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Hölzel MB, Kamermans W, Winkelman BHJ, Howlett MHC, De Zeeuw CI, Kamermans M. A common cause for nystagmus in different congenital stationary night blindness mouse models. J Physiol 2023; 601:5317-5340. [PMID: 37864560 DOI: 10.1113/jp284965] [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: 05/01/2023] [Accepted: 09/22/2023] [Indexed: 10/23/2023] Open
Abstract
In Nyxnob mice, a model for congenital nystagmus associated with congenital stationary night blindness (CSNB), synchronous oscillating retinal ganglion cells (RGCs) lead to oscillatory eye movements, i.e. nystagmus. Given the specific expression of mGluR6 and Cav 1.4 in the photoreceptor to bipolar cell synapses, as well as their clinical association with CSNB, we hypothesize that Grm6nob3 and Cav 1.4-KO mutants show, like the Nyxnob mouse, oscillations in both their RGC activity and eye movements. Using multi-electrode array recordings of RGCs and measurements of the eye movements, we demonstrate that Grm6nob3 and Cav 1.4-KO mice also show oscillations of their RGCs as well as a nystagmus. Interestingly, the preferred frequencies of RGC activity as well as the eye movement oscillations of the Grm6nob3 , Cav 1.4-KO and Nyxnob mice differ among mutants, but the neuronal activity and eye movement behaviour within a strain remain aligned in the same frequency domain. Model simulations indicate that mutations affecting the photoreceptor-bipolar cell synapse can form a common cause of the nystagmus of CSNB by driving oscillations in RGCs via AII amacrine cells. KEY POINTS: In Nyxnob mice, a model for congenital nystagmus associated with congenital stationary night blindness (CSNB), their oscillatory eye movements (i.e. nystagmus) are caused by synchronous oscillating retinal ganglion cells. Here we show that the same mechanism applies for two other CSNB mouse models - Grm6nob3 and Cav 1.4-KO mice. We propose that the retinal ganglion cell oscillations originate in the AII amacrine cells. Model simulations show that by only changing the input to ON-bipolar cells, all phenotypical differences between the various genetic mouse models can be reproduced.
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Affiliation(s)
- Maj-Britt Hölzel
- Netherlands Institute for Neuroscience Amsterdam, Amsterdam, the Netherlands
| | - Wouter Kamermans
- Netherlands Institute for Neuroscience Amsterdam, Amsterdam, the Netherlands
| | - Beerend H J Winkelman
- Netherlands Institute for Neuroscience Amsterdam, Amsterdam, the Netherlands
- Department of Neuroscience, Erasmus MC, Rotterdam, the Netherlands
| | - Marcus H C Howlett
- Netherlands Institute for Neuroscience Amsterdam, Amsterdam, the Netherlands
| | - Chris I De Zeeuw
- Netherlands Institute for Neuroscience Amsterdam, Amsterdam, the Netherlands
- Department of Neuroscience, Erasmus MC, Rotterdam, the Netherlands
| | - Maarten Kamermans
- Netherlands Institute for Neuroscience Amsterdam, Amsterdam, the Netherlands
- Department of Biomedical Physics, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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Hwang S, Hwang Y, Kim D, Lee J, Choe HK, Lee J, Kang H, Kung J. ReplaceNet: real-time replacement of a biological neural circuit with a hardware-assisted spiking neural network. Front Neurosci 2023; 17:1161592. [PMID: 37638314 PMCID: PMC10448768 DOI: 10.3389/fnins.2023.1161592] [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: 02/08/2023] [Accepted: 07/28/2023] [Indexed: 08/29/2023] Open
Abstract
Recent developments in artificial neural networks and their learning algorithms have enabled new research directions in computer vision, language modeling, and neuroscience. Among various neural network algorithms, spiking neural networks (SNNs) are well-suited for understanding the behavior of biological neural circuits. In this work, we propose to guide the training of a sparse SNN in order to replace a sub-region of a cultured hippocampal network with limited hardware resources. To verify our approach with a realistic experimental setup, we record spikes of cultured hippocampal neurons with a microelectrode array (in vitro). The main focus of this work is to dynamically cut unimportant synapses during SNN training on the fly so that the model can be realized on resource-constrained hardware, e.g., implantable devices. To do so, we adopt a simple STDP learning rule to easily select important synapses that impact the quality of spike timing learning. By combining the STDP rule with online supervised learning, we can precisely predict the spike pattern of the cultured network in real-time. The reduction in the model complexity, i.e., the reduced number of connections, significantly reduces the required hardware resources, which is crucial in developing an implantable chip for the treatment of neurological disorders. In addition to the new learning algorithm, we prototype a sparse SNN hardware on a small FPGA with pipelined execution and parallel computing to verify the possibility of real-time replacement. As a result, we can replace a sub-region of the biological neural circuit within 22 μs using 2.5 × fewer hardware resources, i.e., by allowing 80% sparsity in the SNN model, compared to the fully-connected SNN model. With energy-efficient algorithms and hardware, this work presents an essential step toward real-time neuroprosthetic computation.
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Affiliation(s)
- Sangwoo Hwang
- Department of Electrical Engineering and Computer Science, DGIST, Daegu, Republic of Korea
| | - Yujin Hwang
- Department of Electrical Engineering and Computer Science, DGIST, Daegu, Republic of Korea
| | - Duhee Kim
- Department of Electrical Engineering and Computer Science, DGIST, Daegu, Republic of Korea
| | - Junhee Lee
- Department of Electrical Engineering and Computer Science, DGIST, Daegu, Republic of Korea
| | - Han Kyoung Choe
- Department of Brain Sciences, DGIST, Daegu, Republic of Korea
| | - Junghyup Lee
- Department of Electrical Engineering and Computer Science, DGIST, Daegu, Republic of Korea
| | - Hongki Kang
- Department of Electrical Engineering and Computer Science, DGIST, Daegu, Republic of Korea
| | - Jaeha Kung
- School of Electrical Engineering, Korea University, Seoul, Republic of Korea
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Ahtiainen A, Annala I, Rosenholm M, Kohtala S, Hyttinen J, Tanskanen JMA, Rantamäki T. Ketamine reduces electrophysiological network activity in cortical neuron cultures already at sub-micromolar concentrations - Impact on TrkB-ERK1/2 signaling. Neuropharmacology 2023; 229:109481. [PMID: 36868403 DOI: 10.1016/j.neuropharm.2023.109481] [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: 02/05/2023] [Revised: 02/24/2023] [Accepted: 02/26/2023] [Indexed: 03/05/2023]
Abstract
The dissociative anesthetic ketamine regulates cortical activity in a dose-dependent manner. Subanesthetic-dose ketamine has paradoxical excitatory effects which is proposed to facilitate brain-derived neurotrophic factor (BDNF) (a ligand of tropomyosin receptor kinase B, TrkB) signaling, and activation of extracellular signal-regulated kinase 1/2 (ERK1/2). Previous data suggests that ketamine, at sub-micromolar concentrations, induces glutamatergic activity, BDNF release, and activation of ERK1/2 also on primary cortical neurons. We combined western blot analysis with multiwell-microelectrode array (mw-MEA) measurements to examine ketamine's concentration-dependent effects on network-level electrophysiological responses and TrkB-ERK1/2 phosphorylation in rat cortical cultures at 14 days in vitro. Ketamine did not cause an increase in neuronal network activity at sub-micromolar concentrations, but instead a decrease in spiking that was evident already at 500 nM concentration. TrkB phosphorylation was unaffected by the low concentrations, although BDNF elicited prominent phosphorylation response. High concentration of ketamine (10 μM) strongly reduced spiking, bursting and burst duration, which was accompanied with decreased phosphorylation of ERK1/2 but not TrkB. Notably, robust increases in spiking and bursting activity could be produced with carbachol, while it did not affect phosphorylation of TrkB or ERK1/2. Diazepam abolished neuronal activity, which was accompanied by reduced ERK1/2 phosphorylation without change on TrkB. In conclusion, sub-micromolar ketamine concentrations did not cause an increase in neuronal network activity or TrkB-ERK1/2 phosphorylation in cortical neuron cultures that readily respond to exogenously applied BDNF. Instead, pharmacological inhibition of network activity can be readily observed with high concentration of ketamine and it is associated with reduced ERK1/2 phosphorylation.
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Affiliation(s)
- A Ahtiainen
- Computational Biophysics and Imaging Group, BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520, Tampere, Finland.
| | - I Annala
- Laboratory of Neurotherapeutics, Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, Biocenter 2, 00790, Helsinki, Finland; SleepWell Research Program, Faculty of Medicine, University of Helsinki, P.O. Box 9, Helsinki, 00014, Finland.
| | - M Rosenholm
- Laboratory of Neurotherapeutics, Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, Biocenter 2, 00790, Helsinki, Finland; Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - S Kohtala
- Laboratory of Neurotherapeutics, Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, Biocenter 2, 00790, Helsinki, Finland; SleepWell Research Program, Faculty of Medicine, University of Helsinki, P.O. Box 9, Helsinki, 00014, Finland; Department of Psychiatry, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, 407 E 61st St, New York, NY, 10065, USA
| | - J Hyttinen
- Computational Biophysics and Imaging Group, BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520, Tampere, Finland
| | - J M A Tanskanen
- Computational Biophysics and Imaging Group, BioMediTech, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, 33520, Tampere, Finland
| | - T Rantamäki
- Laboratory of Neurotherapeutics, Drug Research Program, Division of Pharmacology and Pharmacotherapy, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5E, Biocenter 2, 00790, Helsinki, Finland; SleepWell Research Program, Faculty of Medicine, University of Helsinki, P.O. Box 9, Helsinki, 00014, Finland
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Hanssen KS, Witter MP, Sandvig A, Sandvig I, Kobro-Flatmoen A. Dissection and culturing of adult lateral entorhinal cortex layer II neurons from APP/PS1 Alzheimer model mice. J Neurosci Methods 2023; 390:109840. [PMID: 36948358 DOI: 10.1016/j.jneumeth.2023.109840] [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: 12/06/2022] [Revised: 03/03/2023] [Accepted: 03/17/2023] [Indexed: 03/24/2023]
Abstract
BACKGROUND Primary neuronal cultures enable cell-biological studies of Alzheimer's disease (AD), albeit typically non-neuron-specific. The first cortical neurons affected in AD reside in layer II of the lateralmost part of the entorhinal cortex, and they undergo early accumulation of intracellular amyloid-β, form subsequent tau pathology, and start degenerating pre-symptomatically. These vulnerable entorhinal neurons uniquely express the glycoprotein reelin and provide selective inputs to the hippocampal memory system. Gaining a more direct access to study these neurons is therefore highly relevant. NEW METHOD We demonstrate a methodological approach for dissection and long-term culturing of adult lateral entorhinal layer II-neurons from AD-model mice. RESULTS We maintain adult dissected lateralmost entorhinal layer II-neurons beyond two months in culture. We show that they express neuronal markers, and that they are electrophysiologically active by 15 days in vitro and continuing beyond 2 months. COMPARISON WITH EXISTING METHODS Primary neurons are typically harvested from embryonic or early postnatal brains because such neurons are easier to culture compared to adult neurons. Methods to culture adult primary neurons have been reported, however, to our knowledge, culturing of adult entorhinal neuron-type specific primary neurons from AD-model animals have not been reported. CONCLUSIONS Our methodological approach offers a window to study initial pathological changes in the AD disease-cascade. This includes the study of proteinopathy, single-neuron changes, and network-level dysfunction.
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Affiliation(s)
- Katrine Sjaastad Hanssen
- Kavli Institute for Systems Neuroscience, Centre for Neural Computation, Egil and Pauline Braathen and Fred Kavli Centre for Cortical Microcircuits, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway
| | - Menno P Witter
- Kavli Institute for Systems Neuroscience, Centre for Neural Computation, Egil and Pauline Braathen and Fred Kavli Centre for Cortical Microcircuits, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; K.G. Jebsen Centre for Alzheimer's Disease, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway
| | - Axel Sandvig
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway; Umeå University Hospital, Division of Neuro, Head and Neck, Umeå, Sweden; Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden; Department of Neurology and Clinical Neurophysiology, St Olav´s Hospital, Trondheim, Norway
| | - Ioanna Sandvig
- Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway
| | - Asgeir Kobro-Flatmoen
- Kavli Institute for Systems Neuroscience, Centre for Neural Computation, Egil and Pauline Braathen and Fred Kavli Centre for Cortical Microcircuits, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; K.G. Jebsen Centre for Alzheimer's Disease, Faculty of Medicine and Health Sciences, NTNU, Trondheim, Norway.
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Goshi N, Kim H, Girardi G, Gardner A, Seker E. Electrophysiological Activity of Primary Cortical Neuron-Glia Mixed Cultures. Cells 2023; 12:cells12050821. [PMID: 36899957 PMCID: PMC10001406 DOI: 10.3390/cells12050821] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/17/2023] [Accepted: 02/28/2023] [Indexed: 03/09/2023] Open
Abstract
Neuroinflammation plays a central role in many neurological disorders, ranging from traumatic brain injuries to neurodegeneration. Electrophysiological activity is an essential measure of neuronal function, which is influenced by neuroinflammation. In order to study neuroinflammation and its electrophysiological fingerprints, there is a need for in vitro models that accurately capture the in vivo phenomena. In this study, we employed a new tri-culture of primary rat neurons, astrocytes, and microglia in combination with extracellular electrophysiological recording techniques using multiple electrode arrays (MEAs) to determine the effect of microglia on neural function and the response to neuroinflammatory stimuli. Specifically, we established the tri-culture and its corresponding neuron-astrocyte co-culture (lacking microglia) counterpart on custom MEAs and monitored their electrophysiological activity for 21 days to assess culture maturation and network formation. As a complementary assessment, we quantified synaptic puncta and averaged spike waveforms to determine the difference in excitatory to inhibitory neuron ratio (E/I ratio) of the neurons. The results demonstrate that the microglia in the tri-culture do not disrupt neural network formation and stability and may be a better representation of the in vivo rat cortex due to its more similar E/I ratio as compared to more traditional isolated neuron and neuron-astrocyte co-cultures. In addition, only the tri-culture displayed a significant decrease in both the number of active channels and spike frequency following pro-inflammatory lipopolysaccharide exposure, highlighting the critical role of microglia in capturing electrophysiological manifestations of a representative neuroinflammatory insult. We expect the demonstrated technology to assist in studying various brain disease mechanisms.
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Affiliation(s)
- Noah Goshi
- Department of Biomedical Engineering, University of California—Davis, Davis, CA 95616, USA
| | - Hyehyun Kim
- Department of Biomedical Engineering, University of California—Davis, Davis, CA 95616, USA
| | - Gregory Girardi
- Department of Biomedical Engineering, University of California—Davis, Davis, CA 95616, USA
| | - Alexander Gardner
- Department of Electrical and Computer Engineering, University of California—Davis, Davis, CA 95616, USA
| | - Erkin Seker
- Department of Electrical and Computer Engineering, University of California—Davis, Davis, CA 95616, USA
- Correspondence:
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6
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Habibey R. Incubator-independent perfusion system integrated with microfluidic device for continuous electrophysiology and microscopy readouts. Biofabrication 2023; 15. [PMID: 36652708 DOI: 10.1088/1758-5090/acb466] [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: 09/02/2022] [Accepted: 01/18/2023] [Indexed: 01/20/2023]
Abstract
Advances in primary and stem cell derived neuronal cell culture techniques and abundance of available neuronal cell types have enabledin vitroneuroscience as a substantial approach to modelin vivoneuronal networks. Survival of the cultured neurons is inevitably dependent on the cell culture incubators to provide stable temperature and humidity and to supply required CO2levels for controlling the pH of culture medium. Therefore, imaging and electrophysiology recordings outside of the incubator are often limited to the short-term experimental sessions. This restricts our understanding of physiological events to the short snapshots of recorded data while the major part of temporal data is neglected. Multiple custom-made and commercially available platforms like integrated on-stage incubators have been designed to enable long-term microscopy. Nevertheless, long-term high-spatiotemporal electrophysiology recordings from developing neuronal networks needs to be addressed. In the present work an incubator-independent polydimethylsiloxane-based double-wall perfusion chamber was designed and integrated with multi-electrode arrays (MEAs) electrophysiology and compartmentalized microfluidic device to continuously record from engineered neuronal networks at sub-cellular resolution. Cell culture media underwent iterations of conditioning to the ambient CO2and adjusting its pH to physiological ranges to retain a stable pH for weeks outside of the incubator. Double-wall perfusion chamber and an integrated air bubble trapper reduced media evaporation and osmolality drifts of the conditioned media for two weeks. Aligned microchannel-microfluidic device on MEA electrodes allowed neurite growth on top of the planar electrodes and amplified their extracellular activity. This enabled continuous sub-cellular resolution imaging and electrophysiology recordings from developing networks and their growing neurites. The on-chip versatile and self-contained system provides long-term, continuous and high spatiotemporal access to the network data and offers a robustin vitroplatform with many potentials to be applied on advanced cell culture systems including organ-on-chip and organoid models.
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Affiliation(s)
- Rouhollah Habibey
- Department of Ophthalmology, Universitäts-Augenklinik Bonn, University of Bonn, Ernst-Abbe-Straße 2, D-53127 Bonn, Germany.,CRTD-Center for Regenerative Therapies TU Dresden, 01307 Dresden, Germany
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7
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Abend A, Steele C, Schmidt S, Frank R, Jahnke HG, Zink M. Neuronal and glial cell co-culture organization and impedance spectroscopy on nanocolumnar TiN films for lab-on-a-chip devices. Biomater Sci 2022; 10:5719-5730. [PMID: 36039696 DOI: 10.1039/d2bm01066f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lab-on-a-chip devices, such as multielectrode arrays (MEAs), offer great advantages to study function and behavior of biological cells, such as neurons, outside the complex tissue structure. Nevertheless, in vitro systems can only succeed if they represent realistic conditions such as cell organization as similarly found in tissues. In our study, we employ a co-culture system of neuron-like (SH-SY5Y) and glial-like (U-87 MG) cells with various neuron-glial ratios to model different brain regions with different cellular compositions in vitro. We find that cell behavior in terms of cellular organization, as well as proliferation, depends on neuron-glial cell ratio, as well as the underlying substrate material. In fact, nanocolumnar titanium nitride (TiN nano), which exhibits improved electric properties for neural recording on MEA, shows improved biocompatible features compared to indium tin oxide (ITO). Moreover, electrochemical impedance spectroscopy experiments allow us to monitor cellular processes label-free in real-time over several days with multielectrode arrays. Additionally, electrochemical impedance experiments reveal superiority of TiN with nanocolumnar surface modification in comparison with ITO. TiN nano exhibits enhanced relative cell signals and improved signal-to-noise ratio, especially for smaller electrode sizes, which makes nanocolumnar TiN a promising candidate for research on neural recording and stimulation.
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Affiliation(s)
- Alice Abend
- Research Group Biotechnology and Biomedicine, Peter Debye Institute for Soft Matter Physics, Leipzig University, 04103 Leipzig, Germany.
| | - Chelsie Steele
- Research Group Biotechnology and Biomedicine, Peter Debye Institute for Soft Matter Physics, Leipzig University, 04103 Leipzig, Germany.
| | - Sabine Schmidt
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, 04103 Leipzig, Germany
| | - Ronny Frank
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, 04103 Leipzig, Germany
| | - Heinz-Georg Jahnke
- Centre for Biotechnology and Biomedicine, Molecular Biological-Biochemical Processing Technology, Leipzig University, 04103 Leipzig, Germany
| | - Mareike Zink
- Research Group Biotechnology and Biomedicine, Peter Debye Institute for Soft Matter Physics, Leipzig University, 04103 Leipzig, Germany.
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The Association between Hypoxia-Induced Low Activity and Apoptosis Strongly Resembles That between TTX-Induced Silencing and Apoptosis. Int J Mol Sci 2022; 23:ijms23052754. [PMID: 35269895 PMCID: PMC8911517 DOI: 10.3390/ijms23052754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/16/2022] [Accepted: 02/26/2022] [Indexed: 01/27/2023] Open
Abstract
In the penumbra of a brain infarct, neurons initially remain structurally intact, but perfusion is insufficient to maintain neuronal activity at physiological levels. Improving neuronal recovery in the penumbra has large potential to advance recovery of stroke patients, but penumbral pathology is incompletely understood, and treatments are scarce. We hypothesize that low activity in the penumbra is associated with apoptosis and thus contributes to irreversible neuronal damage. We explored the putative relationship between low neuronal activity and apoptosis in cultured neurons exposed to variable durations of hypoxia or TTX. We combined electrophysiology and live apoptosis staining in 42 cultures, and compared effects of hypoxia and TTX silencing in terms of network activity and apoptosis. Hypoxia rapidly reduced network activity, but cultures showed limited apoptosis during the first 12 h. After 24 h, widespread apoptosis had occurred. This was associated with full activity recovery observed upon reoxygenation within 12 h, but not after 24 h. Similarly, TTX exposure strongly reduced activity, with full recovery upon washout within 12 h, but not after 24 h. Mean temporal evolution of apoptosis in TTX-treated cultures was the same as in hypoxic cultures. These results suggest that prolonged low activity may be a common factor in the pathways towards apoptosis.
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9
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Moretti J, Rodger J. A little goes a long way: Neurobiological effects of low intensity rTMS and implications for mechanisms of rTMS. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 3:100033. [PMID: 36685761 PMCID: PMC9846462 DOI: 10.1016/j.crneur.2022.100033] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 01/26/2022] [Accepted: 02/15/2022] [Indexed: 01/25/2023] Open
Abstract
Repetitive transcranial magnetic stimulation (rTMS) is a widespread technique in neuroscience and medicine, however its mechanisms are not well known. In this review, we consider intensity as a key therapeutic parameter of rTMS, and review the studies that have examined the biological effects of rTMS using magnetic fields that are orders of magnitude lower that those currently used in the clinic. We discuss how extensive characterisation of "low intensity" rTMS has set the stage for translation of new rTMS parameters from a mechanistic evidence base, with potential for innovative and effective therapeutic applications. Low-intensity rTMS demonstrates neurobiological effects across healthy and disease models, which include depression, injury and regeneration, abnormal circuit organisation, tinnitus etc. Various short and long-term changes to metabolism, neurotransmitter release, functional connectivity, genetic changes, cell survival and behaviour have been investigated and we summarise these key changes and the possible mechanisms behind them. Mechanisms at genetic, molecular, cellular and system levels have been identified with evidence that low-intensity rTMS and potentially rTMS in general acts through several key pathways to induce changes in the brain with modulation of internal calcium signalling identified as a major mechanism. We discuss the role that preclinical models can play to inform current clinical research as well as uncover new pathways for investigation.
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Affiliation(s)
- Jessica Moretti
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia,Perron Institute for Neurological and Translational Science, Perth, WA, Australia
| | - Jennifer Rodger
- School of Biological Sciences, The University of Western Australia, Perth, WA, Australia,Perron Institute for Neurological and Translational Science, Perth, WA, Australia,Corresponding author. School of Biological Sciences M317, The University of Western Australia, 35 Stirling Highway, Crawley WA, 6009, Australia.
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10
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Salmina AB, Malinovskaya NA, Morgun AV, Khilazheva ED, Uspenskaya YA, Illarioshkin SN. Reproducibility of developmental neuroplasticity in in vitro brain tissue models. Rev Neurosci 2022; 33:531-554. [PMID: 34983132 DOI: 10.1515/revneuro-2021-0137] [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: 10/13/2021] [Accepted: 12/13/2021] [Indexed: 11/15/2022]
Abstract
The current prevalence of neurodevelopmental, neurodegenerative diseases, stroke and brain injury stimulates studies aimed to identify new molecular targets, to select the drug candidates, to complete the whole set of preclinical and clinical trials, and to implement new drugs into routine neurological practice. Establishment of protocols based on microfluidics, blood-brain barrier- or neurovascular unit-on-chip, and microphysiological systems allowed improving the barrier characteristics and analyzing the regulation of local microcirculation, angiogenesis, and neurogenesis. Reconstruction of key mechanisms of brain development and even some aspects of experience-driven brain plasticity would be helpful in the establishment of brain in vitro models with the highest degree of reliability. Activity, metabolic status and expression pattern of cells within the models can be effectively assessed with the protocols of system biology, cell imaging, and functional cell analysis. The next generation of in vitro models should demonstrate high scalability, 3D or 4D complexity, possibility to be combined with other tissues or cell types within the microphysiological systems, compatibility with bio-inks or extracellular matrix-like materials, achievement of adequate vascularization, patient-specific characteristics, and opportunity to provide high-content screening. In this review, we will focus on currently available and prospective brain tissue in vitro models suitable for experimental and preclinical studies with the special focus on models enabling 4D reconstruction of brain tissue for the assessment of brain development, brain plasticity, and drug kinetics.
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Affiliation(s)
- Alla B Salmina
- Laboratory of Experimental Brain Cytology, Research Center of Neurology, Volokolamskoe Highway 80, Moscow, 125367, Russia.,Research Institute of Molecular Medicine & Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, P. Zhelenzyaka str., 1, Krasnoyarsk 660022, Russia
| | - Natalia A Malinovskaya
- Research Institute of Molecular Medicine & Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, P. Zhelenzyaka str., 1, Krasnoyarsk 660022, Russia
| | - Andrey V Morgun
- Department of Ambulatory Pediatrics, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, P. Zheleznyaka str., 1, Krasnoyarsk 660022, Russia
| | - Elena D Khilazheva
- Research Institute of Molecular Medicine & Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, P. Zhelenzyaka str., 1, Krasnoyarsk 660022, Russia
| | - Yulia A Uspenskaya
- Research Institute of Molecular Medicine & Pathobiochemistry, Prof. V.F. Voino-Yasenetsky Krasnoyarsk State Medical University, P. Zhelenzyaka str., 1, Krasnoyarsk 660022, Russia
| | - Sergey N Illarioshkin
- Department of Brain Studies, Research Center of Neurology, Volokolamskoe Highway, 80, Moscow 125367, Russia
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11
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Muzzi L, Di Lisa D, Arnaldi P, Aprile D, Pastorino L, Martinoia S, Frega M. Rapid generation of functional engineered 3D human neuronal assemblies: network dynamics evaluated by micro-electrodes arrays. J Neural Eng 2021; 18. [PMID: 34844234 DOI: 10.1088/1741-2552/ac3e02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 11/29/2021] [Indexed: 12/31/2022]
Abstract
Objective.In this work we adapted a protocol for the fast generation of human neurons to build 3D neuronal networks with controlled structure and cell composition suitable for systematic electrophysiological investigations.Approach.We used biocompatible chitosan microbeads as scaffold to build 3D networks and to ensure nutrients-medium exchange from the core of the structure to the external environment. We used excitatory neurons derived from human-induced pluripotent stem cells (hiPSCs) co-cultured with astrocytes. By adapting the well-established NgN2 differentiation protocol, we obtained 3D engineered networks with good control over cell density, volume and cell composition. We coupled the 3D neuronal networks to 60-channel micro electrode arrays (MEAs) to monitor and characterize their electrophysiological development. In parallel, we generated two-dimensional neuronal networks cultured on chitosan to compare the results of the two models.Main results.We sustained samples until 60 din vitro(DIV) and 3D cultures were healthy and functional. From the structural point of view, the hiPSC derived neurons were able to adhere to chitosan microbeads and to form a stable 3D assembly thanks to the connections among cells. From a functional point of view, neuronal networks showed spontaneous activity after a couple of weeks.Significance.We presented a particular method to generate 3D engineered cultures for the first time with human-derived neurons coupled to MEAs, overcoming some of the limitations related to 2D and 3D neuronal networks and thus increasing the therapeutic target potential of these models for biomedical applications.
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Affiliation(s)
- L Muzzi
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - D Di Lisa
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - P Arnaldi
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - D Aprile
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - L Pastorino
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - S Martinoia
- Department of Informatics, Bioengineering, Robotics, and Systems Engineering (DIBRIS), University of Genova, Genova, Italy
| | - M Frega
- Department of Clinical Neurophysiology, University of Twente, 7522 NB Enschede, The Netherlands.,Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, 6500 HB Nijmegen, The Netherlands
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12
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Machnik P, Schuster S. Recording from an Identified Neuron Efficiently Reveals Hazard for Brain Function in Risk Assessment. Molecules 2021; 26:molecules26226935. [PMID: 34834026 PMCID: PMC8622100 DOI: 10.3390/molecules26226935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 11/16/2022] Open
Abstract
Modern societies use a continuously growing number of chemicals. Because these are released into the environment and are taken up by humans, rigorous (but practicable) risk assessment must precede the approval of new substances for commerce. A number of tests is applicable, but it has been very difficult to efficiently assay the effect of chemicals on communication and information processing in vivo in the adult vertebrate brain. Here, we suggest a straightforward way to rapidly and accurately detect effects of chemical exposure on action potential generation, synaptic transmission, central information processing, and even processing in sensory systems in vivo by recording from a single neuron. The approach is possible in an identified neuron in the hindbrain of fish that integrates various sources of information and whose properties are ideal for rapid analysis of the various effects chemicals can have on the nervous system. The analysis uses fish but, as we discuss here, key neuronal functions are conserved and differences can only be due to differences in metabolism or passage into the brain, factors that can easily be determined. Speed and efficiency of the method, therefore, make it suitable to provide information in risk assessment, as we illustrate here with the effects of bisphenols on adult brain function.
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13
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Secreted Reporter Assay Enables Quantitative and Longitudinal Monitoring of Neuronal Activity. eNeuro 2021; 8:ENEURO.0518-20.2021. [PMID: 34531280 PMCID: PMC8489021 DOI: 10.1523/eneuro.0518-20.2021] [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: 11/30/2020] [Revised: 08/23/2021] [Accepted: 09/08/2021] [Indexed: 11/21/2022] Open
Abstract
The ability to measure changes in neuronal activity in a quantifiable and precise manner is of fundamental importance to understand neuron development and function. Repeated monitoring of neuronal activity of the same population of neurons over several days is challenging and, typically, low-throughput. Here, we describe a new biochemical reporter assay that allows for repeated measurements of neuronal activity in a cell type-specific manner. We coupled activity-dependent elements from the Arc/Arg3.1 gene with a secreted reporter, Gaussia luciferase (Gluc), to quantify neuronal activity without sacrificing the neurons. The reporter predominantly senses calcium and NMDA receptor (NMDAR)-dependent activity. By repeatedly measuring the accumulation of the reporter in cell media, we can profile the developmental dynamics of neuronal activity in cultured neurons from male and female mice. The assay also allows for longitudinal analysis of pharmacological treatments, thus distinguishing acute from delayed responses. Moreover, conditional expression of the reporter allows for monitoring cell type-specific changes. This simple, quantitative, cost-effective, automatable, and cell type-specific activity reporter is a valuable tool to study the development of neuronal activity in normal and disease-model conditions, and to identify small molecules or protein factors that selectively modulate the activity of a specific population of neurons.
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14
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Fu SC, Lin JW, Liu JM, Liu SH, Fang KM, Su CC, Hsu RJ, Wu CC, Huang CF, Lee KI, Chen YW. Arsenic induces autophagy-dependent apoptosis via Akt inactivation and AMPK activation signaling pathways leading to neuronal cell death. Neurotoxicology 2021; 85:133-144. [PMID: 34038756 DOI: 10.1016/j.neuro.2021.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 12/19/2022]
Abstract
Inorganic arsenic (As3+), a well-known worldwide industrial and environmental pollutant, has been linked to neurodegenerative disorders (NDs). Autophagy plays an important role in controlling neuronal cell survival/death. However, limited information is available regarding the toxicological mechanism at the interplay between autophagy and As3+-induced neurotoxicity. The present study found that As3+ exposure induced a concomitant activation of apoptosis and autophagy in Neuro-2a cells, which was accompanied with the increase of phosphatidylserine exposure on outer membrane leaflets and apoptotic cell population, and the activation of caspase-3, -7, and PARP as well as the elevation of protein expressions of LC3-II, Atg-5, and Beclin-1, and the accumulation of autophagosome. Pretreatment of cells with autophagy inhibitor 3-MA, but not that of Z-VAD-FMK (a pan-caspase inhibitor), effectively prevented the As3+-induced autophagic and apoptotic responses, indicating that As3+-triggered autophagy was contributing to neuronal cell apoptosis. Furthermore, As3+ exposure evoked the dephosphorylation of Akt. Pretreatment with SC79, an Akt activator, could significantly attenuated As3+-induced Akt inactivation as well as autophagic and apoptotic events. Expectedly, inhibition of Akt signaling with LY294002 obviously enhanced As3+-triggered autophagy and apoptosis. Exposure to As3+ also dramatically increased the phosphorylation level of AMPKα. Pretreatment of AMPK inhibitor (Compound C) could markedly abrogate the As3+-induced phosphorylated AMPKα expression, and autophagy and apoptosis activation. Taken together, these results indicated that As3+ exerted its cytotoxicity in neuronal cells via the Akt inactivation/AMPK activation downstream-regulated autophagy-dependent apoptosis pathways, which ultimately lead to cell death. Our findings suggest that the regulation of Akt/AMPK signals may be a promising intervention to against As3+-induced neurotoxicity and NDs.
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Affiliation(s)
- Shih-Chang Fu
- Division of Urology, Department of Surgery, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, 330, Taiwan
| | - Jhe-Wei Lin
- Department of Physiology and Graduate Institute of Basic Medical Science, School of Medicine, College of Medicine, China Medical University, Taichung, 404, Taiwan
| | - Jui-Ming Liu
- Division of Urology, Department of Surgery, Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, 330, Taiwan
| | - Shing-Hwa Liu
- Institute of Toxicology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan
| | - Kai-Min Fang
- Department of Otolaryngology, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan
| | - Chin-Chuan Su
- Department of Otorhinolaryngology, Head and Neck Surgery, Changhua Christian Hospital, Changhua County, 500, Taiwan; School of Medicine, Kaohsiung Medical University, Kaohsiung, 807, Taiwan
| | - Ren-Jun Hsu
- Department of Pathology and Graduate Institute of Pathology and Parasitology, Tri-Service General Hospital, Taiwan; Biobank Management Center of Tri-Service General Hospital and Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, 114, Taiwan
| | - Chin-Ching Wu
- Department of Public Health, China Medical University, Taichung, 404, Taiwan
| | - Chun-Fa Huang
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, 404, Taiwan; Department of Nursing, College of Medical and Health Science, Asia University, Taichung, 413, Taiwan
| | - Kuan-I Lee
- Department of Emergency, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, 427, Taiwan.
| | - Ya-Wen Chen
- Department of Physiology and Graduate Institute of Basic Medical Science, School of Medicine, College of Medicine, China Medical University, Taichung, 404, Taiwan.
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15
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Advances in 3D neuronal microphysiological systems: towards a functional nervous system on a chip. In Vitro Cell Dev Biol Anim 2021; 57:191-206. [PMID: 33438114 PMCID: PMC7802613 DOI: 10.1007/s11626-020-00532-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/16/2020] [Indexed: 12/18/2022]
Abstract
Microphysiological systems (MPS) designed to study the complexities of the peripheral and central nervous systems have made marked improvements over the years and have allowed researchers to assess in two and three dimensions the functional interconnectivity of neuronal tissues. The recent generation of brain organoids has further propelled the field into the nascent recapitulation of structural, functional, and effective connectivities which are found within the native human nervous system. Herein, we will review advances in culture methodologies, focused especially on those of human tissues, which seek to bridge the gap from 2D cultures to hierarchical and defined 3D MPS with the end goal of developing a robust nervous system-on-a-chip platform. These advances have far-reaching implications within basic science, pharmaceutical development, and translational medicine disciplines.
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16
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Nikolakopoulou P, Rauti R, Voulgaris D, Shlomy I, Maoz BM, Herland A. Recent progress in translational engineered in vitro models of the central nervous system. Brain 2020; 143:3181-3213. [PMID: 33020798 PMCID: PMC7719033 DOI: 10.1093/brain/awaa268] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 06/17/2020] [Accepted: 06/21/2020] [Indexed: 02/07/2023] Open
Abstract
The complexity of the human brain poses a substantial challenge for the development of models of the CNS. Current animal models lack many essential human characteristics (in addition to raising operational challenges and ethical concerns), and conventional in vitro models, in turn, are limited in their capacity to provide information regarding many functional and systemic responses. Indeed, these challenges may underlie the notoriously low success rates of CNS drug development efforts. During the past 5 years, there has been a leap in the complexity and functionality of in vitro systems of the CNS, which have the potential to overcome many of the limitations of traditional model systems. The availability of human-derived induced pluripotent stem cell technology has further increased the translational potential of these systems. Yet, the adoption of state-of-the-art in vitro platforms within the CNS research community is limited. This may be attributable to the high costs or the immaturity of the systems. Nevertheless, the costs of fabrication have decreased, and there are tremendous ongoing efforts to improve the quality of cell differentiation. Herein, we aim to raise awareness of the capabilities and accessibility of advanced in vitro CNS technologies. We provide an overview of some of the main recent developments (since 2015) in in vitro CNS models. In particular, we focus on engineered in vitro models based on cell culture systems combined with microfluidic platforms (e.g. 'organ-on-a-chip' systems). We delve into the fundamental principles underlying these systems and review several applications of these platforms for the study of the CNS in health and disease. Our discussion further addresses the challenges that hinder the implementation of advanced in vitro platforms in personalized medicine or in large-scale industrial settings, and outlines the existing differentiation protocols and industrial cell sources. We conclude by providing practical guidelines for laboratories that are considering adopting organ-on-a-chip technologies.
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Affiliation(s)
- Polyxeni Nikolakopoulou
- AIMES, Center for the Advancement of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Rossana Rauti
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Dimitrios Voulgaris
- Division of Micro and Nanosystems, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Iftach Shlomy
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Ben M Maoz
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel
| | - Anna Herland
- AIMES, Center for the Advancement of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
- Division of Micro and Nanosystems, KTH Royal Institute of Technology, Stockholm, Sweden
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17
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Enhanced LTP of population spikes in the dentate gyrus of mice haploinsufficient for neurobeachin. Sci Rep 2020; 10:16058. [PMID: 32994505 PMCID: PMC7524738 DOI: 10.1038/s41598-020-72925-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 09/07/2020] [Indexed: 12/16/2022] Open
Abstract
Deletion of the autism candidate molecule neurobeachin (Nbea), a large PH-BEACH-domain containing neuronal protein, has been shown to affect synaptic function by interfering with neurotransmitter receptor targeting and dendritic spine formation. Previous analysis of mice lacking one allele of the Nbea gene identified impaired spatial learning and memory in addition to altered autism-related behaviours. However, no functional data from living heterozygous Nbea mice (Nbea+/−) are available to corroborate the behavioural phenotype. Here, we explored the consequences of Nbea haploinsufficiency on excitation/inhibition balance and synaptic plasticity in the intact hippocampal dentate gyrus of Nbea+/− animals in vivo by electrophysiological recordings. Based on field potential recordings, we show that Nbea+/− mice display enhanced LTP of the granule cell population spike, but no differences in basal synaptic transmission, synapse numbers, short-term plasticity, or network inhibition. These data indicate that Nbea haploinsufficiency causes remarkably specific alterations to granule cell excitability in vivo, which may contribute to the behavioural abnormalities in Nbea+/− mice and to related symptoms in patients.
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18
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Enright HA, Lam D, Sebastian A, Sales AP, Cadena J, Hum NR, Osburn JJ, Peters SKG, Petkus B, Soscia DA, Kulp KS, Loots GG, Wheeler EK, Fischer NO. Functional and transcriptional characterization of complex neuronal co-cultures. Sci Rep 2020; 10:11007. [PMID: 32620908 PMCID: PMC7335084 DOI: 10.1038/s41598-020-67691-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/08/2020] [Indexed: 12/03/2022] Open
Abstract
Brain-on-a-chip systems are designed to simulate brain activity using traditional in vitro cell culture on an engineered platform. It is a noninvasive tool to screen new drugs, evaluate toxicants, and elucidate disease mechanisms. However, successful recapitulation of brain function on these systems is dependent on the complexity of the cell culture. In this study, we increased cellular complexity of traditional (simple) neuronal cultures by co-culturing with astrocytes and oligodendrocyte precursor cells (complex culture). We evaluated and compared neuronal activity (e.g., network formation and maturation), cellular composition in long-term culture, and the transcriptome of the two cultures. Compared to simple cultures, neurons from complex co-cultures exhibited earlier synapse and network development and maturation, which was supported by localized synaptophysin expression, up-regulation of genes involved in mature neuronal processes, and synchronized neural network activity. Also, mature oligodendrocytes and reactive astrocytes were only detected in complex cultures upon transcriptomic analysis of age-matched cultures. Functionally, the GABA antagonist bicuculline had a greater influence on bursting activity in complex versus simple cultures. Collectively, the cellular complexity of brain-on-a-chip systems intrinsically develops cell type-specific phenotypes relevant to the brain while accelerating the maturation of neuronal networks, important features underdeveloped in traditional cultures.
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Affiliation(s)
- Heather A Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - Doris Lam
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Aimy Sebastian
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Ana Paula Sales
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jose Cadena
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas R Hum
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,University of California, Merced, School of Natural Sciences, Merced, CA, USA
| | - Joanne J Osburn
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Sandra K G Peters
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Bryan Petkus
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - David A Soscia
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Kristen S Kulp
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Gabriela G Loots
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,University of California, Merced, School of Natural Sciences, Merced, CA, USA
| | - Elizabeth K Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas O Fischer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
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19
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Etter G, Manseau F, Williams S. A Probabilistic Framework for Decoding Behavior From in vivo Calcium Imaging Data. Front Neural Circuits 2020; 14:19. [PMID: 32499681 PMCID: PMC7243991 DOI: 10.3389/fncir.2020.00019] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 04/06/2020] [Indexed: 11/13/2022] Open
Abstract
Understanding the role of neuronal activity in cognition and behavior is a key question in neuroscience. Previously, in vivo studies have typically inferred behavior from electrophysiological data using probabilistic approaches including Bayesian decoding. While providing useful information on the role of neuronal subcircuits, electrophysiological approaches are often limited in the maximum number of recorded neurons as well as their ability to reliably identify neurons over time. This can be particularly problematic when trying to decode behaviors that rely on large neuronal assemblies or rely on temporal mechanisms, such as a learning task over the course of several days. Calcium imaging of genetically encoded calcium indicators has overcome these two issues. Unfortunately, because calcium transients only indirectly reflect spiking activity and calcium imaging is often performed at lower sampling frequencies, this approach suffers from uncertainty in exact spike timing and thus activity frequency, making rate-based decoding approaches used in electrophysiological recordings difficult to apply to calcium imaging data. Here we describe a probabilistic framework that can be used to robustly infer behavior from calcium imaging recordings and relies on a simplified implementation of a naive Baysian classifier. Our method discriminates between periods of activity and periods of inactivity to compute probability density functions (likelihood and posterior), significance and confidence interval, as well as mutual information. We next devise a simple method to decode behavior using these probability density functions and propose metrics to quantify decoding accuracy. Finally, we show that neuronal activity can be predicted from behavior, and that the accuracy of such reconstructions can guide the understanding of relationships that may exist between behavioral states and neuronal activity.
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Affiliation(s)
- Guillaume Etter
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada
| | | | - Sylvain Williams
- Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada
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20
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Cadena J, Sales AP, Lam D, Enright HA, Wheeler EK, Fischer NO. Modeling the temporal network dynamics of neuronal cultures. PLoS Comput Biol 2020; 16:e1007834. [PMID: 32453727 PMCID: PMC7274455 DOI: 10.1371/journal.pcbi.1007834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/05/2020] [Accepted: 03/31/2020] [Indexed: 11/18/2022] Open
Abstract
Neurons form complex networks that evolve over multiple time scales. In order to thoroughly characterize these networks, time dependencies must be explicitly modeled. Here, we present a statistical model that captures both the underlying structural and temporal dynamics of neuronal networks. Our model combines the class of Stochastic Block Models for community formation with Gaussian processes to model changes in the community structure as a smooth function of time. We validate our model on synthetic data and demonstrate its utility on three different studies using in vitro cultures of dissociated neurons.
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Affiliation(s)
- Jose Cadena
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Ana Paula Sales
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Doris Lam
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Heather A. Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Elizabeth K. Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
| | - Nicholas O. Fischer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, United States of America
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21
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Soscia DA, Lam D, Tooker AC, Enright HA, Triplett M, Karande P, Peters SKG, Sales AP, Wheeler EK, Fischer NO. A flexible 3-dimensional microelectrode array for in vitro brain models. LAB ON A CHIP 2020; 20:901-911. [PMID: 31976505 DOI: 10.1039/c9lc01148j] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Three-dimensional (3D) in vitro models have become increasingly popular as systems to study cell-cell and cell-ECM interactions dependent on the spatial, mechanical, and chemical cues within the environment of the tissue, which is limited in traditional two-dimensional (2D) models. Although electrophysiological recordings of neuronal action potentials through 2D microelectrode arrays (MEAs) are a common and trusted method of evaluating neuronal function, network communication, and response to chemicals and biologicals, there are currently limited options for measuring electrophysiological activity from many locations simultaneously throughout a 3D network of neurons in vitro. Here, we have developed a thin-film, 3D flexible microelectrode array (3DMEA) that non-invasively interrogates a 3D culture of neurons and can accommodate 256 channels of recording or stimulation. Importantly, the 3DMEA is straightforward to fabricate and integrates with standard commercially available electrophysiology hardware. Polyimide probe arrays were microfabricated on glass substrates and mechanically actuated to collectively lift the arrays into a vertical position, relying solely on plastic deformation of their base hinge regions to maintain vertical alignment. Human induced pluripotent stem cell (hiPSC)-derived neurons and astrocytes were entrapped in a collagen-based hydrogel and seeded onto the 3DMEA, enabling growth of suspended cells in the matrix and the formation and maturation of a neural network around the 3DMEA probes. The 3DMEA supported the growth of functional neurons in 3D with action potential spike and burst activity recorded over 45 days in vitro. This platform is an important step in facilitating noninvasive electrophysiological characterization of 3D networks of electroactive cells in vitro.
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Affiliation(s)
- David A Soscia
- Engineering Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA
| | - Doris Lam
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Angela C Tooker
- Engineering Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA
| | - Heather A Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Michael Triplett
- Engineering Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA
| | - Piyush Karande
- Engineering Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA
| | - Sandra K G Peters
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
| | - Ana Paula Sales
- Engineering Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA
| | - Elizabeth K Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA
| | - Nicholas O Fischer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA 94550, USA.
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22
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Carlson LM, Champagne FA, Cory-Slechta DA, Dishaw L, Faustman E, Mundy W, Segal D, Sobin C, Starkey C, Taylor M, Makris SL, Kraft A. Potential frameworks to support evaluation of mechanistic data for developmental neurotoxicity outcomes: A symposium report. Neurotoxicol Teratol 2020; 78:106865. [PMID: 32068112 PMCID: PMC7160758 DOI: 10.1016/j.ntt.2020.106865] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/05/2020] [Accepted: 02/10/2020] [Indexed: 12/16/2022]
Abstract
A key challenge in systematically incorporating mechanistic data into human health assessments is that, compared to studies of apical health endpoints, these data are both more abundant (mechanistic studies routinely outnumber other studies by several orders of magnitude) and more heterogeneous (e.g. different species, test system, tissue, cell type, exposure paradigm, or specific assays performed). A structured decision-making process for organizing, integrating, and weighing mechanistic DNT data for use in human health risk assessments will improve the consistency and efficiency of such evaluations. At the Developmental Neurotoxicology Society (DNTS) 2016 annual meeting, a symposium was held to address the application of existing organizing principles and frameworks for evaluation of mechanistic data relevant to interpreting neurotoxicology data. Speakers identified considerations with potential to advance the use of mechanistic DNT data in risk assessment, including considering the context of each exposure, since epigenetics, tissue type, sex, stress, nutrition and other factors can modify toxicity responses in organisms. It was also suggested that, because behavior is a manifestation of complex nervous system function, the presence and absence of behavioral change itself could be used to organize the interpretation of multiple complex simultaneous mechanistic changes. Several challenges were identified with frameworks and their implementation, and ongoing research to develop these approaches represents an early step toward full evaluation of mechanistic DNT data for assessments.
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Affiliation(s)
- Laura M Carlson
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC.
| | | | - Deborah A Cory-Slechta
- Department of Environmental Medicine, University of Rochester Medical School Rochester, NY
| | - Laura Dishaw
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC
| | - Elaine Faustman
- School of Public Health, Institute for Risk Analysis and Risk Communication, University of Washington, Seattle, WA
| | - William Mundy
- Neurotoxicologist, Durham, NC (formerly National Health and Environmental Effects Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC))
| | - Deborah Segal
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC
| | - Christina Sobin
- Dept of Public Health Sciences, The University of Texas at El Paso, El Paso, Texas, USA
| | - Carol Starkey
- Booz Allen Hamilton (formerly research fellow with the Oak Ridge Institute for Science and Engineering (ORISE) with Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington DC))
| | - Michele Taylor
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC
| | - Susan L Makris
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC
| | - Andrew Kraft
- Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC; Center for Public Health and Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, RTP, NC
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23
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Gilmour A, Poole-Warren L, Green RA. An Improved in vitro Model of Cortical Tissue. Front Neurosci 2019; 13:1349. [PMID: 31920510 PMCID: PMC6928009 DOI: 10.3389/fnins.2019.01349] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/02/2019] [Indexed: 11/20/2022] Open
Abstract
Intracortical electrodes for brain-machine interfaces rely on intimate contact with tissues for recording signals and stimulating neurons. However, the long-term viability of intracortical electrodes in vivo is poor, with a major contributing factor being the development of a glial scar. In vivo approaches for evaluating responses to intracortical devices are resource intensive and complex, making statistically significant, high throughput data difficult to obtain. In vitro models provide an alternative to in vivo studies; however, existing approaches have limitations which restrict the translation of the cellular reactions to the implant scenario. Notably, there is no current robust model that includes astrocytes, microglia, oligodendrocytes and neurons, the four principle cell types, critical to the health, function and wound responses of the central nervous system (CNS). In previous research a co-culture of primary mouse mature mixed glial cells and immature neural precursor cells were shown to mimic several key properties of the CNS response to implanted electrode materials. However, the method was not robust and took up to 63 days, significantly affecting reproducibility and widespread use for assessing brain-material interactions. In the current research a new co-culture approach has been developed and evaluated using immunocytochemistry and quantitative polymerase chain reaction (qPCR). The resulting method reduced the time in culture significantly and the culture model was shown to have a genetic signature similar to that of healthy adult mouse brain. This new robust CNS culture model has the potential to significantly improve the capacity to translate in vitro data to the in vivo responses.
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Affiliation(s)
- Aaron Gilmour
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Clem Jones Centre for Neurobiology and Stem Cell Research, Menzies Health Institute Queensland, Griffiths University, Gold Coast, QLD, Australia
| | - Laura Poole-Warren
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
| | - Rylie A Green
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia
- Department of Bioengineering, Imperial College London, London, United Kingdom
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24
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Optogenetic approaches to study the mammalian brain. Curr Opin Struct Biol 2019; 57:157-163. [PMID: 31082625 DOI: 10.1016/j.sbi.2019.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 03/30/2019] [Accepted: 04/05/2019] [Indexed: 12/24/2022]
Abstract
Optogenetics has revolutionized neurobiological research by allowing to disentangle intricate neuronal circuits at a spatio-temporal precision unmatched by other techniques. Here, we review current advances of optogenetic applications in mammals, especially focusing on freely moving animals. State-of-the-art strategies allow the targeted expression of opsins in neuronal subpopulations, defined either by genetic cell type or neuronal projection pattern. Optogenetic manipulations of these subpopulations become particularly powerful when combined with behavioral paradigms and neurophysiological readout techniques. Thereby, specific roles can be assigned to identified cells. All-optical approaches with the opportunity to write complex three dimensional patterns into neuronal networks have recently emerged. While clinical implications of the new tool set seem tempting, we emphasize here the role of optogenetics for basic research.
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25
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Lam D, Enright HA, Cadena J, Peters SKG, Sales AP, Osburn JJ, Soscia DA, Kulp KS, Wheeler EK, Fischer NO. Tissue-specific extracellular matrix accelerates the formation of neural networks and communities in a neuron-glia co-culture on a multi-electrode array. Sci Rep 2019; 9:4159. [PMID: 30858401 PMCID: PMC6411890 DOI: 10.1038/s41598-019-40128-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 02/08/2019] [Indexed: 11/17/2022] Open
Abstract
The brain’s extracellular matrix (ECM) is a macromolecular network composed of glycosaminoglycans, proteoglycans, glycoproteins, and fibrous proteins. In vitro studies often use purified ECM proteins for cell culture coatings, however these may not represent the molecular complexity and heterogeneity of the brain’s ECM. To address this, we compared neural network activity (over 30 days in vitro) from primary neurons co-cultured with glia grown on ECM coatings from decellularized brain tissue (bECM) or MaxGel, a non-tissue-specific ECM. Cells were grown on a multi-electrode array (MEA) to enable noninvasive long-term interrogation of neuronal networks. In general, the presence of ECM accelerated the formation of networks without affecting the inherent network properties. However, specific features of network activity were dependent on the type of ECM: bECM enhanced network activity over a greater region of the MEA whereas MaxGel increased network burst rate associated with robust synaptophysin expression. These differences in network activity were not attributable to cellular composition, glial proliferation, or astrocyte phenotypes, which remained constant across experimental conditions. Collectively, the addition of ECM to neuronal cultures represents a reliable method to accelerate the development of mature neuronal networks, providing a means to enhance throughput for routine evaluation of neurotoxins and novel therapeutics.
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Affiliation(s)
- Doris Lam
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Heather A Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jose Cadena
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Sandra K G Peters
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Ana Paula Sales
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Joanne J Osburn
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - David A Soscia
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Kristen S Kulp
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Elizabeth K Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas O Fischer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
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