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Kline SA, Mega MS. Stress-Induced Neurodegeneration: The Potential for Coping as Neuroprotective Therapy. Am J Alzheimers Dis Other Demen 2020; 35:1533317520960873. [PMID: 32969239 PMCID: PMC10623922 DOI: 10.1177/1533317520960873] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2024]
Abstract
Stress responses are essential for survival, but become detrimental to health and cognition with chronic activation. Chronic hypothalamic-pituitary-adrenal axis release of glucocorticoids induces hypothalamic-pituitary-adrenal axis dysfunction and neuronal loss, decreases learning and memory, and modifies glucocorticoid receptor/mineralocorticoid receptor expression. Elderly who report increased stress are nearly 3 times more likely to develop Alzheimer's disease, have decreased global cognition and faster cognitive decline than those reporting no stress. Patients with mild cognitive impairment are more sensitive to stress compared to healthy elderly and those with Alzheimer's disease. Stress may also transduce neurodegeneration via the gut microbiome. Coping styles determine hippocampal mineralocorticoid receptor expression in mice, indicating that coping modifies cortisol's effect on the brain. Identifying neuroprotective coping strategies that lessen the burden of stress may prevent or slow cognitive decline. Treatments and education designed to reduce stress should be recognized as neuroprotective.
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Brivio P, Paladini MS, Racagni G, Riva MA, Calabrese F, Molteni R. From Healthy Aging to Frailty: In Search of the Underlying Mechanisms. Curr Med Chem 2019; 26:3685-3701. [PMID: 31333079 DOI: 10.2174/0929867326666190717152739] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/14/2018] [Accepted: 03/08/2019] [Indexed: 11/22/2022]
Abstract
Population aging is accelerating rapidly worldwide, from 461 million people older than 65 years in 2004 to an estimated 2 billion people by 2050, leading to critical implications for the planning and delivery of health and social care. The most problematic expression of population aging is the clinical condition of frailty, which is a state of increased vulnerability that develops as a consequence of the accumulation of microscopic damages in many physiological systems that lead to a striking and disproportionate change in health state, even after an apparently small insult. Since little is known about the biology of frailty, an important perspective to understand this phenomenon is to establish how the alterations that physiologically occur during a condition of healthy aging may instead promote cumulative decline with subsequent depletion of homoeostatic reserve and increase the vulnerability also after minor stressor events. In this context, the present review aims to provide a description of the molecular mechanisms that, by having a critical impact on behavior and neuronal function in aging, might be relevant for the development of frailty. Moreover, since these biological systems are also involved in the coping strategies set in motion to respond to environmental challenges, we propose a role for lifestyle stress as an important player to drive frailty in aging.
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Affiliation(s)
- Paola Brivio
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Maria Serena Paladini
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Giorgio Racagni
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy.,Associazione di Psicofarmacologia, Milan, Italy
| | - Marco Andrea Riva
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Francesca Calabrese
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Raffaella Molteni
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
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3
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Castellano JM, Mosher KI, Abbey RJ, McBride AA, James ML, Berdnik D, Shen JC, Zou B, Xie XS, Tingle M, Hinkson IV, Angst MS, Wyss-Coray T. Human umbilical cord plasma proteins revitalize hippocampal function in aged mice. Nature 2017; 544:488-492. [PMID: 28424512 DOI: 10.1038/nature22067] [Citation(s) in RCA: 276] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/14/2017] [Indexed: 12/31/2022]
Abstract
Ageing drives changes in neuronal and cognitive function, the decline of which is a major feature of many neurological disorders. The hippocampus, a brain region subserving roles of spatial and episodic memory and learning, is sensitive to the detrimental effects of ageing at morphological and molecular levels. With advancing age, synapses in various hippocampal subfields exhibit impaired long-term potentiation, an electrophysiological correlate of learning and memory. At the molecular level, immediate early genes are among the synaptic plasticity genes that are both induced by long-term potentiation and downregulated in the aged brain. In addition to revitalizing other aged tissues, exposure to factors in young blood counteracts age-related changes in these central nervous system parameters, although the identities of specific cognition-promoting factors or whether such activity exists in human plasma remains unknown. We hypothesized that plasma of an early developmental stage, namely umbilical cord plasma, provides a reservoir of such plasticity-promoting proteins. Here we show that human cord plasma treatment revitalizes the hippocampus and improves cognitive function in aged mice. Tissue inhibitor of metalloproteinases 2 (TIMP2), a blood-borne factor enriched in human cord plasma, young mouse plasma, and young mouse hippocampi, appears in the brain after systemic administration and increases synaptic plasticity and hippocampal-dependent cognition in aged mice. Depletion experiments in aged mice revealed TIMP2 to be necessary for the cognitive benefits conferred by cord plasma. We find that systemic pools of TIMP2 are necessary for spatial memory in young mice, while treatment of brain slices with TIMP2 antibody prevents long-term potentiation, arguing for previously unknown roles for TIMP2 in normal hippocampal function. Our findings reveal that human cord plasma contains plasticity-enhancing proteins of high translational value for targeting ageing- or disease-associated hippocampal dysfunction.
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Affiliation(s)
- Joseph M Castellano
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Kira I Mosher
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Neuroscience Graduate Program, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Rachelle J Abbey
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Center for Tissue Regeneration, Repair and Restoration, V.A. Palo Alto Healthcare System, Palo Alto, California 94304, USA
| | - Alisha A McBride
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Center for Tissue Regeneration, Repair and Restoration, V.A. Palo Alto Healthcare System, Palo Alto, California 94304, USA
| | - Michelle L James
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Molecular Imaging Program at Stanford, Radiology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Daniela Berdnik
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Center for Tissue Regeneration, Repair and Restoration, V.A. Palo Alto Healthcare System, Palo Alto, California 94304, USA
| | - Jadon C Shen
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Center for Tissue Regeneration, Repair and Restoration, V.A. Palo Alto Healthcare System, Palo Alto, California 94304, USA
| | - Bende Zou
- AfaSci Research Laboratories, Redwood City, California 94063, USA
| | - Xinmin S Xie
- AfaSci Research Laboratories, Redwood City, California 94063, USA.,Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Martha Tingle
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Izumi V Hinkson
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Center for Tissue Regeneration, Repair and Restoration, V.A. Palo Alto Healthcare System, Palo Alto, California 94304, USA
| | - Martin S Angst
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Tony Wyss-Coray
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California 94305, USA.,Paul F. Glenn Center for the Biology of Aging, Stanford University School of Medicine, Stanford, California 94305, USA.,Neuroscience Graduate Program, Stanford University School of Medicine, Stanford, California 94305, USA.,Center for Tissue Regeneration, Repair and Restoration, V.A. Palo Alto Healthcare System, Palo Alto, California 94304, USA
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4
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Kempermann G. Activity Dependency and Aging in the Regulation of Adult Neurogenesis. Cold Spring Harb Perspect Biol 2015; 7:a018929. [PMID: 26525149 PMCID: PMC4632662 DOI: 10.1101/cshperspect.a018929] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Age and activity might be considered the two antagonistic key regulators of adult neurogenesis. Adult neurogenesis decreases with age but remains present, albeit at a very low level, even in the oldest individuals. Activity, be it physical or cognitive, increases adult neurogenesis and thereby seems to counteract age effects. It is, thus, proposed that activity-dependent regulation of adult neurogenesis might contribute to some sort of "neural reserve," the brain's ability to compensate functional loss associated with aging or neurodegeneration. Activity can have nonspecific and specific effects on adult neurogenesis. Mechanistically, nonspecific stimuli that largely affect precursor cell stages might be related by the local microenvironment, whereas more specific, survival-promoting effects take place at later stages of neuronal development and require the synaptic integration of the new cell and its particular synaptic plasticity.
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Affiliation(s)
- Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden and Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, 01307 Dresden, Germany
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Paul S, Jeon WK, Bizon JL, Han JS. Interaction of basal forebrain cholinergic neurons with the glucocorticoid system in stress regulation and cognitive impairment. Front Aging Neurosci 2015; 7:43. [PMID: 25883567 PMCID: PMC4382969 DOI: 10.3389/fnagi.2015.00043] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/12/2015] [Indexed: 11/28/2022] Open
Abstract
A substantial number of studies on basal forebrain (BF) cholinergic neurons (BFCN) have provided compelling evidence for their role in the etiology of stress, cognitive aging, Alzheimer’s disease (AD), and other neurodegenerative diseases. BFCN project to a broad range of cortical sites and limbic structures, including the hippocampus, and are involved in stress and cognition. In particular, the hippocampus, the primary target tissue of the glucocorticoid stress hormones, is associated with cognitive function in tandem with hypothalamic-pituitary-adrenal (HPA) axis modulation. The present review summarizes glucocorticoid and HPA axis research to date in an effort to establish the manner in which stress affects the release of acetylcholine (ACh), glucocorticoids, and their receptor in the context of cognitive processes. We attempt to provide the molecular interactive link between the glucocorticoids and cholinergic system that contributes to BFCN degeneration in stress-induced acceleration of cognitive decline in aging and AD. We also discuss the importance of animal models in facilitating such studies for pharmacological use, to which could help decipher disease states and propose leads for pharmacological intervention.
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Affiliation(s)
- Saswati Paul
- Department of Biological Sciences, Konkuk University Seoul, South Korea
| | - Won Kyung Jeon
- Herbal Medicine Research Division, Korea Institute of Oriental Medicine Daejeon, South Korea
| | - Jennifer L Bizon
- Department of Neuroscience, College of Medicine, Evelyn F. and William L. McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Jung-Soo Han
- Department of Biological Sciences, Konkuk University Seoul, South Korea
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Marighetto A, Brayda-Bruno L, Etchamendy N. Studying the impact of aging on memory systems: contribution of two behavioral models in the mouse. Curr Top Behav Neurosci 2015; 10:67-89. [PMID: 21805395 DOI: 10.1007/7854_2011_151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the present chapter, we describe our own attempts to improve our understanding of the pathophysiology of memory in aging. First, we tried to improve animal models of memory degradations occurring in aging, and develop common behavioral tools between mice and humans. Second, we began to use these behavioral tools to identify the molecular/intracellular changes occurring within the integrate network of memory systems in order to bridge the gap between the molecular and system level of analysis. The chapter is divided into three parts (i) modeling aging-related degradation in declarative memory (DM) in mice, (ii) assessing the main components of working memory (WM) with a common radial-maze task in mice and humans and (iii) studying the role of the retinoid cellular signaling path in aging-related changes in memory systems.
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Affiliation(s)
- Aline Marighetto
- Neurocentre Magendie-Inserm U862, 146 Rue Leo Saignat, 33077, Bordeaux-Cedex, France,
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Kadakkuzha BM, Akhmedov K, Capo TR, Carvalloza AC, Fallahi M, Puthanveettil SV. Age-associated bidirectional modulation of gene expression in single identified R15 neuron of Aplysia. BMC Genomics 2013; 14:880. [PMID: 24330282 PMCID: PMC3909179 DOI: 10.1186/1471-2164-14-880] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Accepted: 12/05/2013] [Indexed: 01/06/2023] Open
Abstract
Background Despite the advances in our understanding of aging-associated behavioral decline, relatively little is known about how aging affects neural circuits that regulate specific behaviors, particularly the expression of genes in specific neural circuits during aging. We have addressed this by exploring a peptidergic neuron R15, an identified neuron of the marine snail Aplysia californica. R15 is implicated in reproduction and osmoregulation and responds to neurotransmitters such as acetylcholine, serotonin and glutamate and is characterized by its action potential bursts. Results We examined changes in gene expression in R15 neurons during aging by microarray analyses of RNAs from two different age groups, mature and old animals. Specifically we find that 1083 ESTs are differentially regulated in mature and old R15 neurons. Bioinformatics analyses of these genes have identified specific biological pathways that are up or downregulated in mature and old neurons. Comparison with human signaling networks using pathway analyses have identified three major networks [(1) cell signaling, cell morphology, and skeletal muscular system development (2) cell death and survival, cellular function maintenance and embryonic development and (3) neurological diseases, developmental and hereditary disorders] altered in old R15 neurons. Furthermore, qPCR analysis of single R15 neurons to quantify expression levels of candidate regulators involved in transcription (CREB1) and translation (S6K) showed that aging is associated with a decrease in expression of these regulators, and similar analysis in three other neurons (L7, L11 and R2) showed that gene expression change during aging could be bidirectional. Conclusions We find that aging is associated with bidirectional changes in gene expression. Detailed bioinformatics analyses and human homolog searches have identified specific biological processes and human-relevant signaling pathways in R15 that are affected during aging. Evaluation of gene expression changes in different neurons suggests specific transcriptomic signature of single neurons during aging.
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8
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Decreased levels of nuclear glucocorticoid receptor protein in the hippocampus of aged Long-Evans rats with cognitive impairment. Brain Res 2012; 1478:48-54. [PMID: 22971526 DOI: 10.1016/j.brainres.2012.08.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 08/20/2012] [Accepted: 08/21/2012] [Indexed: 11/22/2022]
Abstract
Previous studies using animal models of cognitive aging showed that hypothalamic-pituitary-adrenal (HPA) responses to stress are impaired and glucocorticoid receptor (GR) mRNA is decreased in cognitively impaired aged rats, compared with those in young rats and cognitively unimpaired aged rats. Increased HPA activity is associated with the loss of hippocampal corticosteroid receptors. In the current investigation, GR expressions in the hippocampus were examined in young and aged male Long-Evans rats whose spatial memory was initially assessed on the Morris water maze task. We evaluated GR protein level in the hippocampus in young and aged rats characterized on the basis of the spatial task. In the hippocampus of aged rats with spatial memory impairments, GR protein level was decreased in the nucleus but not in the cytosol, and levels of glucocorticoid response elements binding activity was decreased. These results suggest that GR signaling is impaired in the hippocampus of rats with cognitive impairment. Impaired GR signaling may contribute to HPA axis dysfunction in aged rats and aged humans with cognitive impairment.
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9
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Morris KA, Gold PE. Age-related impairments in memory and in CREB and pCREB expression in hippocampus and amygdala following inhibitory avoidance training. Mech Ageing Dev 2012; 133:291-9. [PMID: 22445851 PMCID: PMC3359401 DOI: 10.1016/j.mad.2012.03.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 02/27/2012] [Accepted: 03/06/2012] [Indexed: 01/09/2023]
Abstract
This experiment examined whether age-related changes in CREB and pCREB contribute to the rapid forgetting seen in aged animals. Young (3-month-old) and aged (24-month-old) Fischer-344 rats received inhibitory avoidance training with a low (0.2 mA, 0.4 s) or moderate (0.5 mA, 0.5 s) foot shock; memory was measured 7 days later. Other rats were euthanized 30 min after training, and CREB and pCREB expression levels were examined in the hippocampus, amygdala, and piriform cortex using immunohistochemistry. CREB levels decreased with age in the hippocampus and amygdala. After training with either shock level, young rats exhibited good memory and increases in pCREB levels in the hippocampus and amygdala. Aged rats exhibited good memory for the moderate but not the low shock but did not show increases in pCREB levels after either shock intensity. These results suggest that decreases in total CREB and in pCREB activation in the hippocampus and amygdala may contribute to rapid forgetting in aged rats. After moderate foot shock, the stable memory in old rats together with absence of CREB activation suggests either that CREB was phosphorylated in a spatiotemporal pattern other than analyzed here or that the stronger training conditions engaged alternate mechanisms that promote long-lasting memory.
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Affiliation(s)
- Ken A. Morris
- Neuroscience Program, Institute for Genomic Biology, University of Illinois at Urbana-Champaign
- College of Medicine, Institute for Genomic Biology, University of Illinois at Urbana-Champaign
| | - Paul E. Gold
- Neuroscience Program, Institute for Genomic Biology, University of Illinois at Urbana-Champaign
- Departments of Psychology, Psychiatry, Molecular and Integrative Physiology, and Bioengineering, Institute for Genomic Biology, University of Illinois at Urbana-Champaign
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10
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11beta-hydroxysteroid dehydrogenase type 1 deficiency prevents memory deficits with aging by switching from glucocorticoid receptor to mineralocorticoid receptor-mediated cognitive control. J Neurosci 2011; 31:4188-93. [PMID: 21411659 DOI: 10.1523/jneurosci.6145-10.2011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Local brain amplification of glucocorticoids (GCs) by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) plays a pivotal role in age-related memory deficits. 11β-HSD1 deficient mice are protected from spatial memory impairments with aging, but the underlying mechanisms are unknown. To determine which brain receptors [high-affinity mineralocorticoid receptors (MRs) or low-affinity glucocorticoid receptors (GRs)] are involved, spatial memory was measured in aged 11β-HSD1(-/-) mice before and during intracerebroventricular infusion (10 d) of spironolactone (MR antagonist) or RU486 (GR antagonist). Aged C57BL/6J control mice showed impaired spatial memory in the Y-maze; this improved with GR blockade, while MR blockade had no effect. In contrast, aged 11β-HSD1(-/-) mice showed intact spatial memory that became impaired with MR blockade, but not GR blockade. Hippocampal MR and GR mRNA expression and plasma corticosterone levels were not significantly altered with spironolactone or RU486 in either genotype. These data support the notion that 11β-HSD1 deficiency in aging mice leads to lower intracellular GC concentrations in brain, particularly in the hippocampus, which activate predominantly MRs to enhance memory, while in aging C57BL/6J controls, the increased intracellular GCs saturate MRs and activate predominantly GRs, thus impairing memory, an effect reversed by GR blockade.
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Matzel LD, Light KR, Wass C, Colas-Zelin D, Denman-Brice A, Waddel AC, Kolata S. Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility. Learn Mem 2011; 18:345-56. [PMID: 21521768 DOI: 10.1101/lm.2034711] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement.
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Affiliation(s)
- Louis D Matzel
- Department of Psychology, Program in Behavioral Neuroscience, Rutgers University, Piscataway, New Jersey 08854, USA.
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Hebda-Bauer EK, Luo J, Watson SJ, Akil H. Female CREBalphadelta- deficient mice show earlier age-related cognitive deficits than males. Neuroscience 2007; 150:260-72. [PMID: 18029102 DOI: 10.1016/j.neuroscience.2007.09.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 08/31/2007] [Accepted: 09/11/2007] [Indexed: 11/25/2022]
Abstract
Age-related changes in the hippocampus increase vulnerability to impaired learning and memory. Our goal is to understand how a genetic vulnerability to cognitive impairment can be modified by aging and sex. Mice with a mutation in the cAMP response element binding (CREB) protein gene (CREB(alphadelta-) deficient mice) have a mild cognitive impairment and show test condition-dependent learning and memory deficits. We tested three ages of CREB(alphadelta-) deficient and wild-type (WT) mice in two Morris water maze (MWM) protocols: four trials per day with a 3-5 min inter-trial interval (ITI) (MWM4) and two trials per day with a 1 min ITI (MWM2). All CREB(alphadelta-) deficient mice performed well in the easier MWM4, except for the aged females that performed poorly. In the harder MWM2, young male and female and middle-aged male CREB(alphadelta-) deficient mice performed well, but aged male and all middle-aged and aged female CREB(alphadelta-) deficient mice were impaired. These results show that mice with a genetic vulnerability to impaired learning and memory exhibit increased vulnerability with age that is most apparent among females. Thus, a genetic predisposition to cognitive impairment may render females more vulnerable than males to such deficits with age.
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Affiliation(s)
- E K Hebda-Bauer
- Molecular and Behavioral Neuroscience Institute, University of Michigan, 205 Zina Pitcher Place, Ann Arbor, MI 48109, USA.
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Abstract
The demographic changes in the foreseeable future stress the need for research on successful cognitive aging. Advancing age constitutes a primary risk factor for disease of the central nervous system most notably neurodegenerative disorders. The hippocampus is one of the brain regions that is prominently affected by neurodegeneration and functional decline even in what is still considered "normal aging". Plasticity is the basis for how the brain adapts to changes over time. The discovery of adult hippocampal neurogenesis has added a whole new dimension to research on structural plasticity in the adult and aging hippocampus. In this article, we briefly summarize and discuss recent findings on the regulation of adult neurogenesis with relevance to aging. Aging is an important co-variable for many regulatory mechanisms affecting adult neurogenesis but so far, only few studies have specifically addressed this interaction. We hypothesize that adult neurogenesis contributes to a neural reserve, i.e. the maintained potential for structural plasticity that allows compensation in situations of functional losses with aging. As such we propose that adult neurogenesis might contribute to the structural correlates of successful aging.
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Affiliation(s)
- Friederike Klempin
- Volkswagen Research Group at the Department of Experimental Neurology, Charité University Medicine Berlin, Schumannstr. 21-22, 10117 Berlin, Germany
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Countryman RA, Gold PE. Rapid forgetting of social transmission of food preferences in aged rats: relationship to hippocampal CREB activation. Learn Mem 2007; 14:350-8. [PMID: 17522026 PMCID: PMC1876759 DOI: 10.1101/lm.524907] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A major characteristic of age-related changes in memory in rodents is an increase in the rate of forgetting of new information, even when tests given soon after training reveal intact memory. Interference with CREB functions similarly results in rapid decay of memory. Using quantitative immunocytochemistry, the present experiment examined the number of CREB- and pCREB-immunoreactive neurons in three regions of the dorsal and ventral hippocampus (dentate gyrus, CA3, and CA1) as a function of age and training. Rats were trained in a social transmission of food preference task. Using different food pairings, memory was tested in each rat immediately and 1, 2, 3, and 7 d later. Both young and old rats had intact and comparable memory scores at the immediate and 24-h tests, but old rats exhibited more rapid forgetting thereafter relative to that of young rats. The main findings were that training resulted in large increases in the number of pCREB-immunoreactive cells throughout the hippocampus in both young and aged rats. However, particularly in the ventral hippocampus, the training-elicited increase in pCREB-positive neurons was significantly lower in old than in young rats. Based on Western blot analyses in a separate set of rats, CREB levels were not responsive to training but were lower in the ventral hippocampus of old rats than of young rats. The present findings suggest that lower activation of CREB after training may contribute to the rapid forgetting seen in aged rats.
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Affiliation(s)
- Renee A. Countryman
- Department of Psychology and Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
| | - Paul E. Gold
- Department of Psychology and Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
- Department of Psychiatry and Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61820, USA
- Corresponding author.E-mail ; fax (217) 244-5876
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Murphy GG, Shah V, Hell JW, Silva AJ. Investigation of age-related cognitive decline using mice as a model system: neurophysiological correlates. Am J Geriatr Psychiatry 2006; 14:1012-21. [PMID: 17138808 DOI: 10.1097/01.jgp.0000209404.54310.b3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Learning and memory impairments without overt pathology often accompany advancing age. To gain a better understanding of the underlying neuronal substrates associated with this age-related cognitive decline, the authors have begun to use mice as an animal model system. As described in the companion paper, mice exhibit age-related impairments in cognition. Here, the authors explore the possibility that age-related changes in neuronal function may be the result of deregulation of cytosolic free calcium homeostasis. METHODS Calcium homeostasis in young and aged mice was examined by measuring the slow afterhyperpolarization (sAHP) in hippocampal neurons as well as assessing voltage-dependent calcium channel mediated long-term potentiation (vdccLTP). In addition, putative changes in phosphorylation of the L-type channel Ca(V)1.2 by cAMP-dependent protein kinase were examined. RESULTS Both neurophysiological measures of calcium homeostasis indicated an increase in activity-dependent calcium influx. This increase was not the result of an age-related increase in phosphorylation of the L-type channel Ca(V)1.2 by cAMP-dependent protein kinase. CONCLUSIONS Like in other areas of biomedical research, mice have become an invaluable research tool in the investigation of learning and memory. It is expected that similar benefits can be realized by developing mouse models for age-related cognitive decline.
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Affiliation(s)
- Geoffrey G Murphy
- Department of Neurobiology, Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095-1761, USA
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Gardiner K. Transcriptional dysregulation in Down syndrome: predictions for altered protein complex stoichiometries and post-translational modifications, and consequences for learning/behavior genes ELK, CREB, and the estrogen and glucocorticoid receptors. Behav Genet 2006; 36:439-53. [PMID: 16502135 DOI: 10.1007/s10519-006-9051-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2005] [Accepted: 08/01/2005] [Indexed: 11/28/2022]
Abstract
The phenotype of Down syndrome, trisomy of chromosome 21, is hypothesized to be produced by the increased expression due to gene dosage of normal chromosome 21 genes. Chromosome 21 encodes a number of proteins that, based on experimental evidence or domain composition, are classed as transcription factors or their co-regulators. Other chromosome 21 proteins contribute to post-translational modification of transcription factors, including their phosphorylation, dephosphorylation and sumoylation. Several of these chromosome 21 proteins and the pathways in which they function have overlapping transcription factor specificities. Thus, altered stoichiometry in complexes and altered levels of activation of individual transcription factors may contribute to the Down syndrome phenotype by perturbation of downstream gene expression. Here we review recent data on four chromosome 21 proteins: NRIP1, GABPA, DYRK1A and SUMO3. We discuss the implications for activation of ELK, CREB, C/EBP alpha, beta estrogen and glucocorticoid receptors, and for expression of BDNF. Each of these proteins is relevant to learning, behavior and/or development and therefore perturbation of their activation may contribute to the Down syndrome phenotype.
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Kannanayakal TJ, Eberwine J. mRNA methods used in dissecting gene expression of the brain. Ageing Res Rev 2005; 4:513-28. [PMID: 16257586 DOI: 10.1016/j.arr.2005.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Accepted: 09/07/2005] [Indexed: 10/25/2022]
Affiliation(s)
- Theresa Joseph Kannanayakal
- Department of Pharmacology, University of Pennsylvania School of Medicine, 37 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA 19104-6084, USA
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