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Irastorza-Valera L, Benítez JM, Montáns FJ, Saucedo-Mora L. An Agent-Based Model to Reproduce the Boolean Logic Behaviour of Neuronal Self-Organised Communities through Pulse Delay Modulation and Generation of Logic Gates. Biomimetics (Basel) 2024; 9:101. [PMID: 38392147 PMCID: PMC10886514 DOI: 10.3390/biomimetics9020101] [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: 11/10/2023] [Revised: 01/16/2024] [Accepted: 02/04/2024] [Indexed: 02/24/2024] Open
Abstract
The human brain is arguably the most complex "machine" to ever exist. Its detailed functioning is yet to be fully understood, let alone modelled. Neurological processes have logical signal-processing and biophysical aspects, and both affect the brain's structure, functioning and adaptation. Mathematical approaches based on both information and graph theory have been extensively used in an attempt to approximate its biological functioning, along with Artificial Intelligence frameworks inspired by its logical functioning. In this article, an approach to model some aspects of the brain learning and signal processing is presented, mimicking the metastability and backpropagation found in the real brain while also accounting for neuroplasticity. Several simulations are carried out with this model to demonstrate how dynamic neuroplasticity, neural inhibition and neuron migration can reshape the brain's logical connectivity to synchronise signal processing and obtain certain target latencies. This work showcases the importance of dynamic logical and biophysical remodelling in brain plasticity. Combining mathematical (agents, graph theory, topology and backpropagation) and biomedical ingredients (metastability, neuroplasticity and migration), these preliminary results prove complex brain phenomena can be reproduced-under pertinent simplifications-via affordable computations, which can be construed as a starting point for more ambitiously accurate simulations.
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Affiliation(s)
- Luis Irastorza-Valera
- E.T.S. de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Pza. Cardenal Cisneros 3, 28040 Madrid, Spain
- PIMM Laboratory, Arts et Métiers Institute of Technology, 151 Bd de l'Hôpital, 75013 Paris, France
| | - José María Benítez
- E.T.S. de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Pza. Cardenal Cisneros 3, 28040 Madrid, Spain
| | - Francisco J Montáns
- E.T.S. de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Pza. Cardenal Cisneros 3, 28040 Madrid, Spain
- Department of Mechanical and Aerospace Engineering, Herbert Wertheim College of Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Luis Saucedo-Mora
- E.T.S. de Ingeniería Aeronáutica y del Espacio, Universidad Politécnica de Madrid, Pza. Cardenal Cisneros 3, 28040 Madrid, Spain
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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2
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Fuchigami T, Itokazu Y, Yu RK. Ganglioside GD3 regulates neural stem cell quiescence and controls postnatal neurogenesis. Glia 2024; 72:167-183. [PMID: 37667994 PMCID: PMC10840680 DOI: 10.1002/glia.24468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/14/2023] [Accepted: 08/26/2023] [Indexed: 09/06/2023]
Abstract
The postnatal neural stem cell (NSC) pool hosts quiescent and activated radial glia-like NSCs contributing to neurogenesis throughout adulthood. However, the underlying regulatory mechanism during the transition from quiescent NSCs to activated NSCs in the postnatal NSC niche is not fully understood. Lipid metabolism and lipid composition play important roles in regulating NSC fate determination. Biological lipid membranes define the individual cellular shape and help maintain cellular organization and are highly heterogeneous in structure and there exist diverse microdomains (also known as lipid rafts), which are enriched with sugar molecules, such as glycosphingolipids. An often overlooked but key aspect is that the functional activities of proteins and genes are highly dependent on their molecular environments. We previously reported that ganglioside GD3 is the predominant species in NSCs and that the reduced postnatal NSC pools are observed in global GD3-synthase knockout (GD3S-KO) mouse brains. The specific roles of GD3 in determining the stage and cell-lineage determination of NSCs remain unclear, since global GD3S-KO mice cannot distinguish if GD3 regulates postnatal neurogenesis or developmental impacts. Here, we show that inducible GD3 deletion in postnatal radial glia-like NSCs promotes NSC activation, resulting in the loss of the long-term maintenance of the adult NSC pools. The reduced neurogenesis in the subventricular zone (SVZ) and the dentate gyrus (DG) of GD3S-conditional-knockout mice led to the impaired olfactory and memory functions. Thus, our results provide convincing evidence that postnatal GD3 maintains the quiescent state of radial glia-like NSCs in the adult NSC niche.
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Affiliation(s)
- Takahiro Fuchigami
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Yutaka Itokazu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Robert K. Yu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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3
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Marzola P, Melzer T, Pavesi E, Gil-Mohapel J, Brocardo PS. Exploring the Role of Neuroplasticity in Development, Aging, and Neurodegeneration. Brain Sci 2023; 13:1610. [PMID: 38137058 PMCID: PMC10741468 DOI: 10.3390/brainsci13121610] [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: 10/23/2023] [Revised: 11/16/2023] [Accepted: 11/18/2023] [Indexed: 12/24/2023] Open
Abstract
Neuroplasticity refers to the ability of the brain to reorganize and modify its neural connections in response to environmental stimuli, experience, learning, injury, and disease processes. It encompasses a range of mechanisms, including changes in synaptic strength and connectivity, the formation of new synapses, alterations in the structure and function of neurons, and the generation of new neurons. Neuroplasticity plays a crucial role in developing and maintaining brain function, including learning and memory, as well as in recovery from brain injury and adaptation to environmental changes. In this review, we explore the vast potential of neuroplasticity in various aspects of brain function across the lifespan and in the context of disease. Changes in the aging brain and the significance of neuroplasticity in maintaining cognitive function later in life will also be reviewed. Finally, we will discuss common mechanisms associated with age-related neurodegenerative processes (including protein aggregation and accumulation, mitochondrial dysfunction, oxidative stress, and neuroinflammation) and how these processes can be mitigated, at least partially, by non-invasive and non-pharmacologic lifestyle interventions aimed at promoting and harnessing neuroplasticity.
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Affiliation(s)
- Patrícia Marzola
- Department of Morphological Sciences and Graduate Neuroscience Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (P.M.); (T.M.); (E.P.)
| | - Thayza Melzer
- Department of Morphological Sciences and Graduate Neuroscience Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (P.M.); (T.M.); (E.P.)
| | - Eloisa Pavesi
- Department of Morphological Sciences and Graduate Neuroscience Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (P.M.); (T.M.); (E.P.)
| | - Joana Gil-Mohapel
- Division of Medical Sciences, University of Victoria, Victoria, BC V8P 5C2, Canada
- Island Medical Program, Faculty of Medicine, University of British Columbia, Victoria, BC V8P 5C2, Canada
| | - Patricia S. Brocardo
- Department of Morphological Sciences and Graduate Neuroscience Program, Center of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, SC, Brazil; (P.M.); (T.M.); (E.P.)
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4
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Barroso J, Branco P, Pinto-Ramos J, Vigotsky AD, Reis AM, Schnitzer TJ, Galhardo V, Apkarian AV. Subcortical brain anatomy as a potential biomarker of persistent pain after total knee replacement in osteoarthritis. Pain 2023; 164:2306-2315. [PMID: 37463229 DOI: 10.1097/j.pain.0000000000002932] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 04/02/2023] [Indexed: 07/20/2023]
Abstract
ABSTRACT The neural mechanisms for the persistence of pain after a technically successful arthroplasty in osteoarthritis (OA) remain minimally studied, and direct evidence of the brain as a predisposing factor for pain chronicity in this setting has not been investigated. We undertook this study as a first effort to identify presurgical brain and clinical markers of postarthroplasty pain in knee OA. Patients with knee OA (n = 81) awaiting total arthroplasty underwent clinical and psychological assessment and brain magnetic resonance imagining. Postoperative pain scores were measured at 6 months after surgery. Brain subcortical anatomic properties (volume and shape) and clinical indices were studied as determinants of postoperative pain. We show that presurgical subcortical volumes (bilateral amygdala, thalamus, and left hippocampus), together with shape deformations of the right anterior hippocampus and right amygdala, associate with pain persistence 6 months after surgery in OA. Longer pain duration, higher levels of presurgical anxiety, and the neuropathic character of pain were also prognostic of postsurgical pain outcome. Brain and clinical indices accounted for unique influences on postoperative pain. Our study demonstrates the presence of presurgical subcortical brain factors that relate to postsurgical persistence of OA pain. These preliminary results challenge the current dominant view that mechanisms of OA pain predominantly underlie local joint mechanisms, implying novel clinical management and treatment strategies.
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Affiliation(s)
- Joana Barroso
- Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, Porto, Portugal
- Departments of Physical Medicine and Rehabilitation and
- Neuroscience, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Center for Translational Pain Research, Center of Excellence for Chronic Pain and Drug Abuse Research, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
| | - Paulo Branco
- Neuroscience, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Center for Translational Pain Research, Center of Excellence for Chronic Pain and Drug Abuse Research, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
| | | | - Andrew D Vigotsky
- Neuroscience, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Center for Translational Pain Research, Center of Excellence for Chronic Pain and Drug Abuse Research, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Departments of Biomedical Engineering and Statistics, Northwestern University, Evanston, IL, United States
| | | | - Thomas J Schnitzer
- Departments of Physical Medicine and Rehabilitation and
- Center for Translational Pain Research, Center of Excellence for Chronic Pain and Drug Abuse Research, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Departments of Rheumatology and
- Anesthesiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
| | - Vasco Galhardo
- Departamento de Biomedicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde-i3S, Universidade do Porto, Porto, Portugal
| | - A Vania Apkarian
- Departments of Physical Medicine and Rehabilitation and
- Neuroscience, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Center for Translational Pain Research, Center of Excellence for Chronic Pain and Drug Abuse Research, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
- Anesthesiology, Northwestern University, Feinberg School of Medicine, Chicago, IL, United States
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5
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Colavitta MF, Barrantes FJ. Therapeutic Strategies Aimed at Improving Neuroplasticity in Alzheimer Disease. Pharmaceutics 2023; 15:2052. [PMID: 37631266 PMCID: PMC10459958 DOI: 10.3390/pharmaceutics15082052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 07/23/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Alzheimer disease (AD) is the most prevalent form of dementia among elderly people. Owing to its varied and multicausal etiopathology, intervention strategies have been highly diverse. Despite ongoing advances in the field, efficient therapies to mitigate AD symptoms or delay their progression are still of limited scope. Neuroplasticity, in broad terms the ability of the brain to modify its structure in response to external stimulation or damage, has received growing attention as a possible therapeutic target, since the disruption of plastic mechanisms in the brain appear to correlate with various forms of cognitive impairment present in AD patients. Several pre-clinical and clinical studies have attempted to enhance neuroplasticity via different mechanisms, for example, regulating glucose or lipid metabolism, targeting the activity of neurotransmitter systems, or addressing neuroinflammation. In this review, we first describe several structural and functional aspects of neuroplasticity. We then focus on the current status of pharmacological approaches to AD stemming from clinical trials targeting neuroplastic mechanisms in AD patients. This is followed by an analysis of analogous pharmacological interventions in animal models, according to their mechanisms of action.
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Affiliation(s)
- María F. Colavitta
- Laboratory of Molecular Neurobiology, Biomedical Research Institute (BIOMED), Universidad Católica Argentina (UCA)—National Scientific and Technical Research Council (CONICET), Buenos Aires C1107AAZ, Argentina
- Centro de Investigaciones en Psicología y Psicopedagogía (CIPP-UCA), Facultad de Psicología, Av. Alicia Moreau de Justo, Buenos Aires C1107AAZ, Argentina;
| | - Francisco J. Barrantes
- Laboratory of Molecular Neurobiology, Biomedical Research Institute (BIOMED), Universidad Católica Argentina (UCA)—National Scientific and Technical Research Council (CONICET), Buenos Aires C1107AAZ, Argentina
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6
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Fuchigami T, Itokazu Y, Yu RK. Ganglioside GD3 regulates neural stem cell quiescence and controls postnatal neurogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.14.532547. [PMID: 36993675 PMCID: PMC10055067 DOI: 10.1101/2023.03.14.532547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
The postnatal neural stem cell (NSC) pool hosts quiescent and activated radial glia-like NSCs contributing to neurogenesis throughout adulthood. However, the underlying regulatory mechanism during the transition from quiescent NSCs to activated NSCs in the postnatal NSC niche is not fully understood. Lipid metabolism and lipid composition play important roles in regulating NSC fate determination. Biological lipid membranes define the individual cellular shape and help maintain cellular organization and are highly heterogenous in structure and there exist diverse microdomains (also known as lipid rafts), which are enriched with sugar molecules, such as glycosphingolipids. An often overlooked but key aspect is that the functional activities of proteins and genes are highly dependent upon their molecular environments. We previously reported that ganglioside GD3 is the predominant species in NSCs and that the reduced postnatal NSC pools are observed in global GD3-synthase knockout (GD3S-KO) mouse brains. The specific roles of GD3 in determining the stage and cell-lineage determination of NSCs remain unclear, since global GD3S-KO mice cannot distinguish if GD3 regulates postnatal neurogenesis or developmental impacts. Here we show that inducible GD3 deletion in postnatal radial glia-like NSCs promotes the NSC activation, resulting in the loss of the long-term maintenance of the adult NSC pools. The reduced neurogenesis in the subventricular zone (SVZ) and the dentate gyrus (DG) of GD3S-conditional-knockout mice led to impaired olfactory and memory functions. Thus, our results provide convincing evidence that postnatal GD3 maintains the quiescent state of radial glia-like NSCs in the adult NSC niche.
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Affiliation(s)
- Takahiro Fuchigami
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Yutaka Itokazu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Robert K. Yu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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7
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Fuchigami T, Itokazu Y, Morgan JC, Yu RK. Restoration of Adult Neurogenesis by Intranasal Administration of Gangliosides GD3 and GM1 in The Olfactory Bulb of A53T Alpha-Synuclein-Expressing Parkinson's-Disease Model Mice. Mol Neurobiol 2023; 60:3329-3344. [PMID: 36849668 PMCID: PMC10140382 DOI: 10.1007/s12035-023-03282-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/16/2023] [Indexed: 03/01/2023]
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting the body and mind of millions of people in the world. As PD progresses, bradykinesia, rigidity, and tremor worsen. These motor symptoms are associated with the neurodegeneration of dopaminergic neurons in the substantia nigra. PD is also associated with non-motor symptoms, including loss of smell (hyposmia), sleep disturbances, depression, anxiety, and cognitive impairment. This broad spectrum of non-motor symptoms is in part due to olfactory and hippocampal dysfunctions. These non-motor functions are suggested to be linked with adult neurogenesis. We have reported that ganglioside GD3 is required to maintain the neural stem cell (NSC) pool in the subventricular zone (SVZ) of the lateral ventricles and the subgranular layer of the dentate gyrus (DG) in the hippocampus. In this study, we used nasal infusion of GD3 to restore impaired neurogenesis in A53T alpha-synuclein-expressing mice (A53T mice). Intriguingly, intranasal GD3 administration rescued the number of bromodeoxyuridine + (BrdU +)/Sox2 + NSCs in the SVZ. Furthermore, the administration of gangliosides GD3 and GM1 increases doublecortin (DCX)-expressing immature neurons in the olfactory bulb, and nasal ganglioside administration recovered the neuronal populations in the periglomerular layer of A53T mice. Given the relevance of decreased ganglioside on olfactory impairment, we discovered that GD3 has an essential role in olfactory functions. Our results demonstrated that intranasal GD3 infusion restored the self-renewal ability of the NSCs, and intranasal GM1 infusion promoted neurogenesis in the adult brain. Using a combination of GD3 and GM1 has the potential to slow down disease progression and rescue dysfunctional neurons in neurodegenerative brains.
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Affiliation(s)
- Takahiro Fuchigami
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Yutaka Itokazu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA.
| | - John C Morgan
- Movement Disorders Program, Parkinson's Foundation Center of Excellence, Department of Neurology, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Robert K Yu
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
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Culig L, Chu X, Bohr VA. Neurogenesis in aging and age-related neurodegenerative diseases. Ageing Res Rev 2022; 78:101636. [PMID: 35490966 PMCID: PMC9168971 DOI: 10.1016/j.arr.2022.101636] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 04/14/2022] [Accepted: 04/25/2022] [Indexed: 12/11/2022]
Abstract
Adult neurogenesis, the process by which neurons are generated in certain areas of the adult brain, declines in an age-dependent manner and is one potential target for extending cognitive healthspan. Aging is a major risk factor for neurodegenerative diseases and, as lifespans are increasing, these health challenges are becoming more prevalent. An age-associated loss in neural stem cell number and/or activity could cause this decline in brain function, so interventions that reverse aging in stem cells might increase the human cognitive healthspan. In this review, we describe the involvement of adult neurogenesis in neurodegenerative diseases and address the molecular mechanistic aspects of neurogenesis that involve some of the key aggregation-prone proteins in the brain (i.e., tau, Aβ, α-synuclein, …). We summarize the research pertaining to interventions that increase neurogenesis and regulate known targets in aging research, such as mTOR and sirtuins. Lastly, we share our outlook on restoring the levels of neurogenesis to physiological levels in elderly individuals and those with neurodegeneration. We suggest that modulating neurogenesis represents a potential target for interventions that could help in the fight against neurodegeneration and cognitive decline.
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Affiliation(s)
- Luka Culig
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Xixia Chu
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - Vilhelm A Bohr
- Section on DNA Repair, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA.
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9
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Li G, Hidalgo A. The Toll Route to Structural Brain Plasticity. Front Physiol 2021; 12:679766. [PMID: 34290618 PMCID: PMC8287419 DOI: 10.3389/fphys.2021.679766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 06/02/2021] [Indexed: 11/13/2022] Open
Abstract
The human brain can change throughout life as we learn, adapt and age. A balance between structural brain plasticity and homeostasis characterizes the healthy brain, and the breakdown of this balance accompanies brain tumors, psychiatric disorders, and neurodegenerative diseases. However, the link between circuit modifications, brain function, and behavior remains unclear. Importantly, the underlying molecular mechanisms are starting to be uncovered. The fruit-fly Drosophila is a very powerful model organism to discover molecular mechanisms and test them in vivo. There is abundant evidence that the Drosophila brain is plastic, and here we travel from the pioneering discoveries to recent findings and progress on molecular mechanisms. We pause on the recent discovery that, in the Drosophila central nervous system, Toll receptors—which bind neurotrophin ligands—regulate structural plasticity during development and in the adult brain. Through their topographic distribution across distinct brain modules and their ability to switch between alternative signaling outcomes, Tolls can enable the brain to translate experience into structural change. Intriguing similarities between Toll and mammalian Toll-like receptor function could reveal a further involvement in structural plasticity, degeneration, and disease in the human brain.
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Affiliation(s)
- Guiyi Li
- Plasticity and Regeneration Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Alicia Hidalgo
- Plasticity and Regeneration Lab, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
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10
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Tracking white-matter brain modifications in chronic non-bothersome acoustic trauma tinnitus. NEUROIMAGE-CLINICAL 2021; 31:102696. [PMID: 34029920 PMCID: PMC8163994 DOI: 10.1016/j.nicl.2021.102696] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 11/30/2022]
Abstract
Tractography was compared between two groups of tinnitus and control participants. Diffusion was modeled with ss3t-CSD allowing apparent fiber density (AFD) calculation. 27 bundles of interest were chosen for their link to the auditory and limbic systems. AFD was significantly increased in the tinnitus group in the right frontal isthmus. AFD in the acoustic radiations was not significantly different between the groups.
Subjective tinnitus is a symptom characterized by the perception of sound with no external acoustic source, most often accompanied by co-morbidities. To date, the specific role of white matter abnormalities related to tinnitus reaches no consensus in the literature. The goal of this study was to explore the structural connectivity related to tinnitus percept per se, thus focusing on a specific population presenting chronic non-bothersome tinnitus of similar etiology (noise induced) without co-morbidities. We acquired diffusion-weighted images with high angular resolution in a homogeneous group of mildly impacted tinnitus participants (n = 19) and their matched controls (n = 19). We focused the study on two subsets of fiber bundles of interest: on one hand, we extracted the acoustic radiation and further included any intersecting fiber bundles; on the other hand, we explored the tracts related to the limbic system. We modeled the diffusion signal using constrained spherical deconvolution. We conducted a deep-learning based tractography segmentation and mapped Apparent Fiber Density (AFD) on the bundles of interest. C, as well as Fractional Anisotropy (FA) and FOD peak amplitude for comparison. Between group statistical comparison was performed along the 27 tracts of interest controlling for confounding hearing loss, tinnitus severity, and duration since onset. We tested a potential correlation with hearing loss, tinnitus duration and tinnitus handicap score along these tracts. In the tinnitus group, we observed increased AFD related to chronic tinnitus percept after acoustic trauma in two main white matter regions. First, in the right hemisphere, in the isthmus between inferior temporal and inferior frontal cortices, in the uncinate fasciculus (UF), and in the inferior fronto-occipital bundle (IFO). Second, in the left hemisphere, underneath the superior parietal region in the thalamo parietal tract and parieto-occipital pontine tract. Between-group differences in the acoustic radiations were not significant with AFD but were with FA. Furthermore, significant correlations with hearing loss were found in the left hemisphere in the inferior longitudinal fasciculus and in the fronto-pontine tract. No additional correlation was found with tinnitus duration nor with tinnitus handicap, as reflected by THI scores. The regions that displayed tinnitus related increased AFD also displayed increased FA. The isthmus of the UF and IFO in the right hemisphere appear to be involved with a number of neuropsychiatric and traumatic disorders confirming the involvement of the limbic system even in chronic non-bothersome tinnitus subjects, potentially suggesting a common pathway between these pathologies. White matter changes underneath the superior parietal cortex found here in tinnitus participants supports the implication of an auditory-somatosensory pathway in tinnitus perception.
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11
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Bettio LEB, Thacker JS, Rodgers SP, Brocardo PS, Christie BR, Gil-Mohapel J. Interplay between hormones and exercise on hippocampal plasticity across the lifespan. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165821. [PMID: 32376385 DOI: 10.1016/j.bbadis.2020.165821] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 04/19/2020] [Accepted: 04/25/2020] [Indexed: 12/15/2022]
Abstract
The hippocampus is a brain structure known to play a central role in cognitive function (namely learning and memory) as well as mood regulation and affective behaviors due in part to its ability to undergo structural and functional changes in response to intrinsic and extrinsic stimuli. While structural changes are achieved through modulation of hippocampal neurogenesis as well as alterations in dendritic morphology and spine remodeling, functional (i.e., synaptic) changes can be noted through the strengthening (i.e., long-term potentiation) or weakening (i.e., long-term depression) of the synapses. While age, hormone homeostasis, and levels of physical activity are some of the factors known to module these forms of hippocampal plasticity, the exact mechanisms through which these factors interact with each other at a given moment in time are not completely understood. It is well known that hormonal levels vary throughout the lifespan of an individual and it is also known that physical exercise can impact hormonal homeostasis. Thus, it is reasonable to speculate that hormone modulation might be one of the various mechanisms through which physical exercise differently impacts hippocampal plasticity throughout distinct periods of an individual's life. The present review summarizes the potential relationship between physical exercise and different types of hormones (namely sex, metabolic, and stress hormones) and how this relationship may mediate the effects of physical activity during three distinct life periods, adolescence, adulthood, and senescence. Overall, the vast majority of studies support a beneficial role of exercise in maintaining hippocampal hormonal levels and consequently, hippocampal plasticity, cognition, and mood regulation.
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Affiliation(s)
- Luis E B Bettio
- Division of Medical Sciences and Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - Jonathan S Thacker
- Division of Medical Sciences and Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada
| | - Shaefali P Rodgers
- Developmental, Cognitive & Behavioral Neuroscience Program, Department of Psychology, Texas Institute for Measurement, Evaluation, and Statistics, University of Houston, TX, USA
| | - Patricia S Brocardo
- Department of Morphological Sciences, Centre of Biological Sciences, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Brian R Christie
- Division of Medical Sciences and Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada; Island Medical Program, Faculty of Medicine, University of British Columbia, Victoria, BC, Canada
| | - Joana Gil-Mohapel
- Division of Medical Sciences and Neuroscience Graduate Program, University of Victoria, Victoria, BC, Canada; Island Medical Program, Faculty of Medicine, University of British Columbia, Victoria, BC, Canada.
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Stillman CM, Jakicic J, Rogers R, Alfini AJ, Smith JC, Watt J, Kang C, Erickson KI. Changes in cerebral perfusion following a 12-month exercise and diet intervention. Psychophysiology 2020; 58:e13589. [PMID: 32343445 DOI: 10.1111/psyp.13589] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/17/2019] [Accepted: 04/03/2020] [Indexed: 01/18/2023]
Abstract
Overweight and obesity may damage the cerebrovascular architecture, resulting in a significant reduction in cerebral blood flow. To date, there have been few randomized clinical trials (RCT) examining whether obesity-related reductions in cerebral blood flow could be modified by weight loss. Further, it is unknown whether the behavioral intervention strategy for weight loss (i.e., diet alone or diet combined with exercise) differentially influences cerebral blood flow in adults with overweight or obesity. The primary aim of this study was to determine whether a 12-month RCT of exercise and diet increases cerebral blood flow in 125 midlife (Mean age ± SD = 44.63 ± 8.36 years) adults with overweight and obesity. Further, we evaluated whether weight loss via diet combined with aerobic exercise has an added effect on changes in cerebral blood flow compared to weight loss via diet alone and whether there were regionally specific effects of the type of behavioral intervention on cerebral blood flow patterns. Consistent with our predictions, a 12-month diet and exercise program resulting in 10% weight loss increased cerebral blood flow. These effects were widespread and extended throughout frontal, parietal, and subcortical regions. Further, there was some regional specificity of effects for both diet-only and diet combined with exercise. Our results demonstrate that weight-related reductions in cerebral blood flow can be modified by 10% weight loss over the course of 12 months and that interventions involving exercise exposure may provide unique effects on cerebral blood flow compared to interventions involving only diet.
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Affiliation(s)
| | - John Jakicic
- Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA, USA
| | - Renee Rogers
- Department of Health and Physical Activity, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alfonso J Alfini
- Department of Mental Health, Johns Hopkins University, Baltimore, MD, USA
| | - J Carson Smith
- Department of Kinesiology, University of Maryland, College Park, MD, USA
| | - Jennifer Watt
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chaeryon Kang
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kirk I Erickson
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA
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Ramachandran VS, Rogers-Ramachandran D. Mirror feedback assisted recovery from hemiparesis following stroke. In Reply to Morkisch et al.: How to perform mirror therapy after stroke? Evidence from a meta-analysis. Restor Neurol Neurosci 2020; 37:437-443. [PMID: 31594264 DOI: 10.3233/rnn-190971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
1 out of 6 people worldwide will have suffered a stroke in their lifetime, 1/3rd of whom will die. Of the 2/3rd who survive, half will be permanently disabled (World Stroke Organization). Given these alarming statistics, it's not surprising that tremendous of amounts of time, resources and funding have been devoted towards research into stroke rehab. In view of this, simple, easy-to-implement procedures are highly sought after. One such procedure is the use of visual feedback conveyed by a mirror, which seems to reactivate some dormant pathways in patients who have suffered a recent stroke (Altschuler et al., 1999; Ramachandran & Altschuler, 2009). This procedure has been validated in several dozen clinical trials, of which a substantial number were conducted rigorously. Morkisch et al. (2019) now present a systematic review and meta-analysis of this dense literature pertaining to this topic. They conclude that "there is a high level evidence for mirror therapy's effectiveness in treating post-stroke hemiparesis". A novel conclusion that emerged from this meta-analysis was that the larger the mirror the more effective the treatment is. Additionally, if an object is manipulated by the normal hand and its reflection viewed in the mirror, the procedure is not as effective, possibly because the discrepancy of signals between the visual feedback (reflection of the object) and the lack of confirmatory somatosensory input from the affected limb leads to inhibition rather than synergy. Lastly, for reasons yet unclear, sending movement commands to the unaffected hand alone (unilateral) is more effective than sending bilateral commands, contrary to the original protocol.Taken collectively, research in this field has two implications - First, the immediate practical utility in the clinic by optimizing mirror therapy's efficacy for hemiparesis after stroke. Second, it leads to a rejection of the model of the brain as made up of isolated, autonomous modules, towards a more dynamic picture, in which the brain is composed of a fluctuating mosaic of neural activity as it adapts to changing sensory inputs. Therefore, dysfunction results not from 'punch out a module - lose a function', but by shifts in equilibria, which can be corrected, perhaps, by hitting a reset button. Even if this turns out to be true for a minority of syndromes, it will be well worth the effort.
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Llorens-Martín M. Exercising New Neurons to Vanquish Alzheimer Disease. Brain Plast 2018; 4:111-126. [PMID: 30564550 PMCID: PMC6296267 DOI: 10.3233/bpl-180065] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2018] [Indexed: 02/07/2023] Open
Abstract
Alzheimer disease (AD) is the most common type of dementia in individuals over 65 years of age. The neuropathological hallmarks of the condition are Tau neurofibrillary tangles and Amyloid-β senile plaques. Moreover, certain susceptible regions of the brain experience a generalized lack of neural plasticity and marked synaptic alterations during the progression of this as yet incurable disease. One of these regions, the hippocampus, is characterized by the continuous addition of new neurons throughout life. This phenomenon, named adult hippocampal neurogenesis (AHN), provides a potentially endless source of new synaptic elements that increase the complexity and plasticity of the hippocampal circuitry. Numerous lines of evidence show that physical activity and environmental enrichment (EE) are among the most potent positive regulators of AHN. Given that neural plasticity is markedly decreased in many neurodegenerative diseases, the therapeutic potential of making certain lifestyle changes, such as increasing physical activity, is being recognised in several non-pharmacologic strategies seeking to slow down or prevent the progression of these diseases. This review article summarizes current evidence supporting the putative therapeutic potential of EE and physical exercise to increase AHN and hippocampal plasticity both under physiological and pathological circumstances, with a special emphasis on neurodegenerative diseases and AD.
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Affiliation(s)
- María Llorens-Martín
- Department of Molecular Neuropathology, Centro de Biología Molecular “Severo Ochoa”, CBMSO, CSIC-UAM, Madrid, Spain
- Center for Networked Biomedical Research on Neurodegenerative Diseases CIBERNED, Madrid, Spain
- Department of Molecular Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain
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Longhena F, Zaltieri M, Grigoletto J, Faustini G, La Via L, Ghidoni R, Benussi L, Missale C, Spano P, Bellucci A. Depletion of Progranulin Reduces GluN2B-Containing NMDA Receptor Density, Tau Phosphorylation, and Dendritic Arborization in Mouse Primary Cortical Neurons. J Pharmacol Exp Ther 2017; 363:164-175. [DOI: 10.1124/jpet.117.242164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
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Hashemi M, Hutt A, Hight D, Sleigh J. Anesthetic action on the transmission delay between cortex and thalamus explains the beta-buzz observed under propofol anesthesia. PLoS One 2017; 12:e0179286. [PMID: 28622355 PMCID: PMC5473556 DOI: 10.1371/journal.pone.0179286] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 05/26/2017] [Indexed: 11/18/2022] Open
Abstract
In recent years, more and more surgeries under general anesthesia have been performed with the assistance of electroencephalogram (EEG) monitors. An increase in anesthetic concentration leads to characteristic changes in the power spectra of the EEG. Although tracking the anesthetic-induced changes in EEG rhythms can be employed to estimate the depth of anesthesia, their precise underlying mechanisms are still unknown. A prominent feature in the EEG of some patients is the emergence of a strong power peak in the β-frequency band, which moves to the α-frequency band while increasing the anesthetic concentration. This feature is called the beta-buzz. In the present study, we use a thalamo-cortical neural population feedback model to reproduce observed characteristic features in frontal EEG power obtained experimentally during propofol general anesthesia, such as this beta-buzz. First, we find that the spectral power peak in the α- and δ-frequency ranges depend on the decay rate constant of excitatory and inhibitory synapses, but the anesthetic action on synapses does not explain the beta-buzz. Moreover, considering the action of propofol on the transmission delay between cortex and thalamus, the model reveals that the beta-buzz may result from a prolongation of the transmission delay by increasing propofol concentration. A corresponding relationship between transmission delay and anesthetic blood concentration is derived. Finally, an analytical stability study demonstrates that increasing propofol concentration moves the systems resting state towards its stability threshold.
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Affiliation(s)
- Meysam Hashemi
- INRIA Grand Est - Nancy, Team NEUROSYS, Villers-lès-Nancy, France
- CNRS, Loria, UMR nō 7503, Vandoeuvre-lès-Nancy, France
- Université de Lorraine, Loria, UMR nō 7503, Vandoeuvre-lès-Nancy, France
- Aix Marseille Université, INSERM, INS, Institut de Neurosciences des Systèmes, Marseille, France
| | - Axel Hutt
- German Meteorology Service, Offenbach am Main, Germany
- Department of Mathematics and Statistics, University of Reading, Reading, United Kingdom
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Visuotactile interactions in the congenitally acallosal brain: Evidence for early cerebral plasticity. Neuropsychologia 2011; 49:3908-16. [DOI: 10.1016/j.neuropsychologia.2011.10.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 09/21/2011] [Accepted: 10/07/2011] [Indexed: 11/20/2022]
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