1
|
Kałużny O. The effect of dance workshops participation on reaction time in persons with moderate intellectual disabilities - pilot study. JOURNAL OF INTELLECTUAL DISABILITIES : JOID 2024; 28:469-477. [PMID: 36914621 DOI: 10.1177/17446295231163247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Background: Persons with intellectual disabilities who are physically active have faster reaction time compared to the physically inactive persons with intellectual disabilities (Yildirim et al. 2010). Aim: To recognize how participation in a series of hip-hop dance workshops can improve reaction time in persons with intellectual disabilities. Methods: 13 persons with moderate intellectual disabilities aged 14-22 (M = 17,30; SD = 2,52). A quasi-experiment was prepared using a single-group plan (nine dance workshops). Study design applied: pre-test - post-test. Measurement Tool - Optogait - acoustic response test. Results: Reaction time measured prior to dance workshops was M = 1,58; SD = 0,48 and after workshops was M = 1,34; SD = 0,69. The analysis using Wilcoxon signed-ranks test showed that this difference is statistically significant, Z = 2,06; p < .05. Conclusions: Hip-hop dance classes improve response times in persons with moderate intellectual disabilities.
Collapse
Affiliation(s)
- Olga Kałużny
- Wroclaw University of Health and Sport Sciences, Wroclaw, Poland
| |
Collapse
|
2
|
Scott-McKean JJ, Jones R, Johnson MW, Mier J, Basten IA, Stasko MR, Costa ACS. Emergence of Treadmill Running Ability and Quantitative Assessment of Gait Dynamics in Young Ts65Dn Mice: A Mouse Model for Down Syndrome. Brain Sci 2023; 13:brainsci13050743. [PMID: 37239215 DOI: 10.3390/brainsci13050743] [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: 04/01/2023] [Revised: 04/18/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Down syndrome (DS), which results from the complete or partial trisomy of chromosome 21 (trisomy-21), is the most common genetically defined cause of intellectual disability. Trisomy-21 also produces, or is associated with, many neurodevelopmental phenotypes and neurological comorbidities, including delays and deficits in fine and gross motor development. The Ts65Dn mouse is the most studied animal model for DS and displays the largest known subset of DS-like phenotypes. To date, however, only a small number of developmental phenotypes have been quantitatively defined in these animals. Here, we used a commercially available high-speed, video-based system to record and analyze the gait of Ts65Dn and euploid control mice. Longitudinal treadmill recordings were performed from p17 to p35. One of the main findings was the detection of genotype- and sex-dependent developmental delays in the emergence of consistent, progressive-intensity gait in Ts65Dn mice when compared to control mice. Gait dynamic analysis showed wider normalized front and hind stances in Ts65Dn mice compared to control mice, which may reflect deficits in dynamic postural balance. Ts65Dn mice also displayed statistically significant differences in the variability in several normalized gait measures, which were indicative of deficits in precise motor control in generating gait.
Collapse
Affiliation(s)
- Jonah J Scott-McKean
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-6090, USA
| | - Ryan Jones
- College of Medicine and Life Sciences, The University of Toledo, Toledo, OH 43606-3390, USA
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106-6090, USA
| | - Mark W Johnson
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106-6090, USA
| | - Joyce Mier
- Physical Therapy Program, University of Wisconsin, Madison, WI 53706-1532, USA
- Department of Biology, Case Western Reserve University, Cleveland, OH 44106-6090, USA
| | - Ines A Basten
- Psychiatric Hospital Asster, 3800 Sint-Truiden, Belgium
| | - Melissa R Stasko
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH 44106-6090, USA
| | - Alberto C S Costa
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-6090, USA
- Department of Psychiatry, Case Western Reserve University, Cleveland, OH 44106-6090, USA
| |
Collapse
|
3
|
Khan S. Endoplasmic Reticulum in Metaplasticity: From Information Processing to Synaptic Proteostasis. Mol Neurobiol 2022; 59:5630-5655. [PMID: 35739409 DOI: 10.1007/s12035-022-02916-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 06/05/2022] [Indexed: 11/29/2022]
Abstract
The ER (endoplasmic reticulum) is a Ca2+ reservoir and the unique protein-synthesizing machinery which is distributed throughout the neuron and composed of multiple different structural domains. One such domain is called EMC (endoplasmic reticulum membrane protein complex), pleiotropic nature in cellular functions. The ER/EMC position inside the neurons unmasks its contribution to synaptic plasticity via regulating various cellular processes from protein synthesis to Ca2+ signaling. Since presynaptic Ca2+ channels and postsynaptic ionotropic receptors are organized into the nanodomains, thus ER can be a crucial player in establishing TMNCs (transsynaptic molecular nanocolumns) to shape efficient neural communications. This review hypothesized that ER is not only involved in stress-mediated neurodegeneration but also axon regrowth, remyelination, neurotransmitter switching, information processing, and regulation of pre- and post-synaptic functions. Thus ER might not only be a protein-synthesizing and quality control machinery but also orchestrates plasticity of plasticity (metaplasticity) within the neuron to execute higher-order brain functions and neural repair.
Collapse
Affiliation(s)
- Shumsuzzaman Khan
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
4
|
Chelini G, Pangrazzi L, Bozzi Y. At the Crossroad Between Resiliency and Fragility: A Neurodevelopmental Perspective on Early-Life Experiences. Front Cell Neurosci 2022; 16:863866. [PMID: 35465609 PMCID: PMC9023311 DOI: 10.3389/fncel.2022.863866] [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: 01/27/2022] [Accepted: 03/04/2022] [Indexed: 11/13/2022] Open
Abstract
Postnatal development of the brain is characterized by sensitive windows during which, local circuitry are drastically reshaped by life experiences. These critical periods (CPs) occur at different time points for different brain functions, presenting redundant physiological changes in the underlying brain regions. Although circuits malleability during CPs provides a valuable window of opportunity for adaptive fine-tuning to the living environment, this aspect of neurodevelopment also represents a phase of increased vulnerability for the development of a variety of disorders. Consistently, accumulating epidemiological studies point to adverse childhood experience as a major risk factor for many medical conditions, especially stress- and anxiety-related conditions. Thanks to creative approaches to manipulate rodents’ rearing environment, neurobiologist have uncovered a pivotal interaction between CPs and early-life experiences, offering an interesting landscape to improve our understanding of brain disorders. In this short review, we discuss how early-life experience impacts cellular and molecular players involved in CPs of development, translating into long-lasting behavioral consequences in rodents. Bringing together findings from multiple laboratories, we delineate a unifying theory in which systemic factors dynamically target the maturation of brain functions based on adaptive needs, shifting the balance between resilience and vulnerability in response to the quality of the rearing environment.
Collapse
Affiliation(s)
- Gabriele Chelini
- CIMeC-Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy
- *Correspondence: Gabriele Chelini,
| | - Luca Pangrazzi
- CIMeC-Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy
| | - Yuri Bozzi
- CIMeC-Center for Mind/Brain Sciences, University of Trento, Rovereto, Italy
- Consiglio Nazionale delle Ricerche (CNR) Neuroscience Institute, Pisa, Italy
| |
Collapse
|
5
|
Kida E, Walus M, Albertini G, Golabek AA. Long-term voluntary running modifies the levels of proteins of the excitatory/inhibitory system and reduces reactive astrogliosis in the brain of Ts65Dn mouse model for Down syndrome. Brain Res 2021; 1766:147535. [PMID: 34043998 DOI: 10.1016/j.brainres.2021.147535] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 09/30/2022]
Abstract
We showed previously that voluntary long-term running improved cognition and motor skills, but in an age-dependent manner, in the Ts65Dn mouse model for Down syndrome (DS). Presently, we investigated the effect of running on the levels of some key proteins of the excitatory/inhibitory system, which is impaired in the trisomic brain, and on astroglia, a vital component of this system. Ts65Dn mice had free access to a running wheel for 9-13 months either from weaning or from the age of 7 months. Sedentary Ts65Dn mice served as controls. We found that running modified the levels of four of the seven proteins we tested that are associated with the glutamatergic/GABA-ergic system. Thus, Ts65Dn runners demonstrated increased levels of glutamine synthetase and metabotropic glutamate receptor 1 and decreased levels of glutamate transporter 1 and glutamic acid decarboxylase 65 (GAD65) versus sedentary mice, but of metabotropic glutamate receptor 1 and GAD65 only in the post-weaning cohort. GAD67, ionotropic N-methyl-D-aspartate type receptor subunit 1, and GABAAα5 receptors' levels were similar in runners and sedentary animals. The number of glial fibrillary acidic protein (GFAP)-positive astrocytes and the levels of GFAP were significantly reduced in runners relative to sedentary mice. Our study provides new insight into the mechanisms underlying the beneficial effect of voluntary, sustained running on function of the trisomic brain by identifying the involvement of proteins associated with glutamatergic and GABAergic systems and reduction in reactive astrogliosis.
Collapse
Affiliation(s)
- Elizabeth Kida
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
| | - Marius Walus
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
| | - Giorgio Albertini
- Child Development Department, IRCCS San Raffaele Pisana, Rome and San Raffaele Cassino, Italy
| | - Adam A Golabek
- Department of Developmental Neurobiology, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA.
| |
Collapse
|
6
|
Tchantchou F, Goodfellow M, Li F, Ramsue L, Miller C, Puche A, Fiskum G. Hyperhomocysteinemia-Induced Oxidative Stress Exacerbates Cortical Traumatic Brain Injury Outcomes in Rats. Cell Mol Neurobiol 2021; 41:487-503. [PMID: 32405706 DOI: 10.1007/s10571-020-00866-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 05/05/2020] [Indexed: 02/07/2023]
Abstract
Traumatic brain injury (TBI) is a leading cause of morbidity and mortality among military service members and civilians in the United States. Despite significant advances in the understanding of TBI pathophysiology, several clinical reports indicate that multiple genetic and epigenetic factors can influence outcome. Homocysteine (HCY) is a non-proteinogenic amino acid, the catabolism of which can be dysregulated by stress, lifestyle, aging, or genetic abnormalities leading to hyperhomocysteinemia (HHCY). HHCY is a neurotoxic condition and a risk factor for multiple neurological and cardiovascular disorders that occurs when HCY levels is clinically > 15 µM. Although the deleterious impact of HHCY has been studied in human and animal models of neurological disorders such as stroke, Alzheimer's disease and Parkinson's disease, it has not been addressed in TBI models. This study tested the hypothesis that HHCY has detrimental effects on TBI pathophysiology. Moderate HHCY was induced in adult male Sprague Dawley rats via daily administration of methionine followed by impact-induced traumatic brain injury. In this model, HHCY increased oxidative stress, upregulated expression of proteins that promote blood coagulation, exacerbated TBI-associated blood-brain barrier dysfunction and promoted the infiltration of inflammatory cells into the cortex. We also observed an increase of brain injury-induced lesion size and aggravated anxiety-like behavior. These findings show that moderate HHCY exacerbates TBI outcomes and suggest that HCY catabolic dysregulation may be a significant biological variable that could contribute to TBI pathophysiology heterogeneity.
Collapse
Affiliation(s)
- Flaubert Tchantchou
- Department of Anesthesiology and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore Street, Baltimore, MD, 21201, USA.
| | - Molly Goodfellow
- Department of Anesthesiology and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore Street, Baltimore, MD, 21201, USA
| | - Fengying Li
- Department of Anesthesiology and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore Street, Baltimore, MD, 21201, USA
| | - Lyric Ramsue
- Department of Anesthesiology and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore Street, Baltimore, MD, 21201, USA
| | - Catriona Miller
- Aeromedical Research, U.S Air Force School of Aerospace Medicine, Dayton, OH, USA
| | - Adam Puche
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gary Fiskum
- Department of Anesthesiology and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore Street, Baltimore, MD, 21201, USA
| |
Collapse
|
7
|
|
8
|
De Toma I, Ortega M, Catuara-Solarz S, Sierra C, Sabidó E, Dierssen M. Re-establishment of the epigenetic state and rescue of kinome deregulation in Ts65Dn mice upon treatment with green tea extract and environmental enrichment. Sci Rep 2020; 10:16023. [PMID: 32994493 PMCID: PMC7524756 DOI: 10.1038/s41598-020-72625-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022] Open
Abstract
Down syndrome (DS) is the main genetic cause of intellectual disability due to triplication of human chromosome 21 (HSA21). Although there is no treatment for intellectual disability, environmental enrichment (EE) and the administration of green tea extracts containing epigallocatechin-3-gallate (EGCG) improve cognition in mouse models and individuals with DS. Using proteome, and phosphoproteome analysis in the hippocampi of a DS mouse model (Ts65Dn), we investigated the possible mechanisms underlying the effects of green tea extracts, EE and their combination. Our results revealed disturbances in cognitive-related (synaptic proteins, neuronal projection, neuron development, microtubule), GTPase/kinase activity and chromatin proteins. Green tea extracts, EE, and their combination restored more than 70% of the phosphoprotein deregulation in Ts65Dn, and induced possible compensatory effects. Our downstream analyses indicate that re-establishment of a proper epigenetic state and rescue of the kinome deregulation may contribute to the cognitive rescue induced by green tea extracts.
Collapse
Affiliation(s)
- I De Toma
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - M Ortega
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - S Catuara-Solarz
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - C Sierra
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - E Sabidó
- Universitat Pompeu Fabra (UPF), Dr. Aiguader 88, 08003, Barcelona, Spain.,Proteomics Unit, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain
| | - M Dierssen
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, 08003, Barcelona, Spain. .,Universitat Pompeu Fabra (UPF), Dr. Aiguader 88, 08003, Barcelona, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain.
| |
Collapse
|
9
|
Forbes TA, Goldstein EZ, Dupree JL, Jablonska B, Scafidi J, Adams KL, Imamura Y, Hashimoto-Torii K, Gallo V. Environmental enrichment ameliorates perinatal brain injury and promotes functional white matter recovery. Nat Commun 2020; 11:964. [PMID: 32075970 PMCID: PMC7031237 DOI: 10.1038/s41467-020-14762-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 01/31/2020] [Indexed: 12/14/2022] Open
Abstract
Hypoxic damage to the developing brain due to preterm birth causes many anatomical changes, including damage to the periventricular white matter. This results in the loss of glial cells, significant disruptions in myelination, and thereby cognitive and behavioral disabilities seen throughout life. Encouragingly, these neurological morbidities can be improved by environmental factors; however, the underlying cellular mechanisms remain unknown. We found that early and continuous environmental enrichment selectively enhances endogenous repair of the developing white matter by promoting oligodendroglial maturation, myelination, and functional recovery after perinatal brain injury. These effects require increased exposure to socialization, physical activity, and cognitive enhancement of surroundings-a complete enriched environment. Using RNA-sequencing, we identified oligodendroglial-specific responses to hypoxic brain injury, and uncovered molecular mechanisms involved in enrichment-induced recovery. Together, these results indicate that myelin plasticity induced by modulation of the neonatal environment can be targeted as a therapeutic strategy for preterm birth.
Collapse
Affiliation(s)
- Thomas A Forbes
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA.,Institute for Biomedical Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Evan Z Goldstein
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, 23284, USA
| | - Beata Jablonska
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA.,Institute for Biomedical Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Joseph Scafidi
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA.,Institute for Biomedical Sciences, The George Washington University, Washington, DC, 20052, USA
| | - Katrina L Adams
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA
| | - Yuka Imamura
- Institute for Personalized Medicine, Penn State University, College of Medicine, Hershey, PA, 17033, USA
| | - Kazue Hashimoto-Torii
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC, 20010, USA. .,Institute for Biomedical Sciences, The George Washington University, Washington, DC, 20052, USA.
| |
Collapse
|
10
|
Tayebati SK, Cecchi A, Martinelli I, Carboni E, Amenta F. Pharmacotherapy of Down’s Syndrome: When and Which? CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2020; 18:750-757. [DOI: 10.2174/1871527318666191114092924] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 10/19/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
:
Down Syndrome (DS) is an essential genetic disease that involves many other body systems
along with cerebral functions. The postnatal approach to treat this genetic disease includes intervention
on various related disorders (e.g., heart failure, respiratory, oral, ear, and hearing disorders). However,
different proposed treatments do not significantly improve the quality of life of these subjects. Another
approach to the treatment of DS considering the possibility to intervene on the embryo was recently
introduced. As of this, the current study has reviewed different outcomes regarding DS treatment in an
animal model, namely the Ts65Dn mouse. The obtained results encouraged spending more time, efforts,
and resources in this field. Besides, various treatment strategies were tried to include genetic
modification, treatment with vasoactive intestinal peptide derivatives or fluoxetine. However, the main
obstacle to the use of these possible treatments is the ethical issues it raises. The progression of the
pregnancy in spite of awareness that DS affects the unborn and prenatal treatment of DS injured embryo
are relevant dilemmas. Thus, talented researchers should spend more efforts to improve the quality
of life for people affected by DS, which will allow probably a better approach to the ethical issues.
Collapse
Affiliation(s)
- Seyed K. Tayebati
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy
| | | | - Ilenia Martinelli
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy
| | - Elisa Carboni
- Regional Centre for Prenatal Diagnosis, Loreto, Italy
| | - Francesco Amenta
- School of Medicinal Sciences and Health Products, University of Camerino, Camerino, Italy
| |
Collapse
|
11
|
Martínez Cué C, Dierssen M. Plasticity as a therapeutic target for improving cognition and behavior in Down syndrome. PROGRESS IN BRAIN RESEARCH 2020; 251:269-302. [DOI: 10.1016/bs.pbr.2019.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Gorantla VR, Thomas SE, Millis RM. Environmental Enrichment and Brain Neuroplasticity in the Kainate Rat Model of Temporal Lobe Epilepsy. J Epilepsy Res 2019; 9:51-64. [PMID: 31482057 PMCID: PMC6706649 DOI: 10.14581/jer.19006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/19/2019] [Accepted: 06/21/2019] [Indexed: 12/12/2022] Open
Abstract
Background and Purpose Environmental enrichment (EE) improves brain function and ameliorates cognitive impairments; however, whether EE can reverse the learning and memory deficits seen following seizures remains unknown. Methods We tested the hypothesis that EE augments neurogenesis and attenuates the learning and memory deficits in rats subjected to kainate-induced seizures in hippocampus, amygdala and motor cortex. EE consisted of daily exposures immediately after KA lesioning (early EE) and after a 60-day period (late EE). Morphometric counting of neuron numbers (NN), dendritic branch-points and intersections (DDBPI) were performed. Spatial learning in a T-maze test was described as percent correct responses and memory in a passive-avoidance test was calculated as time spent in the small compartment where they were previously exposed to an aversive stimulus. Results EE increased NN and DDBPI in the normal control and in the KA-lesioned rats in all brain areas studied, after both early and late exposure to EE. Late EE resulted in significantly fewer surviving neurons than early EE in all brain areas (p < 0.0001). EE increased the percent correct responses and decreased time spent in the small compartment, after both early and late EE. The timing of EE (early vs. late) had no effect on the behavioral measurements. Conclusions These findings demonstrate that, after temporal lobe and motor cortex epileptic seizures in rats, EE improves neural plasticity in areas of the brain involved with emotional regulation and motor coordination, even if the EE treatment is delayed for 60 days. Future studies should determine whether EE is a useful therapeutic strategy for patients affected by seizures.
Collapse
Affiliation(s)
- Vasavi R Gorantla
- Department of Behavioral Science and Neuroscience, American University of Antigua College of Medicine, Coolidge, Antigua and Barbuda
| | - Sneha E Thomas
- Department of Behavioral Science and Neuroscience, American University of Antigua College of Medicine, Coolidge, Antigua and Barbuda
| | - Richard M Millis
- Department of Behavioral Science and Neuroscience, American University of Antigua College of Medicine, Coolidge, Antigua and Barbuda.,Department of Medical Physiology, American University of Antigua College of Medicine, Coolidge, Antigua and Barbuda
| |
Collapse
|
14
|
Bells S, Lefebvre J, Longoni G, Narayanan S, Arnold DL, Yeh EA, Mabbott DJ. White matter plasticity and maturation in human cognition. Glia 2019; 67:2020-2037. [PMID: 31233643 DOI: 10.1002/glia.23661] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/21/2019] [Accepted: 05/29/2019] [Indexed: 12/17/2022]
Abstract
White matter plasticity likely plays a critical role in supporting cognitive development. However, few studies have used the imaging methods specific to white matter tissue structure or experimental designs sensitive to change in white matter necessary to elucidate these relations. Here we briefly review novel imaging approaches that provide more specific information regarding white matter microstructure. Furthermore, we highlight recent studies that provide greater clarity regarding the relations between changes in white matter and cognition maturation in both healthy children and adolescents and those with white matter insult. Finally, we examine the hypothesis that white matter is linked to cognitive function via its impact on neural synchronization. We test this hypothesis in a population of children and adolescents with recurrent demyelinating syndromes. Specifically, we evaluate group differences in white matter microstructure within the optic radiation; and neural phase synchrony in visual cortex during a visual task between 25 patients and 28 typically developing age-matched controls. Children and adolescents with demyelinating syndromes show evidence of myelin and axonal compromise and this compromise predicts reduced phase synchrony during a visual task compared to typically developing controls. We investigate one plausible mechanism at play in this relationship using a computational model of gamma generation in early visual cortical areas. Overall, our findings show a fundamental connection between white matter microstructure and neural synchronization that may be critical for cognitive processing. In the future, longitudinal or interventional studies can build upon our knowledge of these exciting relations between white matter, neural communication, and cognition.
Collapse
Affiliation(s)
- Sonya Bells
- Neurosciences and Mental Health Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jérémie Lefebvre
- Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Mathematics, University of Toronto, Toronto, Ontario, Canada
| | - Giulia Longoni
- Neurosciences and Mental Health Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Neurology, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Sridar Narayanan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Douglas L Arnold
- Department of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Eleun Ann Yeh
- Neurosciences and Mental Health Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Neurology, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Paediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Donald J Mabbott
- Neurosciences and Mental Health Program, Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
15
|
From Basic Visual Science to Neurodevelopmental Disorders: The Voyage of Environmental Enrichment-Like Stimulation. Neural Plast 2019; 2019:5653180. [PMID: 31198418 PMCID: PMC6526521 DOI: 10.1155/2019/5653180] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/06/2019] [Accepted: 04/16/2019] [Indexed: 12/31/2022] Open
Abstract
Genes and environmental stimuli cooperate in the regulation of brain development and formation of the adult neuronal architecture. Genetic alterations or exposure to perturbing environmental conditions, therefore, can lead to altered neural processes associated with neurodevelopmental disorders and brain disabilities. In this context, environmental enrichment emerged as a promising and noninvasive experimental treatment for favoring recovery of cognitive and sensory functions in different neurodevelopmental disorders. The aim of this review is to depict, mainly through the much explicative examples of amblyopia, Down syndrome, and Rett syndrome, the increasing interest in the potentialities and applications of enriched environment-like protocols in the field of neurodevelopmental disorders and the understanding of the molecular mechanisms underlying the beneficial effects of these protocols, which might lead to development of pharmacological interventions.
Collapse
|
16
|
Moreno-Jiménez EP, Jurado-Arjona J, Ávila J, Llorens-Martín M. The Social Component of Environmental Enrichment Is a Pro-neurogenic Stimulus in Adult c57BL6 Female Mice. Front Cell Dev Biol 2019; 7:62. [PMID: 31080799 PMCID: PMC6497743 DOI: 10.3389/fcell.2019.00062] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/05/2019] [Indexed: 12/18/2022] Open
Abstract
In rodents, the hippocampal dentate gyrus gives rise to newly generated dentate granule cells (DGCs) throughout life. This process, named adult hippocampal neurogenesis (AHN), converges in the functional integration of mature DGCs into the trisynaptic hippocampal circuit. Environmental enrichment (EE) is one of the most potent positive regulators of AHN. This paradigm includes the combination of three major stimulatory components, namely increased physical activity, constant cognitive stimulation, and higher social interaction. In this regard, the pro-neurogenic effects of physical activity and cognitive stimulation have been widely addressed in adult rodents. However, the pro-neurogenic potential of the social aspect of EE has been less explored to date. Here we tackled this question by specifically focusing on the effects of a prolonged period of social enrichment (SE) in adult female C57BL6 mice. To this end, 7-week-old mice were housed in groups of 12 per cage for 8 weeks. These mice were compared with others housed under control housing (2–3 mice per cage) or EE (12 mice per cage plus running wheels and toys) conditions during the same period. We analyzed the number and morphology of Doublecortin-expressing (DCX+) cells. Moreover, using RGB retroviruses that allowed the labeling of three populations of newborn DGCs of different ages in the same mouse, we performed morphometric, immunohistochemical, and behavioral determinations. Both SE and EE increased the number and maturation of DCX+ cells, and caused an increase in dendritic maturation in certain populations of newborn DGCs. Moreover, both manipulations increased exploratory behavior in the Social Interaction test. Unexpectedly, our data revealed the potent neurogenesis-stimulating potential of SE in the absence of any further cognitive stimulation or increase in physical activity. Given that an increase in physical activity is strongly discouraged under certain circumstances, our findings may be relevant in the context of enhancing AHN via physical activity-independent mechanisms.
Collapse
Affiliation(s)
- Elena P Moreno-Jiménez
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa, CBMSO, CSIC-UAM, Madrid, Spain.,Department of Molecular Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain.,Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Jerónimo Jurado-Arjona
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa, CBMSO, CSIC-UAM, Madrid, Spain
| | - Jesús Ávila
- 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
| | - María Llorens-Martín
- Department of Molecular Neuropathology, Centro de Biología Molecular Severo Ochoa, CBMSO, CSIC-UAM, Madrid, Spain.,Department of Molecular Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain.,Center for Networked Biomedical Research on Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Scafidi J, Ritter J, Talbot BM, Edwards J, Chew LJ, Gallo V. Age-Dependent Cellular and Behavioral Deficits Induced by Molecularly Targeted Drugs Are Reversible. Cancer Res 2018; 78:2081-2095. [PMID: 29559476 DOI: 10.1158/0008-5472.can-17-2254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 01/12/2018] [Accepted: 02/09/2018] [Indexed: 11/16/2022]
Abstract
Newly developed targeted anticancer drugs inhibit signaling pathways commonly altered in adult and pediatric cancers. However, as these pathways are also essential for normal brain development, concerns have emerged of neurologic sequelae resulting specifically from their application in pediatric cancers. The neural substrates and age dependency of these drug-induced effects in vivo are unknown, and their long-term behavioral consequences have not been characterized. This study defines the age-dependent cellular and behavioral effects of these drugs on normally developing brains and determines their reversibility with post-drug intervention. Mice at different postnatal ages received short courses of molecularly targeted drugs in regimens analagous to clinical treatment. Analysis of rapidly developing brain structures important for sensorimotor and cognitive function showed that, while adult administration was without effect, earlier neonatal administration of targeted therapies attenuated white matter oligodendroglia and hippocampal neuronal development more profoundly than later administration, leading to long-lasting behavioral deficits. This functional impairment was reversed by rehabilitation with physical and cognitive enrichment. Our findings demonstrate age-dependent, reversible effects of these drugs on brain development, which are important considerations as treatment options expand for pediatric cancers.Significance: Targeted therapeutics elicit age-dependent long-term consequences on the developing brain that can be ameliorated with environmental enrichment. Cancer Res; 78(8); 2081-95. ©2018 AACR.
Collapse
Affiliation(s)
- Joseph Scafidi
- Neurology, Children's National Health System, Washington, D.C. .,Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, D.C
| | - Jonathan Ritter
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, D.C
| | - Brooke M Talbot
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, D.C
| | - Jorge Edwards
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, D.C
| | - Li-Jin Chew
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, D.C
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's Research Institute, Children's National Health System, Washington, D.C
| |
Collapse
|
19
|
Stagni F, Giacomini A, Emili M, Guidi S, Bartesaghi R. Neurogenesis impairment: An early developmental defect in Down syndrome. Free Radic Biol Med 2018; 114:15-32. [PMID: 28756311 DOI: 10.1016/j.freeradbiomed.2017.07.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 02/06/2023]
Abstract
Down syndrome (DS) is characterized by brain hypotrophy and intellectual disability starting from early life stages. Accumulating evidence shows that the phenotypic features of the DS brain can be traced back to the fetal period since the DS brain exhibits proliferation potency reduction starting from the critical time window of fetal neurogenesis. This defect is worsened by the fact that neural progenitor cells exhibit reduced acquisition of a neuronal phenotype and an increase in the acquisition of an astrocytic phenotype. Consequently, the DS brain has fewer neurons in comparison with the typical brain. Although apoptotic cell death may be increased in DS, this does not seem to be the major cause of brain hypocellularity. Evidence obtained in brains of individuals with DS, DS-derived induced pluripotent stem cells (iPSCs), and DS mouse models has provided some insight into the mechanisms underlying the developmental defects due to the trisomic condition. Although many triplicated genes may be involved, in the light of the studies reviewed here, DYRK1A, APP, RCAN1 and OLIG1/2 appear to be particularly important determinants of many neurodevelopmental alterations that characterize DS because their triplication affects both the proliferation and fate of neural precursor cells as well as apoptotic cell death. Based on the evidence reviewed here, pathways downstream to these genes may represent strategic targets, for the design of possible interventions.
Collapse
Affiliation(s)
- Fiorenza Stagni
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Andrea Giacomini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Marco Emili
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Sandra Guidi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Renata Bartesaghi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.
| |
Collapse
|
20
|
Torres MD, Garcia O, Tang C, Busciglio J. Dendritic spine pathology and thrombospondin-1 deficits in Down syndrome. Free Radic Biol Med 2018; 114:10-14. [PMID: 28965914 PMCID: PMC7185223 DOI: 10.1016/j.freeradbiomed.2017.09.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 11/27/2022]
Abstract
Abnormal dendritic spine structure and function is one of the most prominent features associated with neurodevelopmental disorders including Down syndrome (DS). Defects in both spine morphology and spine density may underlie alterations in neuronal and synaptic plasticity, ultimately affecting cognitive ability. Here we briefly examine the role of astrocytes in spine alterations and more specifically the involvement of astrocyte-secreted thrombospondin 1 (TSP-1) deficits in spine and synaptic pathology in DS.
Collapse
Affiliation(s)
- Maria D Torres
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), and Center for the Neurobiology of Learning and Memory (CNLM), University of California, Irvine, CA 92697, United States
| | - Octavio Garcia
- Facultad de Psicología, Universidad Nacional Autónoma de México, 04510 Coyoacán, Ciudad de México, México
| | - Cindy Tang
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), and Center for the Neurobiology of Learning and Memory (CNLM), University of California, Irvine, CA 92697, United States
| | - Jorge Busciglio
- Department of Neurobiology and Behavior, Institute for Memory Impairments and Neurological Disorders (iMIND), and Center for the Neurobiology of Learning and Memory (CNLM), University of California, Irvine, CA 92697, United States.
| |
Collapse
|
21
|
Wirths O. Altered neurogenesis in mouse models of Alzheimer disease. NEUROGENESIS 2017; 4:e1327002. [PMID: 29564360 DOI: 10.1080/23262133.2017.1327002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 10/19/2022]
Abstract
Amyloid-β (Aβ) peptides, as well as a variety of other protein fragments, are derived from proteolytical cleavage of the amyloid precursor protein (APP) and have been demonstrated to play a key role in the pathological changes underlying Alzheimer disease (AD). In AD mouse models, altered neurogenesis has been repeatedly reported to be associated with further AD-typical pathological hallmarks such as extracellular plaque deposition, behavioral deficits or neuroinflammation. While a toxic role of Aβ in neurodegeneration and impaired neuronal progenitor proliferation is likely and well-accepted, recent findings also suggest an important influence of APP-derived proteolitical fragments like the APP intracellular domain (AICD), as well as of APP itself.
Collapse
Affiliation(s)
- Oliver Wirths
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| |
Collapse
|
22
|
De Giorgio A. The roles of motor activity and environmental enrichment in intellectual disability. Somatosens Mot Res 2017; 34:34-43. [PMID: 28140743 DOI: 10.1080/08990220.2016.1278204] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In people with intellectual disabilities, an enriched environment can stimulate the acquisition of motor skills and could partially repair neuronal impairment thanks to exploration and motor activity. A deficit in environmental and motor stimulation leads to low scores in intelligence tests and can cause serious motor skill problems. Although studies in humans do not give much evidence for explaining basic mechanisms of intellectual disability and for highlighting improvements due to enriched environmental stimulation, animal models have been valuable in the investigation of these conditions. Here, we discuss the role of environmental enrichment in four intellectual disabilities: Foetal Alcohol Spectrum Disorder (FASD), Down, Rett, and Fragile X syndromes.
Collapse
Affiliation(s)
- Andrea De Giorgio
- a Department of Psychology , eCampus University , Novedrate , Italy.,b Department of Psychology , Universita Cattolica del Sacro Cuore , Milano , Italy
| |
Collapse
|
23
|
Combined Treatment With Environmental Enrichment and (-)-Epigallocatechin-3-Gallate Ameliorates Learning Deficits and Hippocampal Alterations in a Mouse Model of Down Syndrome. eNeuro 2016; 3:eN-NWR-0103-16. [PMID: 27844057 PMCID: PMC5099603 DOI: 10.1523/eneuro.0103-16.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 08/26/2016] [Accepted: 09/08/2016] [Indexed: 12/22/2022] Open
Abstract
Intellectual disability in Down syndrome (DS) is accompanied by altered neuro-architecture, deficient synaptic plasticity, and excitation-inhibition imbalance in critical brain regions for learning and memory. Recently, we have demonstrated beneficial effects of a combined treatment with green tea extract containing (-)-epigallocatechin-3-gallate (EGCG) and cognitive stimulation in young adult DS individuals. Although we could reproduce the cognitive-enhancing effects in mouse models, the underlying mechanisms of these beneficial effects are unknown. Here, we explored the effects of a combined therapy with environmental enrichment (EE) and EGCG in the Ts65Dn mouse model of DS at young age. Our results show that combined EE-EGCG treatment improved corticohippocampal-dependent learning and memory. Cognitive improvements were accompanied by a rescue of cornu ammonis 1 (CA1) dendritic spine density and a normalization of the proportion of excitatory and inhibitory synaptic markers in CA1 and dentate gyrus.
Collapse
|
24
|
Short- and long-term effects of neonatal pharmacotherapy with epigallocatechin-3-gallate on hippocampal development in the Ts65Dn mouse model of Down syndrome. Neuroscience 2016; 333:277-301. [DOI: 10.1016/j.neuroscience.2016.07.031] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 07/15/2016] [Accepted: 07/19/2016] [Indexed: 01/01/2023]
|
25
|
Jamal I, Kumar V, Vatsa N, Singh BK, Shekhar S, Sharma A, Jana NR. Environmental Enrichment Improves Behavioral Abnormalities in a Mouse Model of Angelman Syndrome. Mol Neurobiol 2016; 54:5319-5326. [PMID: 27581300 DOI: 10.1007/s12035-016-0080-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/23/2016] [Indexed: 12/27/2022]
Abstract
Angelman syndrome (AS) is a neurodevelopmental disorder largely caused by the loss of function of maternally inherited UBE3A. UBE3A-maternal deficient mice (AS mice) exhibit many typical features of AS including cognitive and motor deficits but the underlying mechanism of these behavioral abnormalities is poorly understood. Here, we demonstrate that rearing of AS mice in the enriched environment for prolonged period significantly improved their cognitive and motor dysfunction. Enriched environment also restored elevated serum corticosterone level and reduced anxiety-like behaviors in these mice. Biochemical analysis further revealed restoration of altered levels of brain-derived neurotrophic factor, glucocorticoid receptor, and phoshphorylated calcium/calmodulin-dependent protein kinase IIα in the hippocampus of AS mice maintained in the enriched environment. Enriched environment also significantly increased the number of parvalbumin-positive GABAergic interneuron in the hippocampus and basolateral amygdala of AS mice. These results indicate potential beneficial effect of enriched environment in the reversal of AS phenotype.
Collapse
Affiliation(s)
- Imran Jamal
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India
| | - Vipendra Kumar
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India
| | - Naman Vatsa
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India
| | - Brijesh Kumar Singh
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India
| | - Shashi Shekhar
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India
| | - Ankit Sharma
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India
| | - Nihar Ranjan Jana
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 051, India.
| |
Collapse
|
26
|
López-Hidalgo R, Ballestín R, Vega J, Blasco-Ibáñez JM, Crespo C, Gilabert-Juan J, Nácher J, Varea E. Hypocellularity in the Murine Model for Down Syndrome Ts65Dn Is Not Affected by Adult Neurogenesis. Front Neurosci 2016; 10:75. [PMID: 26973453 PMCID: PMC4773601 DOI: 10.3389/fnins.2016.00075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 02/17/2016] [Indexed: 01/08/2023] Open
Abstract
Down syndrome (DS) is caused by the presence of an extra copy of the chromosome 21 and it is the most common aneuploidy producing intellectual disability. Neural mechanisms underlying this alteration may include defects in the formation of neuronal networks, information processing and brain plasticity. The murine model for DS, Ts65Dn, presents reduced adult neurogenesis. This reduction has been suggested to underlie the hypocellularity of the hippocampus as well as the deficit in olfactory learning in the Ts65Dn mice. Similar alterations have also been observed in individuals with DS. To determine whether the impairment in adult neurogenesis is, in fact, responsible for the hypocellularity in the hippocampus and physiology of the olfactory bulb, we have analyzed cell proliferation and neuronal maturation in the two major adult neurogenic niches in the Ts656Dn mice: the subgranular zone (SGZ) of the hippocampus and the subventricular zone (SVZ). Additionally, we carried out a study to determine the survival rate and phenotypic fate of newly generated cells in both regions, injecting 5'BrdU and sacrificing the mice 21 days later, and analyzing the number and phenotype of the remaining 5'BrdU-positive cells. We observed a reduction in the number of proliferating (Ki67 positive) cells and immature (doublecortin positive) neurons in the subgranular and SVZ of Ts65Dn mice, but we did not observe changes in the number of surviving cells or in their phenotype. These data correlated with a lower number of apoptotic cells (cleaved caspase 3 positive) in Ts65Dn. We conclude that although adult Ts65Dn mice have a lower number of proliferating cells, it is compensated by a lower level of cell death. This higher survival rate in Ts65Dn produces a final number of mature cells similar to controls. Therefore, the reduction of adult neurogenesis cannot be held responsible for the neuronal hypocellularity in the hippocampus or for the olfactory learning deficit of Ts65Dn mice.
Collapse
Affiliation(s)
- Rosa López-Hidalgo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Raul Ballestín
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Jessica Vega
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - José M. Blasco-Ibáñez
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Carlos Crespo
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| | - Javier Gilabert-Juan
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVAValència, Spain
- CIBERSAM, Spanish National Network for Research in Mental HealthValència, Spain
- Genetics Department, CIBERSAM, Universitat de ValènciaValència, Spain
| | - Juan Nácher
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVAValència, Spain
- CIBERSAM, Spanish National Network for Research in Mental HealthValència, Spain
- Genetics Department, CIBERSAM, Universitat de ValènciaValència, Spain
| | - Emilio Varea
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Department, Universitat de ValènciaValència, Spain
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (BIOTECMED), Universitat de ValènciaValència, Spain
| |
Collapse
|
27
|
Catuara-Solarz S, Espinosa-Carrasco J, Erb I, Langohr K, Notredame C, Gonzalez JR, Dierssen M. Principal Component Analysis of the Effects of Environmental Enrichment and (-)-epigallocatechin-3-gallate on Age-Associated Learning Deficits in a Mouse Model of Down Syndrome. Front Behav Neurosci 2015; 9:330. [PMID: 26696850 PMCID: PMC4675859 DOI: 10.3389/fnbeh.2015.00330] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/16/2015] [Indexed: 11/13/2022] Open
Abstract
Down syndrome (DS) individuals present increased risk for Alzheimer's disease (AD) neuropathology and AD-type dementia. Here, we investigated the use of green tea extracts containing (-)-epigallocatechin-3-gallate (EGCG), as co-adjuvant to enhance the effects of environmental enrichment (EE) in Ts65Dn mice, a segmental trisomy model of DS that partially mimics DS/AD pathology, at the age of initiation of cognitive decline. Classical repeated measures ANOVA showed that combined EE-EGCG treatment was more efficient than EE or EGCG alone to improve specific spatial learning related variables. Using principal component analysis (PCA) we found that several spatial learning parameters contributed similarly to a first PC and explained a large proportion of the variance among groups, thus representing a composite learning measure. This PC1 revealed that EGCG or EE alone had no significant effect. However, combined EE-EGCG significantly ameliorated learning alterations of middle age Ts65Dn mice. Interestingly, PCA revealed an increased variability along learning sessions with good and poor learners in Ts65Dn, and this stratification did not disappear upon treatments. Our results suggest that combining EE and EGCG represents a viable therapeutic approach for amelioration of age-related cognitive decline in DS, although its efficacy may vary across individuals.
Collapse
Affiliation(s)
- Silvina Catuara-Solarz
- Systems Biology Program, Cellular and Systems Neurobiology, Centre for Genomic Regulation, The Barcelona Institute of Science and Technology Barcelona, Spain ; Centre for Genomic Regulation, Universitat Pompeu Fabra Barcelona, Spain
| | - Jose Espinosa-Carrasco
- Systems Biology Program, Cellular and Systems Neurobiology, Centre for Genomic Regulation, The Barcelona Institute of Science and Technology Barcelona, Spain ; Centre for Genomic Regulation, Universitat Pompeu Fabra Barcelona, Spain ; Bioinformatics and Genomics Program, Comparative Bioinformatics, Centre for Genomic Regulation, Barcelona Institute of Science and Technology Barcelona, Spain
| | - Ionas Erb
- Centre for Genomic Regulation, Universitat Pompeu Fabra Barcelona, Spain ; Bioinformatics and Genomics Program, Comparative Bioinformatics, Centre for Genomic Regulation, Barcelona Institute of Science and Technology Barcelona, Spain
| | - Klaus Langohr
- Neurosciences Research Program, Human Pharmacology and Clinical Neurosciences Research Group, IMIM (Hospital del Mar Medical Research Institute) Barcelona, Spain ; Department of Statistics and Operations Research, Universitat Politècnica de Catalunya/BARCELONATECH Barcelona, Spain
| | - Cedric Notredame
- Centre for Genomic Regulation, Universitat Pompeu Fabra Barcelona, Spain ; Bioinformatics and Genomics Program, Comparative Bioinformatics, Centre for Genomic Regulation, Barcelona Institute of Science and Technology Barcelona, Spain
| | - Juan R Gonzalez
- Bioinformatics and Genomics Program, Comparative Bioinformatics, Centre for Genomic Regulation, Barcelona Institute of Science and Technology Barcelona, Spain ; Centre for Research in Environmental Epidemiology Barcelona, Spain ; Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública Barcelona, Spain
| | - Mara Dierssen
- Systems Biology Program, Cellular and Systems Neurobiology, Centre for Genomic Regulation, The Barcelona Institute of Science and Technology Barcelona, Spain ; Centre for Genomic Regulation, Universitat Pompeu Fabra Barcelona, Spain ; Centro de Investigación Biomédica en Red de Enfermedades Raras Barcelona, Spain
| |
Collapse
|
28
|
Begenisic T, Sansevero G, Baroncelli L, Cioni G, Sale A. Early environmental therapy rescues brain development in a mouse model of Down syndrome. Neurobiol Dis 2015; 82:409-419. [PMID: 26244989 DOI: 10.1016/j.nbd.2015.07.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 06/26/2015] [Accepted: 07/31/2015] [Indexed: 01/15/2023] Open
Abstract
Down syndrome (DS), the most common genetic disorder associated with intellectual disabilities, is an untreatable condition characterized by a number of developmental defects and permanent deficits in the adulthood. Ts65Dn mice, the major animal model for DS, display severe cognitive and synaptic plasticity defects closely resembling the human phenotype. Here, we employed a multidisciplinary approach to investigate, for the first time in developing Ts65Dn mice, the effects elicited by early environmental enrichment (EE) on brain maturation and function. We report that exposure to EE resulted in a robust increase in maternal care levels displayed by Ts65Dn mothers and led to a normalization of declarative memory abilities and hippocampal plasticity in trisomic offspring. The positive effects of EE on Ts65Dn phenotype were not limited to the cognitive domain, but also included a rescue of visual system maturation. The beneficial EE effects were accompanied by increased BDNF and correction of over-expression of the GABA vesicular transporter vGAT. These findings highlight the beneficial impact of early environmental stimuli and their potential for application in the treatment of major functional deficits in children with DS.
Collapse
Affiliation(s)
| | | | | | - Giovanni Cioni
- Department of Developmental Neuroscience, IRCCS Stella Maris, University of Pisa, Calambrone, I-56100 Pisa, Italy
| | | |
Collapse
|
29
|
Godavarthi SK, Dey P, Sharma A, Jana NR. Impaired adult hippocampal neurogenesis and its partial reversal by chronic treatment of fluoxetine in a mouse model of Angelman syndrome. Biochem Biophys Res Commun 2015; 464:1196-1201. [PMID: 26231800 DOI: 10.1016/j.bbrc.2015.07.103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 07/21/2015] [Indexed: 01/15/2023]
Abstract
Angelman syndrome (AS) is a neurodevelopmental disorder characterized by severe cognitive and motor deficits, caused by the loss of function of maternally inherited Ube3a. Ube3a-maternal deficient mice (AS model mice) recapitulate many essential features of AS, but how the deficiency of Ube3a lead to such behavioural abnormalities is poorly understood. Here we have demonstrated significant impairment of adult hippocampal neurogenesis in AS mice brain. Although, the number of BrdU and Ki67-positive cell in the hippocampal DG region was nearly equal at early postnatal days among wild type and AS mice, they were significantly reduced in adult AS mice compared to wild type controls. Reduced number of doublecortin-positive immature neurons in this region of AS mice further indicated impaired neurogenesis. Unaltered BrdU and Ki67-positive cells number in the sub ventricular zone of adult AS mice brain along with the absence of imprinted expression of Ube3a in the neural progenitor cell suggesting that Ube3a may not be directly linked with altered neurogenesis. Finally, we show that the impaired hippocampal neurogenesis in these mice can be partially rescued by the chronic treatment of antidepressant fluoxetine. These results suggest that the chronic stress may lead to reduced hippocampal neurogenesis in AS mice and that impaired neurogenesis could contribute to cognitive disturbances observed in these mice.
Collapse
Affiliation(s)
- Swetha K Godavarthi
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 050, India
| | - Parthanarayan Dey
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 050, India
| | - Ankit Sharma
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 050, India
| | - Nihar Ranjan Jana
- Cellular and Molecular Neuroscience Laboratory, National Brain Research Centre, Manesar, Gurgaon, 122 050, India.
| |
Collapse
|
30
|
Pardo M, King MK, Perez-Costas E, Melendez-Ferro M, Martinez A, Beurel E, Jope RS. Impairments in cognition and neural precursor cell proliferation in mice expressing constitutively active glycogen synthase kinase-3. Front Behav Neurosci 2015; 9:55. [PMID: 25788881 PMCID: PMC4349180 DOI: 10.3389/fnbeh.2015.00055] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 02/13/2015] [Indexed: 01/09/2023] Open
Abstract
Brain glycogen synthase kinase-3 (GSK3) is hyperactive in several neurological conditions that involve impairments in both cognition and neurogenesis. This raises the hypotheses that hyperactive GSK3 may directly contribute to impaired cognition, and that this may be related to deficiencies in neural precursor cells (NPC). To study the effects of hyperactive GSK3 in the absence of disease influences, we compared adult hippocampal NPC proliferation and performance in three cognitive tasks in male and female wild-type (WT) mice and GSK3 knockin mice, which express constitutively active GSK3. NPC proliferation was ~40% deficient in both male and female GSK3 knockin mice compared with WT mice. Environmental enrichment (EE) increased NPC proliferation in male, but not female, GSK3 knockin mice and WT mice. Male and female GSK3 knockin mice exhibited impairments in novel object recognition, temporal order memory, and coordinate spatial processing compared with gender-matched WT mice. EE restored impaired novel object recognition and temporal ordering in both sexes of GSK3 knockin mice, indicating that this repair was not dependent on NPC proliferation, which was not increased by EE in female GSK3 knockin mice. Acute 1 h pretreatment with the GSK3 inhibitor TDZD-8 also improved novel object recognition and temporal ordering in male and female GSK3 knockin mice. These findings demonstrate that hyperactive GSK3 is sufficient to impair adult hippocampal NPC proliferation and to impair performance in three cognitive tasks in both male and female mice, but these changes in NPC proliferation do not directly regulate novel object recognition and temporal ordering tasks.
Collapse
Affiliation(s)
- Marta Pardo
- Departments of Psychiatry and Behavioral Sciences and Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami Miami, FL, USA
| | - Margaret K King
- Departments of Psychiatry and Behavioral Sciences and Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami Miami, FL, USA
| | - Emma Perez-Costas
- Department of Psychiatry, University of Alabama at Birmingham Birmingham, AL, USA
| | | | - Ana Martinez
- Centro de Investigaciones Biologicas-CSIC Madrid, Spain
| | - Eleonore Beurel
- Departments of Psychiatry and Behavioral Sciences and Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami Miami, FL, USA
| | - Richard S Jope
- Departments of Psychiatry and Behavioral Sciences and Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami Miami, FL, USA
| |
Collapse
|
31
|
Chronic P7C3 treatment restores hippocampal neurogenesis in the Ts65Dn mouse model of Down Syndrome [Corrected]. Neurosci Lett 2015; 591:86-92. [PMID: 25668489 DOI: 10.1016/j.neulet.2015.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/20/2015] [Accepted: 02/06/2015] [Indexed: 12/11/2022]
Abstract
Down syndrome (DS) is the most common genetic cause of intellectual disability and developmental delay. In addition to cognitive dysfunction, DS patients are marked by diminished neurogenesis, a neuropathological feature also found in the Ts65Dn mouse model of DS. Interestingly, manipulations that enhance neurogenesis - like environmental enrichment or pharmacological agents - improve cognition in Ts65Dn mice. P7C3 is a proneurogenic compound that enhances hippocampal neurogenesis, cell survival, and promotes cognition in aged animals. However, this compound has not been tested in the Ts65Dn mouse model of DS. We hypothesized that P7C3 treatment would reverse or ameliorate the neurogenic deficits in Ts65Dn mice. To test this, adult Ts65Dn and age-matched wild-type (WT) mice were administered vehicle or P7C3 twice daily for 3 months. After 3 months, brains were examined for indices of neurogenesis, including quantification of Ki67, DCX, activated caspase-3 (AC3), and surviving BrdU-immunoreactive(+) cells in the granule cell layer (GCL) of the hippocampal dentate gyrus. P7C3 had no effect on total Ki67+, DCX+, AC3+, or surviving BrdU+ cells in WT mice relative to vehicle. GCL volume was also not changed. In keeping with our hypothesis, however, P7C3-treated Ts65Dn mice had a significant increase in total Ki67+, DCX+, and surviving BrdU+ cells relative to vehicle. P7C3 treatment also decreased AC3+ cell number but had no effect on total GCL volume in Ts65Dn mice. Our findings show 3 months of P7C3 is sufficient to restore the neurogenic deficits observed in the Ts65Dn mouse model of DS.
Collapse
|
32
|
Fernandez F, Reeves RH. Assessing cognitive improvement in people with Down syndrome: important considerations for drug-efficacy trials. Handb Exp Pharmacol 2015; 228:335-80. [PMID: 25977089 DOI: 10.1007/978-3-319-16522-6_12] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Experimental research over just the past decade has raised the possibility that learning deficits connected to Down syndrome (DS) might be effectively managed by medication. In the current chapter, we touch on some of the work that paved the way for these advances and discuss the challenges associated with translating them. In particular, we highlight sources of phenotypic variability in the DS population that are likely to impact performance assessments. Throughout, suggestions are made on how to detect meaningful changes in cognitive-adaptive function in people with DS during drug treatment. The importance of within-subjects evaluation is emphasized.
Collapse
Affiliation(s)
- Fabian Fernandez
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA,
| | | |
Collapse
|
33
|
|
34
|
Deidda G, Bozarth IF, Cancedda L. Modulation of GABAergic transmission in development and neurodevelopmental disorders: investigating physiology and pathology to gain therapeutic perspectives. Front Cell Neurosci 2014; 8:119. [PMID: 24904277 PMCID: PMC4033255 DOI: 10.3389/fncel.2014.00119] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 04/14/2014] [Indexed: 01/30/2023] Open
Abstract
During mammalian ontogenesis, the neurotransmitter GABA is a fundamental regulator of neuronal networks. In neuronal development, GABAergic signaling regulates neural proliferation, migration, differentiation, and neuronal-network wiring. In the adult, GABA orchestrates the activity of different neuronal cell-types largely interconnected, by powerfully modulating synaptic activity. GABA exerts these functions by binding to chloride-permeable ionotropic GABAA receptors and metabotropic GABAB receptors. According to its functional importance during development, GABA is implicated in a number of neurodevelopmental disorders such as autism, Fragile X, Rett syndrome, Down syndrome, schizophrenia, Tourette's syndrome and neurofibromatosis. The strength and polarity of GABAergic transmission is continuously modulated during physiological, but also pathological conditions. For GABAergic transmission through GABAA receptors, strength regulation is achieved by different mechanisms such as modulation of GABAA receptors themselves, variation of intracellular chloride concentration, and alteration in GABA metabolism. In the never-ending effort to find possible treatments for GABA-related neurological diseases, of great importance would be modulating GABAergic transmission in a safe and possibly physiological way, without the dangers of either silencing network activity or causing epileptic seizures. In this review, we will discuss the different ways to modulate GABAergic transmission normally at work both during physiological and pathological conditions. Our aim is to highlight new research perspectives for therapeutic treatments that reinstate natural and physiological brain functions in neuro-pathological conditions.
Collapse
Affiliation(s)
- Gabriele Deidda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Ignacio F Bozarth
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| | - Laura Cancedda
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia Genova, Italy
| |
Collapse
|
35
|
Abstract
PURPOSE OF REVIEW Down syndrome affects more than 5 million people globally. During the last 10 years, there has been a dramatic increase in the research efforts focused on therapeutic interventions to improve learning and memory in Down syndrome. RECENT FINDINGS This review summarizes the different functional abnormalities targeted by researchers in mouse models of Down syndrome. Three main strategies have been used: neural stem cell implantation; environmental enrichment and physical exercise; and pharmacotherapy. Pharmacological targets include the choline pathway, GABA and NMDA receptors, DYRK1A protein, oxidative stress and pathways involved in development and neurogenesis. Many strategies have improved learning and memory as well as electrophysiological and molecular alterations in affected animals. To date, eight molecules have been tested in human adult clinical trials. No studies have yet been performed on infants. However, compelling studies reveal that permanent brain alterations originate during fetal life in Down syndrome. Early prenatal diagnosis offers a 28 weeks window to positively impact brain development and improve postnatal cognitive outcome in affected individuals. Only a few approaches (Epigallocatechine gallate, NAP/SAL, fluoxetine, and apigenin) have been used to treat mice in utero; these showed therapeutic effects that persisted to adulthood. SUMMARY In this article, we discuss the challenges, recent progress, and lessons learned that pave the way for new therapeutic approaches in Down syndrome.
Collapse
Affiliation(s)
- Fayçal Guedj
- aMother Infant Research Institute, Tufts Medical Center and the Floating Hospital for Children, Boston, Massachusetts, USA bUniv Paris Diderot, Sorbonne Paris Cité, CNRS UMR 8251, Adaptive Functional Biology, Paris, France
| | | | | |
Collapse
|
36
|
Dang V, Medina B, Das D, Moghadam S, Martin KJ, Lin B, Naik P, Patel D, Nosheny R, Wesson Ashford J, Salehi A. Formoterol, a long-acting β2 adrenergic agonist, improves cognitive function and promotes dendritic complexity in a mouse model of Down syndrome. Biol Psychiatry 2014; 75:179-88. [PMID: 23827853 DOI: 10.1016/j.biopsych.2013.05.024] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 05/17/2013] [Accepted: 05/17/2013] [Indexed: 12/21/2022]
Abstract
BACKGROUND Down syndrome is associated with significant failure in cognitive function. Our previous investigation revealed age-dependent degeneration of locus coeruleus, a major player in contextual learning, in the Ts65Dn mouse model of Down syndrome. We studied whether drugs already available for use in humans can be used to improve cognitive function in these mice. METHODS We studied the status of β adrenergic signaling in the dentate gyrus of the Ts65Dn mouse model of Down syndrome. Furthermore, we used fear conditioning to study learning and memory in these mice. Postmortem analyses included the analysis of synaptic density, dendritic arborization, and neurogenesis. RESULTS We found significant atrophy of dentate gyrus and failure of β adrenergic signaling in the hippocampus of Ts65Dn mice. Our behavioral analyses revealed that formoterol, a long-acting β2 adrenergic receptor agonist, caused significant improvement in the cognitive function in Ts65Dn mice. Postmortem analyses revealed that the use of formoterol was associated with a significant improvement in the synaptic density and increased complexity of newly born dentate granule neurons in the hippocampus of Ts65Dn mice. CONCLUSIONS Our data suggest that targeting β2 adrenergic receptors is an effective strategy for restoring synaptic plasticity and cognitive function in these mice. Considering its widespread use in humans and positive effects on cognition in Ts65Dn mice, formoterol or similar β2 adrenergic receptor agonists with ability to cross the blood brain barrier might be attractive candidates for clinical trials to improve cognitive function in individuals with Down syndrome.
Collapse
Affiliation(s)
- Van Dang
- Department of Psychiatry and Behavioral Sciences (VD, JWA, AS); Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Brian Medina
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Devsmita Das
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Sarah Moghadam
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Kara J Martin
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Bill Lin
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Priyanka Naik
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Devan Patel
- Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Rachel Nosheny
- Department of Molecular and Cellular Physiology (RN), Stanford University School of Medicine, Stanford
| | - John Wesson Ashford
- Department of Psychiatry and Behavioral Sciences (VD, JWA, AS); Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California
| | - Ahmad Salehi
- Department of Psychiatry and Behavioral Sciences (VD, JWA, AS); Veterans Administration Palo Alto Health Care System (VD, BM, DD, SM, KJM, BL, PN, DP, JWA, AS), Palo Alto, California.
| |
Collapse
|
37
|
Sale A, Berardi N, Maffei L. Environment and Brain Plasticity: Towards an Endogenous Pharmacotherapy. Physiol Rev 2014; 94:189-234. [DOI: 10.1152/physrev.00036.2012] [Citation(s) in RCA: 265] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Brain plasticity refers to the remarkable property of cerebral neurons to change their structure and function in response to experience, a fundamental theoretical theme in the field of basic research and a major focus for neural rehabilitation following brain disease. While much of the early work on this topic was based on deprivation approaches relying on sensory experience reduction procedures, major advances have been recently obtained using the conceptually opposite paradigm of environmental enrichment, whereby an enhanced stimulation is provided at multiple cognitive, sensory, social, and motor levels. In this survey, we aim to review past and recent work concerning the influence exerted by the environment on brain plasticity processes, with special emphasis on the underlying cellular and molecular mechanisms and starting from experimental work on animal models to move to highly relevant work performed in humans. We will initiate introducing the concept of brain plasticity and describing classic paradigmatic examples to illustrate how changes at the level of neuronal properties can ultimately affect and direct key perceptual and behavioral outputs. Then, we describe the remarkable effects elicited by early stressful conditions, maternal care, and preweaning enrichment on central nervous system development, with a separate section focusing on neurodevelopmental disorders. A specific section is dedicated to the striking ability of environmental enrichment and physical exercise to empower adult brain plasticity. Finally, we analyze in the last section the ever-increasing available knowledge on the effects elicited by enriched living conditions on physiological and pathological aging brain processes.
Collapse
Affiliation(s)
- Alessandro Sale
- Institute of Neuroscience, National Research Council, Pisa, Italy; Department of Psychology, Florence University, Florence, Italy; and Scuola Normale Superiore, Pisa, Italy
| | - Nicoletta Berardi
- Institute of Neuroscience, National Research Council, Pisa, Italy; Department of Psychology, Florence University, Florence, Italy; and Scuola Normale Superiore, Pisa, Italy
| | - Lamberto Maffei
- Institute of Neuroscience, National Research Council, Pisa, Italy; Department of Psychology, Florence University, Florence, Italy; and Scuola Normale Superiore, Pisa, Italy
| |
Collapse
|
38
|
Pons-Espinal M, Martinez de Lagran M, Dierssen M. Environmental enrichment rescues DYRK1A activity and hippocampal adult neurogenesis in TgDyrk1A. Neurobiol Dis 2013; 60:18-31. [PMID: 23969234 DOI: 10.1016/j.nbd.2013.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 07/25/2013] [Accepted: 08/08/2013] [Indexed: 11/15/2022] Open
Abstract
Hippocampal adult neurogenesis disruptions have been suggested as one of the neuronal plasticity mechanisms underlying learning and memory impairment in Down syndrome (DS). However, it remains unknown whether specific candidate genes are implicated in these phenotypes in the multifactorial context of DS. Here we report that transgenic mice (TgDyrk1A) with overdosage of Dyrk1A, a DS candidate gene, show important alterations in adult neurogenesis including reduced cell proliferation rate, altered cell cycle progression and reduced cell cycle exit leading to premature migration, differentiation and reduced survival of newly born cells. In addition, less proportion of newborn hippocampal TgDyrk1A neurons are activated upon learning, suggesting reduced integration in learning circuits. Some of these alterations were DYRK1A kinase-dependent since we could rescue those using a DYRK1A inhibitor, epigallocatechin-3-gallate. Environmental enrichment also normalized DYRK1A kinase overdosage in the hippocampus, and rescued adult neurogenesis alterations in TgDyrk1A mice. We conclude that Dyrk1A is a good candidate to explain neuronal plasticity deficits in DS and that normalizing the excess of DYRK1A kinase activity either pharmacologically or using environmental stimulation can correct adult neurogenesis defects in DS.
Collapse
Affiliation(s)
- Meritxell Pons-Espinal
- Systems Biology Program, Centre for Genomic Regulation (CRG), Dr. Aiguader 88, E-08003 Barcelona, Spain; Universitat Pompeu Fabra (UPF), Dr. Aiguader 88, E-08003 Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Dr. Aiguader 88, E-08003 Barcelona, Spain
| | | | | |
Collapse
|
39
|
Velazquez R, Ash JA, Powers BE, Kelley CM, Strawderman M, Luscher ZI, Ginsberg SD, Mufson EJ, Strupp BJ. Maternal choline supplementation improves spatial learning and adult hippocampal neurogenesis in the Ts65Dn mouse model of Down syndrome. Neurobiol Dis 2013; 58:92-101. [PMID: 23643842 PMCID: PMC4029409 DOI: 10.1016/j.nbd.2013.04.016] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 04/12/2013] [Accepted: 04/23/2013] [Indexed: 11/25/2022] Open
Abstract
In addition to intellectual disability, individuals with Down syndrome (DS) exhibit dementia by the third or fourth decade of life, due to the early onset of neuropathological changes typical of Alzheimer's disease (AD). Deficient ontogenetic neurogenesis contributes to the brain hypoplasia and hypocellularity evident in fetuses and children with DS. A murine model of DS and AD (the Ts65Dn mouse) exhibits key features of these disorders, notably deficient ontogenetic neurogenesis, degeneration of basal forebrain cholinergic neurons (BFCNs), and cognitive deficits. Adult hippocampal (HP) neurogenesis is also deficient in Ts65Dn mice and may contribute to the observed cognitive dysfunction. Herein, we demonstrate that supplementing the maternal diet with additional choline (approximately 4.5 times the amount in normal rodent chow) dramatically improved the performance of the adult trisomic offspring in a radial arm water maze task. Ts65Dn offspring of choline-supplemented dams performed significantly better than unsupplemented Ts65Dn mice. Furthermore, adult hippocampal neurogenesis was partially normalized in the maternal choline supplemented (MCS) trisomic offspring relative to their unsupplemented counterparts. A significant correlation was observed between adult hippocampal neurogenesis and performance in the water maze, suggesting that the increased neurogenesis seen in the supplemented trisomic mice contributed functionally to their improved spatial cognition. These findings suggest that supplementing the maternal diet with additional choline has significant translational potential for DS.
Collapse
Affiliation(s)
- Ramon Velazquez
- Div. Nutritional Sciences and Dept of Psychology, Cornell University, Ithaca, NY 14853
| | - Jessica A. Ash
- Div. Nutritional Sciences and Dept of Psychology, Cornell University, Ithaca, NY 14853
| | - Brian E. Powers
- Div. Nutritional Sciences and Dept of Psychology, Cornell University, Ithaca, NY 14853
| | - Christy M. Kelley
- Dept. Neurological Science and Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL 60612
| | - Myla Strawderman
- Div. Nutritional Sciences and Dept of Psychology, Cornell University, Ithaca, NY 14853
| | - Zoe I. Luscher
- Div. Nutritional Sciences and Dept of Psychology, Cornell University, Ithaca, NY 14853
| | - Stephen D. Ginsberg
- Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, and Departments of Psychiatry, and Physiology & Neuroscience, New York University Langone Medical Center, New York, NY 10962
| | - Elliott J. Mufson
- Dept. Neurological Science and Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL 60612
| | - Barbara J. Strupp
- Div. Nutritional Sciences and Dept of Psychology, Cornell University, Ithaca, NY 14853
| |
Collapse
|
40
|
Functional implications of hippocampal adult neurogenesis in intellectual disabilities. Amino Acids 2013; 45:113-31. [DOI: 10.1007/s00726-013-1489-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 03/15/2013] [Indexed: 12/19/2022]
|
41
|
Human and mouse model cognitive phenotypes in Down syndrome: implications for assessment. PROGRESS IN BRAIN RESEARCH 2012; 197:123-51. [PMID: 22541291 DOI: 10.1016/b978-0-444-54299-1.00007-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The study of cognitive function in Down syndrome (DS) has advanced rapidly in the past decade. Mouse models have generated data regarding the neurological basis for the specific cognitive profile of DS (i.e., deficits in aspects of hippocampal, prefrontal, and cerebellar function) and have uncovered pharmacological treatments with the potential to affect this phenotype. Given this progress, the field is at a juncture in which we require assessments that may effectively translate the findings acquired in mouse models to humans with DS. In this chapter, we describe the cognitive profile of humans with DS and associated mouse models, discussing the ways in which we may merge these findings so as to more fully understand cognitive strengths and weaknesses in this population. New directions for approaches to cognitive assessment in mice and humans are discussed.
Collapse
|
42
|
Modulating cognitive deficits and tau accumulation in a mouse model of aging Down syndrome through neonatal implantation of neural progenitor cells. Exp Gerontol 2012; 47:723-33. [DOI: 10.1016/j.exger.2012.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/27/2012] [Accepted: 06/28/2012] [Indexed: 01/04/2023]
|
43
|
From abnormal hippocampal synaptic plasticity in down syndrome mouse models to cognitive disability in down syndrome. Neural Plast 2012; 2012:101542. [PMID: 22848844 PMCID: PMC3403629 DOI: 10.1155/2012/101542] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/02/2012] [Accepted: 05/07/2012] [Indexed: 12/17/2022] Open
Abstract
Down syndrome (DS) is caused by the overexpression of genes on triplicated regions of human chromosome 21 (Hsa21). While the resulting physiological and behavioral phenotypes vary in their penetrance and severity, all individuals with DS have variable but significant levels of cognitive disability. At the core of cognitive processes is the phenomenon of synaptic plasticity, a functional change in the strength at points of communication between neurons. A wide variety of evidence from studies on DS individuals and mouse models of DS indicates that synaptic plasticity is adversely affected in human trisomy 21 and mouse segmental trisomy 16, respectively, an outcome that almost certainly extensively contributes to the cognitive impairments associated with DS. In this review, we will highlight some of the neurophysiological changes that we believe reduce the ability of trisomic neurons to undergo neuroplasticity-related adaptations. We will focus primarily on hippocampal networks which appear to be particularly impacted in DS and where consequently the majority of cellular and neuronal network research has been performed using DS animal models, in particular the Ts65Dn mouse. Finally, we will postulate on how altered plasticity may contribute to the DS cognitive disability.
Collapse
|
44
|
Pang TYC, Hannan AJ. Enhancement of cognitive function in models of brain disease through environmental enrichment and physical activity. Neuropharmacology 2012; 64:515-28. [PMID: 22766390 DOI: 10.1016/j.neuropharm.2012.06.029] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Revised: 06/06/2012] [Accepted: 06/15/2012] [Indexed: 12/21/2022]
Abstract
This review will provide an overview of the non-drug based approaches that have been demonstrated to enhance cognitive function of the compromised brain, primarily focussed on the two most widely adopted paradigms of environmental enrichment and enhanced physical exercise. Environmental enrichment involves the generation of novelty and complexity in animal housing conditions which facilitates enhanced sensory and cognitive stimulation as well as physical activity. In a wide variety of animal models of brain disorders, environmental enrichment and exercise have been found to have beneficial effects, including cognitive enhancement, delayed disease onset, enhanced cellular plasticity and associated molecular processes. Potential cellular and molecular mechanisms will also be discussed, which have relevance for the future development of 'enviromimetics', drugs which could mimic or enhance the beneficial effects of environmental stimulation. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
Collapse
Affiliation(s)
- Terence Y C Pang
- Florey Neuroscience Institutes, Melbourne Brain Centre, University of Melbourne, Parkville, VIC 3010, Australia.
| | | |
Collapse
|
45
|
Mouse models of Down syndrome as a tool to unravel the causes of mental disabilities. Neural Plast 2012; 2012:584071. [PMID: 22685678 PMCID: PMC3364589 DOI: 10.1155/2012/584071] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 03/23/2012] [Accepted: 03/24/2012] [Indexed: 12/16/2022] Open
Abstract
Down syndrome (DS) is the most common genetic cause of mental disability. Based on the homology of Hsa21 and the murine chromosomes Mmu16, Mmu17 and Mmu10, several mouse models of DS have been developed. The most commonly used model, the Ts65Dn mouse, has been widely used to investigate the neural mechanisms underlying the mental disabilities seen in DS individuals. A wide array of neuromorphological alterations appears to compromise cognitive performance in trisomic mice. Enhanced inhibition due to alterations in GABA(A)-mediated transmission and disturbances in the glutamatergic, noradrenergic and cholinergic systems, among others, has also been demonstrated. DS cognitive dysfunction caused by neurodevelopmental alterations is worsened in later life stages by neurodegenerative processes. A number of pharmacological therapies have been shown to partially restore morphological anomalies concomitantly with cognition in these mice. In conclusion, the use of mouse models is enormously effective in the study of the neurobiological substrates of mental disabilities in DS and in the testing of therapies that rescue these alterations. These studies provide the basis for developing clinical trials in DS individuals and sustain the hope that some of these drugs will be useful in rescuing mental disabilities in DS individuals.
Collapse
|
46
|
Begenisic T, Spolidoro M, Braschi C, Baroncelli L, Milanese M, Pietra G, Fabbri ME, Bonanno G, Cioni G, Maffei L, Sale A. Environmental enrichment decreases GABAergic inhibition and improves cognitive abilities, synaptic plasticity, and visual functions in a mouse model of Down syndrome. Front Cell Neurosci 2011; 5:29. [PMID: 22207837 PMCID: PMC3245647 DOI: 10.3389/fncel.2011.00029] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 12/12/2011] [Indexed: 01/20/2023] Open
Abstract
Down syndrome (DS) is the most common genetic disorder associated with mental retardation. It has been repeatedly shown that Ts65Dn mice, the prime animal model for DS, have severe cognitive and neural plasticity defects due to excessive inhibition. We report that increasing sensory-motor stimulation in adulthood through environmental enrichment (EE) reduces brain inhibition levels and promotes recovery of spatial memory abilities, hippocampal synaptic plasticity, and visual functions in adult Ts65Dn mice.
Collapse
|