim test, enhanced Morris water maze performance, and restored regular locomotor activity. On a molecular level, GNT restored levels of key signaling molecules (AC, cAMP, CREB, PKA) and mitochondrial complexes (I-V), disrupted by PRPA exposure. Additionally, GNT reduced neuroinflammation and apoptosis, normalized neurotransmitter levels, and improved the complete blood count profile. Histopathological analyses confirmed that GNT ameliorated PRPA-induced brain injuries, restored normal brain morphology, reduced demyelination, and promoted neurogenesis. The study supports GNT's potential in autism treatment by modulating neural pathways, reducing inflammation, and restoring neurotransmitter balance.
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Affiliation(s)
- Manjeet Kumar
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India; Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India
| | - Sidharth Mehan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India; Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India.
| | - Aakash Kumar
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India; Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India
| | - Tarun Sharma
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India; Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India
| | - Zuber Khan
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India; Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India
| | - Aarti Tiwari
- Division of Neuroscience, Department of Pharmacology, ISF College of Pharmacy, Moga, Punjab, India; Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India
| | - Ghanshyam Das Gupta
- Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab 144603, India; Department of Pharmaceutics, ISF College of Pharmacy, Moga, Punjab, India
| | - Acharan S Narula
- Narula Research, LLC, 107 Boulder Bluff, Chapel Hill, NC 27516, USA
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2
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Ferreira IL, Marinho D, de Rosa V, Castanheira B, Fang Z, Caldeira GL, Mota SI, Rego AC. Linking activation of synaptic NMDA receptors-induced CREB signaling to brief exposure of cortical neurons to oligomeric amyloid-beta peptide. J Neurochem 2024. [PMID: 39263896 DOI: 10.1111/jnc.16222] [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: 02/19/2024] [Revised: 08/13/2024] [Accepted: 08/15/2024] [Indexed: 09/13/2024]
Abstract
Amyloid-beta peptide oligomers (AβO) have been considered "primum movens" for a cascade of events that ultimately cause selective neuronal death in Alzheimer's disease (AD). However, initial events triggered by AβO have not been clearly defined. Synaptic (Syn) N-methyl-d-aspartate receptors (NMDAR) are known to activate cAMP response element-binding protein (CREB), a transcriptional factor involved in gene expression related to cell survival, memory formation and synaptic plasticity, whereas activation of extrasynaptic (ESyn) NMDARs was linked to excitotoxic events. In AD brain, CREB phosphorylation/activation was shown to be altered, along with dyshomeostasis of intracellular Ca2+ (Ca2+ i). Thus, in this work, we analyze acute/early and long-term AβO-mediated changes in CREB activation involving Syn or ESyn NMDARs in mature rat cortical neurons. Our findings show that acute AβO exposure produce early increase in phosphorylated CREB, reflecting CREB activity, in a process occurring through Syn NMDAR-mediated Ca2+ influx. Data also demonstrate that AβO long-term (24 h) exposure compromises synaptic function related to Ca2+-dependent CREB phosphorylation/activation and nuclear CREB levels and related target genes, namely Bdnf, Gadd45γ, and Btg2. Data suggest a dual effect of AβO following early or prolonged exposure in mature cortical neurons through the activation of the CREB signaling pathway, linked to the activation of Syn NMDARs.
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Affiliation(s)
- I Luísa Ferreira
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - Daniela Marinho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - Valéria de Rosa
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Bárbara Castanheira
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Zongwei Fang
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
| | - Gladys L Caldeira
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - Sandra I Mota
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - A Cristina Rego
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
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Lissek T. Aging as a Consequence of the Adaptation-Maladaptation Dilemma. Adv Biol (Weinh) 2024; 8:e2300654. [PMID: 38299389 DOI: 10.1002/adbi.202300654] [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: 11/30/2023] [Revised: 01/11/2024] [Indexed: 02/02/2024]
Abstract
In aging, the organism is unable to counteract certain harmful influences over its lifetime which leads to progressive dysfunction and eventually death, thus delineating aging as one failed process of adaptation to a set of aging stimuli. A central problem in understanding aging is hence to explain why the organism cannot adapt to these aging stimuli. The adaptation-maladaptation theory of aging proposes that in aging adaptation processes such as adaptive transcription, epigenetic remodeling, and metabolic plasticity drive dysfunction themselves over time (maladaptation) and thereby cause aging-related disorders such as cancer and metabolic dysregulation. The central dilemma of aging is thus that the set of adaptation mechanisms that the body uses to deal with internal and external stressors acts as a stressor itself and cannot be effectively counteracted. The only available option for the organism to decrease maladaptation may be a program to progressively reduce the output of adaptive cascades (e.g., via genomic methylation) which then leads to reduced physiological adaptation capacity and syndromes like frailty, immunosenescence, and cognitive decline. The adaptation-maladaptation dilemma of aging entails that certain biological mechanisms can simultaneously protect against aging as well as drive aging. The key to longevity may lie in uncoupling adaptation from maladaptation.
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Affiliation(s)
- Thomas Lissek
- Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
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4
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Sun L, Li Y, Wang D, Hong X. SESN2 attenuates sevoflurane-induced cognitive impairment and neuroinflammation in rats. Exp Brain Res 2024; 242:375-384. [PMID: 38129329 DOI: 10.1007/s00221-023-06757-9] [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: 08/02/2023] [Accepted: 11/26/2023] [Indexed: 12/23/2023]
Abstract
Long-term use of sevoflurane, an inhalation anesthetic, could negatively impact cognitive function. Current studies have suggested that cognitive impairment induced by sevoflurane may be associated with neuroinflammation. Sestrin2 (SESN2), which belongs to a family of stress-inducible genes, has been reported to exert neuroprotective effects against brain injury. However, its role and underlying mechanisms in sevoflurane-induced cognitive dysfunction in aged rats remain unknown. A sevoflurane-induced aging rat injury model with or without SESN2 overexpression was constructed. The learning and memory abilities of rats were evaluated by the MWM test. ELISA assay and qRT-PCR were conducted to analyze the level of pro-inflammatory factors in the hippocampus. Levels of oxidative stress markers were measured by DHE staining or kit methods. Neuronal apoptosis in the hippocampus was detected using TUNEL assay. Expression of proteins were analyzed by western blot. Sevoflurane exposure caused elevated protein level of SESN2 in hippocampus and cognitive impairment of aged rats. Importantly, overexpression of SESN2 alleviated sevoflurane-induced cognitive dysfunction and inhibited the production of pro-inflammatory factors, oxidative stress, and neuronal apoptosis in the hippocampus. Furthermore, SESN2 overexpression suppressed NLRP3 inflammasome activation induced by sevoflurane. These findings suggested that SESN2 could exert neuroprotective against sevoflurane-induced nerve injury of aged rats through anti-oxidant and anti-inflammatory effects.
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Affiliation(s)
- Li Sun
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 1, Huanghe West Road, Huaiyin District, Huai'an, 223000, Jiangsu, China
| | - Yangyang Li
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 1, Huanghe West Road, Huaiyin District, Huai'an, 223000, Jiangsu, China
| | - Daliang Wang
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 1, Huanghe West Road, Huaiyin District, Huai'an, 223000, Jiangsu, China
| | - Xiaoya Hong
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 1, Huanghe West Road, Huaiyin District, Huai'an, 223000, Jiangsu, China.
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5
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Stevenson ME, Bieri G, Kaletsky R, St Ange J, Remesal L, Pratt KJB, Zhou S, Weng Y, Murphy CT, Villeda SA. Neuronal activation of G αq EGL-30/GNAQ late in life rejuvenates cognition across species. Cell Rep 2023; 42:113151. [PMID: 37713310 PMCID: PMC10627507 DOI: 10.1016/j.celrep.2023.113151] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/10/2023] [Accepted: 08/31/2023] [Indexed: 09/17/2023] Open
Abstract
Loss of cognitive function with age is devastating. EGL-30/GNAQ and Gαq signaling pathways are highly conserved between C. elegans and mammals, and murine Gnaq is enriched in hippocampal neurons and declines with age. We found that activation of EGL-30 in aged worms triples memory span, and GNAQ gain of function significantly improved memory in aged mice: GNAQ(gf) in hippocampal neurons of 24-month-old mice (equivalent to 70- to 80-year-old humans) rescued age-related impairments in well-being and memory. Single-nucleus RNA sequencing revealed increased expression of genes regulating synaptic function, axon guidance, and memory in GNAQ-treated mice, and worm orthologs of these genes were required for long-term memory extension in worms. These experiments demonstrate that C. elegans is a powerful model to identify mammalian regulators of memory, leading to the identification of a pathway that improves memory in extremely old mice. To our knowledge, this is the oldest age at which an intervention has improved age-related cognitive decline.
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Affiliation(s)
- Morgan E Stevenson
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Gregor Bieri
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Bakar Aging Research Institute, San Francisco, CA 94143, USA
| | - Rachel Kaletsky
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jonathan St Ange
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - L Remesal
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Bakar Aging Research Institute, San Francisco, CA 94143, USA
| | - Karishma J B Pratt
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Bakar Aging Research Institute, San Francisco, CA 94143, USA
| | - Shiyi Zhou
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Yifei Weng
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Coleen T Murphy
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Saul A Villeda
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Bakar Aging Research Institute, San Francisco, CA 94143, USA.
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Lissek T. Aging, adaptation and maladaptation. FRONTIERS IN AGING 2023; 4:1256844. [PMID: 37701757 PMCID: PMC10493302 DOI: 10.3389/fragi.2023.1256844] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 08/14/2023] [Indexed: 09/14/2023]
Abstract
Aging is accompanied by a dysregulation of adaptive processes. On the one hand, physiological adaptation mechanisms such as learning and memory, immune system plasticity and exercise-dependent muscle remodeling are blunted. On the other hand, several maladaptive processes increase with age including cancer, pathological cardiovascular remodeling and metabolic dysregulation. With increasing age the quotient of beneficial adaptation (Ab) to harmful adaptation (Ah), Ab/Ah, decreases. The adaptation-maladaptation framework of aging entails that there are age-related pathological phenotypes that are the result of activation of physiological adaptation mechanisms (e.g., maladaptation as a result of misdirection of adaptive cascades and molecular damage incurred by adaptation processes) and their occurrence over time might, to some degree, be inevitable. Aging might hence result from the organism's inability to solve the adaptation-maladaptation dilemma. The present work explores the concept of counteracting aging through adaptation and proposes that interventions such as exercise, environmental enrichment and dietary restriction work in counteracting aging because they increase the ratio Ab/Ah by both raising Ab (e.g., by inducing metaplasticity in cells, meaning they raise the adaptability of cells to future stimuli) and decreasing Ah (e.g., through desensitizing certain potentially harmful adaptive mechanisms). Molecules whose aging-related expression changes can explain aspects of dysfunctional adaptation such as CREB and certain immediate early genes are examined and it is delineated how a better understanding of the dynamical organization of adaptation cascades could elucidate the seemingly complex role of adaptation in driving aging as well as protecting against it.
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Affiliation(s)
- Thomas Lissek
- Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
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7
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Fang X, Alsbury-Nealy B, Wang Y, Frankland PW, Josselyn SA, Schlichting ML, Duncan KD. Time separating spatial memories does not influence their integration in humans. PLoS One 2023; 18:e0289649. [PMID: 37561677 PMCID: PMC10414573 DOI: 10.1371/journal.pone.0289649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 07/23/2023] [Indexed: 08/12/2023] Open
Abstract
Humans can navigate through similar environments-like grocery stores-by integrating across their memories to extract commonalities or by differentiating between each to find idiosyncratic locations. Here, we investigate one factor that might impact whether two related spatial memories are integrated or differentiated: Namely, the temporal delay between experiences. Rodents have been shown to integrate memories more often when they are formed within 6 hours of each other. To test if this effect influences how humans spontaneously integrate spatial memories, we had 131 participants search for rewards in two similar virtual environments. We separated these learning experiences by either 30 minutes, 3 hours, or 27 hours. Memory integration was assessed three days later. Participants were able to integrate and simultaneously differentiate related memories across experiences. However, neither memory integration nor differentiation was modulated by temporal delay, in contrast to previous work. We further showed that both the levels of initial memory reactivation during the second experience and memory generalization to novel environments were comparable across conditions. Moreover, perseveration toward the initial reward locations during the second experience was related positively to integration and negatively to differentiation-but again, these associations did not vary by delay. Our findings identify important boundary conditions on the translation of rodent memory mechanisms to humans, motivating more research to characterize how even fundamental memory mechanisms are conserved and diverge across species.
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Affiliation(s)
- Xiaoping Fang
- Department of Psychology, University of Toronto, Toronto, Canada
- School of Psychology, Beijing Language and Culture University, Beijing, China
| | | | - Ying Wang
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
| | - Paul W. Frankland
- Department of Psychology, University of Toronto, Toronto, Canada
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
- Child & Brain Development Program, Canadian Institute for Advanced Research (CIFAR), Toronto, Canada
| | - Sheena A. Josselyn
- Department of Psychology, University of Toronto, Toronto, Canada
- Program in Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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8
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Guskjolen A, Cembrowski MS. Engram neurons: Encoding, consolidation, retrieval, and forgetting of memory. Mol Psychiatry 2023; 28:3207-3219. [PMID: 37369721 PMCID: PMC10618102 DOI: 10.1038/s41380-023-02137-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 06/02/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
Tremendous strides have been made in our understanding of the neurobiological substrates of memory - the so-called memory "engram". Here, we integrate recent progress in the engram field to illustrate how engram neurons transform across the "lifespan" of a memory - from initial memory encoding, to consolidation and retrieval, and ultimately to forgetting. To do so, we first describe how cell-intrinsic properties shape the initial emergence of the engram at memory encoding. Second, we highlight how these encoding neurons preferentially participate in synaptic- and systems-level consolidation of memory. Third, we describe how these changes during encoding and consolidation guide neural reactivation during retrieval, and facilitate memory recall. Fourth, we describe neurobiological mechanisms of forgetting, and how these mechanisms can counteract engram properties established during memory encoding, consolidation, and retrieval. Motivated by recent experimental results across these four sections, we conclude by proposing some conceptual extensions to the traditional view of the engram, including broadening the view of cell-type participation within engrams and across memory stages. In collection, our review synthesizes general principles of the engram across memory stages, and describes future avenues to further understand the dynamic engram.
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Affiliation(s)
- Axel Guskjolen
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
| | - Mark S Cembrowski
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
- Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada.
- Department of Mathematics, University of British Columbia, Vancouver, BC, Canada.
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9
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Gros A, Wang SH. Cognitive rescue in aging through prior training in rats. Aging (Albany NY) 2023; 15:5990-6010. [PMID: 37338529 PMCID: PMC10373978 DOI: 10.18632/aging.204808] [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: 02/22/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023]
Abstract
Cognitive decline in spatial memory is seen in aging. Understanding affected processes in aging is vital for developing methods to improve wellbeing. Daily memory persistence can be influenced by events around the time of learning or by prior experiences in early life. Fading memories in young can last longer if a novel event is introduced around encoding, a process called behavioral tagging. Based on this principle, we asked what processes are affected in aging and if prior training can rescue them. Two groups of aged rats received training in an appetitive delayed matching-to-place task. One of the groups additionally received prior training of the same task in young and in mid-life, constituting a longitudinal study. The results showed long-term memory decline in late aging without prior training. This would reflect affected encoding and consolidation. On the other hand, short-term memory was preserved and novelty at memory reactivation and reconsolidation enabled memory maintenance in aging. Prior training improved cognition through facilitating task performance, strengthening short-term memory and intermediate memory, and enabling encoding-boosted long-term memory. Implication of these findings in understanding brain mechanisms in cognitive aging and in beneficial effects of prior training is discussed.
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Affiliation(s)
- Alexandra Gros
- Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, Edinburgh, Scotland, UK
| | - Szu-Han Wang
- Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, Edinburgh, Scotland, UK
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10
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Chen L, Francisco TR, Baggetta AM, Zaki Y, Ramirez S, Clem RL, Shuman T, Cai DJ. Ensemble-specific deficit in neuronal intrinsic excitability in aged mice. Neurobiol Aging 2023; 123:92-97. [PMID: 36652783 PMCID: PMC9892234 DOI: 10.1016/j.neurobiolaging.2022.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
With the prevalence of age-related cognitive deficits on the rise, it is essential to identify cellular and circuit alterations that contribute to age-related memory impairment. Increased intrinsic neuronal excitability after learning is important for memory consolidation, and changes to this process could underlie memory impairment in old age. Some studies find age-related deficits in hippocampal neuronal excitability that correlate with memory impairment but others do not, possibly due to selective changes only in activated neural ensembles. Thus, we tagged CA1 neurons activated during learning and recorded their intrinsic excitability 5 hours or 7 days post-training. Adult mice exhibited increased neuronal excitability 5 hours after learning, specifically in ensemble (learning-activated) CA1 neurons. As expected, ensemble excitability returned to baseline 7 days post-training. In aged mice, there was no ensemble-specific excitability increase after learning, which was associated with impaired hippocampal memory performance. These results suggest that CA1 may be susceptible to age-related impairments in post-learning ensemble excitability and underscore the need to selectively measure ensemble-specific changes in the brain.
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Affiliation(s)
- Lingxuan Chen
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Taylor R Francisco
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Austin M Baggetta
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Yosif Zaki
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steve Ramirez
- Psychological and Brain Sciences, Boston University, Boston, MA, USA
| | - Roger L Clem
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Tristan Shuman
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Denise J Cai
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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11
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Bac B, Hicheri C, Weiss C, Buell A, Vilcek N, Spaeni C, Geula C, Savas JN, Disterhoft JF. The TgF344-AD rat: behavioral and proteomic changes associated with aging and protein expression in a transgenic rat model of Alzheimer's disease. Neurobiol Aging 2023; 123:98-110. [PMID: 36657371 PMCID: PMC10118906 DOI: 10.1016/j.neurobiolaging.2022.12.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/20/2022] [Accepted: 12/28/2022] [Indexed: 01/01/2023]
Abstract
Animal models of Alzheimer's Disease (AD) are attractive tools for preclinical, prodromal drug testing. The TgF344-AD (Tg) rat exhibits cognitive deficits and 5 major hallmarks of AD. Here we show that spatial water maze (WMZ) memory deficits and proteomic differences in dorsal CA1 were present in young Tg rats. Aged learning-unimpaired (AU) and aged learning-impaired (AI) proteome associated changes were identified and differed by sex. Levels of phosphorylated tau, reactive astrocytes and microglia were significantly increased in aged Tg rats and correlated with the WMZ learning index (LI); in contrast, no significant correlation was present between amyloid plaques or insoluble Aβ levels and LI. Neuroinflammatory markers were also significantly correlated with LI and increased in female Tg rats. The anti-inflammatory marker, triggering receptor expressed on myeloid cells-2 (TREM2), was significantly reduced in aged impaired Tg rats and correlated with LI. Identifying and understanding mechanisms that allow for healthy aging by overcoming genetic drivers for AD, and/or promoting drivers for successful aging, are important for developing successful therapeutics against AD.
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Affiliation(s)
- Birsu Bac
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Cheima Hicheri
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Craig Weiss
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Amelia Buell
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Natalia Vilcek
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Claudia Spaeni
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Changiz Geula
- Mesulam Center for Cognitive Neurology and Alzheimer's Disease, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Jeffrey N Savas
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - John F Disterhoft
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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12
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Grochowska KM, Gomes GM, Raman R, Kaushik R, Sosulina L, Kaneko H, Oelschlegel AM, Yuanxiang P, Reyes‐Resina I, Bayraktar G, Samer S, Spilker C, Woo MS, Morawski M, Goldschmidt J, Friese MA, Rossner S, Navarro G, Remy S, Reissner C, Karpova A, Kreutz MR. Jacob-induced transcriptional inactivation of CREB promotes Aβ-induced synapse loss in Alzheimer's disease. EMBO J 2023; 42:e112453. [PMID: 36594364 PMCID: PMC9929644 DOI: 10.15252/embj.2022112453] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 12/07/2022] [Accepted: 12/09/2022] [Indexed: 01/04/2023] Open
Abstract
Synaptic dysfunction caused by soluble β-amyloid peptide (Aβ) is a hallmark of early-stage Alzheimer's disease (AD), and is tightly linked to cognitive decline. By yet unknown mechanisms, Aβ suppresses the transcriptional activity of cAMP-responsive element-binding protein (CREB), a master regulator of cell survival and plasticity-related gene expression. Here, we report that Aβ elicits nucleocytoplasmic trafficking of Jacob, a protein that connects a NMDA-receptor-derived signalosome to CREB, in AD patient brains and mouse hippocampal neurons. Aβ-regulated trafficking of Jacob induces transcriptional inactivation of CREB leading to impairment and loss of synapses in mouse models of AD. The small chemical compound Nitarsone selectively hinders the assembly of a Jacob/LIM-only 4 (LMO4)/ Protein phosphatase 1 (PP1) signalosome and thereby restores CREB transcriptional activity. Nitarsone prevents impairment of synaptic plasticity as well as cognitive decline in mouse models of AD. Collectively, the data suggest targeting Jacob protein-induced CREB shutoff as a therapeutic avenue against early synaptic dysfunction in AD.
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Affiliation(s)
- Katarzyna M Grochowska
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Leibniz Group ‘Dendritic Organelles and Synaptic Function’, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Guilherme M Gomes
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
| | - Rajeev Raman
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Rahul Kaushik
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Liudmila Sosulina
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Hiroshi Kaneko
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | | | - PingAn Yuanxiang
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | | | - Gonca Bayraktar
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Sebastian Samer
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Christina Spilker
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Marcel S Woo
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Markus Morawski
- Molecular Imaging in NeurosciencesPaul Flechsig Institute of Brain ResearchLeipzigGermany
| | - Jürgen Goldschmidt
- Department of Systems Physiology of Learning and MemoryLeibniz Institute for NeurobiologyMagdeburgGermany
| | - Manuel A Friese
- Institute of Neuroimmunology and Multiple Sclerosis, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
| | - Steffen Rossner
- Molecular Imaging in NeurosciencesPaul Flechsig Institute of Brain ResearchLeipzigGermany
| | - Gemma Navarro
- Department of Biochemistry and Physiology, Faculty of Pharmacy and Food ScienceUniversity of BarcelonaBarcelonaSpain
- Institut de Neurociències de la Universitat de BarcelonaBarcelonaSpain
| | - Stefan Remy
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
- Department of Cellular NeuroscienceLeibniz Institute for NeurobiologyMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
| | - Carsten Reissner
- Institute of Anatomy and Molecular NeurobiologyWestfälische Wilhelms‐UniversityMünsterGermany
| | - Anna Karpova
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
| | - Michael R Kreutz
- RG NeuroplasticityLeibniz Institute for NeurobiologyMagdeburgGermany
- Leibniz Group ‘Dendritic Organelles and Synaptic Function’, Center for Molecular Neurobiology (ZMNH)University Medical Center Hamburg‐EppendorfHamburgGermany
- Center for Behavioral Brain SciencesOtto von Guericke UniversityMagdeburgGermany
- German Center for Neurodegenerative Diseases (DZNE)MagdeburgGermany
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13
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Lissek T. Activity-Dependent Induction of Younger Biological Phenotypes. Adv Biol (Weinh) 2022; 6:e2200119. [PMID: 35976161 DOI: 10.1002/adbi.202200119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/11/2022] [Indexed: 01/28/2023]
Abstract
In several mammalian species, including humans, complex stimulation patterns such as cognitive and physical exercise lead to improvements in organ function, organism health and performance, as well as possibly longer lifespans. A framework is introduced here in which activity-dependent transcriptional programs, induced by these environmental stimuli, move somatic cells such as neurons and muscle cells toward a state that resembles younger cells to allow remodeling and adaptation of the organism. This cellular adaptation program targets several process classes that are heavily implicated in aging, such as mitochondrial metabolism, cell-cell communication, and epigenetic information processing, and leads to functional improvements in these areas. The activity-dependent gene program (ADGP) can be seen as a natural, endogenous cellular reprogramming mechanism that provides deep insight into the principles of inducible improvements in cell and organism function and can guide the development of therapeutic approaches for longevity. Here, these ADGPs are analyzed, exemplary critical molecular nexus points such as cAMP response element-binding protein, myocyte enhancer factor 2, serum response factor, and c-Fos are identified, and it is explored how one may leverage them to prevent, attenuate, and reverse human aging-related decline of body function.
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Affiliation(s)
- Thomas Lissek
- Interdisciplinary Center for Neurosciences, Heidelberg University, Im Neuenheimer Feld 366, 69120, Heidelberg, Germany
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14
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Hafycz JM, Strus E, Naidoo N. Reducing ER stress with chaperone therapy reverses sleep fragmentation and cognitive decline in aged mice. Aging Cell 2022; 21:e13598. [PMID: 35488730 PMCID: PMC9197403 DOI: 10.1111/acel.13598] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 01/03/2023] Open
Abstract
As the aging population grows, the need to understand age-related changes in health is vital. Two prominent behavioral changes that occur with age are disrupted sleep and impaired cognition. Sleep disruptions lead to perturbations in proteostasis and endoplasmic reticulum (ER) stress in mice. Further, consolidated sleep and protein synthesis are necessary for memory formation. With age, the molecular mechanisms that relieve cellular stress and ensure proper protein folding become less efficient. It is unclear if a causal relationship links proteostasis, sleep quality, and cognition in aging. Here, we used a mouse model of aging to determine if supplementing chaperone levels reduces ER stress and improves sleep quality and memory. We administered the chemical chaperone 4-phenyl butyrate (PBA) to aged and young mice, and monitored sleep and cognitive behavior. We found that chaperone treatment consolidates sleep and wake, and improves learning in aged mice. These data correlate with reduced ER stress in the cortex and hippocampus of aged mice. Chaperone treatment increased p-CREB, which is involved in memory formation and synaptic plasticity, in hippocampi of chaperone-treated aged mice. Hippocampal overexpression of the endogenous chaperone, binding immunoglobulin protein (BiP), improved cognition, reduced ER stress, and increased p-CREB in aged mice, suggesting that supplementing BiP levels are sufficient to restore some cognitive function. Together, these results indicate that restoring proteostasis improves sleep and cognition in a wild-type mouse model of aging. The implications of these results could have an impact on the development of therapies to improve health span across the aging population.
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Affiliation(s)
- Jennifer M. Hafycz
- Chronobiology and Sleep Institute and Department of MedicinePerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Ewa Strus
- Chronobiology and Sleep Institute and Department of MedicinePerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Nirinjini Naidoo
- Chronobiology and Sleep Institute and Department of MedicinePerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
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15
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Miyanishi H, Kitazawa A, Izuo N, Muramatsu SI, Nitta A. N-Acetyl Transferase, Shati/Nat8l, in the Dorsal Hippocampus Suppresses Aging-induced Impairment of Cognitive Function in Mice. Neurochem Res 2022; 47:2703-2714. [DOI: 10.1007/s11064-022-03594-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 03/02/2022] [Accepted: 03/30/2022] [Indexed: 12/11/2022]
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16
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Kaushik M, Kaushik P, Parvez S. Memory related molecular signatures: The pivots for memory consolidation and Alzheimer's related memory decline. Ageing Res Rev 2022; 76:101577. [PMID: 35104629 DOI: 10.1016/j.arr.2022.101577] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 12/23/2021] [Accepted: 01/27/2022] [Indexed: 12/31/2022]
Abstract
Age-related cognitive decline is the major cause of concern due to its 70% more incidence than dementia cases worldwide. Moreover, aging is also the major risk factor of Alzheimer's disease (AD), associated with progressive memory loss. Approx. 13 million people will have Alzheimer-related memory decline by 2050. Learning and memory is the fundamental process of brain functions. However, the mechanism for the same is still under investigation. Thus, it is critical to understand the process of memory consolidation in the brain and extrapolate its understanding to the memory decline mechanism. Research on learning and memory has identified several molecular signatures such as Protein kinase M zeta (PKMζ), Calcium/calmodulin-dependent protein kinase II (CaMKII), Brain-derived neurotrophic factor (BDNF), cAMP-response element binding protein (CREB) and Activity-regulated cytoskeleton-associated protein (Arc) crucial for the maintenance and stabilization of long-term memory in the brain. Interestingly, memory decline in AD has also been linked to the abnormality in expressing these memory-related molecular signatures. Hence, in the present consolidated review, we explored the role of these memory-related molecular signatures in long-term memory consolidation. Additionally, the effect of amyloid-beta toxicity on these molecular signatures is discussed in detail.
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Affiliation(s)
- Medha Kaushik
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Pooja Kaushik
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Suhel Parvez
- Department of Toxicology, School of Chemical & Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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17
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Lin C, Oh MM, Disterhoft JF. Aging-Related Alterations to Persistent Firing in the Lateral Entorhinal Cortex Contribute to Deficits in Temporal Associative Memory. Front Aging Neurosci 2022; 14:838513. [PMID: 35360205 PMCID: PMC8963507 DOI: 10.3389/fnagi.2022.838513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022] Open
Abstract
With aging comes a myriad of different disorders, and cognitive decline is one of them. Studies have consistently shown a decline amongst aged subjects in their ability to acquire and maintain temporal associative memory. Defined as the memory of the association between two objects that are separated in time, temporal associative memory is dependent on neocortical structures such as the prefrontal cortex and temporal lobe structures. For this memory to be acquired, a mental trace of the first stimulus is necessary to bridge the temporal gap so the two stimuli can be properly associated. Persistent firing, the ability of the neuron to continue to fire action potentials even after the termination of a triggering stimulus, is one mechanism that is posited to support this mental trace. A recent study demonstrated a decline in persistent firing ability in pyramidal neurons of layer III of the lateral entorhinal cortex with aging, contributing to learning impairments in temporal associative memory acquisition. In this work, we explore the potential ways persistent firing in lateral entorhinal cortex (LEC) III supports temporal associative memory, and how aging may disrupt this mechanism within the temporal lobe system, resulting in impairment in this crucial behavior.
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18
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Ebrahimnejad M, Azizi P, Alipour V, Zarrindast MR, Vaseghi S. Complicated Role of Exercise in Modulating Memory: A Discussion of the Mechanisms Involved. Neurochem Res 2022; 47:1477-1490. [PMID: 35195832 DOI: 10.1007/s11064-022-03552-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 02/03/2022] [Accepted: 02/05/2022] [Indexed: 12/15/2022]
Abstract
Evidence has shown the beneficial effects of exercise on learning and memory. However, many studies have reported controversial results, indicating that exercise can impair learning and memory. In this article, we aimed to review basic studies reporting inconsistent complicated effects of exercise on memory in rodents. Also, we discussed the mechanisms involved in the effects of exercise on memory processes. In addition, we tried to find scientific answers to justify the inconsistent results. In this article, the role of brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (involved in synaptic plasticity and neurogenesis), and vascular endothelial growth factor, nerve growth factor, insulin-like growth factor 1, inflammatory markers, apoptotic factors, and antioxidant system was discussed in the modulation of exercise effects on memory. The role of intensity and duration of exercise, and type of memory task was also investigated. We also mentioned to the interaction of exercise with the function of neurotransmitter systems, which complicates the prediction of exercise effect via altering the level of BDNF. Eventually, we suggested that changes in the function of neurotransmitter systems following different types of exercise (depending on exercise intensity or age of onset) should be investigated in further studies. It seems that exercise-induced changes in the function of neurotransmitter systems may have a stronger role than age, type of memory task, or exercise intensity in modulating memory. Importantly, high levels of interactions between neurotransmitter systems and BDNF play a critical role in the modulation of exercise effects on memory performance.
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Affiliation(s)
- Mahshid Ebrahimnejad
- Department of Physiology, Faculty of Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Paniz Azizi
- School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Vahide Alipour
- Department of Physical Education and Sport Sciences, Faculty of Humanities, Rasht Branch, Islamic Azad University, Rasht, Iran
| | - Mohammad-Reza Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Salar Vaseghi
- Medicinal Plants Research Center, Institute of Medicinal Plants, ACECR, P.O. Box: 1419815477, Karaj, Iran.
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19
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Plagenhoef MR, Callahan PM, Beck WD, Blake DT, Terry AV. Aged rhesus monkeys: Cognitive performance categorizations and preclinical drug testing. Neuropharmacology 2021; 187:108489. [PMID: 33561449 PMCID: PMC8286428 DOI: 10.1016/j.neuropharm.2021.108489] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/25/2021] [Accepted: 01/29/2021] [Indexed: 12/24/2022]
Abstract
Rodent models have facilitated major discoveries in neurobiology, however, the low success rate of novel medications in clinical trials have led to questions about their translational value in neuropsychiatric drug development research. For age-related disorders of cognition such as Alzheimer' disease (AD) there is interest in moving beyond transgenic amyloid-β and/or tau-expressing rodent models and focusing more on natural aging and dissociating "healthy" from "pathological" aging to identify new therapeutic targets and treatments. In complex disorders such as AD, it can also be argued that animals with closer neurobiology to humans (e.g., nonhuman primates) should be employed more often particularly in the later phases of drug development. The purpose of the work described here was to evaluate the cognitive capabilities of rhesus monkeys across a wide range of ages in different delayed response tasks, a computerized delayed match to sample (DMTS) task and a manual delayed match to position (DMTP) task. Based on specific performance criteria and comparisons to younger subjects, the older subjects were generally less proficient, however, some performed as well as young subjects, while other aged subjects were markedly impaired. Accordingly, the older subjects could be categorized as aged "cognitively-unimpaired" or aged "cognitively-impaired" with a third group (aged-other) falling in between. Finally, as a proof of principle, we demonstrated using the DMTP task that aged cognitively-impaired monkeys are sensitive to the pro-cognitive effects of a nicotinic acetylcholine receptor (nAChR) partial agonist, encenicline, suggesting that nAChR ligands remain viable as potential treatments for age-related disorders of cognition.
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Affiliation(s)
- Marc R Plagenhoef
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia
| | - Patrick M Callahan
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia
| | - Wayne D Beck
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia
| | - David T Blake
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia
| | - Alvin V Terry
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, 30912, Georgia.
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20
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Rumman M, Pandey S, Singh B, Gupta M, Ubaid S, Mahdi AA. Genistein Prevents Hypoxia-Induced Cognitive Dysfunctions by Ameliorating Oxidative Stress and Inflammation in the Hippocampus. Neurotox Res 2021; 39:1123-1133. [PMID: 33740236 DOI: 10.1007/s12640-021-00353-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 03/01/2021] [Accepted: 03/09/2021] [Indexed: 12/26/2022]
Abstract
Genistein (GE), a plant-derived isoflavone, is a polyphenolic non-steroidal compound. Studies showed that GE possesses anti-cancer, anti-inflammatory, anti-microbial, anti-oxidant, and anti-apoptotic activities. However, the neuroprotective role of GE in amnesia has not been studied. This study aimed to evaluate the anti-amnesic potential of GE in a mice model of hypoxia-induced amnesia and to understand the underlying mechanism. Mice were exposed to hypoxia (10% O2) and administered vehicle or GE (10, 20, 30 mg/kg) orally for 28 days. Thereafter, Morris water maze (MWM), novel object recognition (NOR), and passive avoidance task (PAT) were performed to evaluate cognitive behavior. Next, we performed biochemical tests and gene expression analysis to uncover the mechanism underlying GE mode of action. Our results showed that GE-treatment ameliorated hypoxia-induced cognitive dysfunctions in mice. Further, GE-treatment suppressed the oxidative stress in the hippocampus of amnesic mice as evidenced by reduced lipid peroxidation, reduced nitrite and ROS levels, and increased levels of reduced glutathione (GSH) and increased total antioxidant capacity. GE treatment reduced the expression of pro-inflammatory cytokines TNFα, IL1β, IL6, and MCP-1 and increased the expression of anti-inflammatory cytokine IL10 in the hippocampus of amnesic mice. Finally, GE treatment enhanced the expression of neuroprotective genes including BDNF, CREB, CBP, and IGF1 in the hippocampus of amnesic mice. Altogether, our results showed that GE treatment prevents hypoxia-induced cognitive dysfunction in mice by reducing oxidative stress and suppressing neuroinflammation while increasing the expression of neuroprotective genes in the hippocampus.
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Affiliation(s)
- Mohammad Rumman
- Department of Biochemistry, King George's Medical University (KGMU), Lucknow, India
| | - Shivani Pandey
- Department of Biochemistry, King George's Medical University (KGMU), Lucknow, India.
| | - Babita Singh
- Department of Biochemistry, King George's Medical University (KGMU), Lucknow, India
| | - Mrinal Gupta
- Department of Biochemistry, King George's Medical University (KGMU), Lucknow, India
| | - Saba Ubaid
- Department of Biochemistry, King George's Medical University (KGMU), Lucknow, India
| | - Abbas Ali Mahdi
- Department of Biochemistry, King George's Medical University (KGMU), Lucknow, India
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21
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Gorny N, Kelly MP. Alterations in cyclic nucleotide signaling are implicated in healthy aging and age-related pathologies of the brain. VITAMINS AND HORMONES 2021; 115:265-316. [PMID: 33706951 DOI: 10.1016/bs.vh.2020.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is not only important to consider how hormones may change with age, but also how downstream signaling pathways that couple to hormone receptors may change. Among these hormone-coupled signaling pathways are the 3',5'-cyclic guanosine monophosphate (cGMP) and 3',5'-cyclic adenosine monophosphate (cAMP) intracellular second messenger cascades. Here, we test the hypothesis that dysfunction of cAMP and/or cGMP synthesis, execution, and/or degradation occurs in the brain during healthy and pathological diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease. Although most studies report lower cyclic nucleotide signaling in the aged brain, with further reductions noted in the context of age-related diseases, there are select examples where cAMP signaling may be elevated in select tissues. Thus, therapeutics would need to target cAMP/cGMP in a tissue-specific manner if efficacy for select symptoms is to be achieved without worsening others.
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Affiliation(s)
- Nicole Gorny
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Michy P Kelly
- Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, MD, United States.
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22
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Ehlers VL, Smies CW, Moyer JR. Apoaequorin differentially modulates fear memory in adult and aged rats. Brain Behav 2020; 10:e01832. [PMID: 32945630 PMCID: PMC7667302 DOI: 10.1002/brb3.1832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 01/06/2023] Open
Abstract
INTRODUCTION Cognitive deficits during aging are pervasive across species and learning paradigms. One of the major mechanisms thought to play a role in age-related memory decline is dysregulated calcium (Ca2+ ) homeostasis. Aging is associated with impaired function of several calcium-regulatory mechanisms, including calcium-binding proteins that normally support intracellular Ca2+ regulation. This age-related calcium-binding protein dysfunction and changes in expression lead to disrupted maintenance of intracellular Ca2+ , thus contributing to memory decline. Other work has found that age-related cognitive deficits can be mitigated by either blocking Ca2+ entry into the cytosol or preventing its release from intracellular Ca2+ stores. However, the effect of calcium-binding protein administration on cognitive function during aging is not well-understood. Our laboratory has previously shown that the calcium-binding protein apoaequorin (AQ) is neuroprotective during oxygen-glucose deprivation, a model of in vitro ischemia characterized by calcium-induced excitotoxicity. The current experiments assessed the effect of direct dorsal hippocampal AQ infusion on trace and context fear memory in adult and aged rats. METHODS Adult (3-6 months) and aged (22-26 months) male F344 rats were randomly assigned to different experimental infusion groups before undergoing trace fear conditioning and testing. In experiment 1, rats received bilateral dorsal hippocampal infusions of either vehicle or AQ (4% w/v) 24 hr before trace fear conditioning. In experiment 2, rats received bilateral dorsal hippocampal infusions of either vehicle or 4% AQ 1 hr before trace fear conditioning and 1 hr before testing. RESULTS Aged rats displayed impaired trace and context fear memory. While a single AQ infusion 24 hr before trace fear conditioning was insufficient to rescue age-related trace fear memory deficits, AQ infusion 1 hr before both conditioning and testing abolished age-related context fear memory deficits. CONCLUSIONS These results suggest that intrahippocampal infusion of AQ may reverse aging-related deficits in hippocampus-dependent context fear memory.
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Affiliation(s)
- Vanessa L Ehlers
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Chad W Smies
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - James R Moyer
- Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, WI, USA.,Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
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23
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Chen L, Cummings KA, Mau W, Zaki Y, Dong Z, Rabinowitz S, Clem RL, Shuman T, Cai DJ. The role of intrinsic excitability in the evolution of memory: Significance in memory allocation, consolidation, and updating. Neurobiol Learn Mem 2020; 173:107266. [PMID: 32512183 PMCID: PMC7429265 DOI: 10.1016/j.nlm.2020.107266] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 05/28/2020] [Accepted: 05/31/2020] [Indexed: 11/30/2022]
Abstract
Memory is a dynamic process that is continuously regulated by both synaptic and intrinsic neural mechanisms. While numerous studies have shown that synaptic plasticity is important in various types and phases of learning and memory, neuronal intrinsic excitability has received relatively less attention, especially regarding the dynamic nature of memory. In this review, we present evidence demonstrating the importance of intrinsic excitability in memory allocation, consolidation, and updating. We also consider the intricate interaction between intrinsic excitability and synaptic plasticity in shaping memory, supporting both memory stability and flexibility.
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Affiliation(s)
- Lingxuan Chen
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Kirstie A Cummings
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - William Mau
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Yosif Zaki
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Zhe Dong
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Sima Rabinowitz
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Roger L Clem
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Tristan Shuman
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States
| | - Denise J Cai
- Icahn School of Medicine at Mount Sinai, Department of Neuroscience, New York, New York, 10029, United States.
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24
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Smith LK, Verovskaya E, Bieri G, Horowitz AM, von Ungern‐Sternberg SNI, Lin K, Seizer P, Passegué E, Villeda SA. The aged hematopoietic system promotes hippocampal-dependent cognitive decline. Aging Cell 2020; 19:e13192. [PMID: 33073926 PMCID: PMC7431826 DOI: 10.1111/acel.13192] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 05/15/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023] Open
Abstract
The aged systemic milieu promotes cellular and cognitive impairments in the hippocampus. Here, we report that aging of the hematopoietic system directly contributes to the pro-aging effects of old blood on cognition. Using a heterochronic hematopoietic stem cell (HSC) transplantation model (in which the blood of young mice is reconstituted with old HSCs), we find that exposure to an old hematopoietic system inhibits hippocampal neurogenesis, decreases synaptic marker expression, and impairs cognition. We identify a number of factors elevated in the blood of young mice reconstituted with old HSCs, of which cyclophilin A (CyPA) acts as a pro-aging factor. Increased systemic levels of CyPA impair cognition in young mice, while inhibition of CyPA in aged mice improves cognition. Together, these data identify age-related changes in the hematopoietic system as drivers of hippocampal aging.
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Affiliation(s)
- Lucas K. Smith
- Department of AnatomyUniversity of California San FranciscoSan FranciscoCAUSA
- Biomedical Sciences Graduate ProgramUniversity of California San FranciscoSan FranciscoCAUSA
| | - Evgenia Verovskaya
- The Eli and Edyth Broad Center for Regenerative Medicine and Stem Cell ResearchSan FranciscoCAUSA
- Columbia Stem Cell InitiativeDepartment of Genetics and DevelopmentColumbia University Irving Medical CenterNew YorkNYUSA
| | - Gregor Bieri
- Department of AnatomyUniversity of California San FranciscoSan FranciscoCAUSA
| | - Alana M. Horowitz
- Department of AnatomyUniversity of California San FranciscoSan FranciscoCAUSA
- Biomedical Sciences Graduate ProgramUniversity of California San FranciscoSan FranciscoCAUSA
| | | | - Karin Lin
- Department of AnatomyUniversity of California San FranciscoSan FranciscoCAUSA
- Neuroscience Graduate ProgramUniversity of California San FranciscoSan FranciscoCAUSA
| | - Peter Seizer
- Department of Cardiology and Cardiovascular MedicineUniversity of TübingenTübingenGermany
| | - Emmanuelle Passegué
- Columbia Stem Cell InitiativeDepartment of Genetics and DevelopmentColumbia University Irving Medical CenterNew YorkNYUSA
| | - Saul A. Villeda
- Department of AnatomyUniversity of California San FranciscoSan FranciscoCAUSA
- Biomedical Sciences Graduate ProgramUniversity of California San FranciscoSan FranciscoCAUSA
- The Eli and Edyth Broad Center for Regenerative Medicine and Stem Cell ResearchSan FranciscoCAUSA
- Neuroscience Graduate ProgramUniversity of California San FranciscoSan FranciscoCAUSA
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Wimmer ME, Blackwell JM, Abel T. Rolipram treatment during consolidation ameliorates long-term object location memory in aged male mice. Neurobiol Learn Mem 2020; 169:107168. [PMID: 31962134 DOI: 10.1016/j.nlm.2020.107168] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 01/08/2020] [Accepted: 01/16/2020] [Indexed: 10/25/2022]
Abstract
Normal aging is accompanied by cognitive and memory impairments that negatively impact quality of life for the growing elderly population. Hippocampal function is most vulnerable to the deleterious effects of aging, and deficits in hippocampus-dependent memories are common amongst aged individuals. Moreover, signaling networks such as the cAMP/PKA/CREB pathway, which are critical for memory consolidation, are dampened in healthy aged subjects. Phosphodiesterase (PDE) enzymes that break down cAMP are also affected by aging, and increased break down of cAMP by PDEs may contribute to reduced activity of the cAMP/PKA/CREB signaling network in the brain of aged individuals. Here, we report that the PDE4 inhibitor rolipram administered during consolidation of hippocampus-dependent object location memory improves aged-related spatial memory deficits in aged mice.
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Affiliation(s)
- Mathieu E Wimmer
- Department of Psychology and Program in Neuroscience, Temple University, Philadelphia, PA 19122, USA
| | - Jennifer M Blackwell
- Neuroscience Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ted Abel
- Department of Molecular Physiology and Biophysics, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA.
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26
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In Vivo Imaging of the Coupling between Neuronal and CREB Activity in the Mouse Brain. Neuron 2019; 105:799-812.e5. [PMID: 31883788 DOI: 10.1016/j.neuron.2019.11.028] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 10/16/2019] [Accepted: 11/25/2019] [Indexed: 01/15/2023]
Abstract
Sensory experiences cause long-term modifications of neuronal circuits by modulating activity-dependent transcription programs that are vital for regulation of long-term synaptic plasticity and memory. However, it has not been possible to precisely determine the interaction between neuronal activity patterns and transcription factor activity. Here we present a technique using two-photon fluorescence lifetime imaging (2pFLIM) with new FRET biosensors to chronically image in vivo signaling of CREB, an activity-dependent transcription factor important for synaptic plasticity, at single-cell resolution. Simultaneous imaging of the red-shifted CREB sensor and GCaMP permitted exploration of how experience shapes the interplay between CREB and neuronal activity in the neocortex of awake mice. Dark rearing increased the sensitivity of CREB activity to Ca2+ elevations and prolonged the duration of CREB activation to more than 24 h in the visual cortex. This technique will allow researchers to unravel the transcriptional dynamics underlying experience-dependent plasticity in the brain.
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Mimicking Age-Associated Gadd45γ Dysregulation Results in Memory Impairments in Young Adult Mice. J Neurosci 2019; 40:1197-1210. [PMID: 31826946 DOI: 10.1523/jneurosci.1621-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/08/2019] [Accepted: 12/05/2019] [Indexed: 01/19/2023] Open
Abstract
Age-related memory loss is observed across multiple mammalian species and preferentially affects hippocampus-dependent memory. Memory impairments are characterized by accelerated decay of spatial memories. Nevertheless, the molecular mechanisms underlying these deficits are still largely unknown. Here, we investigated the expression and function of the growth arrest DNA damage (Gadd45) family during aging and cognition, respectively. We report that aging impairs the expression of Gadd45γ in the hippocampus of cognitively impaired male mice. Mimicking this decrease in young adult male mice led to age-like memory deficits in hippocampus-dependent memory tasks. Gadd45γ reduction impaired the activity of key components of the mitogen-activated protein kinase (MAPK) pathway (p38 and JNK) in mouse hippocampal cultures. Furthermore, we found that activation of downstream targets, such as ATF-2, c-Jun, and CREB (cAMP response element-binding protein), was disrupted. Finally, we showed that Gadd45γ is required for induction of key early- and late-response genes that have been associated with aging. Together, these findings indicate that Gadd45γ expression regulates cognitive abilities and synapse-to-nucleus communication and suggest Gadd45γ dysfunction as a potential mechanism contributing to age-related cognitive impairments.SIGNIFICANCE STATEMENT A high percentage of subjects experience age-related memory loss that burdens daily performance. Although many advances have been made, the precise changes in the brain governing these deficits are unclear. Identifying molecular processes that are required for cognition and are altered during old age is crucial to develop preventive or therapeutic strategies. Here, we show that baseline and learning-induced expression of the growth arrest DNA damage (Gadd45) γ is selectively impaired in the hippocampus of aged mice with cognitive deficits. Next, we show that modeling this impairment in young adult mice with normal cognitive performance disrupts long- and short-term memories in an age-like manner. Finally, we demonstrate that Gadd45γ regulates synapse-to-nucleus communication processes that are needed for plasticity-associated gene expression.
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Oh MM, Disterhoft JF. Learning and aging affect neuronal excitability and learning. Neurobiol Learn Mem 2019; 167:107133. [PMID: 31786311 DOI: 10.1016/j.nlm.2019.107133] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/21/2019] [Accepted: 11/27/2019] [Indexed: 11/20/2022]
Abstract
The first study that demonstrated a change in intrinsic neuronal excitability after learning in ex vivo brain tissue slices from a mammal was published over thirty years ago. Numerous other manuscripts describing similar learning-related changes have followed over the years since the original paper demonstrating the postburst afterhyperpolarization (AHP) reduction in CA1 pyramidal neurons from rabbits that learned delay eyeblink conditioning was published. In addition to the learning-related changes, aging-related enlargement of the postburst AHP in CA1 pyramidal neurons have been reported. Extensive work has been done relating slow afterhyperpolarization enhancement in CA1 hippocampus to slowed learning in some aging animals. These reproducible findings strongly implicate modulation of the postburst AHP as an essential cellular mechanism necessary for successful learning, at least in learning tasks that engage CA1 hippocampal pyramidal neurons.
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Affiliation(s)
- M Matthew Oh
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611-3008, United States
| | - John F Disterhoft
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611-3008, United States.
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Morgan PJ, Bourboulou R, Filippi C, Koenig-Gambini J, Epsztein J. Kv1.1 contributes to a rapid homeostatic plasticity of intrinsic excitability in CA1 pyramidal neurons in vivo. eLife 2019; 8:49915. [PMID: 31774395 PMCID: PMC6881145 DOI: 10.7554/elife.49915] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/08/2019] [Indexed: 12/12/2022] Open
Abstract
In area CA1 of the hippocampus, the selection of place cells to represent a new environment is biased towards neurons with higher excitability. However, different environments are represented by orthogonal cell ensembles, suggesting that regulatory mechanisms exist. Activity-dependent plasticity of intrinsic excitability, as observed in vitro, is an attractive candidate. Here, using whole-cell patch-clamp recordings of CA1 pyramidal neurons in anesthetized rats, we have examined how inducing theta-bursts of action potentials affects their intrinsic excitability over time. We observed a long-lasting, homeostatic depression of intrinsic excitability which commenced within minutes, and, in contrast to in vitro observations, was not mediated by dendritic Ih. Instead, it was attenuated by the Kv1.1 channel blocker dendrotoxin K, suggesting an axonal origin. Analysis of place cells’ out-of-field firing in mice navigating in virtual reality further revealed an experience-dependent reduction consistent with decreased excitability. We propose that this mechanism could reduce memory interference.
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Affiliation(s)
- Peter James Morgan
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
| | - Romain Bourboulou
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
| | - Caroline Filippi
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
| | - Julie Koenig-Gambini
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France.,Institut Universitaire de France, Paris, France
| | - Jérôme Epsztein
- Institute of Neurobiology of the Mediterranean Sea (INMED), Turing Center for Living Systems (CENTURI), Aix-Marseille University, INSERM, Marseille, France
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White LR, Boyle PA, Foster TC, Gazzaley AH, Disterhoft JF. How do we validate approaches that aim to harness reserve to improve the aging brain? Neurobiol Aging 2019; 83:145-149. [PMID: 31732018 PMCID: PMC6859906 DOI: 10.1016/j.neurobiolaging.2019.03.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 03/14/2019] [Indexed: 01/29/2023]
Abstract
An accurate assessment of the impact of reserve on cognitive functioning in older individuals with brain pathology requires careful measurement of each and an assessment of the extent to which each influences the other. Studies to integrate information about molecular biology, neuropathology, behavioral aspects of cognitive decline, and cognitive resilience will be of particular importance. In addition, more work is needed to improve our understanding of the effect of systemic factors on brain health and function. It seems likely that, even in later life, the brain's plasticity may allow for a positive response to stimulation. The ultimate goal of this research is to create a validated set of variables and interventions-and to understand the biology underlying them-that are useful not only in describing an individual's cognitive state but also in identifying promising paths for treatment and prevention of cognitive decline.
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Affiliation(s)
- Lon R White
- Pacific Health Research and Education Institute, Honolulu, HI, USA
| | - Patricia A Boyle
- Department of Behavioral Sciences, Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Thomas C Foster
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Adam H Gazzaley
- Department of Neurology, University of California, San Francisco, CA, USA
| | - John F Disterhoft
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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31
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Wheatley EG, Albarran E, White CW, Bieri G, Sanchez-Diaz C, Pratt K, Snethlage CE, Ding JB, Villeda SA. Neuronal O-GlcNAcylation Improves Cognitive Function in the Aged Mouse Brain. Curr Biol 2019; 29:3359-3369.e4. [PMID: 31588002 PMCID: PMC7199460 DOI: 10.1016/j.cub.2019.08.003] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 06/24/2019] [Accepted: 08/01/2019] [Indexed: 12/31/2022]
Abstract
Mounting evidence in animal models indicates potential for rejuvenation of cellular and cognitive functions in the aging brain. However, the ability to utilize this potential is predicated on identifying molecular targets that reverse the effects of aging in vulnerable regions of the brain, such as the hippocampus. The dynamic post-translational modification O-linked N-Acetylglucosamine (O-GlcNAc) has emerged as an attractive target for regulating aging-specific synaptic alterations as well as neurodegeneration. While speculation exists about the role of O-GlcNAc in neurodegenerative conditions, such as Alzheimer’s disease, its role in physiological brain aging remains largely unexplored. Here, we report that countering age-related decreased O-GlcNAc transferase (OGT) expression and O-GlcNAcylation ameliorates cognitive impairments in aged mice. Mimicking an aged condition in young adults by abrogating OGT, using a temporally controlled neuron-specific conditional knockout mouse model, recapitulated cellular and cognitive features of brain aging. Conversely, overexpressing OGT in mature hippocampal neurons using a viral-mediated approach enhanced associative fear memory in young adult mice. Excitingly, in aged mice overexpressing neuronal OGT in the aged hippocampus rescued in part age-related impairments in spatial learning and memory as well as associative fear memory. Our data identify O-GlcNAcylaton as a key molecular mediator promoting cognitive rejuvenation. Wheatley et al. identify O-GlcNAcylation as a key posttranslational modification promoting cognitive rejuvenation. Mimicking age-related decreased neuronal OGT and O-GlcNAc levels in the young hippocampus impaired cognition, while restoring neuronal OGT and O-GlcNAc in the aged hippocampus rejuvenated cognition.
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Affiliation(s)
- Elizabeth G Wheatley
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Eddy Albarran
- Neuroscience IDP Program, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Charles W White
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Gregor Bieri
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Cesar Sanchez-Diaz
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Karishma Pratt
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Cedric E Snethlage
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jun B Ding
- Neuroscience IDP Program, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Saul A Villeda
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA; Developmental and Stem Cell Biology Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA 94143, USA; The Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, San Francisco, CA 94143, USA.
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Dunn AR, Kaczorowski CC. Regulation of intrinsic excitability: Roles for learning and memory, aging and Alzheimer's disease, and genetic diversity. Neurobiol Learn Mem 2019; 164:107069. [PMID: 31442579 DOI: 10.1016/j.nlm.2019.107069] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/09/2019] [Accepted: 08/17/2019] [Indexed: 12/28/2022]
Abstract
Plasticity of intrinsic neuronal excitability facilitates learning and memory across multiple species, with aberrant modulation of this process being linked to the development of neurological symptoms in models of cognitive aging and Alzheimer's disease. Learning-related increases in intrinsic excitability of neurons occurs in a variety of brain regions, and is generally thought to promote information processing and storage through enhancement of synaptic throughput and induction of synaptic plasticity. Experience-dependent changes in intrinsic neuronal excitability rely on activity-dependent gene expression patterns, which can be influenced by genetic and environmental factors, aging, and disease. Reductions in baseline intrinsic excitability, as well as aberrant plasticity of intrinsic neuronal excitability and in some cases pathological hyperexcitability, have been associated with cognitive deficits in animal models of both normal cognitive aging and Alzheimer's disease. Genetic factors that modulate plasticity of intrinsic excitability likely underlie individual differences in cognitive function and susceptibility to cognitive decline. Thus, targeting molecular mediators that either control baseline intrinsic neuronal excitability, subserve learning-related intrinsic neuronal plasticity, and/or promote resilience may be a promising therapeutic strategy for maintaining cognitive function in aging and disease. In this review, we discuss the complementary relationship between intrinsic excitability and learning, with a particular focus on how this relationship varies as a function of age, disease state, and genetic make-up, and how targeting these factors may help to further elucidate our understanding of the role of intrinsic excitability in cognitive function and cognitive decline.
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Affiliation(s)
- Amy R Dunn
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
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33
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Foster TC. Senescent neurophysiology: Ca 2+ signaling from the membrane to the nucleus. Neurobiol Learn Mem 2019; 164:107064. [PMID: 31394200 DOI: 10.1016/j.nlm.2019.107064] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/29/2019] [Accepted: 08/03/2019] [Indexed: 12/16/2022]
Abstract
The current review provides a historical perspective on the evolution of hypothesized mechanisms for senescent neurophysiology, focused on the CA1 region of the hippocampus, and the relationship of senescent neurophysiology to impaired hippocampal-dependent memory. Senescent neurophysiology involves processes linked to calcium (Ca2+) signaling including an increase in the Ca2+-dependent afterhyperpolarization (AHP), decreasing pyramidal cell excitability, hyporesponsiveness of N-methyl-D-aspartate (NMDA) receptor function, and a shift in Ca2+-dependent synaptic plasticity. Dysregulation of intracellular Ca2+ and downstream signaling of kinase and phosphatase activity lies at the core of senescent neurophysiology. Ca2+-dysregulation involves a decrease in Ca2+ influx through NMDA receptors and an increase release of Ca2+ from internal Ca2+ stores. Recent work has identified changes in redox signaling, arising in middle-age, as an initiating factor for senescent neurophysiology. The shift in redox state links processes of aging, oxidative stress and inflammation, with functional changes in mechanisms required for episodic memory. The link between age-related changes in Ca2+ signaling, epigenetics and gene expression is an exciting area of research. Pharmacological and behavioral intervention, initiated in middle-age, can promote memory function by initiating transcription of neuroprotective genes and rejuvenating neurophysiology. However, with more advanced age, or under conditions of neurodegenerative disease, epigenetic changes may weaken the link between environmental influences and transcription, decreasing resilience of memory function.
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Affiliation(s)
- Thomas C Foster
- Department of Neuroscience and Genetics and Genomics Program, McKnight Brain Institute, University of Florida, Gainesville, FL 32611, USA.
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Xiang W, Li T, Gao T, Wang B. CREB down-regulation in the laterodorsal thalamic nucleus deteriorates memory consolidation in rats. Learn Mem 2019; 26:182-186. [PMID: 31092551 PMCID: PMC6529882 DOI: 10.1101/lm.049742.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 04/19/2019] [Indexed: 11/26/2022]
Abstract
The laterodorsal thalamic nucleus (LD) is believed to play roles in learning and memory, especially spatial tasks. However, the molecular mechanism that underlies the cognitive process in the LD remains unclear and needs to be investigated. So far, there is plenty of evidence indicating that plasticity has been in some of the cortical or subcortical regions closely related to the LD, particularly stimulated by external learning tasks. Therefore, the present study aimed to test the hypothesis that similar effect exists in the LD. The transcription factor, cAMP-response element binding protein (CREB), works essentially in brain plasticity by tightly regulating the transcriptional level of memory-related target genes, and the increase of activated CREB (phosphorylated CREB, p-CREB) could facilitate memory consolidation. In this study, the siRNA against CREB was synthesized to down-regulate the CREB mRNA in the LD. After Morris water maze behavioral training, CREB siRNA rats exhibited a memory deficiency, significantly diverging from the control groups. In subsequent detection, the expression of p-CREB of these memory impairment rats attenuated. These results support the hypothesis that CREB-mediated plasticity contributes to memory facilitation and consolidation in the LD.
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Affiliation(s)
- Wenxi Xiang
- Department of Anatomy, College of Basic Medicine, Dalian Medical University, Dalian 116044, China
| | - Tingting Li
- Department of Anatomy, College of Basic Medicine, Dalian Medical University, Dalian 116044, China
| | - Tianhang Gao
- Department of Anatomy, College of Basic Medicine, Dalian Medical University, Dalian 116044, China
| | - Bin Wang
- Department of Anatomy, College of Basic Medicine, Dalian Medical University, Dalian 116044, China
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Bartolotti N, Lazarov O. CREB signals as PBMC-based biomarkers of cognitive dysfunction: A novel perspective of the brain-immune axis. Brain Behav Immun 2019; 78:9-20. [PMID: 30641141 PMCID: PMC6488430 DOI: 10.1016/j.bbi.2019.01.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 12/21/2018] [Accepted: 01/10/2019] [Indexed: 12/26/2022] Open
Abstract
To date, there is no reliable biomarker for the assessment or determination of cognitive dysfunction in Alzheimer's disease and related dementia. Such a biomarker would not only aid in diagnostics, but could also serve as a measure of therapeutic efficacy. It is widely acknowledged that the hallmarks of Alzheimer's disease, namely, amyloid deposits and neurofibrillary tangles, as well as their precursors and metabolites, are poorly correlated with cognitive function and disease stage and thus have low diagnostic or prognostic value. A lack of biomarkers is one of the major roadblocks in diagnosing the disease and in assessing the efficacy of potential therapies. The phosphorylation of cAMP Response Element Binding protein (pCREB) plays a major role in memory acquisition and consolidation. In the brain, CREB activation by phosphorylation at Ser133 and the recruitment of transcription cofactors such as CREB binding protein (CBP) is a critical step for the formation of memory. This set of processes is a prerequisite for the transcription of genes thought to be important for synaptic plasticity, such as Egr-1. Interestingly, recent work suggests that the expression of pCREB in peripheral blood mononuclear cells (PBMC) positively correlates with pCREB expression in the postmortem brain of Alzheimer's patients, suggesting not only that pCREB expression in PBMC might serve as a biomarker of cognitive dysfunction, but also that the dysfunction of CREB signaling may not be limited to the brain in AD, and that a link may exist between the regulation of CREB in the blood and in the brain. In this review we consider the evidence suggesting a correlation between the level of CREB signals in the brain and blood, the current knowledge about CREB in PBMC and its association with CREB in the brain, and the implications and mechanisms for a neuro-immune cross talk that may underlie this communication. This Review will discuss the possibility that peripheral dysregulation of CREB is an early event in AD pathogenesis, perhaps as a facet of immune system dysfunction, and that this impairment in peripheral CREB signaling modifies CREB signaling in the brain, thus exacerbating cognitive decline in AD. A more thorough understanding of systemic dysregulation of CREB in AD will facilitate the search for a biomarker of cognitive function in AD, and also aid in the understanding of the mechanisms underlying cognitive decline in AD.
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Affiliation(s)
- Nancy Bartolotti
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Orly Lazarov
- Department of Anatomy and Cell Biology, College of Medicine, The University of Illinois at Chicago, Chicago, IL 60612, USA.
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36
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rTMS pre-treatment effectively protects against cognitive and synaptic plasticity impairments induced by simulated microgravity in mice. Behav Brain Res 2019; 359:639-647. [DOI: 10.1016/j.bbr.2018.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/28/2018] [Accepted: 10/01/2018] [Indexed: 12/16/2022]
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37
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Rabin BM, Poulose SM, Bielinski DF, Shukitt-Hale B. Effects of head-only or whole-body exposure to very low doses of 4He (1000 MeV/n) particles on neuronal function and cognitive performance. LIFE SCIENCES IN SPACE RESEARCH 2019; 20:85-92. [PMID: 30797437 DOI: 10.1016/j.lssr.2019.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/21/2018] [Accepted: 02/04/2019] [Indexed: 05/03/2023]
Abstract
On exploratory class missions, astronauts will be exposed to a range of heavy particles which vary in linear energy transfer (LET). Previous research has shown a direct relationship between particle LET and cognitive performance such that, as particle LET decreases the dose needed to affect cognitive performance also decreases. Because a significant portion of the total dose experienced by astronauts may be expected to come from exposure to low LET 4He particles, it would be important to establish the threshold dose of 4He particles that can produce changes in cognitive performance. The results indicated that changes in neuronal function and cognitive performance could be observed following both head-only and whole-body exposures to 4He particles at doses as low as 0.01-0.025 cGy. These results, therefore, suggest the possibility that astronauts on exploratory class missions may be at a greater risk for HZE-induced deficits than previously anticipated.
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Affiliation(s)
- Bernard M Rabin
- Department of Psychology, UMBC, Baltimore, MD 21250, United States.
| | - Shibu M Poulose
- USDA-ARS, Human Nutrition Research Center on Aging at Tufts Univ., Boston, MA 02111, United States
| | - Donna F Bielinski
- USDA-ARS, Human Nutrition Research Center on Aging at Tufts Univ., Boston, MA 02111, United States
| | - Barbara Shukitt-Hale
- USDA-ARS, Human Nutrition Research Center on Aging at Tufts Univ., Boston, MA 02111, United States
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Yu J, Kwon H, Cho E, Jeon J, Kang RH, Youn K, Jun M, Lee YC, Ryu JH, Kim DH. The effects of pinoresinol on cholinergic dysfunction-induced memory impairments and synaptic plasticity in mice. Food Chem Toxicol 2019; 125:376-382. [PMID: 30685474 DOI: 10.1016/j.fct.2019.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/02/2019] [Accepted: 01/17/2019] [Indexed: 12/28/2022]
Abstract
Dementia is a category of brain diseases that cause a decrease in cognitive functions. Alzheimer's disease (AD) is the most frequently mentioned neurodegenerative disease showing dementia. Although many useful drugs for dementia were developed, we still need better and safer drugs. Here, we tested pinoresinol, a lignan found in sesame seed and olive oil, whether it could be a candidate for this purpose. Pinoresinol (25 mg/kg, p.o.) ameliorated memory impairment in dementia model induced by cholinergic blockade in the passive avoidance test in a dose-dependent manner. Moreover, pinoresinol (50 μM) facilitated induction of hippocampal long-term potentiation, a cellular model of learning and memory. Pinoresinol blocked acetylcholinesterase (AchE), an acetylcholine-degrading enzyme, activity in a concentration-dependent manner. Moreover, pinoresinol (50 μM) facilitated calcium influx into neuro2a cell. These results suggest that pinoresinol improves memory impairment and facilitates hippocampal LTP induction and these results might be related to the effect of pinoresinol on AChE and calcium influx.
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Affiliation(s)
- Jimin Yu
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Huiyoung Kwon
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Eunbi Cho
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Jieun Jeon
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Rae Hee Kang
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea
| | - Kumju Youn
- Department of Food Science and Nutrition, Dong-A University, Busan, 49315, Republic of Korea
| | - Mira Jun
- Department of Food Science and Nutrition, Dong-A University, Busan, 49315, Republic of Korea; Institute of Convergence Bio-Health, Dong-A University, Busan, 49315, Republic of Korea
| | - Young Choon Lee
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea; Institute of Convergence Bio-Health, Dong-A University, Busan, 49315, Republic of Korea
| | - Jong Hoon Ryu
- Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Dong Hyun Kim
- Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan, 49315, Republic of Korea; Institute of Convergence Bio-Health, Dong-A University, Busan, 49315, Republic of Korea.
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Zhao S, Zhang L, Yang C, Li Z, Rong S. Procyanidins and Alzheimer’s Disease. Mol Neurobiol 2019; 56:5556-5567. [DOI: 10.1007/s12035-019-1469-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 01/07/2019] [Indexed: 02/07/2023]
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Arey RN, Stein GM, Kaletsky R, Kauffman A, Murphy CT. Activation of G αq Signaling Enhances Memory Consolidation and Slows Cognitive Decline. Neuron 2018; 98:562-574.e5. [PMID: 29656871 DOI: 10.1016/j.neuron.2018.03.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/06/2017] [Accepted: 03/21/2018] [Indexed: 01/25/2023]
Abstract
Perhaps the most devastating decline with age is the loss of memory. Therefore, identifying mechanisms to restore memory function with age is critical. Using C. elegans associative learning and memory assays, we identified a gain-of-function Gαq signaling pathway mutant that forms a long-term (cAMP response element binding protein [CREB]-dependent) memory following one conditioned stimulus-unconditioned stimulus (CS-US) pairing, which usually requires seven CS-US pairings. Increased CREB activity in AIM interneurons reduces the threshold for memory consolidation through transcription of a set of previously identified "long-term memory" genes. Enhanced Gαq signaling in the AWC sensory neuron is both necessary and sufficient for improved memory and increased AIM CREB activity, and activation of Gαq specifically in aged animals rescues the ability to form memory. Activation of Gαq in AWC sensory neurons non-cell autonomously induces consolidation after one CS-US pairing, enabling both cognitive function maintenance with age and restoration of memory function in animals with impaired memory performance without decreased longevity.
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Affiliation(s)
- Rachel N Arey
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Geneva M Stein
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Rachel Kaletsky
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Amanda Kauffman
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Coleen T Murphy
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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Vohra M, Lemieux GA, Lin L, Ashrafi K. Kynurenic acid accumulation underlies learning and memory impairment associated with aging. Genes Dev 2018; 32:14-19. [PMID: 29386332 PMCID: PMC5828390 DOI: 10.1101/gad.307918.117] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/22/2017] [Indexed: 12/27/2022]
Abstract
Vohra et al. show that in C. elegans, a significant portion of the decline in learning and memory associated with aging is due to accumulation of a metabolite called kynurenic acid (KYNA), an endogenous antagonist of neural NMDA receptors. A general feature of animal aging is decline in learning and memory. Here we show that in Caenorhabditis elegans, a significant portion of this decline is due to accumulation of kynurenic acid (KYNA), an endogenous antagonist of neural N-methyl-D-aspartate receptors (NMDARs). We show that activation of a specific pair of interneurons either through genetic means or by depletion of KYNA significantly improves learning capacity in aged animals even when the intervention is applied in aging animals. KYNA depletion also improves memory. We show that insulin signaling is one factor in KYNA accumulation.
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Affiliation(s)
- Mihir Vohra
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
| | - George A Lemieux
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
| | - Lin Lin
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
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Kelly MP. Cyclic nucleotide signaling changes associated with normal aging and age-related diseases of the brain. Cell Signal 2018; 42:281-291. [PMID: 29175000 PMCID: PMC5732030 DOI: 10.1016/j.cellsig.2017.11.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/21/2017] [Indexed: 01/23/2023]
Abstract
Deficits in brain function that are associated with aging and age-related diseases benefit very little from currently available therapies, suggesting a better understanding of the underlying molecular mechanisms is needed to develop improved drugs. Here, we review the literature to test the hypothesis that a break down in cyclic nucleotide signaling at the level of synthesis, execution, and/or degradation may contribute to these deficits. A number of findings have been reported in both the human and animal model literature that point to brain region-specific changes in Galphas (a.k.a. Gαs or Gsα), adenylyl cyclase, 3',5'-adenosine monophosphate (cAMP) levels, protein kinase A (PKA), cAMP response element binding protein (CREB), exchange protein activated by cAMP (Epac), hyperpolarization-activated cyclic nucleotide-gated ion channels (HCNs), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), soluble and particulate guanylyl cyclase, 3',5'-guanosine monophosphate (cGMP), protein kinase G (PKG) and phosphodiesterases (PDEs). Among the most reproducible findings are 1) elevated circulating ANP and BNP levels being associated with cognitive dysfunction or dementia independent of cardiovascular effects, 2) reduced basal and/or NMDA-stimulated cGMP levels in brain with aging or Alzheimer's disease (AD), 3) reduced adenylyl cyclase activity in hippocampus and specific cortical regions with aging or AD, 4) reduced expression/activity of PKA in temporal cortex and hippocampus with AD, 5) reduced phosphorylation of CREB in hippocampus with aging or AD, 6) reduced expression/activity of the PDE4 family in brain with aging, 7) reduced expression of PDE10A in the striatum with Huntington's disease (HD) or Parkinson's disease, and 8) beneficial effects of select PDE inhibitors, particularly PDE10 inhibitors in HD models and PDE4 and PDE5 inhibitors in aging and AD models. Although these findings generally point to a reduction in cyclic nucleotide signaling being associated with aging and age-related diseases, there are exceptions. In particular, there is evidence for increased cAMP signaling specifically in aged prefrontal cortex, AD cerebral vessels, and PD hippocampus. Thus, if cyclic nucleotide signaling is going to be targeted effectively for therapeutic gain, it will have to be manipulated in a brain region-specific manner.
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Affiliation(s)
- Michy P Kelly
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, 6439 Garners Ferry Road, VA Bldg 1, 3rd Floor, D-12, Columbia, SC 29209, United States.
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