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Abstract
Engineered human mini-brains, made possible by knowledge from the convergence of precision microengineering and cell biology, permit systematic studies of complex neurological processes and of pathogenesis beyond what can be done with animal models. By culturing human brain cells with physiological microenvironmental cues, human mini-brain models reconstitute the arrangement of structural tissues and some of the complex biological functions of the human brain. In this Review, we highlight the most significant developments that have led to microphysiological human mini-brain models. We introduce the history of mini-brain development, review methods for creating mini-brain models in static conditions, and discuss relevant state-of-the-art dynamic cell-culture systems. We also review human mini-brain models that reconstruct aspects of major neurological disorders under static or dynamic conditions. Engineered human mini-brains will contribute to advancing the study of the physiology and aetiology of neurological disorders, and to the development of personalized medicines for them.
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Alshammari MA, Khan MR, Alasmari F, Alshehri AO, Ali R, Boudjelal M, Alhosaini KA, Niazy AA, Alshammari TK. Changes in the Fluorescence Tracking of NaV1.6 Protein Expression in a BTBR T+Itpr3tf/J Autistic Mouse Model. Neural Plast 2019; 2019:4893103. [PMID: 31933626 DOI: 10.1155/2019/4893103] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/28/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
The axon initial segment (AIS), the site of action potential initiation in neurons, is a critical determinant of neuronal excitability. Growing evidence indicates that appropriate recruitment of the AIS macrocomplex is essential for synchronized firing. However, disruption of the AIS structure is linked to the etiology of multiple disorders, including autism spectrum disorder (ASD), a condition characterized by deficits in social communication, stereotyped behaviors, and very limited interests. To date, a complete understanding of the molecular components that underlie the AIS in ASD has remained elusive. In this research, we examined the AIS structure in a BTBR T+Itpr3tf/J mouse model (BTBR), a valid model that exhibits behavioral, electrical, and molecular features of autism, and compared this to the C57BL/6J wild-type control mouse. Using Western blot studies and high-resolution confocal microscopy in the prefrontal frontal cortex (PFC), our data indicate disrupted expression of different isoforms of the voltage-gated sodium channels (NaV) at the AIS, whereas other components of AIS such as ankyrin-G and fibroblast growth factor 14 (FGF14) and contactin-associated protein 1 (Caspr) in BTBR were comparable to those in wild-type control mice. A Western blot assay showed that BTBR mice exhibited a marked increase in different sodium channel isoforms in the PFC compared to wild-type mice. Our results provide potential evidence for previously undescribed mechanisms that may play a role in the pathogenesis of autistic-like phenotypes in BTBR mice.
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Dhobale AV, Adewole DO, Chan AHW, Marinov T, Serruya MD, Kraft RH, Cullen DK. Assessing functional connectivity across 3D tissue engineered axonal tracts using calcium fluorescence imaging. J Neural Eng 2018; 15:056008. [PMID: 29855432 PMCID: PMC6999858 DOI: 10.1088/1741-2552/aac96d] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Micro-tissue engineered neural networks (micro-TENNs) are anatomically-inspired constructs designed to structurally and functionally emulate white matter pathways in the brain. These 3D neural networks feature long axonal tracts spanning discrete neuronal populations contained within a tubular hydrogel, and are being developed to reconstruct damaged axonal pathways in the brain as well as to serve as physiologically-relevant in vitro experimental platforms. The goal of the current study was to characterize the functional properties of these neuronal and axonal networks. APPROACH Bidirectional micro-TENNs were transduced to express genetically-encoded calcium indicators, and spontaneous fluorescence activity was recorded using real-time microscopy at 20 Hz from specific regions-of-interest in the neuronal populations. Network activity patterns and functional connectivity across the axonal tracts were then assessed using various techniques from statistics and information theory including Pearson cross-correlation, phase synchronization matrices, power spectral analysis, directed transfer function, and transfer entropy. MAIN RESULTS Pearson cross-correlation, phase synchronization matrices, and power spectral analysis revealed high values of correlation and synchronicity between the spatially segregated neuronal clusters connected by axonal tracts. Specifically, phase synchronization revealed high synchronicity of >0.8 between micro-TENN regions of interest. Normalized directed transfer function and transfer entropy matrices suggested robust information flow between the neuronal populations. Time varying power spectrum analysis revealed the strength of information propagation at various frequencies. Signal power strength was visible at elevated peak levels for dominant delta (1-4 Hz) and theta (4-8 Hz) frequency bands and progressively weakened at higher frequencies. These signal power strength results closely matched normalized directed transfer function analysis where near synchronous information flow was detected between frequencies of 2-5 Hz. SIGNIFICANCE To our knowledge, this is the first report using directed transfer function and transfer entropy methods based on fluorescent calcium activity to estimate functional connectivity of distinct neuronal populations via long-projecting, 3D axonal tracts in vitro. These functional data will further improve the design and optimization of implantable neural networks that could ultimately be deployed to reconstruct the nervous system to treat neurological disease and injury.
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Affiliation(s)
- Anjali Vijay Dhobale
- The Penn State Computational Biomechanics Group, The Pennsylvania State University, University Park, PA, USA
| | - Dayo O. Adewole
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Andy Ho Wing Chan
- Department of Neurology and Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Toma Marinov
- The Penn State Computational Biomechanics Group, The Pennsylvania State University, University Park, PA, USA
| | - Mijail D. Serruya
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
- Department of Neurology and Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Reuben H. Kraft
- The Penn State Computational Biomechanics Group, The Pennsylvania State University, University Park, PA, USA
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA, USA
| | - D. Kacy Cullen
- Center for Brain Injury & Repair, Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Center for Neurotrauma, Neurodegeneration & Restoration, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
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Tang-Schomer MD, Jackvony T, Santaniello S. Cortical Network Synchrony Under Applied Electrical Field in vitro. Front Neurosci 2018; 12:630. [PMID: 30297981 PMCID: PMC6160828 DOI: 10.3389/fnins.2018.00630] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Accepted: 08/22/2018] [Indexed: 01/11/2023] Open
Abstract
Synchronous network activity plays a crucial role in complex brain functions. Stimulating the nervous system with applied electric field (EF) is a common tool for probing network responses. We used a gold wire-embedded silk protein film-based interface culture to investigate the effects of applied EFs on random cortical networks of in vitro cultures. Two-week-old cultures were exposed to EF of 27 mV/mm for <1 h and monitored by time-lapse calcium imaging. Network activity was represented by calcium signal time series mapped to source neurons and analyzed by using a community detection algorithm. Cortical cultures exhibited large scale, synchronized oscillations under alternating EF of changing frequencies. Field polarity and frequency change were both found to be necessary for network synchrony, as monophasic pulses of similar frequency changes or EF of a constant frequency failed to induce correlated activities of neurons. Group-specific oscillatory patterns were entrained by network-level synchronous oscillations when the alternating EF frequency was increased from 0.2 Hz to 200 kHz. Binary responses of either activity increase or decrease contributed to the opposite phase patterns of different sub-populations. Conversely, when the EF frequency decreased over the same range span, more complex behavior emerged showing group-specific amplitude and phase patterns. These findings formed the basis of a hypothesized network control mechanism for temporal coordination of distributed neuronal activity, involving coordinated stimulation by alternating polarity, and time delay by change of frequency. These novel EF effects on random neural networks have important implications for brain functional studies and neuromodulation applications.
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Affiliation(s)
- Min D Tang-Schomer
- Department of Pediatrics, UConn Health, Connecticut Children's Medical Center, Farmington, CT, United States.,The Jackson Laboratory for Genomic Medicine, Farmington, CT, United States.,CT Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, CT, United States
| | - Taylor Jackvony
- School of Medicine, UConn Health, University of Connecticut, Farmington, CT, United States
| | - Sabato Santaniello
- CT Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, CT, United States.,Biomedical Engineering Department, University of Connecticut, Storrs, CT, United States
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Prox J, Smith T, Holl C, Chehade N, Guo L. Integrated biocircuits: engineering functional multicellular circuits and devices. J Neural Eng 2018; 15:023001. [DOI: 10.1088/1741-2552/aaa906] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Tang-schomer MD. 3D axon growth by exogenous electrical stimulus and soluble factors. Brain Res 2018; 1678:288-96. [DOI: 10.1016/j.brainres.2017.10.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 10/28/2017] [Indexed: 11/24/2022]
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Han Y, Li H, Lang Y, Zhao Y, Sun H, Zhang P, Ma X, Han J, Wang Q, Zhou J, Wang C. The Effects of Acute GABA Treatment on the Functional Connectivity and Network Topology of Cortical Cultures. Neurochem Res 2017; 42:1394-1402. [PMID: 28290133 DOI: 10.1007/s11064-017-2190-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 12/05/2016] [Accepted: 01/20/2017] [Indexed: 02/05/2023]
Abstract
γ-Aminobutyric acid (GABA) is an inhibitory transmitter, acting on receptor channels to reduce neuronal excitability in matured neural systems. However, electrophysiological responses of whole neuronal ensembles to the exposure to GABA are still unclear. We used micro-electrode arrays (MEAs) to study the effects of the increasing amount of GABA on functional network of cortical neural cultures. Then the recorded data were analyzed by the cross-covariance analysis and graph theory. Results showed that after the GABA treatment, the activity parameters of firing rate, bursting rate, bursting duration and network burst frequency in neural cultures decreased as expected. In addition, the functional connectivity also decreased in similarity, network density, and the size of the largest component. However, small-worldness was not found to be influenced by the acute GABA treatment. Our results support the position that using graph theory to evaluate the functional connectivity of neural cultures may enhance understanding of the pharmacological impact of neurotransmitters on neuronal networks.
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Affiliation(s)
- Yao Han
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Hong Li
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Yiran Lang
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Yuwei Zhao
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Hongji Sun
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Peng Zhang
- Neural Interface& Rehabilitation Technology Research Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Xuan Ma
- Neural Interface& Rehabilitation Technology Research Center, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jiuqi Han
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Qiyu Wang
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China
| | - Jin Zhou
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China.
| | - Changyong Wang
- Department of advanced Interdisciplinary Studies, Institute of Basic Medical Sciences and Tissue Engineering Research Center, Academy of Military Medical Sciences, Beijing, People's Republic of China.
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Shaban H, O’Connor R, Ovsepian SV, Dinan TG, Cryan JF, Schellekens H. Electrophysiological approaches to unravel the neurobiological basis of appetite and satiety: use of the multielectrode array as a screening strategy. Drug Discov Today 2017; 22:31-42. [DOI: 10.1016/j.drudis.2016.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/03/2016] [Accepted: 09/06/2016] [Indexed: 01/10/2023]
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Hasan MF, Berdichevsky Y. Neural Circuits on a Chip. Micromachines (Basel) 2016; 7:E157. [PMID: 30404330 DOI: 10.3390/mi7090157] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/20/2016] [Accepted: 08/29/2016] [Indexed: 02/07/2023]
Abstract
Neural circuits are responsible for the brain's ability to process and store information. Reductionist approaches to understanding the brain include isolation of individual neurons for detailed characterization. When maintained in vitro for several days or weeks, dissociated neurons self-assemble into randomly connected networks that produce synchronized activity and are capable of learning. This review focuses on efforts to control neuronal connectivity in vitro and construct living neural circuits of increasing complexity and precision. Microfabrication-based methods have been developed to guide network self-assembly, accomplishing control over in vitro circuit size and connectivity. The ability to control neural connectivity and synchronized activity led to the implementation of logic functions using living neurons. Techniques to construct and control three-dimensional circuits have also been established. Advances in multiple electrode arrays as well as genetically encoded, optical activity sensors and transducers enabled highly specific interfaces to circuits composed of thousands of neurons. Further advances in on-chip neural circuits may lead to better understanding of the brain.
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Abstract
Despite huge efforts to decipher the anatomy, composition and function of the brain, it remains the least understood organ of the human body. To gain a deeper comprehension of the neural system scientists aim to simplistically reconstruct the tissue by assembling it in vitro from basic building blocks using a tissue engineering approach. Our group developed a tissue-engineered silk and collagen-based 3D brain-like model resembling the white and gray matter of the cortex. The model consists of silk porous sponge, which is pre-seeded with rat brain-derived neurons, immersed in soft collagen matrix. Polarized neuronal outgrowth and network formation is observed with separate axonal and cell body localization. This compartmental architecture allows for the unique development of niches mimicking native neural tissue, thus enabling research on neuronal network assembly, axonal guidance, cell-cell and cell-matrix interactions and electrical functions.
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Affiliation(s)
| | - Disha Sood
- Department of Biomedical Engineering, Tufts University
| | | | - James D White
- Department of Biomedical Engineering, Tufts University
| | - Min Tang-Schomer
- Department of Pediatrics, University of Connecticut Health Center & Connecticut Children's Medical Center
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Pan L, Alagapan S, Franca E, Leondopulos SS, DeMarse TB, Brewer GJ, Wheeler BC. An in vitro method to manipulate the direction and functional strength between neural populations. Front Neural Circuits 2015; 9:32. [PMID: 26236198 PMCID: PMC4500931 DOI: 10.3389/fncir.2015.00032] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 06/19/2015] [Indexed: 01/04/2023] Open
Abstract
We report the design and application of a Micro Electro Mechanical Systems (MEMs) device that permits investigators to create arbitrary network topologies. With this device investigators can manipulate the degree of functional connectivity among distinct neural populations by systematically altering their geometric connectivity in vitro. Each polydimethylsilxane (PDMS) device was cast from molds and consisted of two wells each containing a small neural population of dissociated rat cortical neurons. Wells were separated by a series of parallel micrometer scale tunnels that permitted passage of axonal processes but not somata; with the device placed over an 8 × 8 microelectrode array, action potentials from somata in wells and axons in microtunnels can be recorded and stimulated. In our earlier report we showed that a one week delay in plating of neurons from one well to the other led to a filling and blocking of the microtunnels by axons from the older well resulting in strong directionality (older to younger) of both axon action potentials in tunnels and longer duration and more slowly propagating bursts of action potentials between wells. Here we show that changing the number of tunnels, and hence the number of axons, connecting the two wells leads to changes in connectivity and propagation of bursting activity. More specifically, the greater the number of tunnels the stronger the connectivity, the greater the probability of bursting propagating between wells, and shorter peak-to-peak delays between bursts and time to first spike measured in the opposing well. We estimate that a minimum of 100 axons are needed to reliably initiate a burst in the opposing well. This device provides a tool for researchers interested in understanding network dynamics who will profit from having the ability to design both the degree and directionality connectivity among multiple small neural populations.
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Affiliation(s)
- Liangbin Pan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
| | - Sankaraleengam Alagapan
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
| | - Eric Franca
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
| | - Stathis S Leondopulos
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
| | - Thomas B DeMarse
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
| | - Gregory J Brewer
- Department of Biomedical Engineering, University of California Irvine Irvine, CA, USA
| | - Bruce C Wheeler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida Gainesville, FL, USA
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