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Barbelivien A, Durieux L, Seys E, Majchrzak M. Intermittent working memory training during adulthood protects against age-related long-term spatial reference memory decline in rats. GeroScience 2024; 46:2223-2237. [PMID: 37910304 PMCID: PMC10828346 DOI: 10.1007/s11357-023-00993-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/20/2023] [Indexed: 11/03/2023] Open
Abstract
Engagement in cognitive activity in adulthood is one of the factors that enable successful cognitive aging, both in humans and rodents. However, some studies emphasize that the beneficial effect on cognition of such an activity may reflect carry over from one test situation to another, including memory for procedural aspects of the behavioral tasks, and thus question whether this effect can be limited to the trained cognitive domain or whether it can be transferred to an untrained ones. In the current study, we assessed whether adulthood intermittent working memory training has beneficial effect on long-term memory of aged rats using two very different test situations. To this aim, rats trained in a delayed non-matching to position task in operant box at 3 and 15 months of age were tested in a place learning task in water maze when they were 24 months. The two tasks differ with regard to the cognitive domain but also in their spatial ability requirement and the nature of the reinforcer used. During the memory tests, accuracy of the platform search indicated age-related impairment only in the aged-untrained group. Thus, intermittent training during adult life in a task involving working memory protects aged animals from the deleterious effects of aging on spatial reference memory. This result highlights the long-term beneficial effects of training on a working memory task on an untrained cognitive domain.
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Affiliation(s)
- Alexandra Barbelivien
- Laboratoire de Neurosciences Cognitives Et Adaptatives, Faculté de Psychologie, Université de Strasbourg, 67000, Strasbourg, France.
- Laboratoire de Neurosciences Cognitives Et Adaptatives, UMR 7364, CNRS, GDR Mémoire, 67000, Strasbourg, France.
| | - Laura Durieux
- Laboratoire de Neurosciences Cognitives Et Adaptatives, Faculté de Psychologie, Université de Strasbourg, 67000, Strasbourg, France
- Laboratoire de Neurosciences Cognitives Et Adaptatives, UMR 7364, CNRS, GDR Mémoire, 67000, Strasbourg, France
| | - Eliabel Seys
- Laboratoire de Neurosciences Cognitives Et Adaptatives, Faculté de Psychologie, Université de Strasbourg, 67000, Strasbourg, France
- Laboratoire de Neurosciences Cognitives Et Adaptatives, UMR 7364, CNRS, GDR Mémoire, 67000, Strasbourg, France
| | - Monique Majchrzak
- Laboratoire de Neurosciences Cognitives Et Adaptatives, Faculté de Psychologie, Université de Strasbourg, 67000, Strasbourg, France
- Laboratoire de Neurosciences Cognitives Et Adaptatives, UMR 7364, CNRS, GDR Mémoire, 67000, Strasbourg, France
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Ernyey AJ, Kassai F, Kozma K, Plangár I, Somfai Z, Miklya I, Gyertyán I. Age-related decline of various cognitive functions in well-experienced male rats treated with the putative anti-aging compound (2R)-1-(1-benzofuran-2-yl)-N-propylpentane-2-amine ((-)BPAP). GeroScience 2024; 46:417-429. [PMID: 37306892 PMCID: PMC10828437 DOI: 10.1007/s11357-023-00821-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 05/09/2023] [Indexed: 06/13/2023] Open
Abstract
Aging-associated cognitive disorders lack proper medication. To meet this need translation-wise, modification of the animal models is also required. In the present study, effect of the putative anti-aging compound (2R)-1-(1-benzofuran-2-yl)-N-propylpentane-2-amine ((-)BPAP, a deprenyl derivative) on age-related cognitive decline was investigated in experienced, aged Long-Evans rats. During their lifetime, animals had acquired knowledge in various cognitive assays. Their performance in these tests was then parallel followed from the age of 27 months until their death meanwhile half of them were treated with BPAP. Cognitive performance in various tasks showed different sensitivities/resistances to age-related impairment. Pot jumping performance (motor skill-learning) started to impair first, at 21 months of age, followed by decreasing performance in five-choice serial reaction time task (attention) at 26 months. Navigation performance in Morris water maze (spatial learning) started to decline at 31 months. Performance in a cooperation task (social cognition) started to decline the latest, at 34 months. Our findings suggest that in this process, the primary factor was the level of motivation to be engaged with the task and not losing the acquired knowledge. The average lifespan of the tested rat population was 36 months. BPAP could not improve the cognitive performance; neither could it prolong lifespan. A possible reason might be that dietary restriction and lifelong cognitive engagement had beneficial effects on cognitive capabilities and lifespan creating a "ceiling effect" for further improvement. The results confirmed that experienced animals provide a translationally relevant model to study age-related cognitive decline and measure the effect of putative anti-aging compounds.
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Affiliation(s)
- Aliz Judit Ernyey
- MTA-SE NAP B Cognitive Translational Behavioural Pharmacology Group, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, H-1089, Budapest, Hungary.
| | - Ferenc Kassai
- MTA-SE NAP B Cognitive Translational Behavioural Pharmacology Group, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, H-1089, Budapest, Hungary
| | - Kata Kozma
- MTA-SE NAP B Cognitive Translational Behavioural Pharmacology Group, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, H-1089, Budapest, Hungary
| | - Imola Plangár
- MTA-SE NAP B Cognitive Translational Behavioural Pharmacology Group, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, H-1089, Budapest, Hungary
| | - Zsuzsa Somfai
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, 1089, Budapest, Hungary
| | - Ildikó Miklya
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, 1089, Budapest, Hungary
| | - István Gyertyán
- MTA-SE NAP B Cognitive Translational Behavioural Pharmacology Group, Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Nagyvárad Tér 4, H-1089, Budapest, Hungary
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3
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Kurogi K, Taniguchi F, Matsuo R, Shinozuka M, Suzaki R, Yasuo S. Increased depression-like behaviors with altered brain dopamine metabolisms in male mice housed in large cages are alleviated by bupropion. Eur J Pharmacol 2023; 960:176126. [PMID: 37858834 DOI: 10.1016/j.ejphar.2023.176126] [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: 01/31/2023] [Revised: 09/29/2023] [Accepted: 10/16/2023] [Indexed: 10/21/2023]
Abstract
Psycho-environmental stress-based animal models of anxiety and depression are useful for investigating pathological mechanisms and drug development. Although several rodent-based studies have reported the beneficial effects of environmental enrichment (EE) on brain plasticity and anxiety- and depression-like behaviors, other studies have reported inverse effects. Here, we found that housing male mice in EE involving large cages and other EE materials increased anxiety- and depression-like behaviors in open field and tail suspension tests (TST). We further confirmed that housing in large cages was sufficient to induce increased depression-like behaviors in the TST and reduce the saccharine preference percentage, a sign of anhedonia, in male mice. In these experiments, the number of animals per cage was equivalent to that in standard cage housing, suggesting that low density in large cages may be a determining factor for behavioral alteration. In mice housed in large cages, sex-specific dysregulation of brain monoamine systems was observed; dopamine turnover to homovanillic acid or norepinephrine in the prefrontal cortex was elevated in males, while serotonin turnover to 5-hydroxyindoleacetic acid in the amygdala was increased in females. Finally, we demonstrated that daily intraperitoneal injections of bupropion, a dopamine and norepinephrine reuptake inhibitor, counteracted large-cage housing-induced changes in depression- and anhedonia-like behaviors in male mice. Our results suggest that housing in large cages with a low density of mice is a novel paradigm to clarify the mechanisms of environmental stress-induced emotional dysregulation and to identify drugs or food factors to alleviate the dysregulation.
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Affiliation(s)
- Kaito Kurogi
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Fuka Taniguchi
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Ryohei Matsuo
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Marina Shinozuka
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Raiki Suzaki
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shinobu Yasuo
- Laboratory of Regulation in Metabolism and Behavior, Faculty of Agriculture, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
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Nachtigall EG, de Freitas JDR, Marcondes LA, Furini CRG. Memory persistence induced by environmental enrichment is dependent on different brain structures. Physiol Behav 2023; 272:114375. [PMID: 37806510 DOI: 10.1016/j.physbeh.2023.114375] [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: 06/18/2023] [Revised: 09/24/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Environmental enrichment (EE) has been demonstrated to have a beneficial effect on different functions of the central nervous system in several mammal species, being used to improve behavior and cell damage in various neurological and psychiatric diseases. However, little has been investigated on the effect of EE in healthy animals, particularly regarding its impact on memory persistence and the brain structures involved. Therefore, here we verified in male Wistar rats that contextual fear conditioning (CFC) memory persistence, tested 28 days after the CFC training session, was facilitated by 5 weeks of exposure to EE, with no effect in groups tested 7 or 14 days after CFC training. However, a two-week exposure to EE did not affect memory persistence. Moreover, we investigated the role of specific brain regions in mediating the effect of EE on memory persistence. We conducted inactivation experiments using the GABAergic agonist Muscimol to target the basolateral amygdala (BLA), medial prefrontal cortex (mPFC), and CA1 region of the hippocampus (CA1). Inactivation of the BLA immediately and 12 h after CFC training impaired the effect of EE on memory persistence. Similarly, inactivation of the CA1 region and mPFC 12 h after training, but not immediately, also impaired the effect of EE on memory persistence. These results have important scientific implications as they shed new light on the effect of an enriched environment on memory persistence and the brain structures involved, thereby helping elucidate how an environment rich in experiences can modify the persistence of learned information.
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Affiliation(s)
- Eduarda G Nachtigall
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3rd floor, 90610-000, Porto Alegre, RS, Brazil
| | - Júlia D R de Freitas
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3rd floor, 90610-000, Porto Alegre, RS, Brazil
| | - Lucas Aschidamini Marcondes
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3rd floor, 90610-000, Porto Alegre, RS, Brazil
| | - Cristiane R G Furini
- Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690 - 3rd floor, 90610-000, Porto Alegre, RS, Brazil.
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5
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Alarcón TA, Presti-Silva SM, Simões APT, Ribeiro FM, Pires RGW. Molecular mechanisms underlying the neuroprotection of environmental enrichment in Parkinson's disease. Neural Regen Res 2023; 18:1450-1456. [PMID: 36571341 PMCID: PMC10075132 DOI: 10.4103/1673-5374.360264] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Parkinson's disease is the most common movement disorder, affecting about 1% of the population over the age of 60 years. Parkinson's disease is characterized clinically by resting tremor, bradykinesia, rigidity and postural instability, as a result of the progressive loss of nigrostriatal dopaminergic neurons. In addition to this neuronal cell loss, Parkinson's disease is characterized by the accumulation of intracellular protein aggregates, Lewy bodies and Lewy neurites, composed primarily of the protein α-synuclein. Although it was first described almost 200 years ago, there are no disease-modifying drugs to treat patients with Parkinson's disease. In addition to conventional therapies, non-pharmacological treatment strategies are under investigation in patients and animal models of neurodegenerative disorders. Among such strategies, environmental enrichment, comprising physical exercise, cognitive stimulus, and social interactions, has been assessed in preclinical models of Parkinson's disease. Environmental enrichment can cause structural and functional changes in the brain and promote neurogenesis and dendritic growth by modifying gene expression, enhancing the expression of neurotrophic factors and modulating neurotransmission. In this review article, we focus on the current knowledge about the molecular mechanisms underlying environmental enrichment neuroprotection in Parkinson's disease, highlighting its influence on the dopaminergic, cholinergic, glutamatergic and GABAergic systems, as well as the involvement of neurotrophic factors. We describe experimental pre-clinical data showing how environmental enrichment can act as a modulator in a neurochemical and behavioral context in different animal models of Parkinson's disease, highlighting the potential of environmental enrichment as an additional strategy in the management and prevention of this complex disease.
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Affiliation(s)
- Tamara Andrea Alarcón
- Department of Physiological Sciences; Laboratory of Molecular and Behavioral Neurobiology, Health Science Center, Universidade Federal do Espirito Santo, Vitoria, Brazil
| | - Sarah Martins Presti-Silva
- Laboratory of Molecular and Behavioral Neurobiology, Health Science Center, Universidade Federal do Espirito Santo, Vitoria; Department of Biochemistry and Immunology, Institute o Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, Brazil
| | - Ana Paula Toniato Simões
- Department of Physiological Sciences; Laboratory of Molecular and Behavioral Neurobiology, Health Science Center, Universidade Federal do Espirito Santo, Vitoria, Brazil
| | - Fabiola Mara Ribeiro
- Department of Biochemistry and Immunology, Institute o Biological Sciences, Universidade Federal de Minas Gerais, Avenida Antônio Carlos, Belo Horizonte, Brazil
| | - Rita Gomes Wanderley Pires
- Department of Physiological Sciences; Laboratory of Molecular and Behavioral Neurobiology, Health Science Center, Universidade Federal do Espirito Santo, Vitoria, Brazil
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Rubinstein MR, Burgueño AL, Quiroga S, Wald MR, Genaro AM. Current Understanding of the Roles of Gut-Brain Axis in the Cognitive Deficits Caused by Perinatal Stress Exposure. Cells 2023; 12:1735. [PMID: 37443769 PMCID: PMC10340286 DOI: 10.3390/cells12131735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/15/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
The term 'perinatal environment' refers to the period surrounding birth, which plays a crucial role in brain development. It has been suggested that dynamic communication between the neuro-immune system and gut microbiota is essential in maintaining adequate brain function. This interaction depends on the mother's status during pregnancy and/or the newborn environment. Here, we show experimental and clinical evidence that indicates that the perinatal period is a critical window in which stress-induced immune activation and altered microbiota compositions produce lasting behavioral consequences, although a clear causative relationship has not yet been established. In addition, we discuss potential early treatments for preventing the deleterious effect of perinatal stress exposure. In this sense, early environmental enrichment exposure (including exercise) and melatonin use in the perinatal period could be valuable in improving the negative consequences of early adversities. The evidence presented in this review encourages the realization of studies investigating the beneficial role of melatonin administration and environmental enrichment exposure in mitigating cognitive alteration in offspring under perinatal stress exposure. On the other hand, direct evidence of microbiota restoration as the main mechanism behind the beneficial effects of this treatment has not been fully demonstrated and should be explored in future studies.
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Affiliation(s)
- Mara Roxana Rubinstein
- Laboratorio de Psiconeuroendocrinoinmunologia, Instituto de Investigaciones Biomédicas, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)—Pontificia Universidad Católica Argentina, Buenos Aires C1107AFF, Argentina; (A.L.B.); (S.Q.); (M.R.W.)
| | | | | | | | - Ana María Genaro
- Laboratorio de Psiconeuroendocrinoinmunologia, Instituto de Investigaciones Biomédicas, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)—Pontificia Universidad Católica Argentina, Buenos Aires C1107AFF, Argentina; (A.L.B.); (S.Q.); (M.R.W.)
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Gros A, Wang SH. Cognitive rescue in aging through prior training in rats. Aging (Albany NY) 2023; 15:5990-6010. [PMID: 37338529 PMCID: PMC10373978 DOI: 10.18632/aging.204808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023]
Abstract
Cognitive decline in spatial memory is seen in aging. Understanding affected processes in aging is vital for developing methods to improve wellbeing. Daily memory persistence can be influenced by events around the time of learning or by prior experiences in early life. Fading memories in young can last longer if a novel event is introduced around encoding, a process called behavioral tagging. Based on this principle, we asked what processes are affected in aging and if prior training can rescue them. Two groups of aged rats received training in an appetitive delayed matching-to-place task. One of the groups additionally received prior training of the same task in young and in mid-life, constituting a longitudinal study. The results showed long-term memory decline in late aging without prior training. This would reflect affected encoding and consolidation. On the other hand, short-term memory was preserved and novelty at memory reactivation and reconsolidation enabled memory maintenance in aging. Prior training improved cognition through facilitating task performance, strengthening short-term memory and intermediate memory, and enabling encoding-boosted long-term memory. Implication of these findings in understanding brain mechanisms in cognitive aging and in beneficial effects of prior training is discussed.
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Affiliation(s)
- Alexandra Gros
- Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, Edinburgh, Scotland, UK
| | - Szu-Han Wang
- Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, Edinburgh, Scotland, UK
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The differential effects of brief environmental enrichment following social isolation in rats. COGNITIVE, AFFECTIVE, & BEHAVIORAL NEUROSCIENCE 2022; 22:818-832. [PMID: 35199313 PMCID: PMC8865499 DOI: 10.3758/s13415-022-00989-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/07/2022] [Indexed: 11/08/2022]
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Dandi E, Spandou E, Tata DA. Investigating the role of environmental enrichment initiated in adolescence against the detrimental effects of chronic unpredictable stress in adulthood: Sex-specific differences in behavioral and neuroendocrinological findings. Behav Processes 2022; 200:104707. [PMID: 35842198 DOI: 10.1016/j.beproc.2022.104707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/10/2022] [Accepted: 07/11/2022] [Indexed: 11/19/2022]
Abstract
Environmental Enrichment (EE) improves cognitive function and enhances brain plasticity, while chronic stress increases emotionality, impairs learning and memory, and has adverse effects on brain anatomy and biochemistry. We explored the beneficial role of environmental enrichment initiated in adolescence against the negative outcomes of Chronic Unpredictable Stress (CUS) during adulthood on emotional behavior, cognitive function, as well as somatic and neuroendocrine markers in both sexes. Adolescent Wistar rats housed either in enriched or standard housing conditions for 10 weeks. On postnatal day 66, a subgroup from each housing condition was daily exposed to a 4-week stress protocol. Following stress, adult rats underwent behavioral testing to evaluate anxiety, exploration/locomotor activity, depressive-like behavior and spatial learning/memory. Upon completion of behavioral testing, animals were exposed to a 10-m stressful event to test the neuroendocrine response to acute stress. CUS decreased body weight gain and increased adrenal weight. Some stress-induced behavioral adverse effects were sex-specific since learning impairments were limited to males while depressive-like behavior to females. EE housing protected against CUS-related behavioral deficits and body weight loss. Exposure to CUS affected the neuroendocrine response of males to acute stress as revealed by the increased corticosterone levels. Our findings highlight the significant role of EE in adolescence as a protective factor against the negative effects of stress and underline the importance of inclusion of both sexes in animal studies.
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Affiliation(s)
- Evgenia Dandi
- Laboratory of Cognitive Neuroscience, School of Psychology, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Evangelia Spandou
- Laboratory of Experimental Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Despina A Tata
- Laboratory of Cognitive Neuroscience, School of Psychology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Balietti M, Conti F. Environmental enrichment and the aging brain: is it time for standardization? Neurosci Biobehav Rev 2022; 139:104728. [PMID: 35691473 DOI: 10.1016/j.neubiorev.2022.104728] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 05/01/2022] [Accepted: 06/06/2022] [Indexed: 11/30/2022]
Abstract
Aging entails a progressive decline of cognitive abilities. However, since the brain is endowed with considerable plasticity, adequate stimulation can delay or partially compensate for age-related structural and functional impairment. Environmental enrichment (EE) has been reported to determine a wide range of cerebral changes. Although most findings have been obtained in young and adult animals, research has recently turned to aged individuals. Notably, EE can contribute identifying key lifestyle factors whose change can help extend the "mind-span", i.e., the time an individual lives in a healthy cognitive condition. Here we discuss specific methodological issues that can affect the outcomes of EE interventions applied to aged rodents, summarize the main variables that would need standardization (e.g., timing and duration, enrichment items, control animals and setting), and offer some suggestions on how this goal may be achieved. Reaching a consensus on EE experiment design would significantly reduce differences between and within laboratories, enable constructive discussions among researchers, and improve data interpretation.
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Affiliation(s)
- Marta Balietti
- Center for Neurobiology of Aging, IRCCS INRCA, Ancona, Italy.
| | - Fiorenzo Conti
- Center for Neurobiology of Aging, IRCCS INRCA, Ancona, Italy; Section of Neuroscience and Cell Biology, Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy.
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11
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Grigoryan GA. Molecular-Cellular Mechanisms of Plastic Restructuring Produced by an Enriched Environment. Effects on Learning and Memory. NEUROCHEM J+ 2021. [DOI: 10.1134/s1819712421030041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Lambert CT, Guillette LM. The impact of environmental and social factors on learning abilities: a meta-analysis. Biol Rev Camb Philos Soc 2021; 96:2871-2889. [PMID: 34342125 DOI: 10.1111/brv.12783] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 07/12/2021] [Accepted: 07/16/2021] [Indexed: 12/20/2022]
Abstract
Since the 1950s, researchers have examined how differences in the social and asocial environment affect learning in rats, mice, and, more recently, a variety of other species. Despite this large body of research, little has been done to synthesize these findings and to examine if social and asocial environmental factors have consistent effects on cognitive abilities, and if so, what aspects of these factors have greater or lesser impact. Here, we conducted a systematic review and meta-analysis examining how different external environmental features, including the social environment, impact learning (both speed of acquisition and performance). Using 531 mean-differences from 176 published articles across 27 species (with studies on rats and mice being most prominent) we conducted phylogenetically corrected mixed-effects models that reveal: (i) an average absolute effect size |d| = 0.55 and directional effect size d = 0.34; (ii) interventions manipulating the asocial environment result in larger effects than social interventions alone; and (iii) the length of the intervention is a significant predictor of effect size, with longer interventions resulting in larger effects. Additionally, much of the variation in effect size remained unexplained, possibly suggesting that species differ widely in how they are affected by environmental interventions due to varying ecological and evolutionary histories. Overall our results suggest that social and asocial environmental factors do significantly affect learning, but these effects are highly variable and perhaps not always as predicted. Most notably, the type (social or asocial) and length of interventions are important in determining the strength of the effect.
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Affiliation(s)
- Connor T Lambert
- Department of Psychology, University of Alberta, P217 Biological Sciences Building, Edmonton, AB, T6G 2R3, Canada
| | - Lauren M Guillette
- Department of Psychology, University of Alberta, P217 Biological Sciences Building, Edmonton, AB, T6G 2R3, Canada
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13
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Geltmeier MK, Fuchs PN. Evaluating the impact of age and inflammatory duration on behavioral assessments of nociception. Neurosci Lett 2021; 756:135966. [PMID: 34022263 DOI: 10.1016/j.neulet.2021.135966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 04/06/2021] [Accepted: 05/12/2021] [Indexed: 11/25/2022]
Abstract
Pain is a prevalent issue for elderly individuals. Unfortunately, it remains unclear how acute and chronic pain differs as a function of age, and surprisingly, there is even disagreement on how the sensory and affective dimensions of pain change with age. Therefore, the current investigation evaluated such age differences with behavioral methodology using a preclinical model of arthritis. The primary factors of interest were age and chronicity of pain using behavioral assessments designed to measure sensory and affective dimensions of pain processing. Mechanical and thermal paw withdrawal thresholds demonstrated unique outcomes associated with sensory processing across age. The processing of pain affect measured by the Place Escape/Avoidance Paradigm (PEAP testing) also demonstrated age related effects. Overall, younger animals appeared more sensitive to nociceptive stimuli than older animals. However, the results from the current study suggest that chronicity of pain can be impactful for how older animals process pain related affect and avoidance. The finding of unique patterns of pain across age and duration of pain highlights the clinical literature. Future research should aim to elucidate mechanisms for affective processing of chronic pain in older subjects.
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Affiliation(s)
- Maxine K Geltmeier
- Department of Psychology, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Perry N Fuchs
- Department of Psychology, University of Texas at Arlington, Arlington, TX, 76019, USA; Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA.
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Duggan MR, Parikh V. Microglia and modifiable life factors: Potential contributions to cognitive resilience in aging. Behav Brain Res 2021; 405:113207. [PMID: 33640394 PMCID: PMC8005490 DOI: 10.1016/j.bbr.2021.113207] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/27/2021] [Accepted: 02/20/2021] [Indexed: 02/08/2023]
Abstract
Given the increasing prevalence of age-related cognitive decline, it is relevant to consider the factors and mechanisms that might facilitate an individual's resiliency to such deficits. Growing evidence suggests a preeminent role of microglia, the prime mediator of innate immunity within the central nervous system. Human and animal investigations suggest aberrant microglial functioning and neuroinflammation are not only characteristic of the aged brain, but also might contribute to age-related dementia and Alzheimer's Disease. Conversely, accumulating data suggest that modifiable lifestyle factors (MLFs), such as healthy diet, exercise and cognitive engagement, can reliably afford cognitive benefits by potentially suppressing inflammation in the aging brain. The present review highlights recent advances in our understanding of the role for microglia in maintaining brain homeostasis and cognitive functioning in aging. Moreover, we propose an integrated, mechanistic model that postulates an individual's resiliency to cognitive decline afforded by MLFs might be mediated by the mitigation of aberrant microglia activation in aging, and subsequent suppression of neuroinflammation.
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Affiliation(s)
- Michael R Duggan
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA, 19122, United States
| | - Vinay Parikh
- Department of Psychology and Neuroscience Program, Temple University, Philadelphia, PA, 19122, United States.
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15
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Zentall TR. Effect of Environmental Enrichment on the Brain and on Learning and Cognition by Animals. Animals (Basel) 2021; 11:ani11040973. [PMID: 33807367 PMCID: PMC8066627 DOI: 10.3390/ani11040973] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 01/12/2023] Open
Abstract
Simple Summary Most people consider the environment in which animals are kept to be an ethical matter, separate from the research that we conduct with them. Those of us who do research on the cognitive behavior of animals try to consider their welfare, but what we often fail to recognize is that the welfare of the animals we study can affect the results of experiments that we investigate. We have but scratched the surface of the question, how do enriched environments affect the cognitive behavior of animals, in our case pigeons. We have found that pigeons with experience in an enriched environment are less impulsive. The reduction in impulsivity results in a reduced tendency to make the suboptimal choice. It also has been claimed to make animals more optimistic, as assessed by their tendency to make choices of more favorable alternatives, under ambiguous conditions. Abstract The humane treatment of animals suggests that they should be housed in an environment that is rich in stimulation and allows for varied activities. However, even if one’s main concern is an accurate assessment of their learning and cognitive abilities, housing them in an enriched environment can have an important effect on the assessment of those abilities. Research has found that the development of the brain of animals is significantly affected by the environment in which they live. Not surprisingly, their ability to learn both simple and complex tasks is affected by even modest time spent in an enriched environment. In particular, animals that are housed in an enriched environment are less impulsive and make more optimal choices than animals housed in isolation. Even the way that they judge the passage of time is affected by their housing conditions. Some researchers have even suggested that exposing animals to an enriched environment can make them more “optimistic” in how they treat ambiguous stimuli. Whether that behavioral effect reflects the subtlety of differences in optimism/pessimism or something simpler, like differences in motivation, incentive, discriminability, or neophobia, it is clear that the conditions of housing can have an important effect on the learning and cognition of animals.
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Affiliation(s)
- Thomas R Zentall
- Department of Psychology, University of Kentucky, Lexington, KY 40506-0044, USA
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16
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Mesa-Gresa P, Ramos-Campos M, Redolat R. Behavioral impact of experience based on environmental enrichment: Influence of age and duration of exposure in male NMRI mice. Dev Psychobiol 2021; 63:1071-1081. [PMID: 33452673 DOI: 10.1002/dev.22093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 12/21/2020] [Accepted: 12/26/2020] [Indexed: 01/22/2023]
Abstract
Prior studies have suggested that short periods of exposure to environmental enrichment (EE) in rodents induce physiological and behavioral effects. In the present study, our aim was to evaluate if the impact of experiences based on EE could be modulated by the age of onset and the developmental period of exposure. NMRI male mice (n = 64) were exposed to EE or standard environment (SE) and behavioral changes (anxiety, exploration, memory and social interaction) were evaluated. Groups compared were: (a) SE: exposure to SE on post-natal day (PND) 28 and lasting 6 months; (b) EE-6: exposure to EE on PND 28 and lasting 6 months; (c) EE-4: exposure to EE on PND 91 and lasting 4 months; (d) EE-2: exposure to EE on PND 154 and lasting 2 months. Results indicated that in the hole-board task the decrease in exploratory behavior reached significance when EE was initiated at adolescence whereas anxiolytic effects in the elevated plus-maze tend to diminish after a longer period of EE. No significant effects of EE on aggressive behavior or novel object recognition were obtained. Taking these results into account, further studies are needed in order to determine the possible modulating role of age and duration of exposure to enriched environments on behavior. Results obtained could explain some discrepancies reported in previous studies, providing new evidence that could contribute to the design of future research related to the benefits of complex and enriched environments.
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Affiliation(s)
- Patricia Mesa-Gresa
- Departamento Psicobiología, Facultad de Psicología, Universitat de València, Valencia, Spain
| | - Marta Ramos-Campos
- Departamento Psicobiología, Facultad de Psicología, Universitat de València, Valencia, Spain
| | - Rosa Redolat
- Departamento Psicobiología, Facultad de Psicología, Universitat de València, Valencia, Spain
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17
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Rizzolo L, Leger M, Corvaisier S, Groussard M, Platel H, Bouet V, Schumann-Bard P, Freret T. Long-Term Music Exposure Prevents Age-Related Cognitive Deficits in Rats Independently of Hippocampal Neurogenesis. Cereb Cortex 2021; 31:620-634. [PMID: 32959057 DOI: 10.1093/cercor/bhaa247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/05/2020] [Accepted: 08/11/2020] [Indexed: 11/14/2022] Open
Abstract
Cognitive decline appears across aging. While some studies report beneficial effects of musical listening and practice on cognitive aging, the underlying neurobiological mechanisms remain unknown. This study aims to determine whether chronic (6 h/day, 3 times/week) and long-lasting (4-8 months) music exposure, initiated at middle age in rats (15 months old), can influence behavioral parameters sensitive to age effects and reduce age-related spatial memory decline in rats. Spontaneous locomotor, circadian rhythmic activity, and anxiety-like behavior as well as spatial working and reference memory were assessed in 14-month-old rats and then after 4 and 8 months of music exposure (19 and 23 months old, respectively). Spatial learning and reference memory data were followed up by considering cognitive status of animals prior to music exposure (14 months old) given by K-means clustering of individual Z-score. Hippocampal cell proliferation and brain-derived neurotrophic factor (BDNF) level in the hippocampus and frontal cortex were measured. Results show that music exposure differentially rescues age-related deficits in spatial navigation tasks according to its duration without affecting spontaneous locomotor, circadian rhythmic activity, and anxiety-like behavior. Hippocampal cell proliferation as well as hippocampal and frontal cortex BDNF levels was not affected by music across aging. Cognitive improvement by music in aging rats may require distinct neurobiological mechanisms than hippocampal cell proliferation and BDNF.
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Affiliation(s)
- Lou Rizzolo
- Normandie University, Unicaen, INSERM, COMETE, CHU de Caen, Cyceron, 14000 Caen, France
| | - Marianne Leger
- Normandie University, Unicaen, INSERM, COMETE, CHU de Caen, Cyceron, 14000 Caen, France
| | - Sophie Corvaisier
- Normandie University, Unicaen, INSERM, COMETE, CHU de Caen, Cyceron, 14000 Caen, France
| | - Mathilde Groussard
- Normandie University, Unicaen, PSL Research University, EPHE, INSERM U1077, CHU de Caen, Cyceron, 14000 Caen, France
- PSL Research University, EPHE, Paris, France
| | - Hervé Platel
- Normandie University, Unicaen, PSL Research University, EPHE, INSERM U1077, CHU de Caen, Cyceron, 14000 Caen, France
- PSL Research University, EPHE, Paris, France
| | - Valentine Bouet
- Normandie University, Unicaen, INSERM, COMETE, CHU de Caen, Cyceron, 14000 Caen, France
| | - Pascale Schumann-Bard
- Normandie University, Unicaen, INSERM, COMETE, CHU de Caen, Cyceron, 14000 Caen, France
| | - Thomas Freret
- Normandie University, Unicaen, INSERM, COMETE, CHU de Caen, Cyceron, 14000 Caen, France
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18
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Pritchett-Corning KR. Environmental Complexity and Research Outcomes. ILAR J 2020; 60:239-251. [PMID: 32559304 DOI: 10.1093/ilar/ilaa007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 11/14/2022] Open
Abstract
Environmental complexity is an experimental paradigm as well as a potential part of animals' everyday housing experiences. In experimental uses, researchers add complexity to stimulate brain development, delay degenerative brain changes, elicit more naturalistic behaviors, and test learning and memory. Complexity can exacerbate or mitigate behavioral problems, give animals a sense of control, and allow for expression of highly driven, species-typical behaviors that can improve animal welfare. Complex environments should be designed thoughtfully with the animal's natural behaviors in mind, reported faithfully in the literature, and evaluated carefully for unexpected effects.
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Affiliation(s)
- Kathleen R Pritchett-Corning
- Office of Animal Resources, Faculty of Arts and Sciences, Harvard University, Cambridge, Massachusetts.,Department of Comparative Medicine, University of Washington, Seattle, Washington
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19
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Heimer-McGinn VR, Wise TB, Hemmer BM, Dayaw JNT, Templer VL. Social housing enhances acquisition of task set independently of environmental enrichment: A longitudinal study in the Barnes maze. Learn Behav 2020; 48:322-334. [PMID: 32040697 PMCID: PMC7415481 DOI: 10.3758/s13420-020-00418-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human studies suggest that healthy social relationships benefit cognition, yet little is known about the underlying neural mechanisms of this protective effect. In rodents, studies on acute isolation and environmental enrichment (EE) confirm the importance of social exposure. Despite the widely recognized importance of sociality, however, rodent models have yet to explore the independent contributions of social housing divorced of other forms of enrichment. This study dissociates the effects of social and physical enrichment on spatial learning and memory from adulthood to old age. Rats were placed in either single or group housing, provided with ample enrichment, and tested at three time points on several phases/versions of the Barnes maze (BM) (standard, retention probes, variable location, and reversal). We found that sustained social housing enhanced cognitive flexibility, as evidenced by superior acquisition of task set (standard BM), adaptability to a new task set (variable BM), and improved reversal learning (reversal BM). Long-term retention (BM retention probes) of spatial memory was unaffected by housing conditions. Recent studies from our lab, including this report, are the first to show that social housing confers cognitive benefits beyond those of physical enrichment. Importantly, our experimental design is ideal for exploring the neural underpinnings of this socially induced cognitive protection. Understanding how sociality influences cognition will be invaluable to translational models of aging, neuropsychiatric disease, and neurological injury.
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Affiliation(s)
- Victoria R Heimer-McGinn
- Department of Psychology, Providence College, 1 Cunningham Square, Providence, RI, 02918, USA
- Department of Psychology, Roger Williams University, 1 Old Ferry Road, Bristol, RI, 02809, USA
| | - Taylor B Wise
- Department of Psychology, Providence College, 1 Cunningham Square, Providence, RI, 02918, USA
| | - Brittany M Hemmer
- Department of Psychology, Providence College, 1 Cunningham Square, Providence, RI, 02918, USA
| | - Judith N T Dayaw
- Department of Psychology, Providence College, 1 Cunningham Square, Providence, RI, 02918, USA
| | - Victoria L Templer
- Department of Psychology, Providence College, 1 Cunningham Square, Providence, RI, 02918, USA.
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20
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Singhal G, Morgan J, Jawahar MC, Corrigan F, Jaehne EJ, Toben C, Manavis J, Hannan AJ, Baune BT. Duration of Environmental Enrichment Determines Astrocyte Number and Cervical Lymph Node T Lymphocyte Proportions but Not the Microglial Number in Middle-Aged C57BL/6 Mice. Front Cell Neurosci 2020; 14:57. [PMID: 32256319 PMCID: PMC7094170 DOI: 10.3389/fncel.2020.00057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 02/27/2020] [Indexed: 11/13/2022] Open
Abstract
Environmental enrichment (EE) has been shown to modulate behavior and immunity. We recently reported that both short and long-term EE enhance baseline locomotion and alleviate depressive-like behavior, but only long-term EE affects locomotion adversely in a threatening environment and enhances anxiety-like behavior in middle-age mice. We have now investigated whether the observed changes in behavior after short- and long-term EE were associated with underlying immune changes. Hence, at the end of behavioral testing, mice were sacrificed, and brains and cervical lymph nodes were collected to investigate the differential effects of the duration of EE (short- and long-term) on the number of immunopositive glial cells in the dentate gyrus, CA1, CA2, and CA3 regions of the hippocampus and proportions of T cell subsets in the cervical lymph nodes using immunohistochemistry and flow cytometry, respectively. EE, regardless of duration, caused an increase in microglia number within the dentate gyrus, CA1 and CA3 hippocampal regions, but only long-term EE increased astrocytes number within the dentate gyrus and CA3 hippocampal regions. A significantly higher proportion of CD8+ naive T cells was observed after long-term EE vs. short-term EE. No significant differences were observed in the proportion of central memory and effector memory T cells or early activated CD25+ cells between any of the test groups. Our results suggest that EE, irrespective of duration, enhances the numbers of microglia, but long-term EE is required to modify astrocyte number and peripheral T cell proportions in middle-aged mice. Our findings provide new insights into the therapeutic effects of EE on various brain disorders, which may be at least partly mediated by glial and neuroimmune modulation.
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Affiliation(s)
- Gaurav Singhal
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, The University of Adelaide, Adelaide, SA, Australia
| | - Julie Morgan
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, The University of Adelaide, Adelaide, SA, Australia
| | - Magdalene C Jawahar
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, The University of Adelaide, Adelaide, SA, Australia
| | - Frances Corrigan
- Division of Health Sciences, The University of South Australia, Adelaide, SA, Australia
| | - Emily J Jaehne
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, The University of Adelaide, Adelaide, SA, Australia.,School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia
| | - Catherine Toben
- Psychiatric Neuroscience Lab, Discipline of Psychiatry, The University of Adelaide, Adelaide, SA, Australia
| | - Jim Manavis
- Faculty of Health, Centre for Neurological Diseases, School of Medicine, The University of Adelaide, Adelaide, SA, Australia
| | - Anthony J Hannan
- Melbourne Brain Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Bernhard T Baune
- Melbourne Brain Centre, Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC, Australia.,Department of Psychiatry, Melbourne Medical School, The University of Melbourne, Melbourne, VIC, Australia.,Department of Psychiatry, University of Münster, Münster, Germany
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21
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Bouchatta O, Manouze H, Ba-M'Hamed S, Landry M, Bennis M. Neonatal 6-OHDA Lesion Model in Mouse Induces Cognitive Dysfunctions of Attention-Deficit/Hyperactivity Disorder (ADHD) During Young Age. Front Behav Neurosci 2020; 14:27. [PMID: 32174817 PMCID: PMC7054716 DOI: 10.3389/fnbeh.2020.00027] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/05/2020] [Indexed: 11/13/2022] Open
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a syndrome characterized by impaired attention, impulsivity and hyperactivity in children. These symptoms are often maintained in adults. During adolescence, prefrontal cortex develops connectivity with other brain regions to engage executive functions such as, latent inhibition, attention and inhibitory control. In our previous work, we demonstrated the validity of the neonatal 6-Hydroxydopamine (6-OHDA) mouse model, a classical neurodevelopmental model mimicking major symptoms of the human ADHD pathology. In order to evaluate pathological forms of executive functions and impulsive behavior in 6-OHDA mice during young age, we first tested latent inhibition (LI) after weaning, and then we evaluated the impulsive behavior using a cliff avoidance reaction test. Our results demonstrated that 6-OHDA mice showed disruption in latent inhibition, suggesting a deficit in selective attention, and displayed repetitive peering-down behavior, indicating a maladaptive impulsive behavior. Subsequently, to assess impulsivity and attention in young mice, we performed a modified 5-choice serial reaction time task test (5-CSRTT), optimizing the degree of food restriction for young animals and shortening the training duration. This test allowed us to demonstrate a deficit in inhibitory control and a loss of accuracy of 6-OHDA mice in the 5-CSRTT. In conclusion, we demonstrated that the 6-OHDA mouse model reproduces human symptoms of ADHD in childhood and early adulthood periods, as seen in human. Taken together, the 6-OHDA mouse model will be useful alongside other animal models to understand the neurobiological mechanisms underlying complex, heterogeneous neurological disorders.
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Affiliation(s)
- Otmane Bouchatta
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences, Cadi Ayyad University, Marrakesh, Morocco.,University of Bordeaux, Bordeaux, France.,CNRS UMR 5297, Centre Paul Broca-Nouvelle Aquitaine, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - Houria Manouze
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences, Cadi Ayyad University, Marrakesh, Morocco
| | - Saadia Ba-M'Hamed
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences, Cadi Ayyad University, Marrakesh, Morocco
| | - Marc Landry
- University of Bordeaux, Bordeaux, France.,CNRS UMR 5297, Centre Paul Broca-Nouvelle Aquitaine, Interdisciplinary Institute of Neuroscience, Bordeaux, France
| | - Mohamed Bennis
- Laboratory of Pharmacology, Neurobiology and Behavior, Faculty of Sciences, Cadi Ayyad University, Marrakesh, Morocco
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22
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Developmental effects of environmental enrichment on selective and auditory sustained attention. Psychoneuroendocrinology 2020; 111:104479. [PMID: 31704636 DOI: 10.1016/j.psyneuen.2019.104479] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/23/2019] [Accepted: 10/11/2019] [Indexed: 01/29/2023]
Abstract
Environmental enrichment (EE) has been used as a positive manipulation in different disease models. However, there is conflicting evidence reported in the literature about the effects of EE. Additionally, the time period that would be most beneficial in implementing environmental enrichment as an intervention is not clear. Our study aimed to systematically compare the prenatal, juvenile, mid-adolescence, and adulthood developmental trajectory to further the understanding of enriched environment's effects on selective and auditory sustained attention, corresponding to behavioral (conceived) and physiological-reflexive (non-conceived) measures. Rats were exposed for 21 days to enriched environment during various developmental periods and compared to age-matched controls. All groups were tested for long-term effects (at postnatal day 120 and onward) on selective and sustained attention. We found that the exposure to enriched environment during mid-adolescence has yielded the most significant and long-term pattern of effects, including selective and auditory sustained attention performance, increased foraging-like behavior and a significant decrease in corticosterone level. Similarly, the exposure to EE at juvenile period improved selective attention, increased foraging-like behavior, and reduced anxiety levels as reflected in the open field as well as in low corticosterone levels. These results specify a crucial period along the developmental trajectory for applying environmental enrichment. Mid-adolescence is suggested, in future basic and translational studies, as the sensitive time period that induces the most beneficial and long-term effects of EE on attention. The current findings suggest that the exposure to EE during mid-adolescence should be further considered and studied as behavioral alternative intervention, or as adjuvant behavioral therapy, aimed to decrease the probability to develop ADHD in post-adolescence period. This suggestion is highly relevant due to the debate regarding the pros and cons of screens usage (e.g. Facebook, online games, etc.) during early life that decreases environmental enrichment, especially, direct social interaction.
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23
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Cassel JC. Environment is not trivial! Epilepsia 2019; 60:2020-2022. [PMID: 31584192 DOI: 10.1111/epi.16346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Jean-Christophe Cassel
- Laboratory of Cognitive and Adaptive Neurosciences, University of Strasbourg, Strasbourg, France.,National Center for Scientific Research, Laboratory of Cognitive and Adaptive Neurosciences, Mixed Unit of Research 7364, Strasbourg, France
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24
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Short-term environmental enrichment, and not physical exercise, alleviate cognitive decline and anxiety from middle age onwards without affecting hippocampal gene expression. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2019; 19:1143-1169. [DOI: 10.3758/s13415-019-00743-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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25
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Singhal G, Morgan J, Jawahar MC, Corrigan F, Jaehne EJ, Toben C, Breen J, Pederson SM, Hannan AJ, Baune BT. The effects of short-term and long-term environmental enrichment on locomotion, mood-like behavior, cognition and hippocampal gene expression. Behav Brain Res 2019; 368:111917. [DOI: 10.1016/j.bbr.2019.111917] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 02/07/2023]
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26
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Biggio F, Mostallino M, Talani G, Locci V, Mostallino R, Calandra G, Sanna E, Biggio G. Social enrichment reverses the isolation-induced deficits of neuronal plasticity in the hippocampus of male rats. Neuropharmacology 2019; 151:45-54. [DOI: 10.1016/j.neuropharm.2019.03.030] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 03/21/2019] [Accepted: 03/26/2019] [Indexed: 02/07/2023]
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27
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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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28
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Li D, Huang CJ, Liu SC, Chang KH, Hung TM. Exercise type relates to inhibitory and error processing functions in older adults. AGING NEUROPSYCHOLOGY AND COGNITION 2018; 26:865-881. [PMID: 30372660 DOI: 10.1080/13825585.2018.1540688] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This study investigated the association between exercise type and inhibition of prepotent responses and error detection. Totally, 75 adults (M = 68.88 years) were classified into one of three exercise groups: those who were regular participants in open- or closed-skill forms of exercise, and those who exercised only irregularly. The participants completed a Stroop and task-switching tasks with event-related brain potentials (ERPs) recorded. The results revealed that regular exercisers displayed faster reaction times (RTs) in the Stroop task compared with irregular exercisers. The open-skill exercisers exhibited smaller N200 and larger P300a amplitudes in the Stroop task compared with irregular exercisers. Furthermore, the open-skill exercisers showed a tendency of shorter error-related negativity latencies at the task-witching test. The findings suggest that older adults may gain extra cognitive benefits in areas such as inhibition functioning and error processing from participating in open-skill forms of physical exercises.
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Affiliation(s)
- Dan Li
- School for Sports Humanities and Social Science, Jilin Sport University , Jilin , China
| | - Chung-Ju Huang
- Graduate Institute of Sport Pedagogy, University of Taipei , Taipei , Taiwan
| | - Sin-Chi Liu
- Department of Physical Education, National Taiwan Normal University , Taipei , Taiwan
| | - Kung-Hung Chang
- Office of Physical Education, Tamkang University , New Taipei City , Taiwan
| | - Tsung-Min Hung
- Department of Physical Education and Institute for Research Excellence in Learning Sciences, National Taiwan Normal University , Taipei , Taiwan
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29
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Neonatal 6-OHDA lesion model in mouse induces Attention-Deficit/ Hyperactivity Disorder (ADHD)-like behaviour. Sci Rep 2018; 8:15349. [PMID: 30337626 PMCID: PMC6193955 DOI: 10.1038/s41598-018-33778-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 10/03/2018] [Indexed: 11/08/2022] Open
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by impaired attention, impulsivity and hyperactivity. The "neonatal 6-hydroxydopamine" (6-OHDA) lesion is a commonly used model of ADHD in rat. However, a comprehensive assessment of ADHD-like symptoms is still missing, and data in mouse remain largely unavailable. Our aim was to analyse symptoms of ADHD in the mouse neonatal 6-OHDA model. 6-OHDA mice exhibited the major ADHD-like symptoms, i.e. hyperactivity (open field), attention deficit and impulsivity (five-choice serial reaction time task). Further, the model revealed discrete co-existing symptoms, i.e. anxiety-like (elevated plus maze test) and antisocial (social interaction) behaviours and decreased cognitive functioning (novel object recognition). The efficacy of methylphenidate, a classical psychostimulant used in the treatment of ADHD, was also evaluated. A histological analysis further supports the model validity by indicating dopamine depletion, changes in cortical thickness and abnormalities in anterior cingulate cortex neurons. A principal component analysis of the behaviour profile confirms that the 6-OHDA mouse model displayed good face and predictive validity. We conclude that neonatal dopamine depletion results in behavioural and morphological changes similar to those seen in patients and therefore could be used as a model for studying ADHD pathophysiological mechanisms and identifying therapeutic targets.
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Sampedro-Piquero P, Álvarez-Suárez P, Moreno-Fernández RD, García-Castro G, Cuesta M, Begega A. Environmental Enrichment Results in Both Brain Connectivity Efficiency and Selective Improvement in Different Behavioral Tasks. Neuroscience 2018; 388:374-383. [PMID: 30086366 DOI: 10.1016/j.neuroscience.2018.07.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/26/2022]
Abstract
Exposure to environmental enrichment (EE) has been a useful model for studying the effects of experience on brain plasticity, but to date, few is known about the impact of this condition on the brain functional networks that probably underlies the multiple behavioral improvements. Hence, we assessed the effect of an EE protocol in adult Wistar rats on the performance in several behavioral tasks testing different domains (Open field (OP): locomotor activity; Elevated-zero maze (EZM): anxiety-related behaviors; 5-choice serial reaction time task (5-CSRTT): attentional processes; 4-arm radial water maze (4-RAWM): spatial memory) in order to check its effectiveness in a wide range of functions. After this, we analyzed the functional brain connectivity underlying each experimental condition through cytochrome C oxidase (COx) histochemistry. Our EE protocol reduced both locomotor activity in the OP and anxiety-related behaviors in the EZM. On the other hand, enriched rats showed more accuracy in the 4-RAWM, whereas 5-CSRTT performance was not significantly ameliorated by EE condition. In relation to COx functional connectivity, we found that EE reduced the number of strong positive correlations both in basal and training conditions, suggesting a modulating effect on specific brain connections. Our results suggest that EE seems to have a selective effect on specific brain regions, such as prefrontal cortex and hippocampus, leading to a more efficient brain connectivity.
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Affiliation(s)
- P Sampedro-Piquero
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Instituto de Investigación Biomédica de Málaga (IBIMA), Facultad de Psicología, Universidad de Málaga, Spain.
| | | | - R D Moreno-Fernández
- Departamento de Psicobiología y Metodología de las Ciencias del Comportamiento, Instituto de Investigación Biomédica de Málaga (IBIMA), Facultad de Psicología, Universidad de Málaga, Spain
| | - G García-Castro
- Instituto de Neurociencias del Principado de Asturias INEUROPA, Departamento de Psicología, Facultad de Psicología, Universidad de Oviedo, Spain
| | - M Cuesta
- Instituto de Neurociencias del Principado de Asturias INEUROPA, Departamento de Psicología, Facultad de Psicología, Universidad de Oviedo, Spain
| | - A Begega
- Instituto de Neurociencias del Principado de Asturias INEUROPA, Departamento de Psicología, Facultad de Psicología, Universidad de Oviedo, Spain
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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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Sampedro-Piquero P, Begega A. Environmental Enrichment as a Positive Behavioral Intervention Across the Lifespan. Curr Neuropharmacol 2018; 15:459-470. [PMID: 27012955 PMCID: PMC5543669 DOI: 10.2174/1570159x14666160325115909] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/30/2015] [Accepted: 03/16/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In recent decades, the interest in behavioral interventions has been growing due to the higher prevalence of age-related cognitive impairments. Hence, behavioral interventions, such as cognitive stimulation and physical activity, and along with these, our lifestyle (education level, work position, frequency of cognitive and social activities) have shown important benefits during the cognitive impairment, dementia and even recovery after brain injury. This is due to the fact that this type of intervention and activities promote the formation of a cognitive and brain reserve that allows tolerating brain damage during a long period of time without the appearance of cognitive symptoms. With regard to this, animal models have proved very useful in providing information about the brain mechanisms involved in the development of these cognitive and brain reserves and how they interact with each other. METHODS We summarize several studies showing the positive effects of Environmental Enrichment (EE), understood as a housing condition in which animals benefit from the sensory, physical, cognitive and social stimulation provided, on brain and cognitive functions usually impaired during aging. RESULTS Most of studies have shown that EE is a successful protocol to improve cognitive functions and reduce anxiety-related behaviors across the lifespan, as well as in animal models of neurodegenerative diseases. CONCLUSION Therefore, EE is a laboratory condition in which some aspects of an active lifestyle are reproduced.
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Affiliation(s)
- P Sampedro-Piquero
- Department of Biological and Health Psychology, Autonomous University of Madrid, Cantoblanco 28049, Madrid, Spain
| | - A Begega
- Neuroscience Laboratory, Psychology Department, University of Oviedo, Plaza Feijoo s/n 33003 Oviedo, INEUROPA, Spain
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Cortese GP, Olin A, O'Riordan K, Hullinger R, Burger C. Environmental enrichment improves hippocampal function in aged rats by enhancing learning and memory, LTP, and mGluR5-Homer1c activity. Neurobiol Aging 2017; 63:1-11. [PMID: 29207276 DOI: 10.1016/j.neurobiolaging.2017.11.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 01/20/2023]
Abstract
Previous studies from our laboratory have shown that environmental enrichment (EE) in young rats results in improved learning ability and enhanced metabotropic glutamate receptor-dependent long-term potentiation (mGluR-dependent LTP) resulting from sustained activation of p70S6 kinase. Here, we investigated whether 1-month EE is sufficient to improve hippocampus-dependent learning and memory and enhance hippocampal LTP in 23-24 month-old Fischer 344 male rats. Aged rats were housed in environmentally enriched, socially enriched, or standard housing conditions. We find that aged rats exposed to 1-month of EE demonstrate enhanced learning and memory relative to standard housed controls when tested in the Morris water maze and novel object recognition behavioral tasks. Furthermore, we find that environmentally enriched rats perform significantly better than socially enriched or standard housed rats in the radial-arm water maze and display enhanced mGluR5-dependent hippocampal LTP. Enhanced hippocampal function results from activity-dependent increases in the levels of mGluR5, Homer1c, and phospho-p70S6 kinase. These findings demonstrate that a short exposure of EE to aged rats can have significant effects on hippocampal function.
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Affiliation(s)
- Giuseppe P Cortese
- Department of Neurology, Medical Sciences Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Andrew Olin
- College of Letters and Science, University of Wisconsin-Madison, Madison, WI, USA
| | - Kenneth O'Riordan
- Department of Pharmacology & Therapeutics, Trinity College, Dublin, Ireland
| | - Rikki Hullinger
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA
| | - Corinna Burger
- Department of Neurology, Medical Sciences Center, University of Wisconsin-Madison, Madison, WI, USA; Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI, USA.
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Chapagain D, Virányi Z, Wallis LJ, Huber L, Serra J, Range F. Aging of Attentiveness in Border Collies and Other Pet Dog Breeds: The Protective Benefits of Lifelong Training. Front Aging Neurosci 2017; 9:100. [PMID: 28473766 PMCID: PMC5397477 DOI: 10.3389/fnagi.2017.00100] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/29/2017] [Indexed: 11/26/2022] Open
Abstract
Aging of attentiveness affects cognitive functions like perception and working memory, which can seriously impact communication between dogs and humans, potentially hindering training and cooperation. Previous studies have revealed that aged laboratory beagles and pet Border collies (BC) show a decline in selective attention. However, much less is known about the aging of attentiveness in pet dogs in general rather than in specific breeds. Using 185 pet dogs (75 BC and 110 dogs of other breeds) divided into three age groups [late adulthood (6- < 8 year), senior (8- < 10 year) and geriatric (≥10 year)], we assessed the progress of aging of attentional capture, sustained and selective attention in older dogs in order to explore if prior results in BC are generalizable and to evaluate the influence of lifelong training on measures of attention. Each dog’s lifelong training score (ranging from 0 to 52) was calculated from a questionnaire filled in by the owners listing what kinds of training the dog participated in during its entire life. Dogs were tested in two tasks; the first, measuring attentional capture and sustained attention toward two stimuli (toy and human); and the second, measuring selective attention by means of clicker training for eye contact and finding food on the floor. In the first task, results revealed a significant effect of age but no effect of lifelong training on latency to orient to the stimuli. Duration of looking decreased with age and increased with lifelong training. In the second task, while lifelong training decreased the latency of dogs to form eye contact, aged dogs needed longer to find food. BC did not differ from other dogs in any measures of attention except latency to find food. In conclusion, aged dogs showed a decline in attentional capture and sustained attention demonstrating that these tests are sensitive to detect aging of attentiveness in older pet dogs. Importantly, selective attention remained unchanged with age and lifelong training seemed to delay or reduce the aging of attentiveness, further highlighting the importance of lifelong training in retaining general cognitive functions.
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Affiliation(s)
- Durga Chapagain
- Clever Dog Lab, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of ViennaVienna, Austria
| | - Zsófia Virányi
- Clever Dog Lab, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of ViennaVienna, Austria
| | - Lisa J Wallis
- Clever Dog Lab, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of ViennaVienna, Austria.,Department of Ethology, Eötvös Loránd UniversityBudapest, Hungary
| | - Ludwig Huber
- Clever Dog Lab, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of ViennaVienna, Austria
| | | | - Friederike Range
- Clever Dog Lab, Messerli Research Institute, University of Veterinary Medicine Vienna, Medical University of Vienna, University of ViennaVienna, Austria
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Requiring collaboration: Hippocampal-prefrontal networks needed in spatial working memory and ageing. A multivariate analysis approach. Neurobiol Learn Mem 2017; 140:33-42. [DOI: 10.1016/j.nlm.2017.02.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/12/2017] [Indexed: 11/21/2022]
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Zeleznikow-Johnston A, Burrows EL, Renoir T, Hannan AJ. Environmental enrichment enhances cognitive flexibility in C57BL/6 mice on a touchscreen reversal learning task. Neuropharmacology 2017; 117:219-226. [PMID: 28196627 DOI: 10.1016/j.neuropharm.2017.02.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/13/2017] [Accepted: 02/09/2017] [Indexed: 01/12/2023]
Abstract
Environmental enrichment (EE) is any positive modification of the 'standard housing' (SH) conditions in which laboratory animals are typically held, usually involving increased opportunity for cognitive stimulation and physical activity. EE has been reported to enhance baseline performance of wild-type animals on traditional cognitive behavioural tasks. Recently, touchscreen operant testing chambers have emerged as a way of performing rodent cognitive assays, providing greater reproducibility, translatability and automatability. Cognitive tests in touchscreen chambers are performed over numerous trials and thus experimenters have the power to detect subtle enhancements in performance. We used touchscreens to analyse the effects of EE on reversal learning, visual discrimination and hippocampal-dependent spatial pattern separation and working memory. We hypothesized that EE would enhance the performance of mice on cognitive touchscreen tasks. Our hypothesis was partially supported in that EE induced enhancements in cognitive flexibility as observed in visual discrimination and reversal learning improvements. However, no other significant effects of EE on cognitive performance were observed. EE decreased the activity level of mice in the touchscreen chambers, which may influence the enrichment level of the animals. Although we did not see enhancements on all hypothesized parameters, our testing paradigm is capable of detecting EE-induced improved cognitive flexibility in mice, which has implications for both understanding the mechanisms of EE and improving screening of putative cognitive-enhancing therapeutics.
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Affiliation(s)
- Ariel Zeleznikow-Johnston
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3010, Australia
| | - Emma L Burrows
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3010, Australia
| | - Thibault Renoir
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3010, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3010, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC 3010, Australia.
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37
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Wang X, Chen A, Wu H, Ye M, Cheng H, Jiang X, Wang X, Zhang X, Wu D, Gu X, Shen F, Shan C, Yu D. Enriched environment improves post-stroke cognitive impairment in mice by potential regulation of acetylation homeostasis in cholinergic circuits. Brain Res 2016; 1650:232-242. [DOI: 10.1016/j.brainres.2016.09.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Revised: 08/18/2016] [Accepted: 09/12/2016] [Indexed: 01/07/2023]
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Nobre MJ. Environmental enrichment may protect against neural and behavioural damage caused by withdrawal from chronic alcohol intake. Int J Dev Neurosci 2016; 55:15-27. [PMID: 27616301 DOI: 10.1016/j.ijdevneu.2016.09.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 09/06/2016] [Accepted: 09/07/2016] [Indexed: 11/18/2022] Open
Abstract
Exposure to stress and prolonged exposure to alcohol leads to neuronal damages in several brain regions, being the medial prefrontal cortex (mPFC) one of the most affected. These changes presumably reduce the ability of the organism to cope with these stimuli and may underlie a series of maladaptive behaviours among which include drug addiction and withdrawal. Drug-addicted individuals show a pattern of behavior similar to patients with lesions of the mPFC. This impairment in the decision-making could be one of the mechanisms responsible for the transition from the casual to compulsive drug use. The environmental enrichment (EE) has a protective effect on the neural and cognitive impairments induced by psychoactive drugs, including ethyl alcohol. The present study aims to determine the influence of withdrawal from intermittent long-term alcohol exposure on alcohol preference, emotional reactivity and neural aspects of early isolated or grouped reared rats kept under standard or complex environments and the influence of social isolation on these measures, as well. Our results point out new insights on this matter showing that the EE can attenuate the adverse effects of withdrawal and social isolation on rat's behavior. This effect is probably due to its protective action on the mPFC integrity, including the cingulate area 1 (Cg1), and the prelimbic (PrL) and infralimbic cortex (IL), what could account for the absence of changes in the emotional reactivity in EE alcohol withdrawal rats. We argue that morphological changes at these cortical levels can afford the emotional, cognitive and behavioural dysregulations verified following withdrawal from chronic alcohol intake.
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Affiliation(s)
- Manoel Jorge Nobre
- Departamento de Psicologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto Universidade de São Paulo (USP), 14040-901 Ribeirão Preto, SP, Brazil; Departamento de Psicologia, Uni-FACEF, 14401-135, Franca, SP, Brazil; Instituto de Neurociências e Comportamento-INeC, Campus USP, 14040-901 Ribeirão Preto, SP, Brazil.
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Late-Life Environmental Enrichment Induces Acetylation Events and Nuclear Factor κB-Dependent Regulations in the Hippocampus of Aged Rats Showing Improved Plasticity and Learning. J Neurosci 2016; 36:4351-61. [PMID: 27076430 DOI: 10.1523/jneurosci.3239-15.2016] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 03/07/2016] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Aging weakens memory functions. Exposing healthy rodents or pathological rodent models to environmental enrichment (EE) housing improves their cognitive functions by changing neuronal levels of excitation, cellular signaling, and plasticity, notably in the hippocampus. At the molecular level, brain derived-neurotrophic factor (BDNF) represents an important player that supports EE-associated changes. EE facilitation of learning was also shown to correlate with chromatin acetylation in the hippocampus. It is not known, however, whether such mechanisms are still into play during aging. In this study, we exposed a cohort of aged rats (18-month-old) to either a 6 month period of EE or standard housing conditions and investigated chromatin acetylation-associated events [histone acetyltranferase activity, gene expression, and histone 3 (H3) acetylation] and epigenetic modulation of the Bdnf gene under rest conditions and during learning. We show that EE leads to upregulation of acetylation-dependent mechanisms in aged rats, whether at rest or following a learning challenge. We found an increased expression of Bdnf through Exon-I-dependent transcription, associated with an enrichment of acetylated H3 at several sites of Bdnf promoter I, more particularly on a proximal nuclear factor κB (NF-κB) site under learning conditions. We further evidenced p65/NF-κB binding to chromatin at promoters of genes important for plasticity and hippocampus-dependent learning (e.g., Bdnf, CamK2D). Altogether, our findings demonstrate that aged rats respond to a belated period of EE by increasing hippocampal plasticity, together with activating sustained acetylation-associated mechanisms recruiting NF-κB and promoting related gene transcription. These responses are likely to trigger beneficial effects associated with EE during aging. SIGNIFICANCE STATEMENT Aging weakens memory functions. Optimizing the neuronal circuitry required for normal brain function can be achieved by increasing sensory, motor, and cognitive stimuli resulting from interactions with the environment (behavioral therapy). This can be experimentally modeled by exposing rodents to environmental enrichment (EE), as with large cages, numerous and varied toys, and interaction with other rodents. However, EE effects in aged rodents has been poorly studied, and it is not known whether beneficial mechanisms evidenced in the young adults can still be recruited during aging. Our study shows that aged rats respond to a belated period of EE by activating specific epigenetic and transcriptional signaling that promotes gene expression likely to facilitate plasticity and learning behaviors.
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Fuchs F, Herbeaux K, Aufrere N, Kelche C, Mathis C, Barbelivien A, Majchrzak M. Late enrichment maintains accurate recent and remote spatial memory only in aged rats that were unimpaired when middle aged. ACTA ACUST UNITED AC 2016; 23:303-12. [PMID: 27194797 PMCID: PMC4880144 DOI: 10.1101/lm.041236.115] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 03/26/2016] [Indexed: 11/29/2022]
Abstract
Exposure of rodents to a stimulating environment has beneficial effects on some cognitive functions that are impaired during physiological aging, and especially spatial reference memory. The present study investigated whether environmental enrichment rescues these functions in already declining subjects and/or protects them from subsequent decline. Subgroups of 17-mo-old female rats with unimpaired versus impaired performance in a spatial reference memory task (Morris water maze) were housed until the age of 24 mo in standard or enriched environment. They were then trained in a second reference memory task, conducted in a different room than the first, and recent (1 d) and remote (10 d) memory were assessed. In unimpaired subgroups, spatial memory declined from 17 to 24 mo in rats housed in standard conditions; an enriched environment during this period allowed maintenance of accurate recent and remote spatial memory. At 24 mo, rats impaired at the age of 17 mo housed in enriched environment learned the task and displayed substantial recent memory, but their performance remained lower than that of unimpaired rats, showing that enrichment failed to rescue spatial memory in already cognitively declining rats. Controls indicated carryover effects of the first water maze training, especially in aged rats housed in standard condition, and confirmed the beneficial effect of enrichment on remote memory of aged rats even if they performed poorly than young adults housed for the same duration in standard or enriched condition.
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Affiliation(s)
- Fanny Fuchs
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
| | - Karine Herbeaux
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
| | - Noémie Aufrere
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
| | - Christian Kelche
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
| | - Chantal Mathis
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
| | - Alexandra Barbelivien
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
| | - Monique Majchrzak
- Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, Unistra, Neuropôle de Strasbourg, Faculté de Psychologie, 67000 Strasbourg, France Laboratoire de Neurosciences Cognitives et Adaptatives, UMR 7364, CNRS, GDR 2905, 67000 Strasbourg, France
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Mesa-Gresa P, Ramos-Campos M, Redolat R. Corticosterone levels and behavioral changes induced by simultaneous exposure to chronic social stress and enriched environments in NMRI male mice. Physiol Behav 2016; 158:6-17. [DOI: 10.1016/j.physbeh.2016.02.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/14/2016] [Accepted: 02/18/2016] [Indexed: 12/15/2022]
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42
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Hankosky ER, Sherrill LK, Ruvola LA, Haake RM, Kim T, Hammerslag LR, Kougias DG, Juraska JM, Gulley JM. Effects of β-hydroxy-β-methyl butyrate on working memory and cognitive flexibility in an animal model of aging. Nutr Neurosci 2016; 20:379-387. [PMID: 26896292 DOI: 10.1080/1028415x.2016.1145376] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
OBJECTIVES Normal aging results in cognitive decline and nutritional interventions have been suggested as potential approaches for mitigating these deficits. Here, we used rats to investigate the effects of short- and long-term dietary supplementation with the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) on working memory and cognitive flexibility. METHODS Beginning ∼12 months of age, male and female Long-Evans rats were given twice daily access to sipper tubes containing calcium HMB (450 mg/kg) or vehicle (285 mg/kg calcium lactate) in a sucrose solution (20% w/v). Supplementation continued for 1 or 7 months (middle- and old-age (OA) groups, respectively) before testing began. Working memory was assessed by requiring rats to respond on a previously sampled lever following various delays. Cognitive flexibility was assessed by training rats to earn food according to a visual strategy and then, once acquired, shifting to an egocentric response strategy. RESULTS Treatment with HMB improved working memory performance in middle-age (MA) males and OA rats of both sexes. In the cognitive flexibility task, there was a significant age-dependent deficit in acquisition of the visual strategy that was not apparent in OA males treated with HMB. Furthermore, HMB ameliorated an apparent deficit in visual strategy acquisition in MA females. DISCUSSION Together, these findings suggest that daily nutritional supplementation with HMB facilitates learning and improves working memory performance. As such, HMB supplementation may mitigate age-related cognitive deficits and may therefore be an effective tool to combat this undesirable feature of the aging process.
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Affiliation(s)
- Emily R Hankosky
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA
| | - Luke K Sherrill
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA
| | - Lauren A Ruvola
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA
| | - Rachel M Haake
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA
| | - Taehyeon Kim
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA
| | | | - Daniel G Kougias
- b Neuroscience Program , University of Illinois , Urbana-Champaign , USA
| | - Janice M Juraska
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA.,b Neuroscience Program , University of Illinois , Urbana-Champaign , USA
| | - Joshua M Gulley
- a Department of Psychology , University of Illinois , Urbana-Champaign , USA.,b Neuroscience Program , University of Illinois , Urbana-Champaign , USA
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Hadas I, Gal R, Bokovza L, Meiran N, Feifel D, Zangen A. Exposure to salient, dynamic sensory stimuli during development increases distractibility in adulthood. Sci Rep 2016; 6:21129. [PMID: 26882890 PMCID: PMC4756326 DOI: 10.1038/srep21129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Accepted: 01/18/2016] [Indexed: 11/23/2022] Open
Abstract
It has been suggested that excessive exposure of children to the dynamic and highly salient audio-visual stimuli conveyed by electronic media may induce attention-related deficits in adulthood. This study was designed to evaluate this hypothesis in a controlled animal model setup. Building on their natural responsiveness to odors, we exposed juvenile rats for 1 h daily to a dynamic series of interchanging, highly salient odors, while controls were exposed to a non-changing mixture of these odors. Upon reaching adulthood, we tested the attentional capacity of the rats and measured their brain-derived neurotrophic factor (BDNF) levels as a proxy of neuronal plasticity. As compared with controls, rats exposed to the dynamic stimulation showed no attentional deficits under baseline task conditions, but their performance was dramatically impaired when an auditory distractor was introduced in the task. In addition, BDNF levels in the dorsal striatum of these rats were significantly increased relative to controls. These findings provide first empirical evidence that a continuous exposure to dynamic, highly salient stimuli has long-term effects on attentional functions later in life, and that these effects may have neural correlates in the dorsal striatum.
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Affiliation(s)
- Itay Hadas
- Department of Life Sciences and the Zlotowski Centre for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ram Gal
- Department of Life Sciences and the Zlotowski Centre for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Lihi Bokovza
- Department of Life Sciences and the Zlotowski Centre for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Nachshon Meiran
- Department of Psychology and the Zlotowski Centre for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - David Feifel
- Department of Psychiatry and Neurosciences Program, University of California, San Diego, USA
| | - Abraham Zangen
- Department of Life Sciences and the Zlotowski Centre for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Exposure to an enriched environment up to middle age allows preservation of spatial memory capabilities in old age. Behav Brain Res 2016; 299:1-5. [DOI: 10.1016/j.bbr.2015.11.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 11/24/2022]
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45
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Environmental enrichment as a method to improve cognitive function. What can we learn from animal models? Neuroimage 2015; 131:42-7. [PMID: 26656208 DOI: 10.1016/j.neuroimage.2015.11.039] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/12/2015] [Accepted: 11/15/2015] [Indexed: 01/21/2023] Open
Abstract
There is substantial evidence that physical and cognitive exercise can enhance memory function in rodents as well as in humans. In addition various behaviors associated with physical activity have been associated with an increased cognitive reserve and a lower risk to develop age-associated memory decline and age-associated neurodegenerative diseases such as Alzheimer's disease. To better understand the molecular mechanisms that increase brain plasticity in response to exercise will therefore help to develop effective therapeutic strategies to treat memory decline. Here we review the currently available data with a specific focus on neurodegenerative diseases.
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Environmental enrichment improves learning and memory and long-term potentiation in young adult rats through a mechanism requiring mGluR5 signaling and sustained activation of p70s6k. Neurobiol Learn Mem 2015; 125:126-34. [PMID: 26341144 DOI: 10.1016/j.nlm.2015.08.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/28/2015] [Accepted: 08/11/2015] [Indexed: 11/22/2022]
Abstract
Previous studies from our lab have demonstrated that mild cognitive impairments identified early in life are predictive of cognitive deficits that develop with age, suggesting that enhancements in cognition at an early age can provide a buffer against age-related cognitive decline. Environmental enrichment has been shown to improve learning and memory in the rodent, but the impact of enrichment on synaptic plasticity and the molecular mechanisms behind enrichment are not completely understood. To address these unresolved issues, we have housed 2-month old rats in environmentally enriched (EE), socially enriched (SE), or standard housing (SC) and conducted tests of learning and memory formation at various time intervals. Here we demonstrate that animals that have been exposed to one month of social or environmental enrichment demonstrate enhanced learning and memory relative to standard housed controls. However, we have found that after 4months EE animals perform better than both SE and SC groups and demonstrate an enhanced hippocampal LTP. Our results demonstrate that this LTP is dependent on mGluR5 signaling, activation of ERK and mTOR signaling cascades, and sustained phosphorylation of p70s6 kinase, thus providing a potential target mechanism for future studies of cognitive enhancement in the rodent.
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Cassarino M, Setti A. Environment as 'Brain Training': A review of geographical and physical environmental influences on cognitive ageing. Ageing Res Rev 2015; 23:167-82. [PMID: 26144974 DOI: 10.1016/j.arr.2015.06.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 06/19/2015] [Accepted: 06/29/2015] [Indexed: 12/15/2022]
Abstract
Global ageing demographics coupled with increased urbanisation pose major challenges to the provision of optimal living environments for older persons, particularly in relation to cognitive health. Although animal studies emphasize the benefits of enriched environments for cognition, and brain training interventions have shown that maintaining or improving cognitive vitality in older age is possible, our knowledge of the characteristics of our physical environment which are protective for cognitive ageing is lacking. The present review analyses different environmental characteristics (e.g. urban vs. rural settings, presence of green) in relation to cognitive performance in ageing. Studies of direct and indirect associations between physical environment and cognitive performance are reviewed in order to describe the evidence that our living contexts constitute a measurable factor in determining cognitive ageing.
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48
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Housing condition-related changes involved in reversal learning and its c-Fos associated activity in the prefrontal cortex. Neuroscience 2015; 307:14-25. [PMID: 26314630 DOI: 10.1016/j.neuroscience.2015.08.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 07/31/2015] [Accepted: 08/18/2015] [Indexed: 12/29/2022]
Abstract
Our study examined how different housing conditions modulated the acquisition of a spatial reference memory task and also, a reversal task in the 4-radial arm water maze (4-RAWM). The animals were randomly assigned to standard or enriched cages, and, as a type of complementary stimulation along with the environmental enrichment (EE), a group of rats also ran 15 min/day in a Rotarod. Elevated-zero maze results allowed us to discard that our exercise training increased anxiety-related behaviors. 4-RAWM results revealed that the non-enriched group had a worse performance during the acquisition and also, during the first trial of each session with respect to the enriched groups. Regarding the reversal task, this group made more perseverative errors in the previous platform position. Interestingly, we hardly found differences between the two enriched groups (with and without exercise). We also analyzed how the reversal learning, depending on the previous housing condition, modulated the expression of c-Fos-positive nuclei in different subdivisions of the medial prefrontal cortex (cingulate (Cg), prelimbic (PL) and infralimbic (IL) cortices) and in the orbitofrontal (OF) cortex. The enriched groups had higher c-Fos expression in the Cg and OF cortices and lower in the IL cortex respect to the non-enriched animals. In the PL cortex, we did not find significant differences between the groups that performed the reversal task. Therefore, our short EE protocol improved the performance in a spatial memory and a reversal task, whereas the exercise training, combined with the EE, did not produce a greater benefit. This better performance seemed to be related with the specific pattern of c-Fos expression in brain regions involved in cognitive flexibility.
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Guidi M, Rani A, Karic S, Severance B, Kumar A, Foster TC. Contribution of N-methyl-D-aspartate receptors to attention and episodic spatial memory during senescence. Neurobiol Learn Mem 2015; 125:36-46. [PMID: 26234588 DOI: 10.1016/j.nlm.2015.07.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/22/2015] [Accepted: 07/24/2015] [Indexed: 01/06/2023]
Abstract
A decrease in N-methyl-D-aspartate receptor (NMDAR) function is associated with age-related cognitive impairments. However, NMDAR antagonists are prescribed for cognitive decline associated with age-related neurodegenerative disease, raising questions as to the role of NMDAR activity in cognitive function during aging. The current studies examined effects of NMDAR blockade on cognitive task that are sensitive to aging. Young and middle-age rats were trained on the five-choice serial reaction time task (5-CSRTT) and challenged with MK-801 (0.025, 0.05, and 0.1mg/kg or vehicle). Attention deficits were apparent in middle-age and performance of young and middle-age rats was enhanced for low doses of MK-801 (0.025 and 0.05). The beneficial effects on attention were reversed by the highest dose of MK-801. Older animals exhibited a delay-dependent impairment of episodic spatial memory examined on a delayed-matching to place water maze task. Similarly, a low dose of MK-801 (0.05mg/kg) impaired performance with increasing delay and aged animals were more susceptible to disruption by NMDAR blockade. Despite MK-801 impairment of episodic spatial memory, MK-801 had minimal effects on spatial reference memory. Our results confirm that NMDARs contribute to rapidly acquired and flexible spatial memory and support the idea that a decline in NMDAR function contributes to the age-related impairments in cognition.
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Affiliation(s)
- Michael Guidi
- Noldus Information Technology, 1503 Edwards Ferry Road, Suite 310, Leesburg, VA 20176, USA
| | - Asha Rani
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Semir Karic
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Barrett Severance
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
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50
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Guidi M, Kumar A, Foster TC. Impaired attention and synaptic senescence of the prefrontal cortex involves redox regulation of NMDA receptors. J Neurosci 2015; 35:3966-77. [PMID: 25740525 PMCID: PMC4348191 DOI: 10.1523/jneurosci.3523-14.2015] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/23/2014] [Accepted: 01/21/2015] [Indexed: 01/05/2023] Open
Abstract
Young (3-6 months) and middle-age (10-14 months) rats were trained on the five-choice serial reaction time task. Attention and executive function deficits were apparent in middle-age animals observed as a decrease in choice accuracy, increase in omissions, and increased response latency. The behavioral differences were not due to alterations in sensorimotor function or a diminished motivational state. Electrophysiological characterization of synaptic transmission in slices from the mPFC indicated an age-related decrease in glutamatergic transmission. In particular, a robust decrease in N-methyl-D-aspartate receptor (NMDAR)-mediated synaptic responses in the mPFC was correlated with several measures of attention. The decrease in NMDAR function was due in part to an altered redox state as bath application of the reducing agent, dithiothreitol, increased the NMDAR component of the synaptic response to a greater extent in middle-age animals. Together with previous work indicating that redox state mediates senescent physiology in the hippocampus, the results indicate that redox changes contribute to senescent synaptic function in vulnerable brain regions involved in age-related cognitive decline.
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Affiliation(s)
- Michael Guidi
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida 32610
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