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Aykan D, Genc M, Unal G. Environmental enrichment enhances the antidepressant effect of ketamine and ameliorates spatial memory deficits in adult rats. Pharmacol Biochem Behav 2024; 240:173790. [PMID: 38761992 DOI: 10.1016/j.pbb.2024.173790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/09/2024] [Accepted: 05/13/2024] [Indexed: 05/20/2024]
Abstract
Ketamine is a rapid-acting antidepressant associated with various cognitive side effects. To mitigate these side effects while enhancing efficacy, it can be co-administered with other antidepressants. In our study, we adopted a similar strategy by combining ketamine with environmental enrichment, a potent sensory-motor paradigm, in adult male Wistar rats. We divided the animals into four groups based on a combination of housing conditions and ketamine versus vehicle injections. The groups included those housed in standard cages or an enriched environment for 50 days, which encompassed a 13-day-long behavioral testing period. Each group received either two doses of ketamine (20 mg/kg, IP) or saline as a vehicle. We tested the animals in the novel object recognition test (NORT), forced swim test (FST), open field test (OFT), elevated plus maze (EPM), and Morris water maze (MWM), which was followed by ex vivo c-Fos immunohistochemistry. We observed that combining environmental enrichment with ketamine led to a synergistic antidepressant effect. Environmental enrichment also ameliorated the spatial memory deficits caused by ketamine in the MWM. There was enhanced neuronal activity in the habenula of the enrichment only group following the probe trial of the MWM. In contrast, no differential activity was observed in enriched animals that received ketamine injections. The present study showed how environmental enrichment can enhance the antidepressant properties of ketamine while reducing some of its side effects, highlighting the potential of combining pharmacological and sensory-motor manipulations in the treatment of mood disorders.
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Affiliation(s)
- Deren Aykan
- Behavioral Neuroscience Laboratory, Department of Psychology, Boğaziçi University, 34342 Istanbul, Turkey
| | - Mert Genc
- Behavioral Neuroscience Laboratory, Department of Psychology, Boğaziçi University, 34342 Istanbul, Turkey
| | - Gunes Unal
- Behavioral Neuroscience Laboratory, Department of Psychology, Boğaziçi University, 34342 Istanbul, Turkey.
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2
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Saxena R, McNaughton BL. Bridging Neuroscience and AI: Environmental Enrichment as a Model for Forward Knowledge Transfer. ARXIV 2024:arXiv:2405.07295v2. [PMID: 38947919 PMCID: PMC11213130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Continual learning (CL) refers to an agent's capability to learn from a continuous stream of data and transfer knowledge without forgetting old information. One crucial aspect of CL is forward transfer, i.e., improved and faster learning on a new task by leveraging information from prior knowledge. While this ability comes naturally to biological brains, it poses a significant challenge for artificial intelligence (AI). Here, we suggest that environmental enrichment (EE) can be used as a biological model for studying forward transfer, inspiring human-like AI development. EE refers to animal studies that enhance cognitive, social, motor, and sensory stimulation and is a model for what, in humans, is referred to as 'cognitive reserve'. Enriched animals show significant improvement in learning speed and performance on new tasks, typically exhibiting forward transfer. We explore anatomical, molecular, and neuronal changes post-EE and discuss how artificial neural networks (ANNs) can be used to predict neural computation changes after enriched experiences. Finally, we provide a synergistic way of combining neuroscience and AI research that paves the path toward developing AI capable of rapid and efficient new task learning.
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Affiliation(s)
- Rajat Saxena
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
| | - Bruce L McNaughton
- Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA 92697, USA
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, T1K 3M4 Canada
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3
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Sinclair D, Canty AJ, Ziebell JM, Woodhouse A, Collins JM, Perry S, Roccati E, Kuruvilla M, Leung J, Atkinson R, Vickers JC, Cook AL, King AE. Experimental laboratory models as tools for understanding modifiable dementia risk. Alzheimers Dement 2024; 20:4260-4289. [PMID: 38687209 PMCID: PMC11180874 DOI: 10.1002/alz.13834] [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: 12/13/2023] [Revised: 02/29/2024] [Accepted: 03/18/2024] [Indexed: 05/02/2024]
Abstract
Experimental laboratory research has an important role to play in dementia prevention. Mechanisms underlying modifiable risk factors for dementia are promising targets for dementia prevention but are difficult to investigate in human populations due to technological constraints and confounds. Therefore, controlled laboratory experiments in models such as transgenic rodents, invertebrates and in vitro cultured cells are increasingly used to investigate dementia risk factors and test strategies which target them to prevent dementia. This review provides an overview of experimental research into 15 established and putative modifiable dementia risk factors: less early-life education, hearing loss, depression, social isolation, life stress, hypertension, obesity, diabetes, physical inactivity, heavy alcohol use, smoking, air pollution, anesthetic exposure, traumatic brain injury, and disordered sleep. It explores how experimental models have been, and can be, used to address questions about modifiable dementia risk and prevention that cannot readily be addressed in human studies. HIGHLIGHTS: Modifiable dementia risk factors are promising targets for dementia prevention. Interrogation of mechanisms underlying dementia risk is difficult in human populations. Studies using diverse experimental models are revealing modifiable dementia risk mechanisms. We review experimental research into 15 modifiable dementia risk factors. Laboratory science can contribute uniquely to dementia prevention.
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Affiliation(s)
- Duncan Sinclair
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Alison J. Canty
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
- Global Brain Health Institute, Trinity CollegeDublinIreland
| | - Jenna M. Ziebell
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Adele Woodhouse
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Jessica M. Collins
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Sharn Perry
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Eddy Roccati
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Maneesh Kuruvilla
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Jacqueline Leung
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Rachel Atkinson
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - James C. Vickers
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Anthony L. Cook
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
| | - Anna E. King
- Wicking Dementia Research and Education Centre, University of TasmaniaHobartTasmaniaAustralia
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Fan B, Lin J, Luo Q, Liao W, Hao C. Enriched Environment Inhibits Neurotoxic Reactive Astrocytes via JAK2-STAT3 to Promote Glutamatergic Synaptogenesis and Cognitive Improvement in Chronic Cerebral Hypoperfusion Rats. Neurotox Res 2024; 42:22. [PMID: 38564082 DOI: 10.1007/s12640-024-00704-4] [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] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Abstract
Chronic cerebral hypoperfusion (CCH) is a primary contributor to cognitive decline in the elderly. Enriched environment (EE) is proved to improve cognitive function. However, mechanisms involved remain unclear. The purpose of the study was exploring the mechanisms of EE in alleviating cognitive deficit in rats with CCH. To create a rat model of CCH, 2-vessel occlusion (2-VO) surgery was performed. All rats lived in standard or enriched environments for 4 weeks. Cognitive function was assessed using the novel object recognition test and Morris water maze test. The protein levels of glutamatergic synapses, neurotoxic reactive astrocytes, reactive microglia, and JAK2-STAT3 signaling pathway were measured using Western blot. The mRNA levels of synaptic regulatory factors, C1q, TNF-α, and IL-1α were identified using quantitative PCR. Immunofluorescence was used to detect glutamatergic synapses, neurotoxic reactive astrocytes, and reactive microglia, as well as the expression of p-STAT3 in astrocytes in the hippocampus. The results demonstrated that the EE mitigated cognitive impairment in rats with CCH and enhanced glutamatergic synaptogenesis. EE also inhibited the activation of neurotoxic reactive astrocytes. Moreover, EE downregulated microglial activation, levels of C1q, TNF-α and IL-1α and phosphorylation of JAK2 and STAT3. Our results suggest that inhibition of neurotoxic reactive astrocytes may be one of the mechanisms by which EE promotes glutamatergic synaptogenesis and improves cognitive function in rats with CCH. The downregulation of reactive microglia and JAK2-STAT3 signaling pathway may be involved in this process.
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Affiliation(s)
- Bin Fan
- Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Junbin Lin
- Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Qihang Luo
- Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Weijing Liao
- Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.
| | - Chizi Hao
- Department of Rehabilitation Medicine, Zhongnan Hospital of Wuhan University, Wuhan, China.
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Pintori N, Piva A, Mottarlini F, Díaz FC, Maggi C, Caffino L, Fumagalli F, Chiamulera C. Brief exposure to enriched environment rapidly shapes the glutamate synapses in the rat brain: A metaplastic fingerprint. Eur J Neurosci 2024; 59:982-995. [PMID: 38378276 DOI: 10.1111/ejn.16279] [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: 07/06/2023] [Revised: 09/22/2023] [Accepted: 01/27/2024] [Indexed: 02/22/2024]
Abstract
Environmental enrichment (EE) has been shown to produce beneficial effects in addiction disorders; however, due to its configurational complexity, the underlying mechanisms are not yet fully elucidated. Recent evidence suggests that EE, acting as a metaplastic agent, may affect glutamatergic mechanisms underlying appetitive memory and, in turn, modulate reward-seeking behaviours: here, we have investigated such a possibility following a brief EE exposure. Adult male Sprague-Dawley rats were exposed to EE for 22 h and the expression of critical elements of the glutamate synapse was measured 2 h after the end of EE in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc) and hippocampus (Hipp) brain areas, which are critical for reward and memory. We focused our investigation on the expression of NMDA and AMPA receptor subunits, their scaffolding proteins SAP102 and SAP97, vesicular and membrane glutamate transporters vGluT1 and GLT-1, and critical structural components such as proteins involved in morphology and function of glutamatergic synapses, PSD95 and Arc/Arg3.1. Our findings demonstrate that a brief EE exposure induces metaplastic changes in glutamatergic mPFC, NAc and Hipp. Such changes are area-specific and involve postsynaptic NMDA/AMPA receptor subunit composition, as well as changes in the expression of their main scaffolding proteins, thus influencing the retention of such receptors at synaptic sites. Our data indicate that brief EE exposure is sufficient to dynamically modulate the glutamatergic synapses in mPFC-NAc-Hipp circuits, which may modulate rewarding and memory processes.
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Affiliation(s)
- Nicholas Pintori
- Section of Pharmacology, Department of Diagnostic & Public Health, University of Verona, Verona, Italy
- Current Affiliation: Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Cagliari, Italy
| | - Alessandro Piva
- Section of Pharmacology, Department of Diagnostic & Public Health, University of Verona, Verona, Italy
| | - Francesca Mottarlini
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Fernando Castillo Díaz
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Coralie Maggi
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences 'Rodolfo Paoletti', University of Milan, Milan, Italy
| | - Cristiano Chiamulera
- Section of Pharmacology, Department of Diagnostic & Public Health, University of Verona, Verona, Italy
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Shishkina GT, Kalinina TS, Lanshakov DA, Bulygina VV, Komysheva NP, Bannova AV, Drozd US, Dygalo NN. Genes Involved by Dexamethasone in Prevention of Long-Term Memory Impairment Caused by Lipopolysaccharide-Induced Neuroinflammation. Biomedicines 2023; 11:2595. [PMID: 37892969 PMCID: PMC10604440 DOI: 10.3390/biomedicines11102595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 10/29/2023] Open
Abstract
Inflammatory activation within the brain is linked to a decrease in cognitive abilities; however, the molecular mechanisms implicated in the development of inflammatory-related cognitive dysfunction and its prevention are poorly understood. This study compared the responses of hippocampal transcriptomes 3 months after the striatal infusion of lipopolysaccharide (LPS; 30 µg), resulting in memory loss, or with dexamethasone (DEX; 5 mg/kg intraperitoneal) pretreatment, which abolished the long-term LPS-induced memory impairment. After LPS treatment, a significant elevation in the expression of immunity/inflammatory-linked genes, including chemokines (Cxcl13), cytokines (Il1b and Tnfsf13b), and major histocompatibility complex (MHC) class II members (Cd74, RT1-Ba, RT1-Bb, RT1-Da, and RT1-Db1) was observed. DEX pretreatment did not change the expression of these genes, but significantly affected the expression of genes encoding ion channels, primarily calcium and potassium channels, regulators of glutamate (Slc1a2, Grm5, Grin2a), and GABA (Gabrr2, Gabrb2) neurotransmission, which enriched in such GO biological processes as "Regulation of transmembrane transport", "Cognition", "Learning", "Neurogenesis", and "Nervous system development". Taken together, these data suggest that (1) pretreatment with DEX did not markedly affect LPS-induced prolonged inflammatory response; (2) DEX pretreatment can affect processes associated with glutamatergic signaling and nervous system development, possibly involved in the recovery of memory impairment induced by LPS.
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Affiliation(s)
- Galina T. Shishkina
- Laboratory of Functional Neurogenomics, Federal Research Center Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Science, Novosibirsk 630090, Russia; (T.S.K.); (D.A.L.); (V.V.B.); (N.P.K.); (A.V.B.); (U.S.D.); (N.N.D.)
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7
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Morè L, Privitera L, Cooper DD, Tsogka M, Arthur JSC, Frenguelli BG. MSK1 is required for the beneficial synaptic and cognitive effects of enriched experience across the lifespan. Aging (Albany NY) 2023; 15:6031-6072. [PMID: 37432063 PMCID: PMC10373962 DOI: 10.18632/aging.204833] [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: 02/28/2023] [Accepted: 05/31/2023] [Indexed: 07/12/2023]
Abstract
Positive experiences, such as social interaction, cognitive training and physical exercise, have been shown to ameliorate some of the harms to cognition associated with ageing. Animal models of positive interventions, commonly known as environmental enrichment, strongly influence neuronal morphology and synaptic function and enhance cognitive performance. While the profound structural and functional benefits of enrichment have been appreciated for decades, little is known as to how the environment influences neurons to respond and adapt to these positive sensory experiences. We show that adult and aged male wild-type mice that underwent a 10-week environmental enrichment protocol demonstrated improved performance in a variety of behavioural tasks, including those testing spatial working and spatial reference memory, and an enhancement in hippocampal LTP. Aged animals in particular benefitted from enrichment, performing spatial memory tasks at levels similar to healthy adult mice. Many of these benefits, including in gene expression, were absent in mice with a mutation in an enzyme, MSK1, which is activated by BDNF, a growth factor implicated in rodent and human cognition. We conclude that enrichment is beneficial across the lifespan and that MSK1 is required for the full extent of these experience-induced improvements of cognitive abilities, synaptic plasticity and gene expression.
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Affiliation(s)
- Lorenzo Morè
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK
| | - Lucia Privitera
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Daniel D. Cooper
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Marianthi Tsogka
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
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The Molecular Effects of Environmental Enrichment on Alzheimer's Disease. Mol Neurobiol 2022; 59:7095-7118. [PMID: 36083518 PMCID: PMC9616781 DOI: 10.1007/s12035-022-03016-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/23/2022] [Indexed: 12/02/2022]
Abstract
Environmental enrichment (EE) is an environmental paradigm encompassing sensory, cognitive, and physical stimulation at a heightened level. Previous studies have reported the beneficial effects of EE in the brain, particularly in the hippocampus. EE improves cognitive function as well as ameliorates depressive and anxiety-like behaviors, making it a potentially effective neuroprotective strategy against neurodegenerative diseases such as Alzheimer's disease (AD). Here, we summarize the current evidence for EE as a neuroprotective strategy as well as the potential molecular pathways that can explain the effects of EE from a biochemical perspective using animal models. The effectiveness of EE in enhancing brain activity against neurodegeneration is explored with a view to differences present in early and late life EE exposure, with its potential application in human being discussed. We discuss EE as one of the non pharmacological approaches in preventing or delaying the onset of AD for future research.
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Domínguez-Oliva A, Mota-Rojas D, Hernández-Avalos I, Mora-Medina P, Olmos-Hernández A, Verduzco-Mendoza A, Casas-Alvarado A, Whittaker AL. The neurobiology of pain and facial movements in rodents: Clinical applications and current research. Front Vet Sci 2022; 9:1016720. [PMID: 36246319 PMCID: PMC9556725 DOI: 10.3389/fvets.2022.1016720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/12/2022] [Indexed: 11/30/2022] Open
Abstract
One of the most controversial aspects of the use of animals in science is the production of pain. Pain is a central ethical concern. The activation of neural pathways involved in the pain response has physiological, endocrine, and behavioral consequences, that can affect both the health and welfare of the animals, as well as the validity of research. The strategy to prevent these consequences requires understanding of the nociception process, pain itself, and how assessment can be performed using validated, non-invasive methods. The study of facial expressions related to pain has undergone considerable study with the finding that certain movements of the facial muscles (called facial action units) are associated with the presence and intensity of pain. This review, focused on rodents, discusses the neurobiology of facial expressions, clinical applications, and current research designed to better understand pain and the nociceptive pathway as a strategy for implementing refinement in biomedical research.
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Affiliation(s)
- Adriana Domínguez-Oliva
- Master in Science Program “Maestría en Ciencias Agropecuarias”, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | - Daniel Mota-Rojas
- Neurophysiology, Behavior and Animal Welfare Assesment, DPAA, Universidad Autónoma Metropolitana, Mexico City, Mexico
- *Correspondence: Daniel Mota-Rojas
| | - Ismael Hernández-Avalos
- Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Mexico
| | - Patricia Mora-Medina
- Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México, Cuautitlán Izcalli, Mexico
| | - Adriana Olmos-Hernández
- Division of Biotechnology-Bioterio and Experimental Surgery, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
| | - Antonio Verduzco-Mendoza
- Division of Biotechnology-Bioterio and Experimental Surgery, Instituto Nacional de Rehabilitación Luis Guillermo Ibarra Ibarra, Mexico City, Mexico
| | - Alejandro Casas-Alvarado
- Neurophysiology, Behavior and Animal Welfare Assesment, DPAA, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | - Alexandra L. Whittaker
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia
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Xu J, Li Y, Tian B, Liu H, Wu S, Wang W. The effects and mechanism of environmental enrichment on MK-801 induced cognitive impairment in rodents with schizophrenia. Front Cell Neurosci 2022; 16:1024649. [PMID: 36246525 PMCID: PMC9556631 DOI: 10.3389/fncel.2022.1024649] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/13/2022] [Indexed: 12/02/2022] Open
Abstract
Schizophrenia is a severe mental disorder characterized by positive, negative, and cognitive symptoms. Cognitive symptoms are a kind of symptoms with high incidence and great impact on patients. There is no effective treatment in clinical practice. N-methyl-d-aspartic acid (NMDA) receptor hypofunction may be an important cause of cognitive symptoms. MK-801 (also named Dizocilpine), a noncompetitive antagonist of NMDA receptor, is often used to construct a model of NMDA receptor dysfunction. In terms of treatment, environmental enrichment (EE) as an environmental intervention can effectively improve the symptoms of cognitive impairment in rodents. In this paper, we first briefly introduce the background of cognitive symptoms and EE in schizophrenia, and then investigate the manifestations of MK-801 induced cognitive impairment, the improvement of EE on these cognitive impairments based on the MK-801 induced schizophrenia rodent models, and the possible mechanism of EE in improving cognitive symptoms. This article reviews the literature in recent years, which provides an important reference for MK-801 to construct a cognitive symptom model of schizophrenia and the mechanism of EE in improving cognitive symptoms of schizophrenia.
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Changes in Stereotypies: Effects over Time and over Generations. Animals (Basel) 2022; 12:ani12192504. [PMID: 36230246 PMCID: PMC9559266 DOI: 10.3390/ani12192504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/06/2022] [Accepted: 09/16/2022] [Indexed: 11/20/2022] Open
Abstract
Simple Summary Herein, we propose that there should be discussion about the function and effects of stereotypies in relation to the time during which they are shown. In the first stages, stereotypies may help animals deal with challenges. However, behavior can potentially alter the brain, impairing its function due the absence of a diverse repertory, and change brain connections, neurophysiology and later neuroanatomy. The neuroanatomical changes in individuals showing stereotypies could be an effect rather than a cause of the stereotypy. As a consequence, studies showing different outcomes for animal welfare from stereotypy expression could be due to variation in a timeline of expression. Stereotypies are widely used as an animal welfare indicator, and their expression can tell us about psychological states. However, there are questions about the longer-term consequences if animals express stereotypies: do the stereotypies help in coping? During the prenatal period, stereotypic behavior expressed by the mother can change the phenotype of the offspring, especially regarding emotionality, one mechanism acting via methylation in the limbic system in the brain. Are individuals that show stereotypies for shorter or longer periods all better adjusted, and hence have better welfare, or is the later welfare of some worse than that of individuals that do not show the behavior? Abstract Stereotypies comprise a wide range of repeated and apparently functionless behaviors that develop in individuals whose neural condition or environment results in poor welfare. While stereotypies are an indicator of poor welfare at the time of occurrence, they may have various consequences. Environmental enrichment modifies causal factors and reduces the occurrence of stereotypies, providing evidence that stereotypies are an indicator of poor welfare. However, stereotypy occurrence and consequences change over time. Furthermore, there are complex direct and epigenetic effects when mother mammals that are kept in negative conditions do or do not show stereotypies. It is proposed that, when trying to deal with challenging situations, stereotypies might initially help animals to cope. After further time in the conditions, the performance of the stereotypy may impair brain function and change brain connections, neurophysiology and eventually neuroanatomy. It is possible that reported neuroanatomical changes are an effect of the stereotypy rather than a cause.
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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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13
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Pintori N, Piva A, Guardiani V, Decimo I, Chiamulera C. Brief Environmental Enrichment exposure enhances contextual-induced sucrose-seeking with and without memory reactivation in rats. Behav Brain Res 2022; 416:113556. [PMID: 34474039 DOI: 10.1016/j.bbr.2021.113556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 07/21/2021] [Accepted: 08/23/2021] [Indexed: 12/16/2022]
Abstract
Chronic Environmental Enrichment (EE) has been shown to prevent the relapse to addictive behaviours, such as drug-taking and -seeking. Recently, acute EE was shown to reduce cue-induced sucrose-seeking, but its effects on contextual (Cx)-induced sucrose-seeking is still unknown. Here we report the effects of brief EE exposure on Cx-induced sucrose-seeking with and without prior Cx-memory reactivation. Adult male Sprague-Dawley rats were trained to sucrose self-administration associated to a specific conditioning Cx (CxA), followed by a 7-day extinction in a different Cx (CxB). Afterwards, rats were exposed for 22 h to EE, and 1 h later to either i) Cx-induced sucrose-seeking (1 h, renewal without Cx-memory reactivation), ii) or two different Cx-memory reactivations: short (2-min) and long (15-min) CxA-retrieval session (Cx-Ret). In Cx-Ret experiments, CxA-induced sucrose-seeking test (1 h) was done after a subsequent 3-day extinction phase. The assessment of molecular markers of memory reactivation/reconsolidation, Zif-268 and rpS6P, was performed 2 h after Cx-Ret. Brief EE exposure enhanced Cx-induced sucrose-seeking without and with short but not long Cx-retrieval. Moreover, EE impaired discriminative responding at test prior to long, whereas improved it with or without short Cx-retrieval. Different changes in Zif-268 and rpS6P expression induced by short vs. long Cx-Ret were correlated to behavioural data, suggesting the occurrence of different memory processes affected by EE. Our data show that brief EE exposure may differently affect subsequent appetitive relapse depending on the modality of re-exposure to conditioned context. This finding suggests caution and further studies to understand the proper conditions for the use of EE against appetitive and addiction disorders.
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Affiliation(s)
- N Pintori
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy.
| | - A Piva
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
| | - V Guardiani
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
| | - I Decimo
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
| | - C Chiamulera
- Section of Pharmacology, Dept. Diagnostic & Public Health, University of Verona, Verona, Italy
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14
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DePasquale C, Kemerer N, White N, Yost M, Wolfkill J, Sturgill J, Li X. The Influence of an Enriched Environment in Enhancing Recognition Memory in Zebrafish ( Danio rerio). Front Vet Sci 2021; 8:749746. [PMID: 34869723 PMCID: PMC8632956 DOI: 10.3389/fvets.2021.749746] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/04/2021] [Indexed: 11/16/2022] Open
Abstract
Environmental enrichment is used to increase social and physical stimulation for animals in captivity which can lead to enhanced cognition. Fundamental to the positive effect enrichment has on the brain is that it provides opportunities for captive animals to recognize and discriminate between different stimuli in the environment. In the wild, being able to discriminate between novel or familiar stimuli has implications for survival, for example finding food, hiding from predators, or even choosing a mate. The novel object recognition (NOR) test is a cognitive task that is used extensively in the rodent literature to assess object recognition and memory, where the amount of time an animal spends exploring a novel vs. familiar object is quantified. Enrichment has been shown to enhance object recognition in rodents. More recently, the use of the NOR test has been applied to another animal model, zebrafish (Danio rerio), however, the effects of enrichment have not yet been explored. In the current study we looked at the effects of enrichment on object recognition in zebrafish using the NOR test. Adult zebrafish were housed in either enriched conditions (gravel substrate, plastic plants, shelter, heater and a filter) or plain conditions (heater and filter only) for 6 months before behavioral NOR tests were conducted. Enriched fish showed a preference for a novel object over a familiar one at a distance but did not show a preference during close inspection. Control fish did not show a preference at either distance. Our results suggest that enrichment can enhance zebrafish ability to discriminate between novel and familiar objects, but distance from the object may be an important factor. Future research is needed to determine whether any enhancements in object recognition are a result of an increase in sensory stimulation from being reared with enrichment, or whether it is due to a reduction in stress reactivity.
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Affiliation(s)
- Cairsty DePasquale
- Department of Biology, Pennsylvania State University - Altoona, Altoona, PA, United States
| | - Nicole Kemerer
- Department of Biology, Pennsylvania State University - Altoona, Altoona, PA, United States
| | - Nathan White
- Department of Biology, Pennsylvania State University - Altoona, Altoona, PA, United States
| | - Monica Yost
- Department of Biology, Pennsylvania State University - Altoona, Altoona, PA, United States
| | - Jordan Wolfkill
- Department of Biology, Pennsylvania State University - Altoona, Altoona, PA, United States
| | - Jennifer Sturgill
- Department of Biology, Pennsylvania State University - Altoona, Altoona, PA, United States
| | - X Li
- Department of Mathematics and Statistics, Pennsylvania State University - Altoona, Altoona, PA, United States
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15
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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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16
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Song MK, Kim YJ, Kim SH, Yeo SG, Kim YJ. Environmental enrichment modulates silent information regulator 1 (SIRT1) activity to attenuate central presbycusis in a rat model of normal aging. Exp Gerontol 2021; 155:111552. [PMID: 34530105 DOI: 10.1016/j.exger.2021.111552] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 08/21/2021] [Accepted: 08/31/2021] [Indexed: 11/15/2022]
Abstract
Age-related hearing loss (ARHL) is sensory impairment in the elderly. This study aimed to identify a critical molecular mechanism that can maintain young phenotypes. We focused on the effect of exposure to environmental enrichment (EE) for 12 weeks in the central auditory pathway and limbic system of aged rats. The effects of EE were compared with the effects of dexamethasone administration. We found that in 74-week-old rats hearing function was significantly reduced and the number of neuronal specific nuclear protein (NeuN)-positive cells was decreased by 10-15% in the auditory cortex, amygdala, and hippocampus. EE exposure did not significantly affect the number of neurons, but DX administration significantly decreased their numbers in the amygdala compared with untreated aged rats. Both treatments reduced inducible nitric oxide synthase (iNOS) expression in the auditory pathway and limbic system. Exposure to EE significantly increased silent information regulator 1 (SIRT1) expression and activity, and nicotinamide phosphoribosyltransferase (NAMPT) concentration. In this study, the exposure to EE resulted in attenuated age-related hearing loss accompanied by reduction of iNOS expression and increase SIRT1 activity and NAMPT level. These data showed that EE may be a potential therapeutic to prevent ARHL.
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Affiliation(s)
- Min Kyung Song
- Department of Nursing, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Yoon Ju Kim
- Department of Nursing, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Sang Hoon Kim
- Department of Otorhinolaryngology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Seung Geun Yeo
- Department of Otorhinolaryngology, School of Medicine, Kyung Hee University, Seoul, Republic of Korea.
| | - Youn-Jung Kim
- College of Nursing Science, Kyung Hee University·East-West Nursing Research Institute, Seoul, Republic of Korea.
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17
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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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18
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Bayat M, Kohlmeier KA, Haghani M, Haghighi AB, Khalili A, Bayat G, Hooshmandi E, Shabani M. Co-treatment of vitamin D supplementation with enriched environment improves synaptic plasticity and spatial learning and memory in aged rats. Psychopharmacology (Berl) 2021; 238:2297-2312. [PMID: 33991198 DOI: 10.1007/s00213-021-05853-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 04/15/2021] [Indexed: 11/26/2022]
Abstract
RATIONALE AND OBJECTIVE Environmental enrichment (EE) has been shown in old rats to improve learning and memory. Vitamin D (VitD) has also been shown to modulate age-related, cognitive dysfunction. As both EE and VitD could work to improve cognition via enhancement of neurotrophic factors, their effects might occlude one another. Therefore, a clinically relevant question is whether noted cognition-promoting effects of EE and VitD can co-occur. METHODS Aged rats were housed for 6 weeks in one of three housing conditions: environmentally enriched (EE), socially enriched (SE), or standard condition (SC). Further, a 4th group was co-treated with VitD supplementation (400 IU kg-1 daily, 6 weeks) under EE conditions (EE + VitD). RESULTS Treatment with VitD and EE housing were associated with higher score on measures of learning and memory and exhibited lower anxiety scores compared to EE alone, SE or SC as assayed in the elevated plus maze, Morris water maze, passive avoidance, and open field tasks. Additionally, in the EE + VitD group, mRNA expression levels of NGF, TrkA, BDNF, Nrf2, and IGF-1 were significantly higher compared to expression seen in the EE group. Furthermore, field potential recordings showed that EE + VitD resulted in a greater enhancement of hippocampal LTP and neuronal excitability when compared to EE alone. CONCLUSIONS These findings demonstrate that in aged rats exposure to EE and VitD results in effects on hippocampal cognitive dysfunction and molecular mechanisms which are greater than effects of EE alone, suggesting potential for synergistic therapeutic effects for management of age-related cognitive decline.
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Affiliation(s)
- Mahnaz Bayat
- Clinical Neurology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Kristi A Kohlmeier
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Masoud Haghani
- Histomorphometry and Stereology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Azadeh Khalili
- Evidence-Based Phytotherapy and Complementary Medicine Research Center, Alborz University of Medical Sciences, Karaj, Iran
| | - Gholamreza Bayat
- Department of Physiology and Pharmacology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Etrat Hooshmandi
- Clinical Neurology Research Centre, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Shabani
- Neuroscience Research Center, Neuropharmacology Institute, Kerman University of Medical Sciences, Kerman, Iran.
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19
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Zocher S, Overall RW, Lesche M, Dahl A, Kempermann G. Environmental enrichment preserves a young DNA methylation landscape in the aged mouse hippocampus. Nat Commun 2021; 12:3892. [PMID: 34162876 PMCID: PMC8222384 DOI: 10.1038/s41467-021-23993-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 05/20/2021] [Indexed: 02/05/2023] Open
Abstract
The decline of brain function during aging is associated with epigenetic changes, including DNA methylation. Lifestyle interventions can improve brain function during aging, but their influence on age-related epigenetic changes is unknown. Using genome-wide DNA methylation sequencing, we here show that experiencing a stimulus-rich environment counteracts age-related DNA methylation changes in the hippocampal dentate gyrus of mice. Specifically, environmental enrichment prevented the aging-induced CpG hypomethylation at target sites of the methyl-CpG-binding protein Mecp2, which is critical to neuronal function. The genes at which environmental enrichment counteracted aging effects have described roles in neuronal plasticity, neuronal cell communication and adult hippocampal neurogenesis and are dysregulated with age-related cognitive decline in the human brain. Our results highlight the stimulating effects of environmental enrichment on hippocampal plasticity at the level of DNA methylation and give molecular insights into the specific aspects of brain aging that can be counteracted by lifestyle interventions.
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Affiliation(s)
- Sara Zocher
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
| | - Rupert W Overall
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
| | - Mathias Lesche
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- DRESDEN-concept Genome Center c/o Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Andreas Dahl
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- DRESDEN-concept Genome Center c/o Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden, Dresden, Germany.
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany.
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20
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Abstract
An environmental enrichment (EE) cage consisting of a broad living area and various stimulators triggers social, cognitive, and physical activities. EE has been utilized in a wide range of neurological and non-neurological studies. However, the details of the environmental enrichment protocol were not well described in these studies. This has resulted in uncertainty and inconsistency in methodology, which may thus fail to replicate environmental enrichment effects, influencing the study outcome. Here we describe the basic guidelines and present an easy-to-follow protocol for environmental enrichment in rat models. © 2021 Wiley Periodicals LLC. Basic Protocol: Environmental enrichment housing.
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Affiliation(s)
- Teh Rasyidah Ismail
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor Darul Ehsan, Malaysia.,Clinical Laboratory Science Section, Institute of Medical Science Technology, Universiti Kuala Lumpur, Kajang, Selangor Darul Ehsan, Malaysia
| | - Christina Gertrude Yap
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Rakesh Naidu
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Narendra Pamidi
- Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Bandar Sunway, Selangor Darul Ehsan, Malaysia
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21
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van der Geest JN, Spoor M, Frens MA. Environmental Enrichment Improves Vestibular Oculomotor Learning in Mice. Front Behav Neurosci 2021; 15:676416. [PMID: 34211378 PMCID: PMC8239173 DOI: 10.3389/fnbeh.2021.676416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
We assessed the behavioral effects of environmental enrichment on contrast sensitivity, reflexive eye movements and on oculomotor learning in mice that were housed in an enriched environment for a period of 3 weeks. Research has shown that a larger cage and a more complex environment have positive effects on the welfare of laboratory mice and other animals held in captivity. It has also been shown that environmental enrichment affects various behavior and neuroanatomical and molecular characteristics. We found a clear effect on oculomotor learning. Animals that were housed in an enriched environment learned significantly faster than controls that were housed under standard conditions. In line with existing literature, the enriched group also outperformed the controls in behavioral tests for explorative behavior. Meanwhile, both visual and reflexive oculomotor performance in response to visual and vestibular stimuli was unaffected. This points toward an underlying mechanism that is specific for motor learning, rather than overall motor performance.
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Affiliation(s)
| | - Marcella Spoor
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
| | - Maarten A Frens
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands
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22
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Cooper DD, Frenguelli BG. The influence of sensory experience on the glutamatergic synapse. Neuropharmacology 2021; 193:108620. [PMID: 34048870 DOI: 10.1016/j.neuropharm.2021.108620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/13/2021] [Accepted: 05/17/2021] [Indexed: 12/17/2022]
Abstract
The ability of glutamatergic synaptic strength to change in response to prevailing neuronal activity is believed to underlie the capacity of animals, including humans, to learn from experience. This learning better equips animals to safely navigate challenging and potentially harmful environments, while reinforcing behaviours that are conducive to survival. Early descriptions of the influence of experience on behaviour were provided by Donald Hebb who showed that an enriched environment improved performance of rats in a variety of behavioural tasks, challenging the widely-held view at the time that psychological development and intelligence were largely predetermined through genetic inheritance. Subsequent studies in a variety of species provided detailed cellular and molecular insights into the neurobiological adaptations associated with enrichment and its counterparts, isolation and deprivation. Here we review those experience-dependent changes that occur at the glutamatergic synapse, and which likely underlie the enhanced cognition associated with enrichment. We focus on the importance of signalling initiated by the release of BDNF and a prime downstream effector, MSK1, in orchestrating the many structural and functional neuronal adaptations associated with enrichment. In particular we discuss the MSK1-dependent expansion of the dynamic range of the glutamatergic synapse, which may allow enhanced information storage or processing, and the establishment of a genomic homeostasis that may both stabilise the enriched brain, and may make it better able to respond to novel experiences.
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Affiliation(s)
- Daniel D Cooper
- School of Life Sciences, University of Warwick, Coventry, UK
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23
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McQuail JA, Dunn AR, Stern Y, Barnes CA, Kempermann G, Rapp PR, Kaczorowski CC, Foster TC. Cognitive Reserve in Model Systems for Mechanistic Discovery: The Importance of Longitudinal Studies. Front Aging Neurosci 2021; 12:607685. [PMID: 33551788 PMCID: PMC7859530 DOI: 10.3389/fnagi.2020.607685] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/30/2020] [Indexed: 12/14/2022] Open
Abstract
The goal of this review article is to provide a resource for longitudinal studies, using animal models, directed at understanding and modifying the relationship between cognition and brain structure and function throughout life. We propose that forthcoming longitudinal studies will build upon a wealth of knowledge gleaned from prior cross-sectional designs to identify early predictors of variability in cognitive function during aging, and characterize fundamental neurobiological mechanisms that underlie the vulnerability to, and the trajectory of, cognitive decline. Finally, we present examples of biological measures that may differentiate mechanisms of the cognitive reserve at the molecular, cellular, and network level.
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Affiliation(s)
- Joseph A. McQuail
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, United States
| | - Amy R. Dunn
- The Jackson Laboratory, Bar Harbor, ME, United States
| | - Yaakov Stern
- Cognitive Neuroscience Division, Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Carol A. Barnes
- Departments of Psychology and Neuroscience, University of Arizona, Tucson, AZ, United States
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Gerd Kempermann
- CRTD—Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers (HZ), Dresden, Germany
| | - Peter R. Rapp
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, Baltimore, MD, United States
| | | | - Thomas C. Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Genetics and Genomics Program, University of Florida, Gainesville, FL, United States
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24
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Balietti M, Pugliese A, Conti F. In aged rats, differences in spatial learning and memory influence the response to late-life Environmental Enrichment. Exp Gerontol 2020; 146:111225. [PMID: 33388381 DOI: 10.1016/j.exger.2020.111225] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/05/2020] [Accepted: 12/23/2020] [Indexed: 11/26/2022]
Abstract
It has clearly been demonstrated that cognitive stimulation, physical exercise, and social engagement help counteract age-related cognitive decline. However, several important issues remain to be addressed. Given the wide differences in cognitive impairment found among individuals of the same age, identifying the subjects who will benefit most from late-life interventions is one such issue. Environmental Enrichment (EE) is a particularly valuable approach to do this. In this study, aged (21-month-old) rats were assigned to a better (BL) or a worse (WL) learner group (training phase) and to a non-impaired (NI) or an impaired (I) group (probe phase) by their performance on the Morris Water Maze, using the test performances of adult (12-month-old) rats as the cut-offs. The aged rats were retested after a 12-week EE or standard housing (SH) protocol. After 12 weeks, the performances of SH rats had deteriorated, whereas all rats benefited from EE, albeit in different ways. In particular, the animals assigned to the BL and the NI groups prior to EE still performed as well as the adult rats (performance preservation) whereas, critically, the animals assigned to the WL and the I groups before EE showed such improved performances that they reached the level of the adult rats (performance improvement), despite having aged further. EE seems to induce the preservation in BLs and the improvement in WLs of spatial search strategies and the preservation in NIs and the increase in Is of a focused and protract research of the escape point. Our findings suggest that late-life EE prevents spatial learning and memory decline in still cognitively preserved animals and stimulates residual functional reserve in already cognitively compromised animals. Future research should focus on individually tailored stimulation protocols to improve their effect and afford a better understanding of the underlying processes.
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Affiliation(s)
- Marta Balietti
- Center for Neurobiology of Aging, IRCCS INRCA, Ancona, Italy.
| | - Arianna Pugliese
- Section of Neuroscience and Cell Biology, Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 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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Effects of Gestational Inflammation with Postpartum Enriched Environment on Age-Related Changes in Cognition and Hippocampal Synaptic Plasticity-Related Proteins. Neural Plast 2020. [DOI: 10.1155/2020/9082945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Increasing evidence indicates that exposure to inflammation during pregnancy intensifies the offspring’s cognitive impairment during aging, which might be correlated with changes in some synaptic plasticity-related proteins. In addition, an enriched environment (EE) can significantly exert a beneficial impact on cognition and synaptic plasticity. However, it is unclear whether gestational inflammation combined with postnatal EE affects the changes in cognition and synaptic plasticity-related proteins during aging. In this study, pregnant mice were intraperitoneally injected with lipopolysaccharides (LPS, 50 μg/kg) or normal saline at days 15–17 of pregnancy. At 21 days after delivery, some LPS-treated mice were randomly selected for EE treatment. At the age of 6 and 18 months, Morris water maze (MWM) and western blotting were, respectively, used to evaluate or measure the ability of spatial learning and memory and the levels of postsynaptic plasticity-related proteins in the hippocampus, including postsynaptic density protein 95 (PSD-95), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) GluA1 subunit, and Homer-1b/c. The results showed that 18-month-old control mice had worse spatial learning and memory and lower levels of these synaptic plasticity-related proteins (PSD-95, GluA1, and Homer-1b/c) than the 6-month-old controls. Gestational LPS exposure exacerbated these age-related changes of cognition and synaptic proteins, but EE could alleviate the treatment effect of LPS. In addition, the performance during learning and memory periods in the MWM correlated with the hippocampal levels of PSD-95, GluA1, and Homer-1b/c. Our results suggested that gestational inflammation accelerated age-related cognitive impairment and the decline of PSD-95, GluA1, and Homer-1b/c protein expression, and postpartum EE could alleviate these changes.
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26
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Wu XR, Zhang Y, Liu XD, Han WB, Xu NJ, Sun S. EphB2 mediates social isolation-induced memory forgetting. Transl Psychiatry 2020; 10:389. [PMID: 33168800 PMCID: PMC7653962 DOI: 10.1038/s41398-020-01051-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 09/16/2020] [Accepted: 10/06/2020] [Indexed: 01/05/2023] Open
Abstract
Social isolation in adolescence leads to lasting deficits, including emotional and cognitive dysregulation. It remains unclear, however, how social isolation affects certain processes of memory and what molecular mechanisms are involved. In this study, we found that social isolation during the post-weaning period resulted in forgetting of the long-term fear memory, which was attributable to the downregulation of synaptic function in the hippocampal CA1 region mediated by EphB2, a receptor tyrosine kinase which involves in the glutamate receptor multiprotein complex. Viral-mediated EphB2 knockdown in CA1 mimicked the memory defects in group-housed mice, whereas restoration of EphB2 by either viral overexpression or resocialization reversed the memory decline in isolated mice. Taken together, our finding indicates that social isolation gives rise to memory forgetting by disrupting EphB2-mediated synaptic plasticity, which may provide a potential target for preventing memory loss caused by social isolation or loneliness.
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Affiliation(s)
- Xin-Rong Wu
- grid.16821.3c0000 0004 0368 8293Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China
| | - Yu Zhang
- grid.16821.3c0000 0004 0368 8293Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China
| | - Xian-Dong Liu
- grid.16821.3c0000 0004 0368 8293Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China ,grid.16821.3c0000 0004 0368 8293Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China
| | - Wu-Bo Han
- grid.16821.3c0000 0004 0368 8293Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025 Shanghai, China
| | - Nan-Jie Xu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China. .,Key Laboratory of Cell Differentiation and Apoptosis of the Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China. .,Shanghai Key Laboratory of Reproductive Medicine, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China.
| | - Suya Sun
- Department of Neurology and Institute of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, 200025, Shanghai, China.
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Zhao B, Wang Y, Liu R, Jia XL, Hu N, An XW, Zheng CG, Chen C, Sun HT, Chen F, Wang JJ, Li XH. Rutaecarpine Ameliorated High Sucrose-Induced Alzheimer's Disease Like Pathological and Cognitive Impairments in Mice. Rejuvenation Res 2020; 24:181-190. [PMID: 32892706 DOI: 10.1089/rej.2020.2349] [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] [Indexed: 01/05/2023] Open
Abstract
High sucrose can induce tau hyperphosphorylation and cognitive dysfunction/memory impairment as observed in Alzheimer's disease (AD). Rutaecarpine, a specific (transient receptor potential vanilloid 1 [TRPV1]) agonist, is neuroprotective against high sucrose diet-induced impairment, but detailed mechanisms are still elusive. In this study, we investigated whether rutaecarpine mitigates high sucrose diet-induced pathological alterations and cognitive in AD-like mice. Mice were administered fodder containing 0.01% rutaecarpine and 20% sucrose solution. Our results showed that rutaecarpine significantly attenuated high sucrose diet-induced spatial memory impairment and enhanced synaptic plasticity; rutaecarpine prevented high sucrose diet-induced tau hyperphosphorylation by decreasing glycogen synthase kinase-3β (GSK-3β) activity; activation of GSK-3β reversed the protective effect of rutaecarpine on learning and memory deficits, synaptic plasticity, and tau hyperphosphorylation induced by high-glucose diet significantly, suggesting that GSK-3β activation is required for high glucose-induced tau hyperphosphorylation. These results demonstrated that rutaecarpine can mitigate high sucrose diet-induced hyperphosphorylation of AD-associated tau protein and cognitive impairment by inhibiting GSK-3β, which supported that dietary rutaecarpine might have a promising use for therapeutic intervention of AD.
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Affiliation(s)
- Bin Zhao
- Department of Neurology, Tianjin Medical University General Hospital, Tianjin, China
| | - Yi Wang
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China.,Tianjin Key Laboratory of Neurotrauma Repair, Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, China.,Department of Neurology, Tianjin Hospital of Tianjin, Tianjin, China
| | - Rui Liu
- Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Tianjin, China
| | - Xiao-Li Jia
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Nan Hu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Xing-Wei An
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Chen-Guang Zheng
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Chong Chen
- Tianjin Key Laboratory of Neurotrauma Repair, Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, China
| | - Hong-Tao Sun
- Tianjin Key Laboratory of Neurotrauma Repair, Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, China
| | - Feng Chen
- Tianjin Key Laboratory of Neurotrauma Repair, Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, China
| | - Jing-Jing Wang
- Tianjin Key Laboratory of Neurotrauma Repair, Characteristic Medical Center of the Chinese People's Armed Police Force, Tianjin, China
| | - Xiao-Hong Li
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
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28
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Dahan L, Rampon C, Florian C. Age-related memory decline, dysfunction of the hippocampus and therapeutic opportunities. Prog Neuropsychopharmacol Biol Psychiatry 2020; 102:109943. [PMID: 32298784 DOI: 10.1016/j.pnpbp.2020.109943] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 04/01/2020] [Accepted: 04/01/2020] [Indexed: 12/13/2022]
Abstract
While the aging of the population is a sign of progress for societies, it also carries its load of negative aspects. Among them, cognitive decline and in particular memory loss is a common feature of non-pathological aging. Autobiographical memories, which rely on the hippocampus, are a primary target of age-related cognitive decline. Here, focusing on the neurobiological mechanisms of memory formation and storage, we describe how hippocampal functions are altered across time in non-pathological mammalian brains. Several hallmarks of aging have been well described over the last decades; among them, we consider altered synaptic communication and plasticity, reduction of adult neurogenesis and epigenetic alterations. Building on the neurobiological processes of cognitive aging that have been identified to date, we review some of the strategies based on lifestyle manupulation allowing to address age-related cognitive deficits.
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Affiliation(s)
- Lionel Dahan
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse Cedex 9, France
| | - Claire Rampon
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse Cedex 9, France
| | - Cédrick Florian
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse; CNRS, UPS, Toulouse Cedex 9, France.
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29
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Rigby MJ, Ding Y, Farrugia MA, Feig M, Cortese GP, Mitchell H, Burger C, Puglielli L. The endoplasmic reticulum acetyltransferases ATase1/NAT8B and ATase2/NAT8 are differentially regulated to adjust engagement of the secretory pathway. J Neurochem 2020; 154:404-423. [PMID: 31945187 PMCID: PMC7363514 DOI: 10.1111/jnc.14958] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/20/2019] [Accepted: 01/09/2020] [Indexed: 01/13/2023]
Abstract
Nε-lysine acetylation of nascent glycoproteins within the endoplasmic reticulum (ER) lumen regulates the efficiency of the secretory pathway. The ER acetylation machinery consists of the membrane transporter, acetyl-CoA transporter 1 (AT-1/SLC33A1), and two acetyltransferases, ATase1/NAT8B and ATase2/NAT8. Dysfunctional ER acetylation is associated with severe neurological diseases with duplication of AT-1/SLC33A1 being associated with autism spectrum disorder, intellectual disability, and dysmorphism. Neuron-specific AT-1 over-expression in the mouse alters neuron morphology and function, causing an autism-like phenotype, indicating that ER acetylation plays a key role in neurophysiology. As such, characterizing the molecular mechanisms that regulate the acetylation machinery could reveal critical information about its biology. By using structure-biochemistry approaches, we discovered that ATase1 and ATase2 share enzymatic properties but differ in that ATase1 is post-translationally regulated via acetylation. Furthermore, gene expression studies revealed that the promoters of AT-1, ATase1, and ATase2 contain functional binding sites for the neuron-related transcription factors cAMP response element-binding protein and the immediate-early genes c-FOS and c-JUN, and that ATase1 and ATase2 exhibit additional modes of transcriptional regulation relevant to aging and Alzheimer's disease. In vivo rodent gene expression experiments revealed that Atase2 is specifically induced following activity-dependent events. Finally, over-expression of either ATase1 or ATase2 was sufficient to increase the engagement of the secretory pathway in PC12 cells. Our results indicate important regulatory roles for ATase1 and ATase2 in neuron function with induction of ATase2 expression potentially serving as a critical event that adjusts the efficiency of the secretory pathway for activity-dependent neuronal functions.
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Affiliation(s)
- Michael J. Rigby
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705
| | - Yun Ding
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705
| | - Mark A. Farrugia
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705
| | - Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824
| | | | | | - Corinna Burger
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705
| | - Luigi Puglielli
- Department of Medicine, University of Wisconsin-Madison, Madison, WI 53705
- Neuroscience Training Program, University of Wisconsin-Madison, Madison, WI 53705
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705
- Geriatric Research Education Clinical Center, Veterans Affairs Medical Center, Madison, WI 53705
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30
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How TRPC Channels Modulate Hippocampal Function. Int J Mol Sci 2020; 21:ijms21113915. [PMID: 32486187 PMCID: PMC7312571 DOI: 10.3390/ijms21113915] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
Transient receptor potential canonical (TRPC) proteins constitute a group of receptor-operated calcium-permeable nonselective cationic membrane channels of the TRP superfamily. They are largely expressed in the hippocampus and are able to modulate neuronal functions. Accordingly, they have been involved in different hippocampal functions such as learning processes and different types of memories, as well as hippocampal dysfunctions such as seizures. This review covers the mechanisms of activation of these channels, how these channels can modulate neuronal excitability, in particular the after-burst hyperpolarization, and in the persistent activity, how they control synaptic plasticity including pre- and postsynaptic processes and how they can interfere with cell survival and neurogenesis.
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31
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Amirazodi F, Mehrabi A, Amirazodi M, Parsania S, Rajizadeh MA, Esmaeilpour K. The Combination Effects of Resveratrol and Swimming HIIT Exercise on Novel Object Recognition and Open-field Tasks in Aged Rats. Exp Aging Res 2020; 46:336-358. [PMID: 32324489 DOI: 10.1080/0361073x.2020.1754015] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Resveratrol, a natural polyphenol abundant in grapes and red wine, has been reported to exert numerous beneficial health effects in the body. High-Intensity Interval Exercise (HIIT) is a form of interval training that provides improved athletic capacity and has a protective effect on health. The purpose of this study was to investigate the interactive effects of swimming HIIT and Resveratrol supplementation on behavioral function in Novel object recognition and open-field tests in aged rats. METHODS A total of 45 aged male Wistar rats with an age of 20 months were randomly assigned into five groups of control (C), swimming HIIT (SW-HIIT), swimming HIIT with Resveratrol supplementation (SW-HIIT-R), Resveratrol supplementation (R), and solvent of Resveratrol supplementation (SR). There was also another group that included young animals (2-month-old) and was used to compare with older animals. Swimming HIIT and Resveratrol supplementation groups performed the exercise and received Resveratrol (10 mg/kg/day, gavage) for six weeks. Novel object recognition and open-field tests were used for evaluating the behavioral functions in animals. RESULTS The results showed that HIIT and Resveratrol significantly improved recognition memory compared to old animals. Moreover, it seems that HIIT and Resveratrol partly could modulate anxiety-like behaviors compared to old animals in the open-field test.
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Affiliation(s)
- Fatemeh Amirazodi
- Department of Education, Department of Foundations of Education, International Division, Shiraz University , Shiraz, Iran.,Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman, Iran
| | - Amin Mehrabi
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman, Iran.,Department of Exercise Physiology, Kish International Campus, University of Tehran , Kish, Iran
| | - Maryam Amirazodi
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman, Iran.,Shiraz University International Division, Shiraz University , Shiraz, Iran
| | - Shahrnaz Parsania
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman, Iran
| | - Mohammad Amin Rajizadeh
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman, Iran.,Department of Physiology & Pharmacology, Kerman Medical University of Sciences , Kerman, Iran
| | - Khadijeh Esmaeilpour
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences , Kerman, Iran.,Department of Physiology & Pharmacology, Kerman Medical University of Sciences , Kerman, Iran
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32
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Blok J, Black DA, Petersen J, Sawatari A, Leamey CA. Environmental Enrichment Rescues Visually-Mediated Behavior in Ten-m3 Knockout Mice During an Early Critical Period. Front Behav Neurosci 2020; 14:22. [PMID: 32158383 PMCID: PMC7052109 DOI: 10.3389/fnbeh.2020.00022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 01/31/2020] [Indexed: 11/13/2022] Open
Abstract
Environmental enrichment (EE) has been shown to promote neural plasticity. Its capacity to induce functional repair in models which exhibit profound sensory deficits due to aberrant axonal guidance has not been well-characterized. Ten-m3 knockout (KO) mice exhibit a highly-stereotyped miswiring of ipsilateral retinogeniculate axons and associated profound deficits in binocularly-mediated visual behavior. We determined whether, and when, EE can drive functional recovery by analyzing Ten-m3 KO and wildtype (WT) mice that were enriched for 6 weeks from adulthood, weaning or birth in comparison to standard-housed controls. EE initiated from birth, but not later, rescued the response of Ten-m3 KOs to the "looming" stimulus (expanding disc in dorsal visual field), suggesting improved visual function. EE can thus induce recovery of visual behavior, but only during an early developmentally-restricted time-window.
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Affiliation(s)
- James Blok
- Department of Physiology, School of Medical Sciences and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - Dylan A Black
- Department of Physiology, School of Medical Sciences and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - Justin Petersen
- Department of Physiology, School of Medical Sciences and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - Atomu Sawatari
- Department of Physiology, School of Medical Sciences and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
| | - Catherine A Leamey
- Department of Physiology, School of Medical Sciences and Bosch Institute, Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia
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33
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Althobaiti YS, Almalki AH. Effects of environmental enrichment on reinstatement of methamphetamine-induced conditioned place preference. Behav Brain Res 2020; 379:112372. [PMID: 31759048 DOI: 10.1016/j.bbr.2019.112372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 11/15/2019] [Accepted: 11/19/2019] [Indexed: 12/17/2022]
Abstract
OBJECTIVE The influence of environmental enrichment (EE) on reinstatement to methamphetamine (METH) seeking in rat model was investigated. METHODS Wistar rats were divided to receive saline (1 ml/kg) or METH (1 mg/kg, i.p.) for 8 days during the conditioning training in the conditioned place preference (CPP) paradigm, which is one of the most popular models to study the motivational effects of drugs and non-drug treatments in experimental animals. Rats were then kept in either isolated (IE) or enriched environment (EE) for 30 days during the extinction training. Animals were finally examined for reinstatement provoked by i.p. injections of METH. RESULTS Saline injections during the conditioning phase did not change CPP during reinstatement in animals of IE or EE control groups. METH injections reinstated place preference in the IE animal group. Interestingly, EE significantly blocked this reinstatement effects of METH. CONCLUSION These results show the important role of social interactions and positive environment conditions in preventing reinstatement to drug use.
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Affiliation(s)
- Yusuf S Althobaiti
- Taif University, College of Pharmacy, Department of Pharmacology and Toxicology, Taif, Saudi Arabia; Taif University, College of Pharmacy, Addiction and Neuroscience Research Unit, Taif, Saudi Arabia.
| | - Atiah H Almalki
- Taif University, College of Pharmacy, Addiction and Neuroscience Research Unit, Taif, Saudi Arabia; Taif University, College of Pharmacy, Department of Pharmaceutical chemistry, Taif, Saudi Arabia
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Synaptic Plasticity Shapes Brain Connectivity: Implications for Network Topology. Int J Mol Sci 2019; 20:ijms20246193. [PMID: 31817968 PMCID: PMC6940892 DOI: 10.3390/ijms20246193] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/02/2019] [Accepted: 12/06/2019] [Indexed: 12/13/2022] Open
Abstract
Studies of brain network connectivity improved understanding on brain changes and adaptation in response to different pathologies. Synaptic plasticity, the ability of neurons to modify their connections, is involved in brain network remodeling following different types of brain damage (e.g., vascular, neurodegenerative, inflammatory). Although synaptic plasticity mechanisms have been extensively elucidated, how neural plasticity can shape network organization is far from being completely understood. Similarities existing between synaptic plasticity and principles governing brain network organization could be helpful to define brain network properties and reorganization profiles after damage. In this review, we discuss how different forms of synaptic plasticity, including homeostatic and anti-homeostatic mechanisms, could be directly involved in generating specific brain network characteristics. We propose that long-term potentiation could represent the neurophysiological basis for the formation of highly connected nodes (hubs). Conversely, homeostatic plasticity may contribute to stabilize network activity preventing poor and excessive connectivity in the peripheral nodes. In addition, synaptic plasticity dysfunction may drive brain network disruption in neuropsychiatric conditions such as Alzheimer's disease and schizophrenia. Optimal network architecture, characterized by efficient information processing and resilience, and reorganization after damage strictly depend on the balance between these forms of plasticity.
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35
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Serra L, Gelfo F, Petrosini L, Di Domenico C, Bozzali M, Caltagirone C. Rethinking the Reserve with a Translational Approach: Novel Ideas on the Construct and the Interventions. J Alzheimers Dis 2019; 65:1065-1078. [PMID: 30149458 DOI: 10.3233/jad-180609] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The concept of brain, cognitive, and neural reserves has been introduced to account for the apparent discrepancies between neurological damage and clinical manifestations. However, these ideas are yet theoretical suggestions that are not completely assimilated in the clinical routine. The mechanisms of the reserves have been extensively studied in neurodegenerative pathologies, in particular in Alzheimer's disease. Both human and animal studies addressed this topic by following two parallel pathways. The specific aim of the present review is to attempt to combine the suggestions derived from the two different research fields to deepen the knowledge about reserves. In fact, the achievement of a comprehensive theoretical framework on reserve mechanisms is an essential step to propose well-timed interventions tailored to the clinical characteristics of patients. The present review highlights the importance of addressing three main aspects: the definition of reserve proxy measures, the interaction between reserve level and therapeutic interventions, and the specific time-window of reserve efficacy.
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Affiliation(s)
- Laura Serra
- Neuroimaging Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesca Gelfo
- Department of Clinical and Behavioural Neurology, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Human Sciences, Guglielmo Marconi University, Rome, Italy
| | - Laura Petrosini
- Laboratory of Experimental Neurophysiology and Behaviour, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Psychology, University Sapienza of Rome, Rome, Italy
| | | | - Marco Bozzali
- Neuroimaging Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy.,Clinical Imaging Science Center, Brighton and Sussex Medical School, Brighton, UK
| | - Carlo Caltagirone
- Department of Clinical and Behavioural Neurology, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systemic Medicine, University of Rome Tor Vergata, Rome, Italy
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36
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Writers and Readers of DNA Methylation/Hydroxymethylation in Physiological Aging and Its Impact on Cognitive Function. Neural Plast 2019; 2019:5982625. [PMID: 31396272 PMCID: PMC6664507 DOI: 10.1155/2019/5982625] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 04/25/2019] [Accepted: 05/26/2019] [Indexed: 12/31/2022] Open
Abstract
The chromatin landscape has acquired deep attention from several fields ranging from cell biology to neurological and psychiatric diseases. The role that DNA modifications have on gene expression regulation has become apparent in several physiological processes, and numerous efforts have been performed to establish a relationship between DNA modifications and physiological conditions, such as cognitive performance and aging. DNA modifications are incorporated by specific sets of enzymes-the writers-and the modified DNA-interacting partners-the readers-are ultimately responsible for maintaining a functional epigenetic landscape. Therefore, understanding how these epigenetic mediators-writers and readers-are modulated in physiological aging will contribute to unraveling how aging-associated neuronal disturbances arise and contribute to the cognitive decline associated with this period of life. In this review, we focused on DNA modifications, writers and readers, highlighting that despite some methodological disparities, the evidence suggests a critical role for epigenetic mediators in the aging-associated neuronal dysfunction.
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37
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Gelfo F. Does Experience Enhance Cognitive Flexibility? An Overview of the Evidence Provided by the Environmental Enrichment Studies. Front Behav Neurosci 2019; 13:150. [PMID: 31338030 PMCID: PMC6629767 DOI: 10.3389/fnbeh.2019.00150] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/21/2019] [Indexed: 12/16/2022] Open
Abstract
Neuroplasticity accounts for the ability of the brain to change in both structure and function in consequence of life experiences. An enhanced stimulation provided by the environment is able to create a form of brain, neural, and cognitive reserve, which allows an individual to cope better with the environmental demands, also in case of neural damage leading to cognitive decline. With its complex manipulation of several stimuli, the animal experimental paradigm of environmental enrichment (EE) appears particularly effective in modulating the ability to successfully respond to the ever-changing characteristics of the environment. According to this point, it could be very relevant to analyze the specific effects of EE on cognitive flexibility (CF). CF could be defined as the ability to effectively change behavior in response to the environmental condition changing. This review article is specifically aimed to summarize and focus on the available evidence in relation to the effects of EE on CF. To this aim, findings obtained in behavioral tasks specifically structured to investigate animal CF, such as reversal learning and attentional set-shifting tests (tasks based on the request of responding to a rewarding rule that changes, within one or multiple perceptual dimensions), are reviewed. Data provided on the structural and biochemical correlates of these findings are also enumerated. Studies realized in healthy animals and also in pathological models are considered. On the whole, the summarized evidence clearly supports the specific beneficial effects of EE on CF. However, further studies on this key topic are strictly required to gain a comprehensive and detailed framework on the mechanisms by which an enhanced stimulation could improve CF.
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Affiliation(s)
- Francesca Gelfo
- Department of Human Sciences, Guglielmo Marconi University, Rome, Italy.,Department of Clinical and Behavioural Neurology, IRCCS Fondazione Santa Lucia, Rome, Italy
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38
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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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39
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Giacobbo BL, de Freitas BS, Vedovelli K, Schlemmer LM, Pires VN, Antoniazzi V, Santos CDSD, Paludo L, Borges JV, de Lima DB, Schröder N, de Vries EFJ, Bromberg E. Long-term environmental modifications affect BDNF concentrations in rat hippocampus, but not in serum. Behav Brain Res 2019; 372:111965. [PMID: 31125621 DOI: 10.1016/j.bbr.2019.111965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/19/2019] [Accepted: 05/20/2019] [Indexed: 01/01/2023]
Abstract
The role of mBDNF on the beneficial effects of cognitive stimulation on the brain remains controversial, as well as the potential of peripheral mBDNF as a biomarker of environmental effects on its central status. We investigated the effect of different environmental conditions on recognition memory, proBDNF, mBDNF and synaptophysin levels in the hippocampus, and on mBDNF levels in blood. Male Wistar rats (6 and 17 months-old) were assigned to cognitively enriched (EE), standard (SE) and impoverished (IE) environmental conditions for twelve weeks. Novel object recognition was performed at week 10. When the animals were 9 and 20-months old, hippocampus was collected for mBDNF, proBDNF and synaptophysin analysis; serum was analyzed for mBDNF levels. The cognitively EE improved recognition memory, resulted in a trend to increased hippocampal mBDNF and augmented synaptophysin levels. Accordingly, hippocampal mBDNF, proBDNF and synaptophysin were significantly higher in EE than IE animals. Hippocampal mBDNF was positively correlated to proBDNF, cellular and behavioral plasticity markers. No effect of age was seen on the studied variables. Moreover, no significant effects of EE or IE on serum mBDNF were observed. Serum mBDNF also failed to correlate with hippocampal mBDNF, proBDNF and with the cellular and behavioral plasticity markers. These findings indicate that mBDNF is involved in neuronal and behavioral plasticity mechanisms induced by cognitively enriched environments, and that peripheral mBDNF may not always be a reliable biomarker of the effects of environmental settings on central mBDNF and plasticity, which is of special interest from a translational research perspective.
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Affiliation(s)
- Bruno Lima Giacobbo
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil; Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 31.001, 9713 GZ, Groningen, the Netherlands
| | - Betânia Souza de Freitas
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Kelem Vedovelli
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil; Institute of Geriatrics and Gerontology, School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6690, 90610-000, Porto Alegre, Brazil
| | - Lívia Machado Schlemmer
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Vivian Naziaseno Pires
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Vinicius Antoniazzi
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Cristophod de Souza Dos Santos
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Leticia Paludo
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Juliano Viana Borges
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Daiane Borba de Lima
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil
| | - Nadja Schröder
- National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil; Department of Physiology, Institute for Basic Health Sciences, Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500, 90050-170 Porto Alegre, Brazil
| | - Erik F J de Vries
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. Box 31.001, 9713 GZ, Groningen, the Netherlands
| | - Elke Bromberg
- Laboratory of Biology and Development of the Nervous System, School of Sciences, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6681, 90619-900, Porto Alegre, Brazil; Institute of Geriatrics and Gerontology, School of Medicine, Pontifical Catholic University of Rio Grande do Sul, Ipiranga Av. 6690, 90610-000, Porto Alegre, Brazil; National Institute of Science and Technology for Translational Medicine (INCT-TM), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brasília, Brazil.
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40
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Aged rats with different performances at environmental enrichment onset display different modulation of habituation and aversive memory. Neurobiol Learn Mem 2019; 161:83-91. [PMID: 30951838 DOI: 10.1016/j.nlm.2019.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/20/2019] [Accepted: 04/01/2019] [Indexed: 12/22/2022]
Abstract
A wide agreement exists that environmental enrichment (EE) is most beneficial if introduced early in life, but numerous studies reported that also aged animals remain responsive. As age-related memory and cognition impairments are not uniform, an open question is whether EE might exert different effects in animals with different age-related deficits. A 12-week EE protocol was applied to late adult rats pretested for habituation and aversive memory. Animals were classified as low (LP) and high (HP) performers according to percent exploration change in Open Field test (OF) and as impaired (I) and not impaired (NI) according to latency in Step-through Passive Avoidance test (PA). Standard housing (SH) animals pretested by OF and PA, and naïve (non-pretested) EE and SH rats were used as controls. In comparison to pretest, after the housing protocol, EE LP ameliorated while EE HP and both SH HP and LP worsened their habituation pattern. The positive influence of EE on LP was probably due to the more active interaction with and the faster adaptation to surroundings promoted by continuous, multiple stimuli provided during the enriched housing. Regarding HP, EE did not boost the basal behavior, which likely represented the maximum achievable for that age, and the post housing exploration change dropped, as in SH animals, because of the retesting. After EE, a significant percentage of NI animals became I and a significant percentage of I animals became NI. The changes evidenced in the NI group likely depended on EE-related reduction of anxiety and the consequent more efficient coping with fearful situations. This hypothesis was strengthened by the observation that naïve EE animals were almost all I. Pretested EE I rats were not influenced by the rearing condition: their behavior was comparable to SH animals' behavior and determined by retesting. In conclusion, these results demonstrated that, when applied to aging rats, EE produces different effects based on pre-housing cognitive performances. The issue needs further analyses, but the observation that not all animals are able to take advantage of EE to the same extent suggests the opportunity to design individually tailored approaches to optimize their efficacy and minimize possible unwanted consequences.
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Llorens-Martín M. Exercising New Neurons to Vanquish Alzheimer Disease. Brain Plast 2018; 4:111-126. [PMID: 30564550 PMCID: PMC6296267 DOI: 10.3233/bpl-180065] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2018] [Indexed: 02/07/2023] Open
Abstract
Alzheimer disease (AD) is the most common type of dementia in individuals over 65 years of age. The neuropathological hallmarks of the condition are Tau neurofibrillary tangles and Amyloid-β senile plaques. Moreover, certain susceptible regions of the brain experience a generalized lack of neural plasticity and marked synaptic alterations during the progression of this as yet incurable disease. One of these regions, the hippocampus, is characterized by the continuous addition of new neurons throughout life. This phenomenon, named adult hippocampal neurogenesis (AHN), provides a potentially endless source of new synaptic elements that increase the complexity and plasticity of the hippocampal circuitry. Numerous lines of evidence show that physical activity and environmental enrichment (EE) are among the most potent positive regulators of AHN. Given that neural plasticity is markedly decreased in many neurodegenerative diseases, the therapeutic potential of making certain lifestyle changes, such as increasing physical activity, is being recognised in several non-pharmacologic strategies seeking to slow down or prevent the progression of these diseases. This review article summarizes current evidence supporting the putative therapeutic potential of EE and physical exercise to increase AHN and hippocampal plasticity both under physiological and pathological circumstances, with a special emphasis on neurodegenerative diseases and AD.
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Affiliation(s)
- María Llorens-Martín
- Department of Molecular Neuropathology, Centro de Biología Molecular “Severo Ochoa”, CBMSO, CSIC-UAM, Madrid, Spain
- Center for Networked Biomedical Research on Neurodegenerative Diseases CIBERNED, Madrid, Spain
- Department of Molecular Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain
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Gimse K, Gorzek RC, Olin A, Osting S, Burger C. Hippocampal Homer1b/c is necessary for contextual fear conditioning and group I metabotropic glutamate receptor mediated long-term depression. Neurobiol Learn Mem 2018; 156:17-23. [PMID: 30336208 PMCID: PMC6226007 DOI: 10.1016/j.nlm.2018.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 10/08/2018] [Accepted: 10/11/2018] [Indexed: 01/24/2023]
Abstract
Coiled-coil forms of Homer1, including Homer1b and c (Homer1b/c) have been shown to play a role in hippocampal learning and memory and synaptic plasticity. We have previously found that overexpression of hippocampal Homer1c is sufficient to rescue learning and memory ability in aged learning impaired rats and in Homer1 knockout (KO) mice, and to rescue group I metabotropic glutamate receptor (mGluR1/5) mediated long-term potentiation in KO mice. Here, to determine if Homer1b/c is necessary for successful learning and memory we have utilized a rAAV5 vector expressing a Homer1b/c-targeting short hairpin RNA to knock down the expression of hippocampal Homer1b/c in adult 4-6-month old male Sprague Dawley rats. We have found that reduced hippocampal Homer1b/c expression elicits significant learning deficits in contextual fear conditioning, but not in the Morris water maze or novel object recognition tasks. Furthermore, we demonstrate that reduced hippocampal Homer1b/c is sufficient to completely block mGluR1/5 mediated long-term depression in the Schaffer collateral pathway. These results support a significant role for Homer1b/c in learning and synaptic plasticity; however, the exact role of each of these two protein isoforms in learning and memory remains elusive.
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Affiliation(s)
- Kirstan Gimse
- Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Medical Sciences Center, 1300 University Ave, Room 73 Bardeen, Madison, WI 53706, USA
| | - Ryan C Gorzek
- College of Letters and Science, University of Wisconsin, Madison, WI, USA
| | - Andrew Olin
- Department of Neurology, University of Wisconsin, Madison, WI, USA
| | - Sue Osting
- Department of Neurology, University of Wisconsin, Madison, WI, USA
| | - Corinna Burger
- Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Medical Sciences Center, 1300 University Ave, Room 73 Bardeen, Madison, WI 53706, USA; Department of Neurology, University of Wisconsin, Madison, WI, USA.
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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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Griñán-Ferré C, Izquierdo V, Otero E, Puigoriol-Illamola D, Corpas R, Sanfeliu C, Ortuño-Sahagún D, Pallàs M. Environmental Enrichment Improves Cognitive Deficits, AD Hallmarks and Epigenetic Alterations Presented in 5xFAD Mouse Model. Front Cell Neurosci 2018; 12:224. [PMID: 30158856 PMCID: PMC6104164 DOI: 10.3389/fncel.2018.00224] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 07/10/2018] [Indexed: 01/05/2023] Open
Abstract
Cumulative evidence shows that modifications in lifestyle factors constitute an effective strategy to modulate molecular events related to neurodegenerative diseases, confirming the relevant role of epigenetics. Accordingly, Environmental Enrichment (EE) represents an approach to ameliorate cognitive decline and neuroprotection in Alzheimer’s disease (AD). AD is characterized by specific neuropathological hallmarks, such as β-amyloid plaques and Neurofibrillary Tangles, which severely affect the areas of the brain responsible for learning and memory. We evaluated EE neuroprotective influence on 5xFAD mice. We found a better cognitive performance on EE vs. Control (Ct) 5xFAD mice, until being similar to Wild-Type (Wt) mice group. Neurodegenerative markers as β-CTF and tau hyperphosphorylation, reduced protein levels whiles APPα, postsynaptic density 95 (PSD95) and synaptophysin (SYN) protein levels increased protein levels in the hippocampus of 5xFAD-EE mice group. Furthermore, a reduction in gene expression of Il-6, Gfap, Hmox1 and Aox1 was determined. However, no changes were found in the gene expression of neurotrophins, such as Brain-derived neurotrophic factor (Bdnf), Nerve growth factor (Ngf), Tumor growth factor (Tgf) and Nerve growth factor inducible (Vgf) in mice with EE. Specifically, we found a reduced DNA-methylation level (5-mC) and an increased hydroxymethylation level (5-hmC), as well as an increased histone H3 and H4 acetylation level. Likewise, we found changes in the hippocampal gene expression of some chromatin-modifying enzyme, such as Dnmt3a/b, Hdac1, and Tet2. Extensive molecular analysis revealed a correlation between neuronal function and changes in epigenetic marks after EE that explain the cognitive improvement in 5xFAD.
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Affiliation(s)
- Christian Griñán-Ferré
- Department of Pharmacology and Therapeutic Chemistry, Institut de Neurociències, University of Barcelona, Barcelona, Spain
| | - Vanesa Izquierdo
- Department of Pharmacology and Therapeutic Chemistry, Institut de Neurociències, University of Barcelona, Barcelona, Spain
| | - Eduard Otero
- Department of Pharmacology and Therapeutic Chemistry, Institut de Neurociències, University of Barcelona, Barcelona, Spain
| | - Dolors Puigoriol-Illamola
- Department of Pharmacology and Therapeutic Chemistry, Institut de Neurociències, University of Barcelona, Barcelona, Spain
| | - Rubén Corpas
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC, IDIBAPS and CIBERESP, Barcelona, Spain
| | - Coral Sanfeliu
- Institut d'Investigacions Biomèdiques de Barcelona (IIBB), CSIC, IDIBAPS and CIBERESP, Barcelona, Spain
| | - Daniel Ortuño-Sahagún
- Laboratorio de Neuroinmunomodulación Molecular, Instituto de Investigación en Ciencias Biomédicas (IICB), Centro Universitario de Ciencias de las Salud (CUCS), Universidad de Guadalajara, Guadalajara, Mexico
| | - Mercè Pallàs
- Department of Pharmacology and Therapeutic Chemistry, Institut de Neurociències, University of Barcelona, Barcelona, Spain
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Song SY, Chae M, Yu JH, Lee MY, Pyo S, Shin YK, Baek A, Park JW, Park ES, Choi JY, Cho SR. Environmental Enrichment Upregulates Striatal Synaptic Vesicle-Associated Proteins and Improves Motor Function. Front Neurol 2018; 9:465. [PMID: 30061854 PMCID: PMC6054977 DOI: 10.3389/fneur.2018.00465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 05/31/2018] [Indexed: 11/13/2022] Open
Abstract
Environmental enrichment (EE) is a therapeutic paradigm that consists of complex combinations of physical, cognitive, and social stimuli. The mechanisms underlying EE-mediated synaptic plasticity have yet to be fully elucidated. In this study, we investigated the effects of EE on synaptic vesicle-associated proteins and whether the expression of these proteins is related to behavioral outcomes. A total of 44 CD-1® (ICR) mice aged 6 weeks were randomly assigned to either standard cages or EE (N = 22 each). Rotarod and ladder walking tests were then performed to evaluate motor function. To identify the molecular mechanisms underlying the effects of EE, we assessed differentially expressed proteins (DEPs) in the striatum by proteomic analysis. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry were conducted to validate the expressions of these proteins. In the behavioral assessment, EE significantly enhanced performance on the rotarod and ladder walking tests. A total of 116 DEPs (54 upregulated and 62 downregulated proteins) were identified in mice exposed to EE. Gene ontology (GO) analysis demonstrated that the upregulated proteins in EE mice were primarily related to biological processes of synaptic vesicle transport and exocytosis. The GO terms for these biological processes commonly included Synaptic vesicle glycoprotein 2B (SV2B), Rabphilin-3A, and Piccolo. The qRT-PCR and western blot analyses revealed that EE increased the expression of SV2B, Rabphilin-3A and Piccolo in the striatum compared to the control group. Immunohistochemistry showed that the density of Piccolo in the vicinity of the subventricular zone was significantly increased in the EE mice compared with control mice. In conclusion, EE upregulates proteins associated with synaptic vesicle transport and exocytosis such as SV2B, Rabphilin-3A and Piccolo in the striatum. These upregulated proteins may be responsible for locomotor performance improvement, as shown in rotarod and ladder walking tests. Elucidation of these changes in synaptic protein expression provides new insights into the mechanism and potential role of EE.
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Affiliation(s)
- Suk-Young Song
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, South Korea
| | - Minji Chae
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, South Korea
| | - Ji Hea Yu
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Min Young Lee
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Soonil Pyo
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Yoon-Kyum Shin
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Ahreum Baek
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Rehabilitation Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Jung-Won Park
- Department of Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Eun Sook Park
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Ja Young Choi
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Rehabilitation Medicine, Eulji University School of Medicine, Daejeon, South Korea
| | - Sung-Rae Cho
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, South Korea.,Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
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46
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Dandi Ε, Kalamari A, Touloumi O, Lagoudaki R, Nousiopoulou E, Simeonidou C, Spandou E, Tata DA. Beneficial effects of environmental enrichment on behavior, stress reactivity and synaptophysin/BDNF expression in hippocampus following early life stress. Int J Dev Neurosci 2018; 67:19-32. [PMID: 29545098 DOI: 10.1016/j.ijdevneu.2018.03.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/07/2018] [Accepted: 03/08/2018] [Indexed: 01/01/2023] Open
Abstract
Exposure to environmental enrichment can beneficially influence the behavior and enhance synaptic plasticity. The aim of the present study was to investigate the mediated effects of environmental enrichment on postnatal stress-associated impact with regard to behavior, stress reactivity as well as synaptic plasticity changes in the dorsal hippocampus. Wistar rat pups were submitted to a 3 h maternal separation (MS) protocol during postnatal days 1-21, while another group was left undisturbed. On postnatal day 23, a subgroup from each rearing condition (maternal separation, no-maternal separation) was housed in enriched environmental conditions until postnatal day 65 (6 weeks duration). At approximately three months of age, adult rats underwent behavioral testing to evaluate anxiety (Elevated Plus Maze), locomotion (Open Field Test), spatial learning and memory (Morris Water Maze) as well as non-spatial recognition memory (Novel Object Recognition Test). After completion of behavioral testing, blood samples were taken for evaluation of stress-induced plasma corticosterone using an enzyme-linked immunosorbent assay (ELISA), while immunofluorescence was applied to evaluate hippocampal BDNF and synaptophysin expression in dorsal hippocampus. We found that environmental enrichment protected against the effects of maternal separation as indicated by the lower anxiety levels and the reversal of spatial memory deficits compared to animals housed in standard conditions. These changes were associated with increased BDNF and synaptophysin expression in the hippocampus. Regarding the neuroendocrine response to stress, while exposure to an acute stressor potentiated corticosterone increases in maternally-separated rats, environmental enrichment of these rats prevented this effect. The current study aimed at investigating the compensatory role of enriched environment against the negative outcomes of adverse experiences early in life concurrently on emotional and cognitive behaviors, HPA function and neuroplasticity markers.
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Affiliation(s)
- Εvgenia Dandi
- Laboratory of Cognitive Neuroscience, School of Psychology, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece
| | - Aikaterini Kalamari
- Laboratory of Cognitive Neuroscience, School of Psychology, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece
| | - Olga Touloumi
- Laboratory of Neuroimmunology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece
| | - Rosa Lagoudaki
- Laboratory of Neuroimmunology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece
| | - Evangelia Nousiopoulou
- Laboratory of Neuroimmunology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece
| | - Constantina Simeonidou
- Laboratory of Experimental Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece
| | - Evangelia Spandou
- Laboratory of Experimental Physiology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece.
| | - Despina A Tata
- Laboratory of Cognitive Neuroscience, School of Psychology, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece.
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