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Gomez-Cruz C, Fernandez-de la Torre M, Lachowski D, Prados-de-Haro M, Del Río Hernández AE, Perea G, Muñoz-Barrutia A, Garcia-Gonzalez D. Mechanical and Functional Responses in Astrocytes under Alternating Deformation Modes Using Magneto-Active Substrates. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2312497. [PMID: 38610101 DOI: 10.1002/adma.202312497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/21/2024] [Indexed: 04/14/2024]
Abstract
This work introduces NeoMag, a system designed to enhance cell mechanics assays in substrate deformation studies. NeoMag uses multidomain magneto-active materials to mechanically actuate the substrate, transmitting reversible mechanical cues to cells. The system boasts full flexibility in alternating loading substrate deformation modes, seamlessly adapting to both upright and inverted microscopes. The multidomain substrates facilitate mechanobiology assays on 2D and 3D cultures. The integration of the system with nanoindenters allows for precise evaluation of cellular mechanical properties under varying substrate deformation modes. The system is used to study the impact of substrate deformation on astrocytes, simulating mechanical conditions akin to traumatic brain injury and ischemic stroke. The results reveal local heterogeneous changes in astrocyte stiffness, influenced by the orientation of subcellular regions relative to substrate strain. These stiffness variations, exceeding 50% in stiffening and softening, and local deformations significantly alter calcium dynamics. Furthermore, sustained deformations induce actin network reorganization and activate Piezo1 channels, leading to an initial increase followed by a long-term inhibition of calcium events. Conversely, fast and dynamic deformations transiently activate Piezo1 channels and disrupt the actin network, causing long-term cell softening. These findings unveil mechanical and functional alterations in astrocytes during substrate deformation, illustrating the multiple opportunities this technology offers.
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Affiliation(s)
- Clara Gomez-Cruz
- Department of Continuum Mechanics and Structural Analysis, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
- Departamento de Bioingeniería, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
| | - Miguel Fernandez-de la Torre
- Department of Continuum Mechanics and Structural Analysis, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
| | - Dariusz Lachowski
- Department of Continuum Mechanics and Structural Analysis, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Martin Prados-de-Haro
- Department of Continuum Mechanics and Structural Analysis, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
| | - Armando E Del Río Hernández
- Cellular and Molecular Biomechanics Laboratory, Department of Bioengineering, Imperial College London, London, SW7 2AZ, UK
| | - Gertrudis Perea
- Department of Functional and Systems Neurobiology, Instituto Cajal, CSIC, Av. Doctor Arce, 37., 28002, Leganés, Madrid, Spain
| | - Arrate Muñoz-Barrutia
- Departamento de Bioingeniería, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
- Área de Ingeniería Biomédica, Instituto de Investigación Sanitaria Gregorio Marañón, Calle del Doctor Esquerdo 46, Leganés, Madrid, ES28007, Spain
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N Charles St, Baltimore, Maryland, 21218, USA
| | - Daniel Garcia-Gonzalez
- Department of Continuum Mechanics and Structural Analysis, Universidad Carlos III de Madrid, Avda. de la Universidad 30, 28911, Leganés, Madrid, Spain
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2
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Witkin JM, Shafique H, Cerne R, Smith JL, Marini AM, Lipsky RH, Delery E. Mechanistic and therapeutic relationships of traumatic brain injury and γ-amino-butyric acid (GABA). Pharmacol Ther 2024; 256:108609. [PMID: 38369062 DOI: 10.1016/j.pharmthera.2024.108609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 01/18/2024] [Accepted: 02/01/2024] [Indexed: 02/20/2024]
Abstract
Traumatic brain injury (TBI) is a highly prevalent medical condition for which no medications specific for the prophylaxis or treatment of the condition as a whole exist. The spectrum of symptoms includes coma, headache, seizures, cognitive impairment, depression, and anxiety. Although it has been known for years that the inhibitory neurotransmitter γ-amino-butyric acid (GABA) is involved in TBI, no novel therapeutics based upon this mechanism have been introduced into clinical practice. We review the neuroanatomical, neurophysiological, neurochemical, and neuropharmacological relationships of GABA neurotransmission to TBI with a view toward new potential GABA-based medicines. The long-standing idea that excitatory and inhibitory (GABA and others) balances are disrupted by TBI is supported by the experimental data but has failed to invent novel methods of restoring this balance. The slow progress in advancing new treatments is due to the complexity of the disorder that encompasses multiple dynamically interacting biological processes including hemodynamic and metabolic systems, neurodegeneration and neurogenesis, major disruptions in neural networks and axons, frank brain lesions, and a multitude of symptoms that have differential neuronal and neurohormonal regulatory mechanisms. Although the current and ongoing clinical studies include GABAergic drugs, no novel GABA compounds are being explored. It is suggested that filling the gap in understanding the roles played by specific GABAA receptor configurations within specific neuronal circuits could help define new therapeutic approaches. Further research into the temporal and spatial delivery of GABA modulators should also be useful. Along with GABA modulation, research into the sequencing of GABA and non-GABA treatments will be needed.
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Affiliation(s)
- Jeffrey M Witkin
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA; Departments of Neuroscience and Trauma Research, Ascension St. Vincent Hospital, Indianapolis, IN, USA; RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA.
| | | | - Rok Cerne
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA; RespireRx Pharmaceuticals Inc, Glen Rock, NJ, USA; Department of Anatomy and Cell Biology, Indiana University/Purdue University, Indianapolis, IN, USA
| | - Jodi L Smith
- Laboratory of Antiepileptic Drug Discovery, Ascension St. Vincent Hospital, Indianapolis, IN, USA
| | - Ann M Marini
- Department of Neurology, Program in Neuroscience, and Molecular and Cellular Biology Program, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Robert H Lipsky
- Department of Neurology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Elizabeth Delery
- College of Osteopathic Medicine, Marian University, Indianapolis, IN, USA.
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3
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Sullivan D, Vaglio BJ, Cararo-Lopes MM, Wong RDP, Graudejus O, Firestein BL. Stretch-Induced Injury Affects Cortical Neuronal Networks in a Time- and Severity-Dependent Manner. Ann Biomed Eng 2024; 52:1021-1038. [PMID: 38294641 DOI: 10.1007/s10439-023-03438-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024]
Abstract
Traumatic brain injury (TBI) is the leading cause of accident-related death and disability in the world and can lead to long-term neuropsychiatric symptoms, such as a decline in cognitive function and neurodegeneration. TBI includes primary and secondary injury, with head trauma and deformation of the brain caused by the physical force of the impact as primary injury, and cellular and molecular cascades that lead to cell death as secondary injury. Currently, there is no treatment for TBI-induced cell damage and neural circuit dysfunction in the brain, and thus, it is important to understand the underlying cellular mechanisms that lead to cell damage. In the current study, we use stretchable microelectrode arrays (sMEAs) to model the primary injury of TBI to study the electrophysiological effects of physically injuring cortical cells. We recorded electrophysiological activity before injury and then stretched the flexible membrane of the sMEAs to injure the cells to varying degrees. At 1, 24, and 72 h post-stretch, we recorded activity to analyze differences in spike rate, Fano factor, burstlet rate, burstlet width, synchrony of firing, local network efficiency, and Q statistic. Our results demonstrate that mechanical injury changes the firing properties of cortical neuron networks in culture in a time- and severity-dependent manner. Our results suggest that changes to electrophysiological properties after stretch are dependent on the strength of synchronization between neurons prior to injury.
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Affiliation(s)
- Dylan Sullivan
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Cell and Developmental Biology Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Brandon J Vaglio
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Biomedical Engineering Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Marina M Cararo-Lopes
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
- Cell and Developmental Biology Graduate Program, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Ruben D Ponce Wong
- BioMedical Sustainable Elastic Electronic Devices (BMSEED), Mesa, AZ, USA
| | - Oliver Graudejus
- BioMedical Sustainable Elastic Electronic Devices (BMSEED), Mesa, AZ, USA
- School of Molecular Science, Arizona State University, Tempe, AZ, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ, USA.
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, NJ, 08854-8082, USA.
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Dwyer MKR, Amelinez-Robles N, Polsfuss I, Herbert K, Kim C, Varghese N, Parry TJ, Buller B, Verdoorn TA, Billing CB, Morrison B. NTS-105 decreased cell death and preserved long-term potentiation in an in vitro model of moderate traumatic brain injury. Exp Neurol 2024; 371:114608. [PMID: 37949202 DOI: 10.1016/j.expneurol.2023.114608] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/27/2023] [Accepted: 11/05/2023] [Indexed: 11/12/2023]
Abstract
Traumatic brain injury (TBI) is a major cause of hospitalization and death. To mitigate these human costs, the search for effective drugs to treat TBI continues. In the current study, we evaluated the efficacy of the novel neurosteroid, NTS-105, to reduce post-traumatic pathobiology in an in vitro model of moderate TBI that utilizes an organotypic hippocampal slice culture. NTS-105 inhibited activation of the androgen receptor and the mineralocorticoid receptor, partially activated the progesterone B receptor and was not active at the glucocorticoid receptor. Treatment with NTS-105 starting one hour after injury decreased post-traumatic cell death in a dose-dependent manner, with 10 nM NTS-105 being most effective. Post-traumatic administration of 10 nM NTS-105 also prevented deficits in long-term potentiation (LTP) without adversely affecting neuronal activity in naïve cultures. We propose that the high potency pleiotropic action of NTS-105 beneficial effects at multiple receptors (e.g. androgen, mineralocorticoid and progesterone) provides significant mechanistic advantages over native neurosteroids such as progesterone, which lacked clinical success for the treatment of TBI. Our results suggest that this pleiotropic pharmacology may be a promising strategy for the effective treatment of TBI, and future studies should test its efficacy in pre-clinical animal models of TBI.
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Affiliation(s)
- Mary Kate R Dwyer
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
| | - Nicolas Amelinez-Robles
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
| | - Isabella Polsfuss
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
| | - Keondre Herbert
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
| | - Carolyn Kim
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
| | - Nevin Varghese
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America
| | - Tom J Parry
- NeuroTrauma Sciences, LLC, Alpharetta, GA 30009, United States of America
| | - Benjamin Buller
- NeuroTrauma Sciences, LLC, Alpharetta, GA 30009, United States of America
| | - Todd A Verdoorn
- NeuroTrauma Sciences, LLC, Alpharetta, GA 30009, United States of America
| | - Clare B Billing
- BioPharmaWorks, LLC, Groton, CT 06340, United States of America
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, United States of America.
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Pischiutta F, Cavaleiro H, Caruso E, Tribuzio F, Di Marzo N, Moro F, Kobeissy F, Wang KK, Salgado AJ, Zanier ER. A novel organotypic cortical slice culture model for traumatic brain injury: molecular changes induced by injury and mesenchymal stromal cell secretome treatment. Front Cell Neurosci 2023; 17:1217987. [PMID: 37534042 PMCID: PMC10390737 DOI: 10.3389/fncel.2023.1217987] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 06/23/2023] [Indexed: 08/04/2023] Open
Abstract
Traumatic brain injury (TBI) is a major worldwide neurological disorder with no neuroprotective treatment available. Three-dimensional (3D) in vitro models of brain contusion serving as a screening platform for drug testing are lacking. Here we developed a new in vitro model of brain contusion on organotypic cortical brain slices and tested its responsiveness to mesenchymal stromal cell (MSC) derived secretome. A focal TBI was induced on organotypic slices by an electromagnetic impactor. Compared to control condition, a temporal increase in cell death was observed after TBI by propidium iodide incorporation and lactate dehydrogenase release assays up to 48 h post-injury. TBI induced gross neuronal loss in the lesion core, with disruption of neuronal arborizations measured by microtubule-associated protein-2 (MAP-2) immunostaining and associated with MAP-2 gene down-regulation. Neuronal damage was confirmed by increased levels of neurofilament light chain (NfL), microtubule associated protein (Tau) and ubiquitin C-terminal hydrolase L1 (UCH-L1) released into the culture medium 48 h after TBI. We detected glial activation with microglia cells acquiring an amoeboid shape with less ramified morphology in the contusion core. MSC-secretome treatment, delivered 1 h post-injury, reduced cell death in the contusion core, decreased NfL release in the culture media, promoted neuronal reorganization and improved microglia survival/activation. Our 3D in vitro model of brain contusion recapitulates key features of TBI pathology. We showed protective effects of MSC-secretome, suggesting the model stands as a tractable medium/high throughput, ethically viable, and pathomimetic biological asset for testing new cell-based therapies.
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Affiliation(s)
- Francesca Pischiutta
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Helena Cavaleiro
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s–PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Enrico Caruso
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
- Neuroscience Intensive Care Unit, Department of Anesthesia and Critical Care, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Francesca Tribuzio
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Noemi Di Marzo
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
- Centro Ricerca Tettamanti, Clinica Pediatrica, Università di Milano-Bicocca, Fondazione MBBM, Monza, Italy
| | - Federico Moro
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Firas Kobeissy
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Departments of Emergency Medicine, Psychiatry, Neuroscience and Chemistry, University of Florida, Gainesville, FL, United States
- Department of Neurobiology, Center for Neurotrauma, Multiomics and Biomarkers (CNMB), Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States
| | - Kevin K. Wang
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Departments of Emergency Medicine, Psychiatry, Neuroscience and Chemistry, University of Florida, Gainesville, FL, United States
- Department of Neurobiology, Center for Neurotrauma, Multiomics and Biomarkers (CNMB), Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States
| | - António J. Salgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal
- ICVS/3B’s–PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Elisa R. Zanier
- Department of Acute Brain and Cardiovascular Injury, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
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Kumosa LS. Commonly Overlooked Factors in Biocompatibility Studies of Neural Implants. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2205095. [PMID: 36596702 PMCID: PMC9951391 DOI: 10.1002/advs.202205095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Biocompatibility of cutting-edge neural implants, surgical tools and techniques, and therapeutic technologies is a challenging concept that can be easily misjudged. For example, neural interfaces are routinely gauged on how effectively they determine active neurons near their recording sites. Tissue integration and toxicity of neural interfaces are frequently assessed histologically in animal models to determine tissue morphological and cellular changes in response to surgical implantation and chronic presence. A disconnect between histological and efficacious biocompatibility exists, however, as neuronal numbers frequently observed near electrodes do not match recorded neuronal spiking activity. The downstream effects of the myriad surgical and experimental factors involved in such studies are rarely examined when deciding whether a technology or surgical process is biocompatible. Such surgical factors as anesthesia, temperature excursions, bleed incidence, mechanical forces generated, and metabolic conditions are known to have strong systemic and thus local cellular and extracellular consequences. Many tissue markers are extremely sensitive to the physiological state of cells and tissues, thus significantly impacting histological accuracy. This review aims to shed light on commonly overlooked factors that can have a strong impact on the assessment of neural biocompatibility and to address the mismatch between results stemming from functional and histological methods.
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Affiliation(s)
- Lucas S. Kumosa
- Neuronano Research CenterDepartment of Experimental Medical ScienceMedical FacultyLund UniversityMedicon Village, Byggnad 404 A2, Scheelevägen 8Lund223 81Sweden
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Adegoke MA, Teter O, Meaney DF. Flexibility of in vitro cortical circuits influences resilience from microtrauma. Front Cell Neurosci 2022; 16:991740. [PMID: 36589287 PMCID: PMC9803265 DOI: 10.3389/fncel.2022.991740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
Background Small clusters comprising hundreds to thousands of neurons are an important level of brain architecture that correlates single neuronal properties to fulfill brain function, but the specific mechanisms through which this scaling occurs are not well understood. In this study, we developed an in vitro experimental platform of small neuronal circuits (islands) to probe the importance of structural properties for their development, physiology, and response to microtrauma. Methods Primary cortical neurons were plated on a substrate patterned to promote attachment in clusters of hundreds of cells (islands), transduced with GCaMP6f, allowed to mature until 10-13 days in vitro (DIV), and monitored with Ca2+ as a non-invasive proxy for electrical activity. We adjusted two structural factors-island size and cellular density-to evaluate their role in guiding spontaneous activity and network formation in neuronal islands. Results We found cellular density, but not island size, regulates of circuit activity and network function in this system. Low cellular density islands can achieve many states of activity, while high cellular density biases islands towards a limited regime characterized by low rates of activity and high synchronization, a property we summarized as "flexibility." The injury severity required for an island to lose activity in 50% of its population was significantly higher in low-density, high flexibility islands. Conclusion Together, these studies demonstrate flexible living cortical circuits are more resilient to microtrauma, providing the first evidence that initial circuit state may be a key factor to consider when evaluating the consequences of trauma to the cortex.
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Affiliation(s)
- Modupe A. Adegoke
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
| | - Olivia Teter
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
| | - David F. Meaney
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States,Department of Neurosurgery, Penn Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,*Correspondence: David F. Meaney,
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8
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Schumm SN, Gabrieli D, Meaney DF. Plasticity impairment alters community structure but permits successful pattern separation in a hippocampal network model. Front Cell Neurosci 2022; 16:977769. [PMID: 36505514 PMCID: PMC9729278 DOI: 10.3389/fncel.2022.977769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 10/25/2022] [Indexed: 11/25/2022] Open
Abstract
Patients who suffer from traumatic brain injury (TBI) often complain of learning and memory problems. Their symptoms are principally mediated by the hippocampus and the ability to adapt to stimulus, also known as neural plasticity. Therefore, one plausible injury mechanism is plasticity impairment, which currently lacks comprehensive investigation across TBI research. For these studies, we used a computational network model of the hippocampus that includes the dentate gyrus, CA3, and CA1 with neuron-scale resolution. We simulated mild injury through weakened spike-timing-dependent plasticity (STDP), which modulates synaptic weights according to causal spike timing. In preliminary work, we found functional deficits consisting of decreased firing rate and broadband power in areas CA3 and CA1 after STDP impairment. To address structural changes with these studies, we applied modularity analysis to evaluate how STDP impairment modifies community structure in the hippocampal network. We also studied the emergent function of network-based learning and found that impaired networks could acquire conditioned responses after training, but the magnitude of the response was significantly lower. Furthermore, we examined pattern separation, a prerequisite of learning, by entraining two overlapping patterns. Contrary to our initial hypothesis, impaired networks did not exhibit deficits in pattern separation with either population- or rate-based coding. Collectively, these results demonstrate how a mechanism of injury that operates at the synapse regulates circuit function.
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Affiliation(s)
- Samantha N. Schumm
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
| | - David Gabrieli
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
| | - David F. Meaney
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, United States
- Department of Neurosurgery, Penn Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
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Srinivasan G, Brafman DA. The Emergence of Model Systems to Investigate the Link Between Traumatic Brain Injury and Alzheimer's Disease. Front Aging Neurosci 2022; 13:813544. [PMID: 35211003 PMCID: PMC8862182 DOI: 10.3389/fnagi.2021.813544] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 12/20/2021] [Indexed: 12/12/2022] Open
Abstract
Numerous epidemiological studies have demonstrated that individuals who have sustained a traumatic brain injury (TBI) have an elevated risk for developing Alzheimer's disease and Alzheimer's-related dementias (AD/ADRD). Despite these connections, the underlying mechanisms by which TBI induces AD-related pathology, neuronal dysfunction, and cognitive decline have yet to be elucidated. In this review, we will discuss the various in vivo and in vitro models that are being employed to provide more definite mechanistic relationships between TBI-induced mechanical injury and AD-related phenotypes. In particular, we will highlight the strengths and weaknesses of each of these model systems as it relates to advancing the understanding of the mechanisms that lead to TBI-induced AD onset and progression as well as providing platforms to evaluate potential therapies. Finally, we will discuss how emerging methods including the use of human induced pluripotent stem cell (hiPSC)-derived cultures and genome engineering technologies can be employed to generate better models of TBI-induced AD.
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Affiliation(s)
| | - David A. Brafman
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, United States
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10
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Ozgun A, Lomboni D, Arnott H, Staines WA, Woulfe J, Variola F. Biomaterial-based strategies for in vitro neural models. Biomater Sci 2022; 10:1134-1165. [PMID: 35023513 DOI: 10.1039/d1bm01361k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In vitro models have been used as a complementary tool to animal studies in understanding the nervous system's physiological mechanisms and pathological disorders, while also serving as platforms to evaluate the safety and efficiency of therapeutic candidates. Following recent advances in materials science, micro- and nanofabrication techniques and cell culture systems, in vitro technologies have been rapidly gaining the potential to bridge the gap between animal and clinical studies by providing more sophisticated models that recapitulate key aspects of the structure, biochemistry, biomechanics, and functions of human tissues. This was made possible, in large part, by the development of biomaterials that provide cells with physicochemical features that closely mimic the cellular microenvironment of native tissues. Due to the well-known material-driven cellular response and the importance of mimicking the environment of the target tissue, the selection of optimal biomaterials represents an important early step in the design of biomimetic systems to investigate brain structures and functions. This review provides a comprehensive compendium of commonly used biomaterials as well as the different fabrication techniques employed for the design of neural tissue models. Furthermore, the authors discuss the main parameters that need to be considered to develop functional platforms not only for the study of brain physiological functions and pathological processes but also for drug discovery/development and the optimization of biomaterials for neural tissue engineering.
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Affiliation(s)
- Alp Ozgun
- Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Canada. .,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - David Lomboni
- Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Canada. .,Ottawa-Carleton Institute for Biomedical Engineering (OCIBME), Ottawa, Canada
| | - Hallie Arnott
- Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Canada. .,Ottawa-Carleton Institute for Biomedical Engineering (OCIBME), Ottawa, Canada
| | - William A Staines
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - John Woulfe
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada.,The Ottawa Hospital, Ottawa, Canada
| | - Fabio Variola
- Department of Mechanical Engineering, Faculty of Engineering, University of Ottawa, Ottawa, Canada. .,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, Canada.,Ottawa-Carleton Institute for Biomedical Engineering (OCIBME), Ottawa, Canada.,The Ottawa Hospital, Ottawa, Canada.,Children's Hospital of Eastern Ontario (CHEO), Ottawa, Canada
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11
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Schroeder ME, Bassett DS, Meaney DF. A multilayer network model of neuron-astrocyte populations in vitro reveals mGluR5 inhibition is protective following traumatic injury. Netw Neurosci 2022; 6:499-527. [PMID: 35733423 PMCID: PMC9208011 DOI: 10.1162/netn_a_00227] [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: 01/11/2021] [Accepted: 01/04/2022] [Indexed: 11/16/2022] Open
Abstract
Astrocytes communicate bidirectionally with neurons, enhancing synaptic plasticity and promoting the synchronization of neuronal microcircuits. Despite recent advances in understanding neuron-astrocyte signaling, little is known about astrocytic modulation of neuronal activity at the population level, particularly in disease or following injury. We used high-speed calcium imaging of mixed cortical cultures in vitro to determine how population activity changes after disruption of glutamatergic signaling and mechanical injury. We constructed a multilayer network model of neuron-astrocyte connectivity, which captured distinct topology and response behavior from single-cell-type networks. mGluR5 inhibition decreased neuronal activity, but did not on its own disrupt functional connectivity or network topology. In contrast, injury increased the strength, clustering, and efficiency of neuronal but not astrocytic networks, an effect that was not observed in networks pretreated with mGluR5 inhibition. Comparison of spatial and functional connectivity revealed that functional connectivity is largely independent of spatial proximity at the microscale, but mechanical injury increased the spatial-functional correlation. Finally, we found that astrocyte segments of the same cell often belong to separate functional communities based on neuronal connectivity, suggesting that astrocyte segments function as independent entities. Our findings demonstrate the utility of multilayer network models for characterizing the multiscale connectivity of two distinct but functionally dependent cell populations. Astrocytes communicate bidirectionally with neurons, enhancing synaptic plasticity and promoting the synchronization of neuronal microcircuits. We constructed a multilayer network model of neuron-astrocyte connectivity based on calcium activity in mixed cortical cultures, and used this model to evaluate the effect of glutamatergic inhibition and mechanical injury on network topology. We found that injury increased the strength, clustering, and efficiency of neuronal but not astrocytic networks, an effect that was not observed in injured networks pretreated with a glutamate receptor antagonist. Our findings demonstrate the utility of multilayer network models for characterizing the multiscale connectivity of two distinct but functionally dependent cell populations.
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Affiliation(s)
- Margaret E. Schroeder
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Danielle S. Bassett
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Physics & Astronomy, College of Arts & Sciences, University of Pennsylvania, Philadelphia, PA, USA
- Department of Electrical & Systems Engineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David F. Meaney
- Department of Bioengineering, School of Engineering & Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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12
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Motanis H, Khorasani LN, Giza CC, Harris NG. Peering into the Brain through the Retrosplenial Cortex to Assess Cognitive Function of the Injured Brain. Neurotrauma Rep 2021; 2:564-580. [PMID: 34901949 PMCID: PMC8655812 DOI: 10.1089/neur.2021.0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The retrosplenial cortex (RSC) is a posterior cortical area that has been drawing increasing interest in recent years, with a growing number of studies studying its contribution to cognitive and sensory functions. From an anatomical perspective, it has been established that the RSC is extensively and often reciprocally connected with the hippocampus, neocortex, and many midbrain regions. Functionally, the RSC is an important hub of the default-mode network. This endowment, with vast anatomical and functional connections, positions the RSC to play an important role in episodic memory, spatial and contextual learning, sensory-cognitive activities, and multi-modal sensory information processing and integration. Additionally, RSC dysfunction has been reported in cases of cognitive decline, particularly in Alzheimer's disease and stroke. We review the literature to examine whether the RSC can act as a cortical marker of persistent cognitive dysfunction after traumatic brain injury (TBI). Because the RSC is easily accessible at the brain's surface using in vivo techniques, we argue that studying RSC network activity post-TBI can shed light into the mechanisms of less-accessible brain regions, such as the hippocampus. There is a fundamental gap in the TBI field about the microscale alterations occurring post-trauma, and by studying the RSC's neuronal activity at the cellular level we will be able to design better therapeutic tools. Understanding how neuronal activity and interactions produce normal and abnormal activity in the injured brain is crucial to understanding cognitive dysfunction. By using this approach, we expect to gain valuable insights to better understand brain disorders like TBI.
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Affiliation(s)
- Helen Motanis
- UCLA Brain Injury Research Center, Department of Neurosurgery, Geffen Medical School, UCLA Mattel Children's Hospital, University of California at Los Angeles, Los Angeles, California, USA
| | - Laila N. Khorasani
- UCLA Brain Injury Research Center, Department of Neurosurgery, Geffen Medical School, UCLA Mattel Children's Hospital, University of California at Los Angeles, Los Angeles, California, USA
| | - Christopher C. Giza
- UCLA Brain Injury Research Center, Department of Neurosurgery, Geffen Medical School, UCLA Mattel Children's Hospital, University of California at Los Angeles, Los Angeles, California, USA
- Department of Pediatrics, UCLA Mattel Children's Hospital, University of California at Los Angeles, Los Angeles, California, USA
| | - Neil G. Harris
- UCLA Brain Injury Research Center, Department of Neurosurgery, Geffen Medical School, UCLA Mattel Children's Hospital, University of California at Los Angeles, Los Angeles, California, USA
- Intellectual Development and Disabilities Research Center, UCLA Mattel Children's Hospital, University of California at Los Angeles, Los Angeles, California, USA
- *Address correspondence to: Neil G. Harris, PhD, Department of Neurosurgery, University of California at Los Angeles, Wasserman Building, 300 Stein Plaza, Room 551, Los Angeles, CA 90095, USA;
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13
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Lipopolysaccharide-induced neuroinflammation disrupts functional connectivity and community structure in primary cortical microtissues. Sci Rep 2021; 11:22303. [PMID: 34785714 PMCID: PMC8595892 DOI: 10.1038/s41598-021-01616-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 10/29/2021] [Indexed: 12/15/2022] Open
Abstract
Three-dimensional (3D) neural microtissues are a powerful in vitro paradigm for studying brain development and disease under controlled conditions, while maintaining many key attributes of the in vivo environment. Here, we used primary cortical microtissues to study the effects of neuroinflammation on neural microcircuits. We demonstrated the use of a genetically encoded calcium indicator combined with a novel live-imaging platform to record spontaneous calcium transients in microtissues from day 14-34 in vitro. We implemented graph theory analysis of calcium activity to characterize underlying functional connectivity and community structure of microcircuits, which are capable of capturing subtle changes in network dynamics during early disease states. We found that microtissues cultured for 34 days displayed functional remodeling of microcircuits and that community structure strengthened over time. Lipopolysaccharide, a neuroinflammatory agent, significantly increased functional connectivity and disrupted community structure 5-9 days after exposure. These microcircuit-level changes have broad implications for the role of neuroinflammation in functional dysregulation of neural networks.
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14
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Wu YH, Rosset S, Lee TR, Dragunow M, Park T, Shim V. In Vitro Models of Traumatic Brain Injury: A Systematic Review. J Neurotrauma 2021; 38:2336-2372. [PMID: 33563092 DOI: 10.1089/neu.2020.7402] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Traumatic brain injury (TBI) is a major public health challenge that is also the third leading cause of death worldwide. It is also the leading cause of long-term disability in children and young adults worldwide. Despite a large body of research using predominantly in vivo and in vitro rodent models of brain injury, there is no medication that can reduce brain damage or promote brain repair mainly due to our lack of understanding in the mechanisms and pathophysiology of the TBI. The aim of this review is to examine in vitro TBI studies conducted from 2008-2018 to better understand the TBI in vitro model available in the literature. Specifically, our focus was to perform a detailed analysis of the in vitro experimental protocols used and their subsequent biological findings. Our review showed that the uniaxial stretch is the most frequently used way of load application, accounting for more than two-thirds of the studies reviewed. The rate and magnitude of the loading were varied significantly from study to study but can generally be categorized into mild, moderate, and severe injuries. The in vitro studies reviewed here examined key processes in TBI pathophysiology such as membrane disruptions leading to ionic dysregulation, inflammation, and the subsequent damages to the microtubules and axons, as well as cell death. Overall, the studies examined in this review contributed to the betterment of our understanding of TBI as a disease process. Yet, our review also revealed the areas where more work needs to be done such as: 1) diversification of load application methods that will include complex loading that mimics in vivo head impacts; 2) more widespread use of human brain cells, especially patient-matched human cells in the experimental set-up; and 3) need for building a more high-throughput system to be able to discover effective therapeutic targets for TBI.
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Affiliation(s)
- Yi-Han Wu
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- Center for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Samuel Rosset
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Tae-Rin Lee
- Advanced Institute of Convergence Technology, Seoul National University, Seoul, Korea
| | - Mike Dragunow
- Center for Brain Research, The University of Auckland, Auckland, New Zealand
- Department of Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Thomas Park
- Center for Brain Research, The University of Auckland, Auckland, New Zealand
- Department of Pharmacology, The University of Auckland, Auckland, New Zealand
| | - Vickie Shim
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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15
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Montanino A, Li X, Zhou Z, Zeineh M, Camarillo D, Kleiven S. Subject-specific multiscale analysis of concussion: from macroscopic loads to molecular-level damage. BRAIN MULTIPHYSICS 2021. [DOI: 10.1016/j.brain.2021.100027] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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16
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Graudejus O, Barton C, Ponce Wong RD, Rowan CC, Oswalt D, Greger B. A soft and stretchable bilayer electrode array with independent functional layers for the next generation of brain machine interfaces. J Neural Eng 2020; 17:056023. [PMID: 33052886 DOI: 10.1088/1741-2552/abb4a5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Brain-Machine Interfaces (BMIs) hold great promises for advancing neuroprosthetics, robotics, and for providing treatment options for severe neurological diseases. The objective of this work is the development and in vivo evaluation of electrodes for BMIs that meet the needs to record brain activity at sub-millimeter resolution over a large area of the cortex while being soft and electromechanically robust (i.e. stretchable). APPROACH Current electrodes require a trade-off between high spatiotemporal resolution and cortical coverage area. To address the needs for simultaneous high resolution and large cortical coverage, the prototype electrode array developed in this study employs a novel bilayer routing of soft and stretchable lead wires from the recording sites on the surface of the brain (electrocorticography, ECoG) to the data acquisition system. MAIN RESULTS To validate the recording characteristics, the array was implanted in healthy felines for up to 5 months. Neural signals recorded from both layers of the device showed elevated mid-frequency structures typical of local field potential (LFP) signals that were stable in amplitude over implant duration, and also exhibited consistent frequency-dependent modulation after anesthesia induction by Telazol. SIGNIFICANCE The successful development of a soft and stretchable large-area, high resolution micro ECoG electrode array (lahrμECoG) is an important step to meet the neurotechnological needs of advanced BMI applications.
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Affiliation(s)
- Oliver Graudejus
- School of Molecular Science, Arizona State University, Tempe, AZ, United States of America. BMSEED, Phoenix, AZ, United States of America
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17
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Hamilton KA, Santhakumar V. Current ex Vivo and in Vitro Approaches to Uncovering Mechanisms of Neurological Dysfunction after Traumatic Brain Injury. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2020; 14:18-24. [PMID: 32548365 PMCID: PMC7297186 DOI: 10.1016/j.cobme.2020.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Traumatic brain injury often leads to progressive alterations at the molecular to circuit levels resulting in epilepsy and memory impairments. Ex vivo and in vitro models have provided a powerful platform for investigating the multimodal alteration after trauma. Recent ex vivo analyses using voltage sensitive dye imaging, optogenetics, and glutamate uncaging have revealed circuit abnormalities following in vivo brain injury. In vitro injury models have enabled examination of early and progressive changes in activity while development of three-dimensional organoids derived from human induced pluripotent stem cells have opened novel avenues for injury research. Here, we highlight recent advances in ex vivo and in vitro systems, focusing on their potential for advancing mechanistic understandings, possible limitations, and implications for therapeutics.
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Affiliation(s)
- Kelly Andrew Hamilton
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA, USA
| | - Vijayalakshmi Santhakumar
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA, USA
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, USA
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18
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A mechanoelectrical coupling model of neurons under stretching. J Mech Behav Biomed Mater 2019; 93:213-221. [DOI: 10.1016/j.jmbbm.2019.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 02/04/2019] [Accepted: 02/04/2019] [Indexed: 12/20/2022]
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19
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Bianchi F, George JH, Malboubi M, Jerusalem A, Thompson MS, Ye H. Engineering a uniaxial substrate-stretching device for simultaneous electrophysiological measurements and imaging of strained peripheral neurons. Med Eng Phys 2019; 67:1-10. [PMID: 30878301 DOI: 10.1016/j.medengphy.2019.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Revised: 02/17/2019] [Accepted: 02/25/2019] [Indexed: 12/19/2022]
Abstract
Peripheral nerves are continuously subjected to mechanical strain during everyday movements, but excessive stretch can lead to damage and neuronal cell functionality can also be impaired. To better understand cellular processes triggered by stretch, it is necessary to develop in vitro experimental methods that allow multiple concurrent measurements and replicate in vivo mechanical conditions. Current commercially available cell stretching devices do not allow flexible experimental design, restricting the range of possible multi-physics measurements. Here, we describe and characterise a custom-built uniaxial substrate-straining device, with which neurons cultured on aligned patterned surfaces (50 µm wide grooves) can be strained up to 70% and simultaneously imaged with widefield and confocal imaging (up to 100x magnification). Furthermore, direct and indirect electrophysiological measurements by patch clamping and calcium imaging can be made during strain application. We characterise the strain applied to cells cultured in deformable wells by using finite element method simulations and experimental data, showing local surface strains of up to 60% with applied strains of up to 25%. We also show how patterned substrates do not alter the mechanical properties of the system compared to unpatterned surfaces whilst still inducing a homogeneous cell response to strain. The characterisation of this device will be useful for research into investigating the effect of whole-cell mechanical stretch on neurons at both single cell and network scales, with applications found in peripheral neuropathy modelling and in platforms for preventive and regenerative studies.
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Affiliation(s)
- Fabio Bianchi
- Institute of Biomedical Engineering, Dept. of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK
| | - Julian H George
- Institute of Biomedical Engineering, Dept. of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK
| | - Majid Malboubi
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK; Department of Mechanical Engineering, The University of Birmingham, Birmingham B15 2TT, UK
| | - Antoine Jerusalem
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - Mark S Thompson
- Institute of Biomedical Engineering, Dept. of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK
| | - Hua Ye
- Institute of Biomedical Engineering, Dept. of Engineering Science, University of Oxford, Oxford OX3 7DQ, UK.
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20
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Imboden M, de Coulon E, Poulin A, Dellenbach C, Rosset S, Shea H, Rohr S. High-speed mechano-active multielectrode array for investigating rapid stretch effects on cardiac tissue. Nat Commun 2019; 10:834. [PMID: 30783104 PMCID: PMC6381132 DOI: 10.1038/s41467-019-08757-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 01/24/2019] [Indexed: 11/25/2022] Open
Abstract
Systematic investigations of the effects of mechano-electric coupling (MEC) on cellular cardiac electrophysiology lack experimental systems suitable to subject tissues to in-vivo like strain patterns while simultaneously reporting changes in electrical activation. Here, we describe a self-contained motor-less device (mechano-active multielectrode-array, MaMEA) that permits the assessment of impulse conduction along bioengineered strands of cardiac tissue in response to dynamic strain cycles. The device is based on polydimethylsiloxane (PDMS) cell culture substrates patterned with dielectric actuators (DEAs) and compliant gold ion-implanted extracellular electrodes. The DEAs induce uniaxial stretch and compression in defined regions of the PDMS substrate at selectable amplitudes and with rates up to 18 s−1. Conduction along cardiomyocyte strands was found to depend linearly on static strain according to cable theory while, unexpectedly, being completely independent on strain rates. Parallel operation of multiple MaMEAs provides for systematic high-throughput investigations of MEC during spatially patterned mechanical perturbations mimicking in-vivo conditions. While strain is known to affect cardiac electrophysiology, experimental systems to interrogate the effect of rapid strain cycles on cardiac tissue are lacking. Here the authors introduce a multielectrode array that can induce rapid dynamic strain cycles on cardiomyocyte strands and see effects of strain amplitude but not strain rate on impulse conduction.
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Affiliation(s)
- Matthias Imboden
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland. .,Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland.
| | - Etienne de Coulon
- Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland
| | - Alexandre Poulin
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland
| | - Christian Dellenbach
- Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland
| | - Samuel Rosset
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland
| | - Herbert Shea
- Soft Transducers Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), 2002, Neuchâtel, Switzerland
| | - Stephan Rohr
- Department of Physiology, University of Bern, Bühlplatz 5, 3012, Bern, Switzerland.
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21
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Bianchi F, Malboubi M, Li Y, George JH, Jerusalem A, Szele F, Thompson MS, Ye H. Rapid and efficient differentiation of functional motor neurons from human iPSC for neural injury modelling. Stem Cell Res 2018; 32:126-134. [PMID: 30278374 DOI: 10.1016/j.scr.2018.09.006] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 12/14/2022] Open
Abstract
Primary rodent neurons and immortalised cell lines have overwhelmingly been used for in vitro studies of traumatic injury to peripheral and central neurons, but have some limitations of physiological accuracy. Motor neurons (MN) derived from human induced pluripotent stem cells (iPSCs) enable the generation of cell models with features relevant to human physiology. To facilitate this, it is desirable that MN protocols both rapidly and efficiently differentiate human iPSCs into electrophysiologically active MNs. In this study, we present a simple, rapid protocol for differentiation of human iPSCs into functional spinal (lower) MNs, involving only adherent culture and use of small molecules for directed differentiation, with the ultimate aim of rapid production of electrophysiologically functional cells for short-term neural injury experiments. We show successful differentiation in two unrelated iPSC lines, by quantifying neural-specific marker expression, and by evaluating cell functionality at different maturation stages by calcium imaging and patch clamping. Differentiated neurons were shown to be electrophysiologically altered by uniaxial mechanical deformation. Spontaneous network activity decreased with applied stretch, indicating aberrant network connectivity. These results demonstrate the feasibility of this rapid, simple protocol for differentiating iPSC-derived MNs, suitable for in vitro neural injury studies focussing on electrophysiological alterations caused by mechanical deformation or trauma.
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Affiliation(s)
- Fabio Bianchi
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, OX3 7DQ, UK
| | - Majid Malboubi
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, OX3 7DQ, UK
| | - Yichen Li
- Department Physiology, Anatomy and Genetics, University of Oxford, OX1 3QX, UK
| | - Julian H George
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, OX3 7DQ, UK
| | - Antoine Jerusalem
- Department of Engineering Science, University of Oxford, OX1 3PJ, UK
| | - Francis Szele
- Department Physiology, Anatomy and Genetics, University of Oxford, OX1 3QX, UK
| | - Mark S Thompson
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, OX3 7DQ, UK
| | - Hua Ye
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, OX3 7DQ, UK.
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22
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Buccarello A, Azzarito M, Michoud F, Lacour SP, Kucera JP. Uniaxial strain of cultured mouse and rat cardiomyocyte strands slows conduction more when its axis is parallel to impulse propagation than when it is perpendicular. Acta Physiol (Oxf) 2018; 223:e13026. [PMID: 29282897 DOI: 10.1111/apha.13026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/14/2017] [Accepted: 12/21/2017] [Indexed: 11/28/2022]
Abstract
AIM Cardiac tissue deformation can modify tissue resistance, membrane capacitance and ion currents and hence cause arrhythmogenic slow conduction. Our aim was to investigate whether uniaxial strain causes different changes in conduction velocity (θ) when the principal strain axis is parallel vs perpendicular to impulse propagation. METHODS Cardiomyocyte strands were cultured on stretchable custom microelectrode arrays, and θ was determined during steady-state pacing. Uniaxial strain (5%) with principal axis parallel (orthodromic) or perpendicular (paradromic) to propagation was applied for 1 minute and controlled by imaging a grid of markers. The results were analysed in terms of cable theory. RESULTS Both types of strain induced immediate changes of θ upon application and release. In material coordinates, orthodromic strain decreased θ significantly more (P < .001) than paradromic strain (2.2 ± 0.5% vs 1.0 ± 0.2% in n = 8 mouse cardiomyocyte cultures, 2.3 ± 0.4% vs 0.9 ± 0.5% in n = 4 rat cardiomyocyte cultures, respectively). The larger effect of orthodromic strain can be explained by the increase in axial myoplasmic resistance, which is not altered by paradromic strain. Thus, changes in tissue resistance substantially contributed to the changes of θ during strain, in addition to other influences (eg stretch-activated channels). Besides these immediate effects, the application of strain also consistently initiated a slow progressive decrease in θ and a slow recovery of θ upon release. CONCLUSION Changes in cardiac conduction velocity caused by acute stretch do not only depend on the magnitude of strain but also on its orientation relative to impulse propagation. This dependence is due to different effects on tissue resistance.
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Affiliation(s)
- A. Buccarello
- Department of Physiology; University of Bern; Bern Switzerland
| | - M. Azzarito
- Department of Physiology; University of Bern; Bern Switzerland
| | - F. Michoud
- Bertarelli Foundation Chair in Neuroprosthetic Technology; Laboratory for Soft Bioelectronic Interfaces; Institute of Microengineering; Institute of Bioengineering; Centre for Neuroprosthetics; École Polytechnique Fédérale de Lausanne (EPFL); Geneva Switzerland
| | - S. P. Lacour
- Bertarelli Foundation Chair in Neuroprosthetic Technology; Laboratory for Soft Bioelectronic Interfaces; Institute of Microengineering; Institute of Bioengineering; Centre for Neuroprosthetics; École Polytechnique Fédérale de Lausanne (EPFL); Geneva Switzerland
| | - J. P. Kucera
- Department of Physiology; University of Bern; Bern Switzerland
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23
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Swiatkowski P, Nikolaeva I, Kumar G, Zucco A, Akum BF, Patel MV, D'Arcangelo G, Firestein BL. Role of Akt-independent mTORC1 and GSK3β signaling in sublethal NMDA-induced injury and the recovery of neuronal electrophysiology and survival. Sci Rep 2017; 7:1539. [PMID: 28484273 PMCID: PMC5431483 DOI: 10.1038/s41598-017-01826-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/03/2017] [Indexed: 01/02/2023] Open
Abstract
Glutamate-induced excitotoxicity, mediated by overstimulation of N-methyl-D-aspartate (NMDA) receptors, is a mechanism that causes secondary damage to neurons. The early phase of injury causes loss of dendritic spines and changes to synaptic activity. The phosphatidylinositol-4,5-bisphosphate 3-kinase/Akt/ mammalian target of rapamycin (PI3K/Akt/mTOR) pathway has been implicated in the modulation and regulation of synaptic strength, activity, maturation, and axonal regeneration. The present study focuses on the physiology and survival of neurons following manipulation of Akt and several downstream targets, such as GSK3β, FOXO1, and mTORC1, prior to NMDA-induced injury. Our analysis reveals that exposure to sublethal levels of NMDA does not alter phosphorylation of Akt, S6, and GSK3β at two and twenty four hours following injury. Electrophysiological recordings show that NMDA-induced injury causes a significant decrease in spontaneous excitatory postsynaptic currents at both two and twenty four hours, and this phenotype can be prevented by inhibiting mTORC1 or GSK3β, but not Akt. Additionally, inhibition of mTORC1 or GSK3β promotes neuronal survival following NMDA-induced injury. Thus, NMDA-induced excitotoxicity involves a mechanism that requires the permissive activity of mTORC1 and GSK3β, demonstrating the importance of these kinases in the neuronal response to injury.
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Affiliation(s)
- Przemyslaw Swiatkowski
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Molecular Biosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Ina Nikolaeva
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Molecular Biosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Gaurav Kumar
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Avery Zucco
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Neurosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Barbara F Akum
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Mihir V Patel
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.,Graduate Program in Neurosciences, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Gabriella D'Arcangelo
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers University, 604 Allison Road, Piscataway, New Jersey, 08854-8082, USA.
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Girgis F, Pace J, Sweet J, Miller JP. Hippocampal Neurophysiologic Changes after Mild Traumatic Brain Injury and Potential Neuromodulation Treatment Approaches. Front Syst Neurosci 2016; 10:8. [PMID: 26903824 PMCID: PMC4746250 DOI: 10.3389/fnsys.2016.00008] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/25/2016] [Indexed: 12/22/2022] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of death and disability in individuals below age 45, and five million Americans live with chronic disability as a result. Mild TBI (mTBI), defined as TBI in the absence of major imaging or histopathological defects, is responsible for a majority of cases. Despite the lack of overt morphological defects, victims of mTBI frequently suffer lasting cognitive deficits, memory difficulties, and behavioral disturbances. There is increasing evidence that cognitive and memory dysfunction is related to subtle physiological changes that occur in the hippocampus, and these impact both the phenotype of deficits observed and subsequent recovery. Therapeutic modulation of physiological activity by means of medications commonly used for other indications or brain stimulation may represent novel treatment approaches. This review summarizes the present body of knowledge regarding neurophysiologic changes that occur in the hippocampus after mTBI, as well as potential targets for therapeutic modulation of neurologic activity.
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Affiliation(s)
- Fady Girgis
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
| | - Jonathan Pace
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
| | - Jennifer Sweet
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
| | - Jonathan P Miller
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
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Vogel EW, Effgen GB, Patel TP, Meaney DF, Bass CRD, Morrison B. Isolated Primary Blast Inhibits Long-Term Potentiation in Organotypic Hippocampal Slice Cultures. J Neurotrauma 2015; 33:652-61. [PMID: 26414012 DOI: 10.1089/neu.2015.4045] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Over the last 13 years, traumatic brain injury (TBI) has affected over 230,000 U.S. service members through the conflicts in Iraq and Afghanistan, mostly as a result of exposure to blast events. Blast-induced TBI (bTBI) is multi-phasic, with the penetrating and inertia-driven phases having been extensively studied. The effects of primary blast injury, caused by the shockwave interacting with the brain, remain unclear. Earlier in vivo studies in mice and rats have reported mixed results for primary blast effects on behavior and memory. Using a previously developed shock tube and in vitro sample receiver, we investigated the effect of isolated primary blast on the electrophysiological function of rat organotypic hippocampal slice cultures (OHSC). We found that pure primary blast exposure inhibited long-term potentiation (LTP), the electrophysiological correlate of memory, with a threshold between 9 and 39 kPa·ms impulse. This deficit occurred well below a previously identified threshold for cell death (184 kPa·ms), supporting our previously published finding that primary blast can cause changes in brain function in the absence of cell death. Other functional measures such as spontaneous activity, network synchronization, stimulus-response curves, and paired-pulse ratios (PPRs) were less affected by primary blast exposure, as compared with LTP. This is the first study to identify a tissue-level tolerance threshold for electrophysiological changes in neuronal function to isolated primary blast.
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Affiliation(s)
- Edward W Vogel
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Gwen B Effgen
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Tapan P Patel
- 2 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - David F Meaney
- 2 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Cameron R Dale Bass
- 3 Department of Biomedical Engineering, Duke University , Durham, North Carolina
| | - Barclay Morrison
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
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