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Del Castilo I, Neumann AS, Lemos FS, De Bastiani MA, Oliveira FL, Zimmer ER, Rêgo AM, Hardoim CCP, Antunes LCM, Lara FA, Figueiredo CP, Clarke JR. Lifelong Exposure to a Low-Dose of the Glyphosate-Based Herbicide RoundUp ® Causes Intestinal Damage, Gut Dysbiosis, and Behavioral Changes in Mice. Int J Mol Sci 2022; 23:5583. [PMID: 35628394 PMCID: PMC9146949 DOI: 10.3390/ijms23105583] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 02/04/2023] Open
Abstract
RoundUp® (RUp) is a comercial formulation containing glyphosate (N-(phosphono-methyl) glycine), and is the world's leading wide-spectrum herbicide used in agriculture. Supporters of the broad use of glyphosate-based herbicides (GBH) claim they are innocuous to humans, since the active compound acts on the inhibition of enzymes which are absent in human cells. However, the neurotoxic effects of GBH have already been shown in many animal models. Further, these formulations were shown to disrupt the microbiome of different species. Here, we investigated the effects of a lifelong exposure to low doses of the GBH-RUp on the gut environment, including morphological and microbiome changes. We also aimed to determine whether exposure to GBH-RUp could harm the developing brain and lead to behavioral changes in adult mice. To this end, animals were exposed to GBH-RUp in drinking water from pregnancy to adulthood. GBH-RUp-exposed mice had no changes in cognitive function, but developed impaired social behavior and increased repetitive behavior. GBH-Rup-exposed mice also showed an activation of phagocytic cells (Iba-1-positive) in the cortical brain tissue. GBH-RUp exposure caused increased mucus production and the infiltration of plama cells (CD138-positive), with a reduction in phagocytic cells. Long-term exposure to GBH-RUp also induced changes in intestinal integrity, as demonstrated by the altered expression of tight junction effector proteins (ZO-1 and ZO-2) and a change in the distribution of syndecan-1 proteoglycan. The herbicide also led to changes in the gut microbiome composition, which is also crucial for the establishment of the intestinal barrier. Altogether, our findings suggest that long-term GBH-RUp exposure leads to morphological and functional changes in the gut, which correlate with behavioral changes that are similar to those observed in patients with neurodevelopmental disorders.
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Affiliation(s)
- Ingrid Del Castilo
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (I.D.C.); (C.P.F.)
| | - Arthur S. Neumann
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (A.S.N.); (F.S.L.); (F.L.O.)
| | - Felipe S. Lemos
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (A.S.N.); (F.S.L.); (F.L.O.)
| | - Marco A. De Bastiani
- Departamento de Farmacologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-193, RS, Brazil; (M.A.D.B.); (E.R.Z.)
| | - Felipe L. Oliveira
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (A.S.N.); (F.S.L.); (F.L.O.)
| | - Eduardo R. Zimmer
- Departamento de Farmacologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-193, RS, Brazil; (M.A.D.B.); (E.R.Z.)
| | - Amanda M. Rêgo
- Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, RJ, Brazil; (A.M.R.); (L.C.M.A.); (F.A.L.)
| | - Cristiane C. P. Hardoim
- Instituto de Biociências, Universidade Estadual Paulista, São Vicente 11380-972, SP, Brazil;
| | - Luis Caetano M. Antunes
- Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, RJ, Brazil; (A.M.R.); (L.C.M.A.); (F.A.L.)
- Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças de Populações Negligenciadas, Centro de Desenvolvimento Tecnológico em Saúde, Fundação Oswaldo Cruz, Rio de Janeiro 21040-361, RJ, Brazil
| | - Flávio A. Lara
- Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro 21040-360, RJ, Brazil; (A.M.R.); (L.C.M.A.); (F.A.L.)
| | - Claudia P. Figueiredo
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (I.D.C.); (C.P.F.)
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (A.S.N.); (F.S.L.); (F.L.O.)
| | - Julia R. Clarke
- Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (I.D.C.); (C.P.F.)
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil; (A.S.N.); (F.S.L.); (F.L.O.)
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Amorim FE, Chapot RL, Moulin TC, Lee JLC, Amaral OB. Memory destabilization during reconsolidation: a consequence of homeostatic plasticity? ACTA ACUST UNITED AC 2021; 28:371-389. [PMID: 34526382 DOI: 10.1101/lm.053418.121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 07/14/2021] [Indexed: 11/24/2022]
Abstract
Remembering is not a static process: When retrieved, a memory can be destabilized and become prone to modifications. This phenomenon has been demonstrated in a number of brain regions, but the neuronal mechanisms that rule memory destabilization and its boundary conditions remain elusive. Using two distinct computational models that combine Hebbian plasticity and synaptic downscaling, we show that homeostatic plasticity can function as a destabilization mechanism, accounting for behavioral results of protein synthesis inhibition upon reactivation with different re-exposure times. Furthermore, by performing systematic reviews, we identify a series of overlapping molecular mechanisms between memory destabilization and synaptic downscaling, although direct experimental links between both phenomena remain scarce. In light of these results, we propose a theoretical framework where memory destabilization can emerge as an epiphenomenon of homeostatic adaptations prompted by memory retrieval.
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Affiliation(s)
- Felippe E Amorim
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Renata L Chapot
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Thiago C Moulin
- Functional Pharmacology Unit, Department of Neuroscience, Uppsala University, Uppsala 751 24, Sweden
| | - Jonathan L C Lee
- University of Birmingham, School of Psychology, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Olavo B Amaral
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
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Zorzo C, Arias JL, Méndez M. Recovering Spatial Information through Reactivation: Brain Oxidative Metabolism Involvement in Males and Females. Neuroscience 2021; 459:1-15. [PMID: 33571597 DOI: 10.1016/j.neuroscience.2021.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/31/2021] [Accepted: 02/01/2021] [Indexed: 10/22/2022]
Abstract
Memory involves a complex network system of interconnected brain areas in which labile trace memories are transformed into enduring ones and reorganized in a time-dependant manner. Although it has been observed that remote memories are less prone to destabilizing, they can become fragile and lead to behavioural decline. We explored the behavioural outcomes of male and female rats in response to the reactivation of a previously acquired allocentric spatial reference memory, under conditions in which animals have shown a retrieval decay. In addition, we assessed their brain metabolic activity through cytochrome c oxidase (CCO) histochemistry. Our results show that a spatial memory amnesia-like behaviour with a time interval of 45 days can be recovered after re-exposure to the environmental configuration with the reinforced contingencies. Moreover, we observed that, following reactivation, male rats reveal a decrease in metabolic activity in septal nuclei and thalamic structures, whereas female rats add a metabolic reduction in the hippocampus, amygdala, mPFC, and retrosplenial, parietal and rhinal cortices, suggesting that they efficiently employ these brain areas when reactivation a memory that has suffered a decay with time. Finally, although male and female rats perform the behavioural task equally, we found sex differences at the brain metabolism level, revealing the differential contribution of brain limbic system energy demands by sex, even when their performance is similar. In conclusion, our work provides behavioural and brain data about remote spatial retrieval and memory reactivation processes.
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Affiliation(s)
- Candela Zorzo
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Plaza Feijoo, s/n, E-33003 Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), E-33003 Oviedo, Spain.
| | - Jorge L Arias
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Plaza Feijoo, s/n, E-33003 Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), E-33003 Oviedo, Spain
| | - Marta Méndez
- Laboratory of Neuroscience, Department of Psychology, University of Oviedo, Plaza Feijoo, s/n, E-33003 Oviedo, Spain; Instituto de Neurociencias del Principado de Asturias (INEUROPA), E-33003 Oviedo, Spain
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Marschner L, Schreurs A, Lechat B, Mogensen J, Roebroek A, Ahmed T, Balschun D. Single mild traumatic brain injury results in transiently impaired spatial long-term memory and altered search strategies. Behav Brain Res 2019; 365:222-230. [DOI: 10.1016/j.bbr.2018.02.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 10/02/2017] [Accepted: 02/26/2018] [Indexed: 11/16/2022]
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Rashid H, Ahmed T. Muscarinic activity in hippocampus and entorhinal cortex is crucial for spatial and fear memory retrieval. Pharmacol Rep 2019; 71:449-456. [PMID: 31003156 DOI: 10.1016/j.pharep.2019.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 02/06/2019] [Accepted: 02/07/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Hippocampus and entorhinal cortex are key players of learning and memory. Despite their established role in memory processes, the contribution of muscarinic receptor activity in these brain regions during memory retrieval remains elusive. This study was aimed to assess the role of hippocampal CA1 and medial entorhinal cortex muscarinic receptors in memory retrieval. METHOD Mice were implanted with bilateral cannulas in the hippocampus CA1 and medial entorhinal cortex. After recovery they were trained for Morris water maze test, novel object recognition test and contextual fear conditioning. Scopolamine was infused 10 min prior to retrieval test. RESULTS Pre-test scopolamine infusion in hippocampal CA1 and medial entorhinal cortex significantly reduced overall exploration of objects (p<0.001). Similarly, pre-retrieval inactivation dorsal hippocampal CA1 and medial entorhinal cortex muscarinic activity caused significant impairment of spatial and fear memories retrieval (p<0.05). CONCLUSION These findings showed vital role of muscarinic activity in retrieving hippocampal and entorhinal cortex dependent memories and suggest a possible target for treating retrograde amnesia.
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Affiliation(s)
- Habiba Rashid
- Neurobiology Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan
| | - Touqeer Ahmed
- Neurobiology Laboratory, Department of Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences, National University of Sciences and Technology, Islamabad, Pakistan.
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West RK, Wooden JI, Barton EA, Leasure JL. Recurrent binge ethanol is associated with significant loss of dentate gyrus granule neurons in female rats despite concomitant increase in neurogenesis. Neuropharmacology 2019; 148:272-283. [PMID: 30659841 DOI: 10.1016/j.neuropharm.2019.01.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 12/18/2022]
Abstract
Binge drinking is becoming increasingly common among American women and girls. We have previously shown significant cell loss, downregulation of neurotrophins and microgliosis in female rats after a single 4-day ethanol exposure. To determine whether recurrent binge exposure would produce similar effects, we administered ethanol (5 g/kg) or iso-caloric control diet once-weekly for 11 weeks to adult female rats. As we have previously shown exercise neuroprotection against binge-induced damage, half the rats were given access to exercise wheels. Blood ethanol concentration (BEC) did not differ between sedentary and exercised groups, nor did it change across time. Using stereology, we quantified the number and/or size of neurons in the medial prefrontal cortex (mPFC) and hippocampal dentate gyrus (DG), as well as the number and activation state of microglia. Binged sedentary rats had significant cell loss in the dentate gyrus, but exercise eliminated this effect. Compared to sedentary controls, sedentary binged rats and all exercised rats showed increased neurogenesis in the DG. Number and nuclear volume of neurons in the mPFC were not changed. In the hippocampus and mPFC, the number of microglia with morphology indicative of partial activation was increased by recurrent binge ethanol and decreased by exercise. In summary, we show significant binge-induced loss of DG granule neurons despite increased neurogenesis, suggesting an unsuccessful compensatory response. Although exercise eliminated cell loss, our results indicate that infrequent, but recurrent exposure to clinically relevant BEC is neurotoxic.
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Affiliation(s)
- Rebecca K West
- Department of Psychology, University of Houston, Houston, TX, 77204-5022, United States
| | - Jessica I Wooden
- Department of Psychology, University of Houston, Houston, TX, 77204-5022, United States
| | - Emily A Barton
- Department of Psychology, University of Houston, Houston, TX, 77204-5022, United States
| | - J Leigh Leasure
- Department of Psychology, University of Houston, Houston, TX, 77204-5022, United States; Department of Biology & Biochemistry, University of Houston, Houston, TX, 77204-5022, United States.
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PKMζ Inhibition Disrupts Reconsolidation and Erases Object Recognition Memory. J Neurosci 2019; 39:1828-1841. [PMID: 30622166 DOI: 10.1523/jneurosci.2270-18.2018] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/09/2018] [Accepted: 12/27/2018] [Indexed: 11/21/2022] Open
Abstract
Object recognition memory (ORM) confers the ability to discriminate the familiarity of previously encountered items. Reconsolidation is the process by which reactivated memories become labile and susceptible to modifications. The hippocampus is specifically engaged in reconsolidation to integrate new information into the original ORM through a mechanism involving activation of brain-derived neurotrophic factor (BDNF) signaling and induction of LTP. It is known that BDNF can control LTP maintenance through protein kinase Mζ (PKMζ), an atypical protein kinase C isoform that is thought to sustain memory storage by modulating glutamatergic neurotransmission. However, the potential involvement of PKMζ in ORM reconsolidation has never been studied. Using a novel ORM task combined with pharmacological, biochemical, and electrophysiological tools, we found that hippocampal PKMζ is essential to update ORM through reconsolidation, but not to maintain the inactive recognition memory trace stored over time, in adult male Wistar rats. Our results also indicate that hippocampal PKMζ acts downstream of BDNF and controls AMPAR synaptic insertion to elicit reconsolidation and suggest that blocking PKMζ activity during this process deletes active ORM.SIGNIFICANCE STATEMENT Object recognition memory (ORM) is essential to remember facts and events. Reconsolidation integrates new information into ORM through changes in hippocampal plasticity and brain-derived neurotrophic factor (BDNF) signaling. In turn, BDNF enhances synaptic efficacy through protein kinase Mζ (PKMζ), which might preserve memory. Here, we present evidence that hippocampal PKMζ acts downstream of BDNF to regulate AMPAR recycling during ORM reconsolidation and show that this kinase is essential to update the reactivated recognition memory trace, but not to consolidate or maintain an inactive ORM. We also demonstrate that the amnesia provoked by disrupting ORM reconsolidation through PKMζ inhibition is due to memory erasure and not to retrieval failure.
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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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9
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Emotional memory expression is misleading: delineating transitions between memory processes. Curr Opin Behav Sci 2018. [DOI: 10.1016/j.cobeha.2017.12.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Gönner L, Vitay J, Hamker FH. Predictive Place-Cell Sequences for Goal-Finding Emerge from Goal Memory and the Cognitive Map: A Computational Model. Front Comput Neurosci 2017; 11:84. [PMID: 29075187 PMCID: PMC5643423 DOI: 10.3389/fncom.2017.00084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/01/2017] [Indexed: 01/19/2023] Open
Abstract
Hippocampal place-cell sequences observed during awake immobility often represent previous experience, suggesting a role in memory processes. However, recent reports of goals being overrepresented in sequential activity suggest a role in short-term planning, although a detailed understanding of the origins of hippocampal sequential activity and of its functional role is still lacking. In particular, it is unknown which mechanism could support efficient planning by generating place-cell sequences biased toward known goal locations, in an adaptive and constructive fashion. To address these questions, we propose a model of spatial learning and sequence generation as interdependent processes, integrating cortical contextual coding, synaptic plasticity and neuromodulatory mechanisms into a map-based approach. Following goal learning, sequential activity emerges from continuous attractor network dynamics biased by goal memory inputs. We apply Bayesian decoding on the resulting spike trains, allowing a direct comparison with experimental data. Simulations show that this model (1) explains the generation of never-experienced sequence trajectories in familiar environments, without requiring virtual self-motion signals, (2) accounts for the bias in place-cell sequences toward goal locations, (3) highlights their utility in flexible route planning, and (4) provides specific testable predictions.
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Affiliation(s)
- Lorenz Gönner
- Artificial Intelligence, Department of Computer Science, Technische Universität Chemnitz, Chemnitz, Germany
| | - Julien Vitay
- Artificial Intelligence, Department of Computer Science, Technische Universität Chemnitz, Chemnitz, Germany
| | - Fred H Hamker
- Artificial Intelligence, Department of Computer Science, Technische Universität Chemnitz, Chemnitz, Germany.,Bernstein Center Computational Neuroscience, Humboldt-Universität Berlin, Berlin, Germany
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Buhusi M, Etheredge C, Granholm AC, Buhusi CV. Increased Hippocampal ProBDNF Contributes to Memory Impairments in Aged Mice. Front Aging Neurosci 2017; 9:284. [PMID: 28912711 PMCID: PMC5583170 DOI: 10.3389/fnagi.2017.00284] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 08/14/2017] [Indexed: 01/27/2023] Open
Abstract
Memory decline during aging or accompanying neurodegenerative diseases, represents a major health problem. Neurotrophins have long been considered relevant to the mechanisms of aging-associated cognitive decline and neurodegeneration. Mature Brain-Derived Neurotrophic Factor (BDNF) and its precursor (proBDNF) can both be secreted in response to neuronal activity and exert opposing effects on neuronal physiology and plasticity. In this study, biochemical analyses revealed that increased levels of proBDNF are present in the aged mouse hippocampus relative to young and that the level of hippocampal proBDNF inversely correlates with the ability to perform in a spatial memory task, the water radial arm maze (WRAM). To ascertain the role of increased proBDNF levels on hippocampal function and memory we performed infusions of proBDNF into the CA1 region of the dorsal hippocampus in male mice trained in the WRAM paradigm: In well-performing aged mice, intra-hippocampal proBDNF infusions resulted in a progressive and significant impairment of memory performance. This impairment was associated with increased p-cofilin levels, an important regulator of dendritic spines and synapse physiology. On the other hand, in poor performers, intra-hippocampal infusions of TAT-Pep5, a peptide which blocks the interaction between the p75 Neurotrophin Receptor (p75NTR) and RhoGDI, significantly improved learning and memory, while saline infusions had no effect. Our results support a role for proBDNF and its receptor p75NTR in aging-related memory impairments.
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Affiliation(s)
- Mona Buhusi
- Interdisciplinary Program in Neuroscience, Department of Psychology, Utah State UniversityLogan, UT, United States
| | - Chris Etheredge
- Department of Neuroscience, Medical University of South CarolinaCharleston, SC, United States
| | - Ann-Charlotte Granholm
- Department of Neuroscience, Medical University of South CarolinaCharleston, SC, United States
| | - Catalin V Buhusi
- Interdisciplinary Program in Neuroscience, Department of Psychology, Utah State UniversityLogan, UT, United States
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Radiske A, Rossato JI, Gonzalez MC, Köhler CA, Bevilaqua LR, Cammarota M. BDNF controls object recognition memory reconsolidation. Neurobiol Learn Mem 2017; 142:79-84. [PMID: 28274823 DOI: 10.1016/j.nlm.2017.02.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/20/2017] [Accepted: 02/25/2017] [Indexed: 01/16/2023]
Abstract
Reconsolidation restabilizes memory after reactivation. Previously, we reported that the hippocampus is engaged in object recognition memory reconsolidation to allow incorporation of new information into the original engram. Here we show that BDNF is sufficient for this process, and that blockade of BDNF function in dorsal CA1 impairs updating of the reactivated recognition memory trace.
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Affiliation(s)
- Andressa Radiske
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Av. Nascimento de Castro 2155, RN 59056-450 Natal, Brazil
| | - Janine I Rossato
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Av. Nascimento de Castro 2155, RN 59056-450 Natal, Brazil
| | - Maria Carolina Gonzalez
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Av. Nascimento de Castro 2155, RN 59056-450 Natal, Brazil
| | - Cristiano A Köhler
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Av. Nascimento de Castro 2155, RN 59056-450 Natal, Brazil
| | - Lia R Bevilaqua
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Av. Nascimento de Castro 2155, RN 59056-450 Natal, Brazil
| | - Martín Cammarota
- Memory Research Laboratory, Brain Institute, Federal University of Rio Grande do Norte, Av. Nascimento de Castro 2155, RN 59056-450 Natal, Brazil.
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Ozawa T, Yamada K, Ichitani Y. Differential requirements of hippocampal de novo protein and mRNA synthesis in two long-term spatial memory tests: Spontaneous place recognition and delay-interposed radial maze performance in rats. PLoS One 2017; 12:e0171629. [PMID: 28178292 PMCID: PMC5298318 DOI: 10.1371/journal.pone.0171629] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/24/2017] [Indexed: 11/18/2022] Open
Abstract
Hippocampal de novo mRNA and protein synthesis has been suggested to be critical for long-term spatial memory. However, its requirement in each memory process (i.e. encoding, consolidation and retrieval) and the differences in the roles of de novo mRNA and protein synthesis in different situations where spatial memory is tested have not been thoroughly investigated. To address these questions, we examined the effects of hippocampal administration of the protein synthesis inhibitors, anisomycin (ANI) and emetine (EME), as well as that of an mRNA synthesis inhibitor, 5,6-dichlorobenzimidazole 1-β-D-ribofuranoside (DRB), on rat performance in two long-term spatial memory tests. In a spontaneous place recognition test with a 6 h delay, ANI, administered either before or immediately after the sample phase, but not before the test phase, eliminated the exploratory preference for the object in a novel place. This amnesic effect was replicated by both EME and DRB. In a 6 h delay-interposed radial maze task, however, administering ANI before the first-half and before the second-half, but not immediately or 2 h after the first-half, impaired performance in the second-half. This disruptive effect of ANI was successfully replicated by EME. However, DRB administered before the first-half performance did not impair the second-half performance, while it did impair it if injected before the second-half. None of these drugs caused amnesic effects during the short (5 min)/non-delayed conditions in either tests. These results suggest that 1) hippocampal protein synthesis is required for the consolidation of spatial memory, while mRNA synthesis is not necessarily required, and 2) hippocampal mRNA and protein synthesis requirement for spatial memory retrieval depends on the types of memory tested, probably because their demands are different.
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Affiliation(s)
- Takaaki Ozawa
- Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Kazuo Yamada
- Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yukio Ichitani
- Institute of Psychology and Behavioral Neuroscience, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Urban KR, Li YC, Xing B, Gao WJ. A Clinically-Relevant Dose of Methylphenidate Enhances Synaptic Inhibition in the Juvenile Rat Prefrontal Cortex. ACTA ACUST UNITED AC 2017; 2:69-77. [PMID: 30221243 PMCID: PMC6136665 DOI: 10.17756/jrdsas.2016-030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Methylphenidate (MPH) is perhaps the most commonly prescribed psychoactive substance for young children and adolescents; however, its effects on the immature brain are not well understood. MPH is increasingly abused by adolescents and prescriptions are being issued to increasingly younger children without rigorous psychological testing, raising the potential for misdiagnosis; it is therefore crucial to understand how this drug might impact a healthy, developing brain. Recently, we have shown that a clinically-relevant dose of MPH depresses the activity of pyramidal neurons in the prefrontal cortex of normal juvenile rats, but its effects on inhibitory synaptic transmission remain to be explored. We therefore recorded spontaneous (s), miniature (m), and evoked (e) inhibitory postsynaptic currents (IPSCs) in layer 5 pyramidal neurons in juvenile rat prefrontal cortex. We found a dose-dependent effect of MPH on sIPSC frequency but not amplitude, where 0.3 mg/kg significantly decreased frequency, but 1 mg/kg significantly increased frequency. Moreover, mIPSCs were not affected by either dose of MPH, whereas the amplitudes, as well as paired-pulse ratios and coefficient of variations of evoked IPSCs were significantly increased after MPH treatment, indicating a presynaptic action. Tonic GABA current was also not affected by MPH treatment. Taken together, these results suggest that MPH administration to a healthy juvenile may enhance excitation of GABAergic interneurons; thus shifting the excitation-inhibition balance in the prefrontal cortex towards inhibition, and depressing overall prefrontal cortical activity. Our findings also indicate that the adolescent brain is more sensitive to MPH than previously thought, and dose ranges need to be reconsidered for age as well as size.
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Affiliation(s)
- Kimberly R Urban
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA.,Department of General Anesthesia, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Yan-Chun Li
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Bo Xing
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Wen-Jun Gao
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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Barnes AK, Smith SB, Datta S. Beyond Emotional and Spatial Processes: Cognitive Dysfunction in a Depressive Phenotype Produced by Long Photoperiod Exposure. PLoS One 2017; 12:e0170032. [PMID: 28060930 PMCID: PMC5218505 DOI: 10.1371/journal.pone.0170032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 12/27/2016] [Indexed: 01/04/2023] Open
Abstract
Cognitive dysfunction in depression has recently been given more attention and legitimacy as a core symptom of the disorder. However, animal investigations of depression-related cognitive deficits have generally focused on emotional or spatial memory processing. Additionally, the relationship between the cognitive and affective disturbances that are present in depression remains obscure. Interestingly, sleep disruption is one aspect of depression that can be related both to cognition and affect, and may serve as a link between the two. Previous studies have correlated sleep disruption with negative mood and impaired cognition. The present study investigated whether a long photoperiod-induced depressive phenotype showed cognitive deficits, as measured by novel object recognition, and displayed a cognitive vulnerability to an acute period of total sleep deprivation. Adult male Wistar rats were subjected to a long photoperiod (21L:3D) or a normal photoperiod (12L:12D) condition. Our results indicate that our long photoperiod exposed animals showed behaviors in the forced swim test consistent with a depressive phenotype, and showed significant deficits in novel object recognition. Three hours of total sleep deprivation, however, did not significantly change novel object recognition in either group, but the trends suggest that the long photoperiod and normal photoperiod groups had different cognitive responses to total sleep deprivation. Collectively, these results underline the extent of cognitive dysfunction present in depression, and suggest that altered sleep plays a role in generating both the affective and cognitive symptoms of depression.
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Affiliation(s)
- Abigail K. Barnes
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, TN, United States of America
- Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, TN, United States of America
| | - Summer B. Smith
- Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, TN, United States of America
| | - Subimal Datta
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, TN, United States of America
- Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, TN, United States of America
- Program in Comparative and Experimental Medicine, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, United States of America
- * E-mail:
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The Yin and Yang of Memory Consolidation: Hippocampal and Neocortical. PLoS Biol 2017; 15:e2000531. [PMID: 28085883 PMCID: PMC5234779 DOI: 10.1371/journal.pbio.2000531] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 12/14/2016] [Indexed: 01/06/2023] Open
Abstract
While hippocampal and cortical mechanisms of memory consolidation have long been studied, their interaction is poorly understood. We sought to investigate potential interactions with respect to trace dominance, strengthening, and interference associated with postencoding novelty or sleep. A learning procedure was scheduled in a watermaze that placed the impact of novelty and sleep in opposition. Distinct behavioural manipulations-context preexposure or interference during memory retrieval-differentially affected trace dominance and trace survival, respectively. Analysis of immediate early gene expression revealed parallel up-regulation in the hippocampus and cortex, sustained in the hippocampus in association with novelty but in the cortex in association with sleep. These findings shed light on dynamically interacting mechanisms mediating the stabilization of hippocampal and neocortical memory traces. Hippocampal memory traces followed by novelty were more dominant by default but liable to interference, whereas sleep engaged a lasting stabilization of cortical traces and consequent trace dominance after preexposure.
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