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Bienkowski MS, Sepehrband F, Kurniawan ND, Stanis J, Korobkova L, Khanjani N, Clark K, Hintiryan H, Miller CA, Dong HW. Homologous laminar organization of the mouse and human subiculum. Sci Rep 2021; 11:3729. [PMID: 33580088 PMCID: PMC7881248 DOI: 10.1038/s41598-021-81362-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 08/10/2020] [Indexed: 11/09/2022] Open
Abstract
The subiculum is the major output component of the hippocampal formation and one of the major brain structures most affected by Alzheimer's disease. Our previous work revealed a hidden laminar architecture within the mouse subiculum. However, the rotation of the hippocampal longitudinal axis across species makes it unclear how the laminar organization is represented in human subiculum. Using in situ hybridization data from the Allen Human Brain Atlas, we demonstrate that the human subiculum also contains complementary laminar gene expression patterns similar to the mouse. In addition, we provide evidence that the molecular domain boundaries in human subiculum correspond to microstructural differences observed in high resolution MRI and fiber density imaging. Finally, we show both similarities and differences in the gene expression profile of subiculum pyramidal cells within homologous lamina. Overall, we present a new 3D model of the anatomical organization of human subiculum and its evolution from the mouse.
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Affiliation(s)
- Michael S Bienkowski
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA. .,Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA.
| | - Farshid Sepehrband
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA.,Department of Neurology, Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA
| | - Nyoman D Kurniawan
- Center for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Jim Stanis
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA
| | - Laura Korobkova
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA
| | - Neda Khanjani
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA
| | - Kristi Clark
- Department of Neurology, Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA
| | - Houri Hintiryan
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA.,Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Carol A Miller
- Department of Pathology, Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA
| | - Hong-Wei Dong
- USC Stevens Neuroimaging and Informatics Institute, Laboratory of Neuro Imaging (LONI), Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA. .,Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA. .,Department of Neurology, Keck School of Medicine of University of Southern California, Los Angeles, CA, 90033, USA. .,Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA.
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52
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Ehsanifar M, Montazeri Z, Taheri MA, Rafati M, Behjati M, Karimian M. Hippocampal inflammation and oxidative stress following exposure to diesel exhaust nanoparticles in male and female mice. Neurochem Int 2021; 145:104989. [PMID: 33582162 DOI: 10.1016/j.neuint.2021.104989] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/17/2021] [Accepted: 02/10/2021] [Indexed: 01/30/2023]
Abstract
Air pollution exposure is among the most prevalent reasons for environmentally-induced oxidative stress and inflammation, both of which are involved in the development and progression of central nervous system (CNS) diseases. Ultrafine particles (UFPs) plays an important role in global air pollution and the diesel exhaust particles (DEPs) are the most important component in this regard. There are more than 40 toxic air pollutants in diesel exhaust (DE), which is one of the main constituents of an environmental pollutant and including particulate matter (PM) especially UFPs. Thus, in this study, adult female and male NMRI mice were exposed to DEPs (350-400 μg/m3) for 14 weeks (6 h per day and 5 days per week). After 14 weeks of exposure, expression of pro-inflammatory cytokines (IL-1α, IL-1β, IL-6, TNF-α), nNOS, HO1, NR2A, and NR2B and malondialdehyde (MDA) level were analyzed in various brain regions such as the hippocampus (HI) and olfactory bulb (OB). Exposure to DEPs caused neuroinflammation and oxidative stress in female and male mice. That these effects observed in females were less pronounced than in male mice. The male mice emerged to be more susceptible significantly than the female mice to induced neuroinflammation following DEPs exposure. Also, our findings indicate that long term exposure to DEPs results in altered expression of hippocampal NMDA receptor subunits, and suggests that gender can play important role in the modulating susceptibility to neurotoxicity induced by DEPs exposure.
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Affiliation(s)
- Mojtaba Ehsanifar
- Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, Iran.
| | - Zeinab Montazeri
- Institute of Endocrinology and Metabolism Research and Training Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Mehravar Rafati
- Department of Medical Physics and Radiology, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Mohaddeseh Behjati
- Shahid Rajaei Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Karimian
- Department of Molecular and Cell Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Iran
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53
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Prolonged Social Isolation, Started Early in Life, Impairs Cognitive Abilities in Rats Depending on Sex. Brain Sci 2020; 10:brainsci10110799. [PMID: 33143056 PMCID: PMC7692092 DOI: 10.3390/brainsci10110799] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 11/23/2022] Open
Abstract
Background: The chronic stress of social isolation is a valid predictor of cognitive pathology. This study aimed to compare the effects of long-term social isolation on female versus male Wistar rats’ learning and memory. We hypothesized that prolonged social isolation stress, which starts early in life, would affect learning in a sex-dependent manner. Methods: Social isolation started at the edge of early to mid-adolescence and lasted 9 months. The rat’s cognitive abilities were assessed by habituation and reactivity to novelty in the open field (OF) test, spatial memory in the Morris water maze (MWM), and the conditioned passive avoidance (PA) reflex. Basal serum corticosterone levels were assessed using an enzyme-linked immunosorbent assay. Results: Regardless of the housing conditions, females habituated to the OF under low illumination slower than males. Under bright light, the single-housed rats showed hyporeactivity to novelty. In the MWM, all the rats learned to locate the platform; however, on the first training day, the single-housed females’ speed was lower relative to other groups. Four months later, in the post-reminder probe trial, the single-housed rats reached the area around the platform site later, and only males, regardless of housing conditions, preferred the target quadrant. Single-housed rats, irrespective of sex, showed a PA deficit. There was a more pronounced conditioned fear in the single-housed males than in females. In both male and female rats, basal corticosterone levels in rat blood serum after 9 months of social isolation did not differ from that in the group-housed rats of the corresponding sex. Meanwhile, females’ basal corticosterone level was higher than in males, regardless of the housing conditions. The relative weight of the adrenal glands was increased only in single-housed females. Conclusions: Under long-term social isolation, started early in life, single-housed females compared with males showed more pronounced cognitive impairments in the MWM and PA paradigm, findings that specify their greater vulnerability to the stress of prolonged social isolation.
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54
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Pajkossy P, Szőllősi Á, Racsmány M. Pupil size changes signal hippocampus-related memory functions. Sci Rep 2020; 10:16393. [PMID: 33009460 PMCID: PMC7532445 DOI: 10.1038/s41598-020-73374-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 09/14/2020] [Indexed: 11/08/2022] Open
Abstract
A major task of episodic memory is to create unique, distinguishable representations of highly overlapping perceptual inputs. Several studies on this basic function have shown that it is based on the intact functioning of certain subregions of the hippocampus and is among the most sensitive behavioral indicators of mild cognitive impairment (MCI) and dementia. Here we assessed pupil dilation associated with performance in a widely used recognition paradigm that aims to uncover the intactness of fine-graded mnemonic discrimination. A sample of healthy undergraduate students was used. First, we showed that the correct discrimination between highly similar lure items and target items elicit larger pupil response than correct target identification. Second, we found that mnemonic discrimination is associated with larger pupil response in general as compared to target identification, regardless of whether the response was correct or not. These results suggest the pupil changes differentiate mnemonic discrimination and memory identification processes in recognition performance.
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Affiliation(s)
- Péter Pajkossy
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary.
- Department of Cognitive Science, Budapest University of Technology and Economics, Egry József u. 1, 1111, Budapest, Hungary.
| | - Ágnes Szőllősi
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Department of Cognitive Science, Budapest University of Technology and Economics, Egry József u. 1, 1111, Budapest, Hungary
| | - Mihály Racsmány
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Magyar tudósok körútja 2, 1117, Budapest, Hungary
- Department of Cognitive Science, Budapest University of Technology and Economics, Egry József u. 1, 1111, Budapest, Hungary
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Brito DVC, Gulmez Karaca K, Kupke J, Mudlaff F, Zeuch B, Gomes R, Lopes LV, Oliveira AMM. Modeling human age-associated increase in Gadd45γ expression leads to spatial recognition memory impairments in young adult mice. Neurobiol Aging 2020; 94:281-286. [PMID: 32711258 DOI: 10.1016/j.neurobiolaging.2020.06.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 05/22/2020] [Accepted: 06/27/2020] [Indexed: 12/18/2022]
Abstract
Aging is associated with the progressive decay of cognitive function. Hippocampus-dependent processes, such as the formation of spatial memory, are particularly vulnerable to aging. Currently, the molecular mechanisms responsible for age-dependent cognitive decline are largely unknown. Here, we investigated the expression and function of the growth arrest DNA damage gamma (Gadd45γ) during aging and cognition. We report that Gadd45γ expression is increased in the hippocampus of aged humans and that Gadd45γ overexpression in the young adult mouse hippocampus compromises cognition. Moreover, Gadd45γ overexpression in hippocampal neurons disrupted cAMP response element-binding protein signaling and the expression of well-established activity-regulated genes. This work shows that Gadd45γ expression is tightly controlled in the hippocampus and its disruption may be a mechanism contributing to age-related cognitive impairments observed in humans.
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Affiliation(s)
- David V C Brito
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Kubra Gulmez Karaca
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany; Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Janina Kupke
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Franziska Mudlaff
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Benjamin Zeuch
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany; Directors' Research, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Rui Gomes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - Luísa V Lopes
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina de Lisboa, Universidade de Lisboa, Lisbon, Portugal
| | - Ana M M Oliveira
- Department of Neurobiology, Interdisciplinary Centre for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany.
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56
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Severin D, Gallagher M, Kirkwood A. Afterhyperpolarization amplitude in CA1 pyramidal cells of aged Long-Evans rats characterized for individual differences. Neurobiol Aging 2020; 96:43-48. [PMID: 32932137 DOI: 10.1016/j.neurobiolaging.2020.07.022] [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: 04/09/2020] [Revised: 07/06/2020] [Accepted: 07/25/2020] [Indexed: 11/18/2022]
Abstract
Altered neural excitability is considered a prominent contributing factor to cognitive decline during aging. A clear example is the excess neural activity observed in several temporal lobe structures of cognitively impaired older individuals in rodents and humans. At a cellular level, aging-related changes in mechanisms regulating intrinsic excitability have been well examined in pyramidal cells of the CA1 hippocampal subfield. Studies in the inbred Fisher 344 rat strain document an age-related increase in the slow afterhyperpolarization (AHP) that normally occurs after a burst of action potentials, and serves to reduce subsequent firing. We evaluated the status of the AHP in the outbred Long-Evans rat, a well-established model for studying individual differences in neurocognitive aging. In contrast to the findings reported in the Fisher 344 rats, in the Long-Evan rats we detected a selective reduction in AHP in cognitively impaired aged individuals. We discuss plausible scenarios to account for these differences and also discuss possible implications of these differences.
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Affiliation(s)
- Daniel Severin
- Department of Neurosciences, Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Alfredo Kirkwood
- Department of Neurosciences, Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA.
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57
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Callow DD, Canada KL, Riggins T. Microstructural Integrity of the Hippocampus During Childhood: Relations With Age and Source Memory. Front Psychol 2020; 11:568953. [PMID: 33041934 PMCID: PMC7525028 DOI: 10.3389/fpsyg.2020.568953] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/19/2020] [Indexed: 12/30/2022] Open
Abstract
The hippocampus is a brain structure known to be important for memory. However, studies examining relations between hippocampal volume and memory across development yield mixed results. This may be due in part to the fact that volume is a coarser measure of hippocampal composition. Studies have begun to examine measures of diffusion, which capture characteristics of the microstructure of the hippocampus, and thus may provide additional information about the integrity of the underlying neural circuits. The present study applied this approach to a developmental period characterized by dramatic changes in both hippocampal microstructure and memory behavior - early childhood. Specifically, measures of hippocampal microstructural integrity were related to age and source memory performance in 93 children aged 4-8 years. Results revealed significant negative associations between hippocampal mean diffusivity and both age and memory, even after controlling for differences in hippocampal volume. These results suggest that hippocampal diffusion may provide additional, independent information about hippocampal integrity compared to volume, particularly during early childhood when important developmental changes have been proposed.
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Affiliation(s)
- Daniel D. Callow
- Department of Kinesiology, University of Maryland, College Park, MD, United States
- Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD, United States
| | - Kelsey L. Canada
- Department of Psychology, University of Maryland, College Park, MD, United States
| | - Tracy Riggins
- Department of Kinesiology, University of Maryland, College Park, MD, United States
- Department of Psychology, University of Maryland, College Park, MD, United States
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58
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Different patterns of recollection for matched real-world and laboratory-based episodes in younger and older adults. Cognition 2020; 202:104309. [DOI: 10.1016/j.cognition.2020.104309] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/12/2020] [Accepted: 04/13/2020] [Indexed: 11/19/2022]
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59
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Zakirov F, Krasilnikov A. Age-related differences in decision-making process in the context of healthy aging. BIO WEB OF CONFERENCES 2020. [DOI: 10.1051/bioconf/20202201022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
During aging cognitive functions change differently from others. Unlike most of the body systems, there is no clear decline pattern in cognitive processes. One of the most significant cognitive processes is decision-making, which defines social interactions, economical relationships, and risky behavior. Among factors influence decisionmaking process, individual lifelong experience is considered to be an important one. Obviously, older adults have more life experience, than the younger groups. However, the former often do not tend to rational choices and beneficial strategies. In this case it is important to assess how aging processes in brain contribute into searching for the most beneficial option during decision-making. On the basis of today’s studies about risky behavior, judgement of fairness, financial games, and modern neuroimaging data this review will observe and discuss age-related differences in decision-making. Thus, a correct cognitive profile of older adult in decision-making context can be determined.
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60
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Gardner RS, Gold PE, Korol DL. Inactivation of the striatum in aged rats rescues their ability to learn a hippocampus-sensitive spatial navigation task. Neurobiol Learn Mem 2020; 172:107231. [DOI: 10.1016/j.nlm.2020.107231] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/29/2020] [Accepted: 04/13/2020] [Indexed: 01/23/2023]
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61
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Weeks JC, Grady CL, Hasher L, Buchsbaum BR. Holding On to the Past: Older Adults Show Lingering Neural Activation of No-Longer-Relevant Items in Working Memory. J Cogn Neurosci 2020; 32:1946-1962. [PMID: 32573381 DOI: 10.1162/jocn_a_01596] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Goal-relevant information can be maintained in working memory over a brief delay interval to guide an upcoming decision. There is also evidence suggesting the existence of a complementary process: namely, the ability to suppress information that is no longer relevant to ongoing task goals. Moreover, this ability to suppress or inhibit irrelevant information appears to decline with age. In this study, we compared younger and older adults undergoing fMRI on a working memory task designed to address whether the modulation of neural representations of relevant and no-longer-relevant items during a delay interval is related to age and overall task performance. Following from the theoretical predictions of the inhibitory deficit hypothesis of aging, we hypothesized that older adults would show higher activation of no-longer-relevant items during a retention delay compared to young adults and that higher activation of these no-longer-relevant items would predict worse recognition memory accuracy for relevant items. Our results support this prediction and more generally demonstrate the importance of goal-driven modulation of neural activity in successful working memory maintenance. Furthermore, we showed that the largest age differences in the regulation of category-specific pattern activity during working memory maintenance were seen throughout the medial temporal lobe and prominently in the hippocampus, further establishing the importance of "long-term memory" retrieval mechanisms in the context of high-load working memory tasks that place large demands on attentional selection mechanisms.
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Affiliation(s)
- Jennifer C Weeks
- University of Toronto.,Rotman Research Institute at Baycrest, Toronto, Ontario, Canada
| | - Cheryl L Grady
- University of Toronto.,Rotman Research Institute at Baycrest, Toronto, Ontario, Canada
| | - Lynn Hasher
- University of Toronto.,Rotman Research Institute at Baycrest, Toronto, Ontario, Canada
| | - Bradley R Buchsbaum
- University of Toronto.,Rotman Research Institute at Baycrest, Toronto, Ontario, Canada
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Adult-Born Hippocampal Neurons Undergo Extended Development and Are Morphologically Distinct from Neonatally-Born Neurons. J Neurosci 2020; 40:5740-5756. [PMID: 32571837 DOI: 10.1523/jneurosci.1665-19.2020] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 02/28/2020] [Accepted: 05/04/2020] [Indexed: 11/21/2022] Open
Abstract
During immature stages, adult-born neurons pass through critical periods for survival and plasticity. It is generally assumed that by 2 months of age adult-born neurons are mature and equivalent to the broader neuronal population, raising questions of how they might contribute to hippocampal function in old age when neurogenesis has declined. However, few have examined adult-born neurons beyond the critical period or directly compared them to neurons born in infancy. Here, we used a retrovirus to visualize functionally relevant morphological features of 2- to 24-week-old adult-born neurons in male rats. From 2 to 7 weeks, neurons grew and attained a relatively mature phenotype. However, several features of 7-week-old neurons suggested a later wave of growth: these neurons had larger nuclei, thicker dendrites, and more dendritic filopodia than all other groups. Indeed, between 7 and 24 weeks, adult-born neurons gained additional dendritic branches, formed a second primary dendrite, acquired more mushroom spines, and had enlarged mossy fiber presynaptic terminals. Compared with neonatal-born neurons, old adult-born neurons had greater spine density, larger presynaptic terminals, and more putative efferent filopodial contacts onto inhibitory neurons. By integrating rates of cell birth and growth across the life span, we estimate that adult neurogenesis ultimately produces half of the cells and the majority of spines in the dentate gyrus. Critically, protracted development contributes to the plasticity of the hippocampus through to the end of life, even after cell production declines. Persistent differences from neonatal-born neurons may additionally endow adult-born neurons with unique functions even after they have matured.SIGNIFICANCE STATEMENT Neurogenesis occurs in the hippocampus throughout adult life and contributes to memory and emotion. It is generally assumed that new neurons have the greatest impact on behavior when they are immature and plastic. However, since neurogenesis declines dramatically with age, it is unclear how they might contribute to behavior later in life when cell proliferation has slowed. Here we find that newborn neurons mature over many months in rats and may end up with distinct morphological features compared with neurons born in infancy. Using a mathematical model, we estimate that a large fraction of neurons is added in adulthood. Moreover, their extended growth produces a reserve of plasticity that persists even after neurogenesis has declined to low rates.
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63
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Hou M, de Chastelaine M, Jayakumar M, Donley BE, Rugg MD. Recollection-related hippocampal fMRI effects predict longitudinal memory change in healthy older adults. Neuropsychologia 2020; 146:107537. [PMID: 32569610 DOI: 10.1016/j.neuropsychologia.2020.107537] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/11/2020] [Accepted: 06/12/2020] [Indexed: 02/07/2023]
Abstract
Prior fMRI studies have reported relationships between memory-related activity in the hippocampus and in-scanner memory performance, but whether such activity is predictive of longitudinal memory change remains unclear. Here, we administered a neuropsychological test battery to a sample of cognitively healthy older adults on three occasions, the second and third sessions occurring one month and three years after the first session. Structural and functional MRI data were acquired between the first two sessions. The fMRI data were derived from an associative recognition procedure and allowed estimation of hippocampal effects associated with both successful associative encoding and successful associative recognition (recollection). Baseline memory performance and memory change were evaluated using memory component scores derived from a principal components analysis of the neuropsychological test scores. Across participants, right hippocampal encoding effects correlated significantly with baseline memory performance after controlling for chronological age. Additionally, both left and right hippocampal associative recognition effects correlated negatively with longitudinal memory decline after controlling for age, and the relationship with the left hippocampal effect remained after also controlling for left hippocampal volume. Thus, in cognitively healthy older adults, the magnitude of hippocampal recollection effects appears to be a robust predictor of future memory change.
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Affiliation(s)
- Mingzhu Hou
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA.
| | - Marianne de Chastelaine
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Manasi Jayakumar
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Brian E Donley
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA
| | - Michael D Rugg
- Center for Vital Longevity and School of Behavioral and Brain Sciences, The University of Texas at Dallas, Dallas, TX, 75235, USA; School of Psychology, University of East Anglia, Norwich, NR4 7TJ, UK
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T1-11, an adenosine derivative, ameliorates aging-related behavioral physiology and senescence markers in aging mice. Aging (Albany NY) 2020; 12:10556-10577. [PMID: 32501291 PMCID: PMC7346012 DOI: 10.18632/aging.103279] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 04/20/2020] [Indexed: 12/25/2022]
Abstract
Aging is a natural human process. It is uniquely individual, taking into account experiences, lifestyle habits and environmental factors. However, many disorders and syndromes, such as osteoporosis, neurodegenerative disorders, cognitive decline etc., often come with aging. The present study was designed to investigate the possible anti-aging effect of N6-(4-hydroxybenzyl)adenine riboside (T1-11), an adenosine analog isolated from Gastrodia elata, in a mouse model of aging created by D-galactose (D-gal) and the underlying mechanism, as well as explore the role of adenosine signaling in aging. T1-11 activated A2AR and suppressed D-gal- and BeSO4-induced cellular senescence in vitro. In vivo results in mice revealed that T1-11 abated D-gal-induced reactive oxygen species generation and ameliorated cognitive decline by inducing neurogenesis and lowering D-gal-caused neuron death. T1-11 could be a potent agent for postponing senility and preventing aging-related neuroinflammation and neurodegeneration.
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65
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Xia C, Cao X, Cui L, Liu H, Wang S, Chen T. Anti-aging effect of the combination of Bifidobacterium longum and B. animalis in a d-galactose-treated mice. J Funct Foods 2020. [DOI: 10.1016/j.jff.2020.103938] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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66
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Syal C, Kosaraju J, Hamilton L, Aumont A, Chu A, Sarma SN, Thomas J, Seegobin M, Dilworth FJ, He L, Wondisford FE, Zimmermann R, Parent M, Fernandes K, Wang J. Dysregulated expression of monoacylglycerol lipase is a marker for anti-diabetic drug metformin-targeted therapy to correct impaired neurogenesis and spatial memory in Alzheimer's disease. Am J Cancer Res 2020; 10:6337-6360. [PMID: 32483456 PMCID: PMC7255032 DOI: 10.7150/thno.44962] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/28/2020] [Indexed: 12/17/2022] Open
Abstract
Rationale: Monoacylglycerol lipase (Mgll), a hydrolase that breaks down the endocannabinoid 2-arachidonoyl glycerol (2-AG) to produce arachidonic acid (ARA), is a potential target for neurodegenerative diseases, such as Alzheimer's disease (AD). Increasing evidence shows that impairment of adult neurogenesis by perturbed lipid metabolism predisposes patients to AD. However, it remains unknown what causes aberrant expression of Mgll in AD and how Mgll-regulated lipid metabolism impacts adult neurogenesis, thus predisposing to AD during aging. Here, we identify Mgll as an aging-induced factor that impairs adult neurogenesis and spatial memory in AD, and show that metformin, an FDA-approved anti-diabetic drug, can reduce the expression of Mgll to reverse impaired adult neurogenesis, prevent spatial memory decline and reduce β-amyloid accumulation. Methods: Mgll expression was assessed in both human AD patient post-mortem hippocampal tissues and 3xTg-AD mouse model. In addition, we used both the 3xTg-AD animal model and the CbpS436A genetic knock-in mouse model to identify that elevated Mgll expression is caused by the attenuation of the aPKC-CBP pathway, involving atypical protein kinase C (aPKC)-stimulated Ser436 phosphorylation of histone acetyltransferase CBP through biochemical methods. Furthermore, we performed in vivo adult neurogenesis assay with BrdU/EdU labelling and Morris water maze task in both animal models following pharmacological treatments to show the key role of Mgll in metformin-corrected neurogenesis and spatial memory deficits of AD through reactivating the aPKC-CBP pathway. Finally, we performed in vitro adult neurosphere assays using both animal models to study the role of the aPKC-CBP mediated Mgll repression in determining adult neural stem/progenitor cell (NPC) fate. Results: Here, we demonstrate that aging-dependent induction of Mgll is observed in the 3xTg-AD model and human AD patient post-mortem hippocampal tissues. Importantly, we discover that elevated Mgll expression is caused by the attenuation of the aPKC-CBP pathway. The accumulation of Mgll in the 3xTg-AD mice reduces the genesis of newborn neurons and perturbs spatial memory. However, we find that metformin-stimulated aPKC-CBP pathway decreases Mgll expression to recover these deficits in 3xTg-AD. In addition, we reveal that elevated Mgll levels in cultured adult NPCs from both 3xTg-AD and CbpS436A animal models are responsible for their NPC neuronal differentiation deficits. Conclusion: Our findings set the stage for development of a clinical protocol where Mgll would serve as a biomarker in early stages of AD to identify potential metformin-responsive AD patients to restore their neurogenesis and spatial memory.
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Abstract
In the present study we investigated the long-standing question whether and why emotionally arousing memories are more distinct as compared to neutral experiences. We assumed that memory benefits from the distinctiveness of emotional information, and that emotions affect encoding by reducing interference among overlapping memory representations. Since pattern separation is the process which minimizes interference between memory representations with similar features, we examined the behavioral manifestation of putative neural mechanisms enabling pattern separation (i.e. mnemonic discrimination) for emotionally arousing materials using the Mnemonic Similarity Task with negative, positive, and neutral images as stimuli. Immediately after incidental encoding, subjects were presented with stimuli they had seen at encoding and also with new items. Crucially, participants were also presented with lure images that were visually similar to ones they had seen before. Response options were old, new, and similar. Our results showed that individuals were better in discriminating between similar, emotionally arousing memories, when compared to the neutral stimuli. Moreover, this so-called lure discrimination performance was better for the negative images, than it was for the positive stimuli. Finally, we showed that the high arousing negative stimuli were better separated than the low arousing negative stimuli, and a similar pattern of results was found for the positive items. Altogether, these findings suggest that lure discrimination is modulated by arousal and not by valence. We argue that noradrenergic activity might facilitate interference resolution among memory representations with similar features, and that superior pattern separation might play a key role in memory enhancement for emotional experiences.
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Foster CM, Giovanello KS. Domain general processes moderate age-related performance differences on the mnemonic similarity task. Memory 2020; 28:528-536. [PMID: 32204659 DOI: 10.1080/09658211.2020.1743321] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Several prominent domain general theories (e.g., processing speed and inhibitory function) have been developed to explain cognitive changes associated with aging. A bias to "pattern complete" in aging has also been suggested to account for some of the age-related changes in episodic memory. The current experiments test whether domain-general processes of cognitive aging moderate age-related performance decrements on the mnemonic similarity task, a task thought to rely on hippocampal pattern separation and completion. The study phase of the mnemonic similarity task, a memory task with old, new, and similar trials at recognition, was manipulated to assess the contribution of processing speed (Experiment 1 - different encoding times) and inhibitory function (Experiment 2 - item-level directed forgetting) to age-related performance differences in a sample of 100 healthy younger and older adults. Both experiments exhibited significant interactions between age group and encoding manipulation, replicating a decrement in performance in older adults, and indicating that processing speed and inhibitory function moderate this effect. Results suggest that age-related differences in performance on the mnemonic similarity task can at least partially be accounted for by experimental manipulations of domain general processes that also decline with age.
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Affiliation(s)
- Chris M Foster
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kelly S Giovanello
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Biomedical Research Imaging Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Increasing neurogenesis refines hippocampal activity rejuvenating navigational learning strategies and contextual memory throughout life. Nat Commun 2020; 11:135. [PMID: 31919362 PMCID: PMC6952376 DOI: 10.1038/s41467-019-14026-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 12/12/2019] [Indexed: 01/24/2023] Open
Abstract
Functional plasticity of the brain decreases during ageing causing marked deficits in contextual learning, allocentric navigation and episodic memory. Adult neurogenesis is a prime example of hippocampal plasticity promoting the contextualisation of information and dramatically decreases during ageing. We found that a genetically-driven expansion of neural stem cells by overexpression of the cell cycle regulators Cdk4/cyclinD1 compensated the age-related decline in neurogenesis. This triggered an overall inhibitory effect on the trisynaptic hippocampal circuit resulting in a changed profile of CA1 sharp-wave ripples known to underlie memory consolidation. Most importantly, increased neurogenesis rescued the age-related switch from hippocampal to striatal learning strategies by rescuing allocentric navigation and contextual memory. Our study demonstrates that critical aspects of hippocampal function can be reversed in old age, or compensated throughout life, by exploiting the brain’s endogenous reserve of neural stem cells. Ageing affects several brain areas causing a decrease in cognitive abilities and memory. We find that increasing the endogenous potential of the hippocampus to generate new neurons throughout life rejuvenates learning and memory, indicating that neural reserves can be exploited during ageing to compensate for age- or disease-related cognitive impairments.
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70
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Kwapis JL, Alaghband Y, Keiser AA, Dong TN, Michael CM, Rhee D, Shu G, Dang RT, Matheos DP, Wood MA. Aging mice show impaired memory updating in the novel OUL updating paradigm. Neuropsychopharmacology 2020; 45:337-346. [PMID: 31202213 PMCID: PMC6901557 DOI: 10.1038/s41386-019-0438-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/31/2019] [Accepted: 06/07/2019] [Indexed: 11/09/2022]
Abstract
Memories do not persist in a permanent, static state but instead must be dynamically modified in response to new information. Although new memory formation is typically studied in a laboratory setting, most real-world associations are modifications to existing memories, particularly in the aging, experienced brain. To date, the field has lacked a simple behavioral paradigm that can measure whether original and updated information is remembered in a single test session. To address this gap, we have developed a novel memory updating paradigm, called the Objects in Updated Locations (OUL) task that is capable of assessing memory updating in a non-stressful task that is appropriate for both young and old rodents. We first show that young mice successfully remember both the original memory and the updated information in OUL. Next, we demonstrate that intrahippocampal infusion of the protein synthesis inhibitor anisomycin disrupts both the updated information and the original memory at test, suggesting that memory updating in OUL engages the original memory. To verify this, we used the Arc CatFISH technique to show that the OUL update session reactivates a largely overlapping set of neurons as the original memory. Finally, using OUL, we show that memory updating is impaired in aging, 18-m.o. mice. Together, these results demonstrate that hippocampal memory updating is impaired with aging and establish that the OUL paradigm is an effective, sensitive method of assessing memory updating in rodents.
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Affiliation(s)
- Janine L Kwapis
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA.
- Department of Biology, Center for Molecular Investigation of Neurological Disorders (CMIND), Pennsylvania State University, University Park, PA, 16802, USA.
| | - Yasaman Alaghband
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Ashley A Keiser
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Tri N Dong
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Christina M Michael
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Diane Rhee
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Guanhua Shu
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Richard T Dang
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Dina P Matheos
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
| | - Marcelo A Wood
- Department of Neurobiology and Behavior, Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, 92697, USA
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Hentrich T, Wassouf Z, Riess O, Schulze-Hentrich JM. SNCA overexpression disturbs hippocampal gene expression trajectories in midlife. Aging (Albany NY) 2019; 10:4024-4041. [PMID: 30543522 PMCID: PMC6326667 DOI: 10.18632/aging.101691] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 11/29/2018] [Indexed: 02/06/2023]
Abstract
Synucleinopathies like Parkinson's disease and dementia with Lewy bodies originate from a complex and still largely enigmatic interplay of genetic predisposition, age, and environmental factors. While progressively declining motor functions hallmark late-life symptoms, first signs of the disease often surface already decades earlier during midlife. To better understand early disease stages with respect to the genetic, temporal, and environmental dimension, we interrogated hippocampal transcriptome data obtained during midlife for a mouse model overexpressing human SNCA, a pivotal gene in synucleinopathies, under different environments. To relate differentially expressed genes to human, we integrated expression signatures for aging and Parkinson's disease. We identified two distinctive modes of age-dependent disturbances: First, cellular processes seemingly activated too early that reflected advanced stages of age and, second, typical longitudinal adaptations of the system that no longer occurred during midlife. Environmental enrichment prevented both disturbances modes despite persistent SNCA overload. Together, our results caution the view that expression changes characterising early stages of SNCA-related pathology reflect accelerated aging alone. Instead, we provide evidence that failure to undergo healthy adaptions during midlife represents a second origin of disturbances. This bimodal disturbance principle could inform therapeutic efforts to distinguish between preventive and restorative attempts to target the disease.
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Affiliation(s)
- Thomas Hentrich
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Zinah Wassouf
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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Rojic-Becker D, Portero-Tresserra M, Martí-Nicolovius M, Vale-Martínez A, Guillazo-Blanch G. Caloric restriction modulates the monoaminergic and glutamatergic systems in the hippocampus, and attenuates age-dependent spatial memory decline. Neurobiol Learn Mem 2019; 166:107107. [DOI: 10.1016/j.nlm.2019.107107] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 12/27/2022]
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Kosmidis S, Polyzos A, Harvey L, Youssef M, Denny CA, Dranovsky A, Kandel ER. RbAp48 Protein Is a Critical Component of GPR158/OCN Signaling and Ameliorates Age-Related Memory Loss. Cell Rep 2019; 25:959-973.e6. [PMID: 30355501 PMCID: PMC7725275 DOI: 10.1016/j.celrep.2018.09.077] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 06/25/2018] [Accepted: 09/24/2018] [Indexed: 10/28/2022] Open
Abstract
Precisely deciphering the molecular mechanisms of age-related memory loss is crucial to create appropriate therapeutic interventions. We have previously shown that the histone-binding protein RbAp48/Rbbp4 is a molecular determinant of Age-Related Memory Loss. By exploring how this protein regulates the genomic landscape of the hippocampal circuit, we find that RbAp48 controls the expression of BDNF and GPR158 proteins, both critical components of osteocalcin (OCN) signaling in the mouse hippocampus. We show that inhibition of RbAp48 in the hippocampal formation inhibits OCN's beneficial functions in cognition and causes deficits in discrimination memory. In turn, disruption of OCN/GPR158 signaling leads to the downregulation of RbAp48 protein, mimicking the discrimination memory deficits observed in the aged hippocampus. We also show that activation of the OCN/GPR158 pathway increases the expression of RbAp48 in the aged dentate gyrus and rescues age-related memory loss.
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Affiliation(s)
- Stylianos Kosmidis
- Department of Neuroscience, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10032, USA
| | - Alexandros Polyzos
- Biomedical Research Foundation of the Academy of Athens, 115 27 Athens, Greece; Department of Medicine, Weill Cornell Medical College, New York, NY 10065, USA
| | - Lucas Harvey
- Department of Neuroscience, Columbia University, New York, NY 10032, USA; Howard Hughes Medical Institute, Columbia University, New York, NY 10032, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10032, USA
| | - Mary Youssef
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
| | - Christine A Denny
- Department of Psychiatry, Columbia University, New York, NY 10032, USA; Division of Systems Neuroscience, New York State Psychiatric Institute (NYSPI)/Research Foundation for Mental Hygiene, Inc. (RFMH), New York, NY 10032, USA
| | - Alex Dranovsky
- New York State Psychiatric Institute, New York, NY 10032, USA; Department of Psychiatry, Columbia University, New York, NY 10032, USA
| | - Eric R Kandel
- Department of Neuroscience, Columbia University, New York, NY 10032, USA; New York State Psychiatric Institute, New York, NY 10032, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10032, USA.
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74
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Short AK, Baram TZ. Early-life adversity and neurological disease: age-old questions and novel answers. Nat Rev Neurol 2019; 15:657-669. [PMID: 31530940 PMCID: PMC7261498 DOI: 10.1038/s41582-019-0246-5] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2019] [Indexed: 12/24/2022]
Abstract
Neurological illnesses, including cognitive impairment, memory decline and dementia, affect over 50 million people worldwide, imposing a substantial burden on individuals and society. These disorders arise from a combination of genetic, environmental and experiential factors, with the latter two factors having the greatest impact during sensitive periods in development. In this Review, we focus on the contribution of adverse early-life experiences to aberrant brain maturation, which might underlie vulnerability to cognitive brain disorders. Specifically, we draw on recent robust discoveries from diverse disciplines, encompassing human studies and experimental models. These discoveries suggest that early-life adversity, especially in the perinatal period, influences the maturation of brain circuits involved in cognition. Importantly, new findings suggest that fragmented and unpredictable environmental and parental signals comprise a novel potent type of adversity, which contributes to subsequent vulnerabilities to cognitive illnesses via mechanisms involving disordered maturation of brain 'wiring'.
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Affiliation(s)
- Annabel K Short
- Departments of Anatomy and Neruobiology, University of California-Irvine, Irvine, CA, USA
- Departments of Pediatrics, University of California-Irvine, Irvine, CA, USA
| | - Tallie Z Baram
- Departments of Anatomy and Neruobiology, University of California-Irvine, Irvine, CA, USA.
- Departments of Pediatrics, University of California-Irvine, Irvine, CA, USA.
- Departments of Neurology, University of California-Irvine, Irvine, CA, USA.
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75
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Nunes PT, Kipp BT, Reitz NL, Savage LM. Aging with alcohol-related brain damage: Critical brain circuits associated with cognitive dysfunction. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2019; 148:101-168. [PMID: 31733663 PMCID: PMC7372724 DOI: 10.1016/bs.irn.2019.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alcoholism is associated with brain damage and impaired cognitive functioning. The relative contributions of different etiological factors, such as alcohol, thiamine deficiency and age vulnerability, to the development of alcohol-related neuropathology and cognitive impairment are still poorly understood. One reason for this quandary is that both alcohol toxicity and thiamine deficiency produce brain damage and cognitive problems that can be modulated by age at exposure, aging following alcohol toxicity or thiamine deficiency, and aging during chronic alcohol exposure. Pre-clinical models of alcohol-related brain damage (ARBD) have elucidated some of the contributions of ethanol toxicity and thiamine deficiency to neuroinflammation, neuronal loss and functional deficits. However, the critical variable of age at the time of exposure or long-term aging with ARBD has been relatively ignored. Acute thiamine deficiency created a massive increase in neuroimmune genes and proteins within the thalamus and significant increases within the hippocampus and frontal cortex. Chronic ethanol treatment throughout adulthood produced very minor fluctuations in neuroimmune genes, regardless of brain region. Intermittent "binge-type" ethanol during the adolescent period established an intermediate neuroinflammatory response in the hippocampus and frontal cortex, that can persist into adulthood. Chronic excessive drinking throughout adulthood, adolescent intermittent ethanol exposure, and thiamine deficiency all led to a loss of the cholinergic neuronal phenotype within the basal forebrain, reduced hippocampal neurogenesis, and alterations in the frontal cortex. Only thiamine deficiency results in gross pathological lesions of the thalamus. The behavioral impairment following these types of treatments is hierarchical: Thiamine deficiency produces the greatest impairment of hippocampal- and prefrontal-dependent behaviors, chronic ethanol drinking ensues mild impairments on both types of tasks and adolescent intermittent ethanol exposure leads to impairments on frontocortical tasks, with sparing on most hippocampal-dependent tasks. However, our preliminary data suggest that as rodents age following adolescent intermittent ethanol exposure, hippocampal functional deficits began to emerge. A necessary requirement for the advancement of understanding the neural consequences of alcoholism is a more comprehensive assessment and understanding of how excessive alcohol drinking at different development periods (adolescence, early adulthood, middle-aged and aged) influences the trajectory of the aging process, including pathological aging and disease.
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Affiliation(s)
- Polliana Toledo Nunes
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University, State University of New York, Binghamton, NY, United States
| | - Brian T Kipp
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University, State University of New York, Binghamton, NY, United States
| | - Nicole L Reitz
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University, State University of New York, Binghamton, NY, United States
| | - Lisa M Savage
- Developmental Exposure Alcohol Research Center, Behavioral Neuroscience Program, Department of Psychology, Binghamton University, State University of New York, Binghamton, NY, United States.
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76
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Multi-input Synapses, but Not LTP-Strengthened Synapses, Correlate with Hippocampal Memory Storage in Aged Mice. Curr Biol 2019; 29:3600-3610.e4. [PMID: 31630953 PMCID: PMC6839404 DOI: 10.1016/j.cub.2019.08.064] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/05/2019] [Accepted: 08/22/2019] [Indexed: 12/18/2022]
Abstract
Long-lasting changes at synapses enable memory storage in the brain. Although aging is associated with impaired memory formation, it is not known whether the synaptic underpinnings of memory storage differ with age. Using a training schedule that results in the same behavioral memory formation in young and aged mice, we examined synapse ultrastructure and molecular signaling in the hippocampus after contextual fear conditioning. Only in young, but not old mice, contextual fear memory formation was associated with synaptic changes that characterize well-known, long-term potentiation, a strengthening of existing synapses with one input. Instead, old-age memory was correlated with generation of multi-innervated dendritic spines (MISs), which are predominantly two-input synapses formed by the attraction of an additional excitatory, presynaptic terminal onto an existing synapse. Accordingly, a blocker used to inhibit MIS generation impaired contextual fear memory only in old mice. Our results reveal how the synaptic basis of hippocampal memory storage changes with age and suggest that these distinct memory-storing mechanisms may explain impaired updating in old age. Aged mice form contextual memory like young mice, but reconsolidation is impaired Only in young mice is contextual memory formation associated with structural LTP In aged mice, contextual memory formation correlates with multi-innervated spines Inhibition of multi-innervated spines impairs memory in aged but not young mice
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Reduced cognitive performance in aged rats correlates with increased excitation/inhibition ratio in the dentate gyrus in response to lateral entorhinal input. Neurobiol Aging 2019; 82:120-127. [DOI: 10.1016/j.neurobiolaging.2019.07.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 11/18/2022]
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78
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Cuanalo-Contreras K, Moreno-Gonzalez I. Natural Products as Modulators of the Proteostasis Machinery: Implications in Neurodegenerative Diseases. Int J Mol Sci 2019; 20:ijms20194666. [PMID: 31547084 PMCID: PMC6801507 DOI: 10.3390/ijms20194666] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 09/13/2019] [Accepted: 09/15/2019] [Indexed: 02/07/2023] Open
Abstract
Proteins play crucial and diverse roles within the cell. To exert their biological function they must fold to acquire an appropriate three-dimensional conformation. Once their function is fulfilled, they need to be properly degraded to hamper any possible damage. Protein homeostasis or proteostasis comprises a complex interconnected network that regulates different steps of the protein quality control, from synthesis and folding, to degradation. Due to the primary role of proteins in cellular function, the integrity of this network is critical to assure functionality and health across lifespan. Proteostasis failure has been reported in the context of aging and neurodegeneration, such as Alzheimer’s and Parkinson’s disease. Therefore, targeting the proteostasis elements emerges as a promising neuroprotective therapeutic approach to prevent or ameliorate the progression of these disorders. A variety of natural products are known to be neuroprotective by protein homeostasis interaction. In this review, we will focus on the current knowledge regarding the use of natural products as modulators of different components of the proteostasis machinery within the framework of age-associated neurodegenerative diseases.
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Affiliation(s)
- Karina Cuanalo-Contreras
- The Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX 77030, USA.
| | - Ines Moreno-Gonzalez
- The Mitchell Center for Alzheimer's Disease and Related Brain Disorders, Department of Neurology, The University of Texas Houston Health Science Center at Houston, Houston, TX 77030, USA.
- Departamento Biologia Celular, Genetica y Fisiologia, Instituto de Investigacion Biomedica de Malaga-IBIMA, Facultad de Ciencias, Universidad de Malaga, 28031 Madrid, Spain.
- Networking Research Center on Neurodegenerative Diseases (CIBERNED), 28031 Madrid, Spain.
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79
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Devinsky O, Boesch JM, Cerda-Gonzalez S, Coffey B, Davis K, Friedman D, Hainline B, Houpt K, Lieberman D, Perry P, Prüss H, Samuels MA, Small GW, Volk H, Summerfield A, Vite C, Wisniewski T, Natterson-Horowitz B. A cross-species approach to disorders affecting brain and behaviour. Nat Rev Neurol 2019; 14:677-686. [PMID: 30287906 DOI: 10.1038/s41582-018-0074-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Structural and functional elements of biological systems are highly conserved across vertebrates. Many neurological and psychiatric conditions affect both humans and animals. A cross-species approach to the study of brain and behaviour can advance our understanding of human disorders via the identification of unrecognized natural models of spontaneous disorders, thus revealing novel factors that increase vulnerability or resilience, and via the assessment of potential therapies. Moreover, diagnostic and therapeutic advances in human neurology and psychiatry can often be adapted for veterinary patients. However, clinical and research collaborations between physicians and veterinarians remain limited, leaving this wealth of comparative information largely untapped. Here, we review pain, cognitive decline syndromes, epilepsy, anxiety and compulsions, autoimmune and infectious encephalitides and mismatch disorders across a range of animal species, looking for novel insights with translational potential. This comparative perspective can help generate novel hypotheses, expand and improve clinical trials and identify natural animal models of disease resistance and vulnerability.
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Affiliation(s)
- Orrin Devinsky
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA.
| | - Jordyn M Boesch
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | | | - Barbara Coffey
- Department of Child and Adolescent Psychiatry, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kathryn Davis
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel Friedman
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA
| | - Brian Hainline
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA
| | - Katherine Houpt
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Daniel Lieberman
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Pamela Perry
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Harald Prüss
- Department of Neurology with Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany, and German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | | | - Gary W Small
- University of California-Los Angeles (UCLA) Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Holger Volk
- Veterinary Neurology and Neurosurgery, The Royal Veterinary College, University of London, London, UK
| | - Artur Summerfield
- Institute of Virology and Immunology and Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Charles Vite
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas Wisniewski
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA
| | - Barbara Natterson-Horowitz
- Department of Ecology and Evolutionary Biology, Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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80
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Tronson NC, Keiser AA. A Dynamic Memory Systems Framework for Sex Differences in Fear Memory. Trends Neurosci 2019; 42:680-692. [PMID: 31473031 DOI: 10.1016/j.tins.2019.07.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 06/17/2019] [Accepted: 07/29/2019] [Indexed: 01/04/2023]
Abstract
Emerging research demonstrates that a pattern of overlapping but distinct molecular and circuit mechanisms are engaged by males and females during memory tasks. Importantly, sex differences in neural mechanisms and behavioral strategies are evident even when performance on a memory task is similar between females and males. We propose that sex differences in memory may be best understood within a dynamic memory systems framework. Specifically, sex differences in hormonal influences and neural circuit development result in biases in the circuits engaged and the information preferentially stored or retrieved in males and females. By using animal models to understand the neural networks and molecular mechanisms required for memory in both sexes, we can gain crucial insights into sex and gender biases in disorders including post-traumatic stress disorder (PTSD) in humans.
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Affiliation(s)
- Natalie C Tronson
- Psychology Department, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Ashley A Keiser
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA
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81
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Cole RC, Hazeltine E, Weng TB, Wharff C, DuBose LE, Schmid P, Sigurdsson G, Magnotta VA, Pierce GL, Voss MW. Cardiorespiratory fitness and hippocampal volume predict faster episodic associative learning in older adults. Hippocampus 2019; 30:143-155. [PMID: 31461198 DOI: 10.1002/hipo.23151] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/06/2019] [Accepted: 08/09/2019] [Indexed: 01/05/2023]
Abstract
Declining episodic memory is common among otherwise healthy older adults, in part due to negative effects of aging on hippocampal circuits. However, there is significant variability between individuals in severity of aging effects on the hippocampus and subsequent memory decline. Importantly, variability may be influenced by modifiable protective physiological factors such as cardiorespiratory fitness (CRF). More research is needed to better understand which aspects of cognition that decline with aging benefit most from CRF. The current study evaluated the relation of CRF with learning rate on the episodic associative learning (EAL) task, a task designed specifically to target hippocampal-dependent relational binding and to evaluate learning with repeated occurrences. Results show higher CRF was associated with faster learning rate. Larger hippocampal volume was also associated with faster learning rate, though hippocampal volume did not mediate the relationship between CRF and learning rate. Furthermore, to support the distinction between learning item relations and learning higher-order sequences, which declines with aging but is largely reliant on extra-hippocampal learning systems, we found learning rate on the EAL task was not related to motor sequence learning on the alternating serial reaction time task. Motor sequence learning was also not correlated with hippocampal volume. Thus, for the first time, we show that both higher CRF and larger hippocampal volume in healthy older adults are related to enhanced rate of relational memory acquisition.
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Affiliation(s)
- Rachel C Cole
- Department of Neurology, University of Iowa, Iowa City, Iowa
| | - Eliot Hazeltine
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa.,Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa
| | - Timothy B Weng
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa
| | - Conner Wharff
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa
| | - Lyndsey E DuBose
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa
| | - Phillip Schmid
- Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Gardar Sigurdsson
- Department of Internal Medicine, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Vincent A Magnotta
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa.,Department of Radiology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Gary L Pierce
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa
| | - Michelle W Voss
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, Iowa.,Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa
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82
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Lowe AJ, Paquola C, Vos de Wael R, Girn M, Lariviere S, Tavakol S, Caldairou B, Royer J, Schrader DV, Bernasconi A, Bernasconi N, Spreng RN, Bernhardt BC. Targeting age-related differences in brain and cognition with multimodal imaging and connectome topography profiling. Hum Brain Mapp 2019; 40:5213-5230. [PMID: 31444896 PMCID: PMC6864903 DOI: 10.1002/hbm.24767] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 07/29/2019] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Aging is characterized by accumulation of structural and metabolic changes in the brain. Recent studies suggest transmodal brain networks are especially sensitive to aging, which, we hypothesize, may be due to their apical position in the cortical hierarchy. Studying an open‐access healthy cohort (n = 102, age range = 30–89 years) with MRI and Aβ PET data, we estimated age‐related cortical thinning, hippocampal atrophy and Aβ deposition. In addition to carrying out surface‐based morphological and metabolic mapping experiments, we stratified effects along neocortical and hippocampal resting‐state functional connectome gradients derived from independent datasets. The cortical gradient depicts an axis of functional differentiation from sensory‐motor regions to transmodal regions, whereas the hippocampal gradient recapitulates its long‐axis. While age‐related thinning and increased Aβ deposition occurred across the entire cortical topography, increased Aβ deposition was especially pronounced toward higher‐order transmodal regions. Age‐related atrophy was greater toward the posterior end of the hippocampal long‐axis. No significant effect of age on Aβ deposition in the hippocampus was observed. Imaging markers correlated with behavioral measures of fluid intelligence and episodic memory in a topography‐specific manner, confirmed using both univariate as well as multivariate analyses. Our results strengthen existing evidence of structural and metabolic change in the aging brain and support the use of connectivity gradients as a compact framework to analyze and conceptualize brain‐based biomarkers of aging.
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Affiliation(s)
- Alexander J Lowe
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Casey Paquola
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Reinder Vos de Wael
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Manesh Girn
- Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
| | - Sara Lariviere
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Shahin Tavakol
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Benoit Caldairou
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Jessica Royer
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Dewi V Schrader
- Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
| | - R Nathan Spreng
- Laboratory of Brain and Cognition, Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, Canada.,Department of Psychiatry and Psychology, McGill University, Montreal, Canada
| | - Boris C Bernhardt
- Multimodal Imaging and Connectome Analysis Laboratory, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada
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83
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Trinchero MF, Herrero M, Monzón-Salinas MC, Schinder AF. Experience-Dependent Structural Plasticity of Adult-Born Neurons in the Aging Hippocampus. Front Neurosci 2019; 13:739. [PMID: 31379489 PMCID: PMC6651579 DOI: 10.3389/fnins.2019.00739] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/02/2019] [Indexed: 12/28/2022] Open
Abstract
Synaptic modification in cortical structures underlies the acquisition of novel information that results in learning and memory formation. In the adult dentate gyrus, circuit remodeling is boosted by the generation of new granule cells (GCs) that contribute to specific aspects of memory encoding. These forms of plasticity decrease in the aging brain, where both the rate of adult neurogenesis and the speed of morphological maturation of newly generated neurons decline. In the young-adult brain, a brief novel experience accelerates the integration of new neurons. The extent to which such degree of plasticity is preserved in the aging hippocampus remains unclear. In this work, we characterized the time course of functional integration of adult-born GCs in middle-aged mice. We performed whole-cell recordings in developing GCs from Ascl1CreERT2;CAGfloxStopTom mice and found a late onset of functional excitatory synaptogenesis, which occurred at 4 weeks (vs. 2 weeks in young-adult mice). Overall mature excitability and maximal glutamatergic connectivity were achieved at 10 weeks. In contrast, large mossy fiber boutons (MFBs) in CA3 displayed mature morphological features including filopodial extensions at 4 weeks, suggesting that efferent connectivity develops faster than afference. Notably, new GCs from middle-aged mice exposed to enriched environment for 7 days showed an advanced degree of maturity at 3 weeks, revealed by the high frequency of excitatory postsynaptic responses, complex dendritic trees, and large size of MFBs with filopodial extensions. These findings demonstrate that adult-born neurons act as sensors that transduce behavioral stimuli into major network remodeling in the aging brain.
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Affiliation(s)
| | | | | | - Alejandro F. Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
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84
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Abstract
OBJECTIVES Reduction in the amount of information (storage capacity) retained in working memory (WM) has been associated with sleep loss. The present study examined whether reduced WM capacity is also related to poor everyday sleep quality and, more importantly, whether the effects of sleep quality could be dissociated from the effects of depressed mood and age on WM. METHODS In two studies, WM was assessed using a short-term recall task, producing behavioral measures for both the amount of retained WM information (capacity) and how precise the retained WM representations were (precision). Self-report measures of sleep quality and depressed mood were obtained using questionnaires. RESULTS In a sample of college students, Study 1 found that poor sleep quality and depressed mood could independently predict reduced WM capacity, but not WM precision. Study 2 generalized these sleep- and mood-related WM capacity effects to a community sample (aged 21-77 years) and further showed that age was associated with reduced WM precision. CONCLUSIONS Together, these findings demonstrate dissociable effects of three health-related factors (sleep, mood, and age) on WM representations and highlighte the importance of assessing different aspects of WM representations (e.g., capacity and precision) in future neuropsychological research.
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85
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Leal SL, Ferguson LA, Harrison TM, Jagust WJ. Development of a mnemonic discrimination task using naturalistic stimuli with applications to aging and preclinical Alzheimer's disease. ACTA ACUST UNITED AC 2019; 26:219-228. [PMID: 31209116 PMCID: PMC6581010 DOI: 10.1101/lm.048967.118] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/30/2019] [Indexed: 11/24/2022]
Abstract
Most tasks test memory within the same day, however, most forgetting occurs after 24 h. Further, testing memory for simple words or objects does not mimic real-world memory experiences. We designed a memory task showing participants video clips of everyday kinds of experiences, including positive, negative, and neutral stimuli, and tested memory immediately and 24 h later. During the memory test, we included repeated and similar stimuli to tax both target recognition and lure discrimination ability. Participants' memory was worse after 24 h, especially the ability to discriminate similar stimuli. Emotional videos were better remembered when tested immediately, however, after 24 h we find gist versus detail trade-offs in emotional forgetting. We also applied this paradigm to a sample of cognitively normal older adults that also underwent amyloid and tau PET imaging. We found that older adults performed worse on the task compared to young adults. While both young and older adults showed similar patterns of forgetting of repeated emotional and neutral clips, older adults showed preserved neutral compared to emotional discrimination after 24 h. Further, lure discrimination performance correlated with medial temporal lobe tau in older adults with preclinical Alzheimer's disease. These results suggest factors such as time between encoding and retrieval, emotion, and similarity influence memory performance and should be considered when examining memory performance for an accurate picture of memory function and dysfunction.
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Affiliation(s)
- Stephanie L Leal
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720, USA
| | - Lorena A Ferguson
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720, USA
| | - Theresa M Harrison
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720, USA
| | - William J Jagust
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, California 94720, USA.,Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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86
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Yang Y, Yang S, Liu J, Feng Y, Qi F, Zhao R. DNA Hypomethylation of GR Promoters is Associated with GR Activation and BDNF/AKT/ERK1/2-Induced Hippocampal Neurogenesis in Mice Derived From Folic-Acid-Supplemented Dams. Mol Nutr Food Res 2019; 63:e1801334. [PMID: 30920123 DOI: 10.1002/mnfr.201801334] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/20/2019] [Indexed: 12/20/2022]
Abstract
SCOPE Glucocorticoid receptor (GR) mediates the nutritional programing of offspring performance. Maternal folic acid has been shown to regulate hippocampal neurogenesis and affect cognitive function in offspring, yet it remains unclear whether and how GR is involved in such effects. METHODS AND RESULTS Adult male mice derived from dams fed basal or folic-acid-supplemented diet (5 mg folic acid/kg) throughout gestation and lactation are used in this study. Maternal folic acid significantly enhances offspring learning and memory with less fear-related behavior. Concurrently, hippocampal neurogenesis is improved with upregulation of brain-derived neurotrophic factor and its downstream AKT/ERK1/2 signaling pathway. More GR immune-positive cells are observed in hippocampus of folic acid group, which are in line with higher GR protein and mRNA abundances. Differential expression of GR exon 1 transcript variants is detected, which is inversely associated with modified DNA methylation on their alternate promoters. CONCLUSION The results indicate that maternal folic acid supplementation promotes hippocampal neurogenesis and improves learning and memory behavior in mouse offspring. The mechanisms involve modification of DNA methylation on GR alternate promoters and GR upregulation in the hippocampus, which is associated with activation of BDNF/AKT/ERK1/2 signaling.
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Affiliation(s)
- Yang Yang
- MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, P. R. China.,Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, P. R. China
| | - Shu Yang
- MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, P. R. China.,Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, P. R. China
| | - Jie Liu
- MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, P. R. China.,Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, P. R. China
| | - Yue Feng
- MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, P. R. China.,Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, P. R. China
| | - Fulei Qi
- MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, P. R. China.,Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, P. R. China
| | - Ruqian Zhao
- MOE Joint International Research Laboratory of Animal Health & Food Safety, Nanjing Agricultural University, Nanjing, 210095, P. R. China.,Key Laboratory of Animal Physiology & Biochemistry, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, P. R. China
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87
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Voss MW, Soto C, Yoo S, Sodoma M, Vivar C, van Praag H. Exercise and Hippocampal Memory Systems. Trends Cogn Sci 2019; 23:318-333. [PMID: 30777641 PMCID: PMC6422697 DOI: 10.1016/j.tics.2019.01.006] [Citation(s) in RCA: 122] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 01/17/2023]
Abstract
No medications prevent or reverse age-related cognitive decline. Physical activity (PA) enhances memory in rodents, but findings are mixed in human studies. As a result, exercise guidelines specific for brain health are absent. Here, we re-examine results from human studies, and suggest the use of more sensitive tasks to evaluate PA effects on age-related changes in the hippocampus, such as relational memory and mnemonic discrimination. We discuss recent advances from rodent and human studies into the underlying mechanisms at both the central and peripheral levels, including neurotrophins and myokines that could contribute to improved memory. Finally, we suggest guidelines for future research to help expedite well-founded PA recommendations for the public.
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Affiliation(s)
- Michelle W Voss
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA.
| | - Carmen Soto
- Laboratory of Neurogenesis and Neuroplasticity, Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
| | - Seungwoo Yoo
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, and Brain Institute, Florida Atlantic University, Jupiter, FL 33458, USA
| | - Matthew Sodoma
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA
| | - Carmen Vivar
- Laboratory of Neurogenesis and Neuroplasticity, Department of Physiology, Biophysics and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
| | - Henriette van Praag
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, and Brain Institute, Florida Atlantic University, Jupiter, FL 33458, USA
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88
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Branch A, Monasterio A, Blair G, Knierim JJ, Gallagher M, Haberman RP. Aged rats with preserved memory dynamically recruit hippocampal inhibition in a local/global cue mismatch environment. Neurobiol Aging 2019; 76:151-161. [PMID: 30716540 DOI: 10.1016/j.neurobiolaging.2018.12.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/14/2018] [Accepted: 12/27/2018] [Indexed: 10/27/2022]
Abstract
Similar to elderly humans, aged outbred Long-Evans rats exhibit individual differences in memory abilities, including a subset of aged rats that maintain memory function on par with young adults. Such individuals provide a basis for investigating mechanisms of resilience to age-related decline. The present study examined hippocampal gene expression in young adults and aged rats with preserved memory function under behavioral task conditions well established for assessing information processing central to the formation of episodic memory. Although behavioral measures and hippocampal gene induction associated with neural activity and synaptic plasticity were similar across age groups, a marker for inhibitory interneuron function in the hippocampal formation was distinctively increased only in aged rats but not in young adults. Because heightened hippocampal neural activity is associated with age-related memory impairment across species, including rats, monkeys, and humans, this finding may represent an adaptive homeostatic adjustment necessary to maintain neural plasticity and memory function in aging.
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Affiliation(s)
- Audrey Branch
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Amy Monasterio
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Grace Blair
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - James J Knierim
- Department of Neuroscience and Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Rebecca P Haberman
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
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89
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Ezzyat Y, Rizzuto DS. Direct brain stimulation during episodic memory. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2018. [DOI: 10.1016/j.cobme.2018.11.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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90
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Templer VL, Wise TB, Heimer-McGinn VR. Social housing protects against age-related working memory decline independently of physical enrichment in rats. Neurobiol Aging 2018; 75:117-125. [PMID: 30557770 DOI: 10.1016/j.neurobiolaging.2018.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/14/2018] [Accepted: 11/15/2018] [Indexed: 12/09/2022]
Abstract
Longitudinal human studies suggest that as we age, sociality provides protective benefits against cognitive decline. However, little is known about the underlying neural mechanisms. Rodent studies, which are ideal for studying cognition, fail to examine the independent effects of social housing while controlling for physical enrichment in all groups. In this study, rats were socially housed or nonsocially housed throughout their lifespan and tested in the radial arm maze to measure working memory (WM) and reference memory longitudinally at 3 ages. In old age, exclusively, socially housed rats made significantly less WM errors than nonsocially housed rats, while reference memory errors did not differ between groups at any age. Anxiety, as assessed behaviorally and physiologically, could not account for the observed differences in WM. These data provide the first evidence that social enrichment alone can prevent age-related WM deficits in spite of the effects of practice seen in longitudinal designs. Importantly, our model will facilitate future investigations into the mechanisms underlying the neuroprotective benefits of sociability in old age.
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Affiliation(s)
| | - Taylor B Wise
- Psychology Department, Providence College, Providence, RI, USA
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91
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Elman JA, Panizzon MS, Gillespie NA, Hagler DJ, Fennema‐Notestine C, Eyler LT, McEvoy LK, Neale MC, Lyons MJ, Franz CE, Dale AM, Kremen WS. Genetic architecture of hippocampal subfields on standard resolution MRI: How the parts relate to the whole. Hum Brain Mapp 2018; 40:1528-1540. [PMID: 30430703 PMCID: PMC6397064 DOI: 10.1002/hbm.24464] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/19/2018] [Accepted: 10/29/2018] [Indexed: 01/30/2023] Open
Abstract
The human hippocampus can be subdivided into subfields with unique functional properties and differential vulnerability to disease or neuropsychiatric conditions. Identifying genes that confer susceptibility to such processes is an important goal in developing treatments. Recent advances in automatic subfield segmentation from magnetic resonance images make it possible to use these measures as phenotypes in large-scale genome-wide association studies. Such analyses are likely to rely largely on standard resolution (~1 mm isotropic) T1 -weighted images acquired on 3.0T scanners. Determining whether the genetic architecture of subfields can be detected from such images is therefore an important step. We used Freesurfer v6.0 to segment hippocampal subfields in two large twin studies, the Vietnam Era Twin Study of Aging and the Human Connectome Project. We estimated heritability of subfields and the genetic overlap with total hippocampal volume. Heritability was similar across samples, but little genetic variance remained after accounting for genetic influences on total hippocampal volume. Importantly, we examined genetic relationships between subfields to determine whether subfields can be grouped based on a smaller number of underlying, genetically independent factors. We identified three genetic factors in both samples, but the high degree of cross loadings precluded formation of genetically distinct groupings of subfields. These results confirm the reliability of Freesurfer v6.0 generated subfields across samples for phenotypic analyses. However, the current results suggest that it will be difficult for large-scale genetic analyses to identify subfield-specific genes that are distinct from both total hippocampal volume and other subfields using segmentations generated from standard resolution T1 -weighted images.
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Affiliation(s)
- Jeremy A. Elman
- Department of PsychiatryUniversity of California San DiegoSan DiegoCalifornia,Center for Behavior Genetics of AgingUniversity of California San DiegoSan DiegoCalifornia
| | - Matthew S. Panizzon
- Department of PsychiatryUniversity of California San DiegoSan DiegoCalifornia,Center for Behavior Genetics of AgingUniversity of California San DiegoSan DiegoCalifornia
| | - Nathan A. Gillespie
- Virginia Institute for Psychiatric and Behavior GeneticsVirginia Commonwealth UniversityRichmondVirginia
| | - Donald J. Hagler
- Department of RadiologyUniversity of California San DiegoSan DiegoCalifornia
| | - Christine Fennema‐Notestine
- Department of PsychiatryUniversity of California San DiegoSan DiegoCalifornia,Department of RadiologyUniversity of California San DiegoSan DiegoCalifornia
| | - Lisa T. Eyler
- Department of PsychiatryUniversity of California San DiegoSan DiegoCalifornia,VA San Diego Health Care SystemSan DiegoCalifornia
| | - Linda K. McEvoy
- Department of RadiologyUniversity of California San DiegoSan DiegoCalifornia
| | - Michael C. Neale
- Virginia Institute for Psychiatric and Behavior GeneticsVirginia Commonwealth UniversityRichmondVirginia
| | - Michael J. Lyons
- Department of Psychological and Brain SciencesBoston UniversityBostonMassachusetts
| | - Carol E. Franz
- Department of PsychiatryUniversity of California San DiegoSan DiegoCalifornia,Center for Behavior Genetics of AgingUniversity of California San DiegoSan DiegoCalifornia
| | - Anders M. Dale
- Department of RadiologyUniversity of California San DiegoSan DiegoCalifornia,Department of NeurosciencesUniversity of California San DiegoSan DiegoCalifornia
| | - William S. Kremen
- Department of PsychiatryUniversity of California San DiegoSan DiegoCalifornia,Center for Behavior Genetics of AgingUniversity of California San DiegoSan DiegoCalifornia,Center of Excellence for Stress and Mental HealthVA San Diego Health Care SystemSan DiegoCalifornia
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92
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Abstract
Global depletion of klotho accelerates aging, whereas klotho overexpression counteracts aging-related impairments. Why klotho is expressed at much higher levels in the choroid plexus than in other brain regions is unknown. We demonstrate in mice that aging is associated with klotho depletion in the choroid plexus. Reducing klotho selectively within the choroid plexus triggered inflammation within this structure and enhanced activation of innate immune cells within an adjacent brain region following a peripheral immune challenge. In cell culture, we identified a signaling pathway by which klotho suppresses activation of macrophages. Our findings shed light on klotho functions in the choroid plexus and provide a plausible mechanism by which klotho depletion from this structure promotes brain inflammation during the aging process. Located within the brain’s ventricles, the choroid plexus produces cerebrospinal fluid and forms an important barrier between the central nervous system and the blood. For unknown reasons, the choroid plexus produces high levels of the protein klotho. Here, we show that these levels naturally decline with aging. Depleting klotho selectively from the choroid plexus via targeted viral vector-induced knockout in Klothoflox/flox mice increased the expression of multiple proinflammatory factors and triggered macrophage infiltration of this structure in young mice, simulating changes in unmanipulated old mice. Wild-type mice infected with the same Cre recombinase-expressing virus did not show such alterations. Experimental depletion of klotho from the choroid plexus enhanced microglial activation in the hippocampus after peripheral injection of mice with lipopolysaccharide. In primary cultures, klotho suppressed thioredoxin-interacting protein-dependent activation of the NLRP3 inflammasome in macrophages by enhancing fibroblast growth factor 23 signaling. We conclude that klotho functions as a gatekeeper at the interface between the brain and immune system in the choroid plexus. Klotho depletion in aging or disease may weaken this barrier and promote immune-mediated neuropathogenesis.
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93
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The effect of ageing on the neural substrates of incidental encoding leading to recollection or familiarity. Brain Cogn 2018; 126:1-12. [PMID: 30029026 DOI: 10.1016/j.bandc.2018.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 05/30/2018] [Accepted: 07/06/2018] [Indexed: 11/20/2022]
Abstract
It is well-known that the ageing process disrupts episodic memory. The aim of this study was to use an fMRI visual recognition task to characterize age-related changes in cerebral regions activated, during encoding, for images that would subsequently lead to a recollection-based or to a familiarity-based recognition. Results show that, for subsequent recollection, young adults activated regions related to semantic processing more extensively than older ones. On the other hand, despite putatively producing less semantic elaboration, older adults activated contralateral regions supplementary to those found in young adults (which might represent attempted compensation), as well as regions of the default-mode network. These results suggest older adults could achieve subsequent recollection through different processes, for instance an appraisal of the self-relevance of the stimuli. For subsequent familiarity, the comparisons only revealed greater activations in young adults, in the dorsal frontoparietal attention system as well as in the hippocampus, again suggesting that, even if older adults are able to produce recollection- and familiarity-based recognition, the semantic processing might still be weaker in old adults, who might nonetheless use qualitatively different strategies in order to produce such responses. Further studies are necessary in order to characterize those strategies.
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94
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Gros A, Wang SH. Behavioral tagging and capture: long-term memory decline in middle-aged rats. Neurobiol Aging 2018; 67:31-41. [PMID: 29609080 PMCID: PMC5964067 DOI: 10.1016/j.neurobiolaging.2018.02.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/02/2018] [Accepted: 02/24/2018] [Indexed: 02/07/2023]
Abstract
Decline in cognitive functions, including hippocampus-dependent spatial memory, is commonly observed at a later stage of aging (e.g., >20 months old in rodents) and typically studied after a discrete learning event. How normal aging, particularly at an early stage, affects the modulatory aspect of memory persistence is underinvestigated. Previous studies in young animals show that weak, fading memories can last longer if a modulating event, such as spatial novelty, is introduced around memory encoding. This is known as behavioral tagging and capture (BTC). Here, we investigated how early aging (10-13 months old) affects BTC in an appetitive delayed-matching-to-place task. We trained rats when they were young and middle aged and found that novelty facilitated long-term memory persistence in young but not in middle-aged rats. However, re-exposure to the encoded environment after learning improved memory persistence in middle-aged rats. BTC, combined with memory reactivation, facilitated memory persistence through reconsolidation. Our results point toward a weakened tagging and capture mechanism before reduction of plasticity-related proteins at an early stage of aging.
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Affiliation(s)
- Alexandra Gros
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland, UK
| | - Szu-Han Wang
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, Scotland, UK.
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95
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Petrican R, Levine BT. Similarity in functional brain architecture between rest and specific task modes: A model of genetic and environmental contributions to episodic memory. Neuroimage 2018; 179:489-504. [PMID: 29936311 DOI: 10.1016/j.neuroimage.2018.06.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/05/2018] [Accepted: 06/19/2018] [Indexed: 01/06/2023] Open
Abstract
The ability to keep a mental record of specific past events, dubbed episodic memory (EM), is key to lifespan adaptation. Nonetheless, the neural mechanisms underlying its typical inter-individual variability remain poorly understood. To address this issue, we tested whether individual differences in EM could be predicted from levels of functional brain re-organization between rest and task modes relevant to the transformation of perceptual information into mental representations (relational processing, meaning extraction, online maintenance versus updating of bound perceptual features). To probe the trait specificity of our model, we included three additional core mental functions, processing speed, abstract reasoning, and cognitive control. Finally, we investigated the extent to which our proposed model reflected genetic versus environmental contributions to EM variability. Hypotheses were tested by applying graph theoretical analysis and structural equation modeling to resting state and task fMRI data from two samples of participants in the Human Connectome Project (Sample 1: N = 338 unrelated individuals; Sample 2: N = 268 monozygotic vs. dizygotic twins [134 same-sex pairs]). Levels of functional brain reorganization between rest and the scrutinized task modes, particularly relational processing and online maintenance of bound perceptual features, contributed substantially to variations in both EM and abstract reasoning (but not in cognitive control or processing speed) among the younger adults in our sample, implying a substantial neurofunctional overlap, at least during this life stage. Similarity in functional organization between rest and each of the scrutinized task modes drew on distinguishable neural resources and showed differential susceptibility to genetic versus environmental influences. Our results suggest that variability on complex traits, such as EM, is supported by neural mechanisms comprising multiple components, each reflecting a distinct pattern of genetic versus environmental contributions and whose relative importance may vary across typical versus psychopathological development.
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Affiliation(s)
| | - Brian T Levine
- Rotman Research Institute and Departments of Psychology and Neurology, University of Toronto, M6A 2E1, Canada
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96
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Sellami A, Abed ASA, Brayda-Bruno L, Etchamendy N, Valério S, Oulé M, Pantaléon L, Lamothe V, Potier M, Bernard K, Jabourian M, Herry C, Mons N, Marighetto A. Protocols to Study Declarative Memory Formation in Mice and Humans:Optogenetics and Translational Behavioral Approaches. Bio Protoc 2018; 8:e2888. [PMID: 34285997 PMCID: PMC8275238 DOI: 10.21769/bioprotoc.2888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/20/2018] [Accepted: 05/21/2018] [Indexed: 11/02/2022] Open
Abstract
Declarative memory formation depends on the hippocampus and declines in aging. Two functions of the hippocampus, temporal binding and relational organization (Rawlins and Tsaltas, 1983; Eichenbaum et al., 1992 ; Cohen et al., 1997 ), are known to decline in aging (Leal and Yassa, 2015). However, in the literature distinct procedures have been used to study these two functions. Here, we describe the experimental procedures used to investigate how these two processes are related in the formation of declarative memory and how they are compromised in aging ( Sellami et al., 2017 ). First, we studied temporal binding using a one-trial learning procedure: trace fear conditioning. It is classical Pavlovian conditioning requiring temporal binding since a brief temporal gap separates the conditioned stimulus (CS) and unconditioned stimulus (US) presentations. We combined the trace fear condition procedure with an optogenetic approach, and we showed that the temporal binding relies on dorsal (d)CA1 activity over temporal gaps. Then, we studied the interaction between temporal binding and relational organization in declarative memory formation using a two-phase radial-maze task in mice and its virtual analog in humans. The behavioral procedure comprises an initial learning phase where subjects learned the constant rewarding /no rewarding valence of each arm, followed by a test phase where the reward contingencies among the arms remained unchanged but where the arms were recombined to assess flexibility, a cardinal property of declarative memory. We demonstrated that dCA1-dependent temporal binding is necessary for the development of a relational organization of memories that allows flexible declarative memory expression. Furthermore, in aging, the degradation of declarative memory is due to a reduction of temporal binding capacity that prevents relation organization.
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Affiliation(s)
- Azza Sellami
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Alice Shaam Al Abed
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Laurent Brayda-Bruno
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Nicole Etchamendy
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Stéphane Valério
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Marie Oulé
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Laura Pantaléon
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Valérie Lamothe
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Mylène Potier
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Katy Bernard
- Institut de Recherche Internationale Servier, Suresnes, France
| | | | - Cyril Herry
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Nicole Mons
- Université de Bordeaux, Bordeaux, France
- Institut de Neurosciences Cognitives et Intégratives d’Aquitaine, UMR 5287, CNRS, Pessac, France
| | - Aline Marighetto
- Neurocentre Magendie, Physiopathologie de la Plasticité Neuronale, U1215, INSERM, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
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97
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Tran T, Gallagher M, Kirkwood A. Enhanced postsynaptic inhibitory strength in hippocampal principal cells in high-performing aged rats. Neurobiol Aging 2018; 70:92-101. [PMID: 30007169 DOI: 10.1016/j.neurobiolaging.2018.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/28/2018] [Accepted: 06/03/2018] [Indexed: 11/20/2022]
Abstract
Hyperactivity within the hippocampal formation, frequently observed in aged individuals, is thought to be a potential contributing mechanism to the memory decline often associated with aging. Consequently, we evaluated the postsynaptic strength of excitatory and inhibitory synapses in the granule cells of the dentate gyrus and CA1 pyramidal cells of a rat model of aging, in which each individual was behaviorally characterized as aged impaired (AI) or aged unimpaired (AU, with performance comparable to young (Y) individuals). In hippocampal slices of these 3 aged groups (Y, AI, AU), we found that compared to the young, the miniature excitatory and inhibitory currents (mEPSCs and mIPSCs) were larger in amplitude in the granule cells of the AU group and smaller in the AI group. In contrast, in CA1 cells, neither the mEPSCs nor the mIPSCs were affected by age, whereas the extrasynaptic conductance responsible for tonic inhibition was selectively enhanced in CA1 cells of AU individuals. Tonic inhibition conductance was not affected by age in the granule cells. These results support the notion that upregulation of synaptic inhibition could be a necessary condition for the maintenance of performance during aging. These findings also underscore the notions that successful aging requires adaptive upregulation, not merely the preservation of youthful functionality, and that age effects are not homogeneous across hippocampal subfields.
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Affiliation(s)
- Trinh Tran
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, 3400 N. Charles St, Baltimore, MD 21218, USA
| | - Michela Gallagher
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 N. Charles St, Baltimore, MD 21218, USA.
| | - Alfredo Kirkwood
- Mind/Brain Institute and Department of Neurosciences, Johns Hopkins University, 3400 N. Charles St, Baltimore, MD 21218, USA.
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98
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Estimates of age-related memory decline are inflated by unrecognized Alzheimer's disease. Neurobiol Aging 2018; 70:170-179. [PMID: 30015036 DOI: 10.1016/j.neurobiolaging.2018.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 05/17/2018] [Accepted: 06/04/2018] [Indexed: 01/23/2023]
Abstract
Cognitive decline is considered an inevitable consequence of aging; however, estimates of cognitive aging may be influenced negatively by undetected preclinical Alzheimer's disease (AD). This study aimed to determine the extent to which estimates of cognitive aging were biased by preclinical AD. Cognitively normal older adults (n = 494) with amyloid-β status determined from positron emission tomography neuroimaging underwent serial neuropsychological assessment at 18-month intervals over 72 months. Estimates of the effects of age on verbal memory, working memory, executive function, and processing speed were derived using linear mixed models. The presence of preclinical AD and clinical progression to mild cognitive impairment or dementia during the study were then added to these models as covariates. Initially, age was associated with decline across all 4 cognitive domains. With the effects of elevated amyloid-β and clinical progression controlled, age was no longer associated with decline in verbal or working memory. However, the magnitude of decline was reduced only slightly for executive function and was unchanged for processing speed. Thus, considered together, the results of the study indicate that undetected preclinical AD negatively biases estimates of age-related cognitive decline for verbal and working memory.
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99
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Smith BM, Yao X, Chen KS, Kirby ED. A Larger Social Network Enhances Novel Object Location Memory and Reduces Hippocampal Microgliosis in Aged Mice. Front Aging Neurosci 2018; 10:142. [PMID: 29904345 PMCID: PMC5990613 DOI: 10.3389/fnagi.2018.00142] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 04/27/2018] [Indexed: 02/03/2023] Open
Abstract
The mammalian hippocampus shows marked decline in function with aging across many species, including humans and laboratory rodent models. This decline frequently manifests in memory impairments that occur even in the absence of dementia pathology. In humans, a number of factors correlate with preserved hippocampal memory in aging, such as exercise, cognitive stimulation and number of social ties. While interventional studies and animal models clearly indicate that exercise and cognitive stimulation lead to hippocampal preservation, there is relatively little research on whether a decline in social ties leads to cognitive decline or vice versa. Even in animal studies of environmental enrichment in aging, the focus typically falls on physical enrichment such as a rotating cast of toys, rather than the role of social interactions. The present studies investigated the hypothesis that a greater number of social ties in aging mice would lead to improved hippocampal function. Aged, female C57/Bl6 mice were housed for 3 months in pairs or large groups (7 mice per cage). Group-housed mice showed greater novel object location memory and stronger preference for a spatial navigation strategy in the Barnes maze, though no difference in escape latency, compared to pair-housed mice. Group-housed mice did not differ from pair-housed mice in basal corticosterone levels or adult hippocampal neurogenesis. Group-housed mice did, however, show reduced numbers of Iba1/CD68+ microglia in the hippocampus. These findings suggest that group housing led to better memory function and reduced markers of neuroinflammation in aged mice. More broadly, they support a causative link between social ties and hippocampal function, suggesting that merely having a larger social network can positively influence the aging brain. Future research should address the molecular mechanisms by which a greater number of social ties alters hippocampal function.
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Affiliation(s)
- Bryon M Smith
- Department of Psychology, The Ohio State University, Columbus, OH, United States
| | - Xinyue Yao
- Department of Psychology, The Ohio State University, Columbus, OH, United States
| | - Kelly S Chen
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, United States
| | - Elizabeth D Kirby
- Department of Psychology, The Ohio State University, Columbus, OH, United States.,Department of Neuroscience, The Ohio State University, Columbus, OH, United States.,Center for Chronic Brain Injury, The Ohio State University, Columbus, OH, United States
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100
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Wu H, Chen M, Yan P, Yao Q, Fan J, Gao Z, Wang H. Erythropoietin suppresses D-galactose-induced aging of rats via the PI3K/Akt/Nrf2-ARE pathway. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2018; 11:2227-2240. [PMID: 31938335 PMCID: PMC6958193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 12/22/2017] [Indexed: 06/10/2023]
Abstract
EPO (erythropoietin) is a hormone-like substance with a putative role in hematopoietic regulation. Current research suggests that it exerts a neuroprotective effect by enhancing the activity of antioxidant enzymes. Our previous studies in vitro have confirmed that EPO can delay senescence of cultured neurons by activation of nuclear factor-erythroid 2-related factor 2 (Nrf2) and the phosphoinositide-3-kinase (PI3K)/AKT pathway. Thus we set out to further substantiate the mechanism in vivo. A rat model of aging was induced by continuous subcutaneous injection of 5% D-galactose for 6 weeks. Starting at the 7th week, physiological saline or EPO was administered twice daily. LY294002, an inhibitor of the PI3K/AKT pathway, was also given to one of the groups. Improvement of learning and memory abilities were observed in the EPO intervention group. Raised levels of Cu-Zn SOD protein were detected by immunohistochemical staining and Western blot after using EPO, together with increased expression of PI3K/AKT pathway proteins. Concomitantly, there was an increase in expression of Nrf2 mRNA and a decrease in expression of Keap1 mRNA by qRT-PCR. All these effects were not found in the group injected with LY294002. We conclude that EPO can suppress aging by reducing oxidative stress. The proposed mechanism is an upregulation of the PI3K/Akt/Nrf2-ARE pathway and thus maintenance of expression and activation of antioxidant enzymes in aging rats.
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Affiliation(s)
- Haiqin Wu
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
| | - Mengyi Chen
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
| | - Pu Yan
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
| | - Qingling Yao
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
| | - Jiaxin Fan
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
| | - Zhen Gao
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
| | - Huqing Wang
- Department of Neurology, The Second Affiliated Hospital of The Medical School, Xi'an Jiaotong University Xi'an, Shaanxi, China
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