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Zhai J, Traebert M, Zimmermann K, Delaunois A, Royer L, Salvagiotto G, Carlson C, Lagrutta A. Comparative study for the IMI2-NeuroDeRisk project on microelectrode arrays to derisk drug-induced seizure liability. J Pharmacol Toxicol Methods 2023; 123:107297. [PMID: 37499956 DOI: 10.1016/j.vascn.2023.107297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/01/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
INTRODUCTION In the framework of the IMI2-NeuroDeRisk consortium, three in vitro electrophysiology assays were compared to improve preclinical prediction of seizure-inducing liabilities. METHODS Two cell models, primary rat cortical neurons and human induced pluripotent stem cell (hiPSC)-derived glutamatergic neurons co-cultured with hiPSC-derived astrocytes were tested on two different microelectrode array (MEA) platforms, Maestro Pro (Axion Biosystems) and Multiwell-MEA-System (Multi Channel Systems), in three separate laboratories. Pentylenetetrazole (PTZ) and/or picrotoxin (PTX) were included in each plate as positive (n = 3-6 wells) and ≤0.2% DMSO was used as negative controls (n = 3-12 wells). In general, concentrations in a range of 0.1-30 μM were tested, anchored, when possible, on clinically relevant exposures (unbound Cmax) were tested. Activity thresholds for drug-induced changes were set at 20%. To evaluate sensitivity, specificity and predictivity of the cell models, seizurogenic responses were defined as changes in 4 or more endpoints. Concentration dependence trends were also considered. RESULTS Neuronal activity of 33 compounds categorized as positive tool drugs, seizure-positive or seizure-negative compounds was evaluated. Acute drug effects (<60 min) were compared to baseline recordings. Time points < 15 min exhibited stronger, less variable responses to many of the test agents. For many compounds a reduction and cessation of neuronal activity was detected at higher test concentrations. There was not a single pattern of seizurogenic activity detected, even among tool compounds, likely due to different mechanisms of actions and/or off-target profiles. A post-hoc analysis focusing on changes indicative of neuronal excitation is presented. CONCLUSION All cell models showed good sensitivity, ranging from 70 to 86%. Specificity ranged from 40 to 70%. Compared to more conventional measurements of evoked activity in hippocampal slices, these plate-based models provide higher throughput and the potential to study subacute responses. Yet, they may be limited by the random, spontaneous nature of their network activity.
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Affiliation(s)
- Jin Zhai
- Merck & Co., Inc., Rahway, NJ, USA
| | | | | | | | | | | | - Coby Carlson
- Fujifilm Cellular Dynamics, Inc., Madison, WI, USA
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Lau LA, Staley KJ, Lillis KP. In vitro ictogenesis is stochastic at the single neuron level. Brain 2022; 145:531-541. [PMID: 34431994 PMCID: PMC9014754 DOI: 10.1093/brain/awab312] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/13/2021] [Accepted: 07/30/2021] [Indexed: 11/14/2022] Open
Abstract
Seizure initiation is the least understood and most disabling element of epilepsy. Studies of ictogenesis require high speed recordings at cellular resolution in the area of seizure onset. However, in vivo seizure onset areas cannot be determined at the level of resolution necessary to enable such studies. To circumvent these challenges, we used novel GCaMP7-based calcium imaging in the organotypic hippocampal slice culture model of post-traumatic epilepsy in mice. Organotypic hippocampal slice cultures generate spontaneous, recurrent seizures in a preparation in which it is feasible to image the activity of the entire network (with no unseen inputs existing). Chronic calcium imaging of the entire hippocampal network, with paired electrophysiology, revealed three patterns of seizure onset: (i) low amplitude fast activity; (ii) sentinel spike; and (iii) spike burst and low amplitude fast activity onset. These patterns recapitulate common features of human seizure onset, including low voltage fast activity and spike discharges. Weeks-long imaging of seizure activity showed a characteristic evolution in onset type and a refinement of the seizure onset zone. Longitudinal tracking of individual neurons revealed that seizure onset is stochastic at the single neuron level, suggesting that seizure initiation activates neurons in non-stereotyped sequences seizure to seizure. This study demonstrates for the first time that transitions to seizure are not initiated by a small number of neuronal 'bad actors' (such as overly connected hub cells), but rather by network changes which enable the onset of pathology among large populations of neurons.
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Affiliation(s)
- Lauren A Lau
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA
| | - Kevin J Staley
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA
| | - Kyle P Lillis
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.,Harvard Medical School, Boston, MA 02115, USA
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Zhai J, Zhou YY, Lagrutta A. Sensitivity, specificity and limitation of in vitro hippocampal slice and neuron-based assays for assessment of drug-induced seizure liability. Toxicol Appl Pharmacol 2021; 430:115725. [PMID: 34536444 DOI: 10.1016/j.taap.2021.115725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 09/01/2021] [Accepted: 09/13/2021] [Indexed: 10/20/2022]
Abstract
An effective in vitro screening assay to detect seizure liability in preclinical development can contribute to better lead molecule optimization prior to candidate selection, providing higher throughput and overcoming potential brain exposure limitations in animal studies. This study explored effects of 26 positive and 14 negative reference pharmacological agents acting through different mechanisms, including 18 reference agents acting on glutamate signaling pathways, in a brain slice assay (BSA) of adult rat to define the assay's sensitivity, specificity, and limitations. Evoked population spikes (PS) were recorded from CA1 pyramidal neurons of hippocampus (HPC) in the BSA. Endpoints for analysis were PS area and PS number. Most positive references (24/26) elicited a concentration-dependent increase in PS area and/or PS number. The negative references (14/14) had little effect on the PS. Moreover, we studied the effects of 15 reference agents testing positive in the BSA on spontaneous activity in E18 rat HPC neurons monitored with microelectrode arrays (MEA), and compared these effects to the BSA results. From these in vitro studies we conclude that the BSA provides 93% sensitivity and 100% specificity in prediction of drug-induced seizure liability, including detecting seizurogenicity by 3 groups of metabotropic glutamate receptor (mGluR) ligands. The MEA results seemed more variable, both quantitatively and directionally, particularly for endpoints capturing synchronized electrical activity. We discuss these results from the two models, comparing each with published results, and provide potential explanations for differences and future directions.
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Affiliation(s)
- Jin Zhai
- Department of Genetic Toxicology and In Vitro Cellular Toxicity, Safety Assessment & Laboratory Animal Resources (SALAR), Merck & Co., Inc., West Point, PA 19486, USA.
| | - Ying-Ying Zhou
- Program Discovery and Development, Safety Assessment & Laboratory Animal Resources (SALAR), Merck & Co., Inc., West Point, PA 19486, USA
| | - Armando Lagrutta
- Program Discovery and Development, Safety Assessment & Laboratory Animal Resources (SALAR), Merck & Co., Inc., West Point, PA 19486, USA
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Chong SA, Balosso S, Vandenplas C, Szczesny G, Hanon E, Claes K, Van Damme X, Danis B, Van Eyll J, Wolff C, Vezzani A, Kaminski RM, Niespodziany I. Intrinsic Inflammation Is a Potential Anti-Epileptogenic Target in the Organotypic Hippocampal Slice Model. Neurotherapeutics 2018; 15:470-488. [PMID: 29464573 PMCID: PMC5935638 DOI: 10.1007/s13311-018-0607-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Understanding the mechanisms of epileptogenesis is essential to develop novel drugs that could prevent or modify the disease. Neuroinflammation has been proposed as a promising target for therapeutic interventions to inhibit the epileptogenic process that evolves from traumatic brain injury. However, it remains unclear whether cytokine-related pathways, particularly TNFα signaling, have a critical role in the development of epilepsy. In this study, we investigated the role of innate inflammation in an in vitro model of post-traumatic epileptogenesis. We combined organotypic hippocampal slice cultures, representing an in vitro model of post-traumatic epilepsy, with multi-electrode array recordings to directly monitor the development of epileptiform activity and to examine the concomitant changes in cytokine release, cell death, and glial cell activation. We report that synchronized ictal- and interictal-like activities spontaneously evolve in this culture. Dynamic changes in the release of the pro-inflammatory cytokines IL-1β, TNFα, and IL-6 were observed throughout the culture period (3 to 21 days in vitro) with persistent activation of microglia and astrocytes. We found that neutralizing TNFα with a polyclonal antibody significantly reduced ictal discharges, and this effect lasted for 1 week after antibody washout. Neither phenytoin nor an anti-IL-6 polyclonal antibody was efficacious in inhibiting the development of epileptiform activity. Our data show a sustained effect of the anti-TNFα antibody on the ictal progression in organotypic hippocampal slice cultures supporting the critical role of inflammatory mediators in epilepsy and establishing a proof-of-principle evidence for the utility of this preparation to test the therapeutic effects of anti-inflammatory treatments.
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Affiliation(s)
- Seon-Ah Chong
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium.
| | - Silvia Balosso
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, 20156, Italy
| | | | - Gregory Szczesny
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Etienne Hanon
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Kasper Claes
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Xavier Van Damme
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Bénédicte Danis
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Jonathan Van Eyll
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Christian Wolff
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Annamaria Vezzani
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, 20156, Italy
| | - Rafal M Kaminski
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
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Chong SA, Balosso S, Vandenplas C, Szczesny G, Hanon E, Claes K, Van Damme X, Danis B, Van Eyll J, Wolff C, Vezzani A, Kaminski RM, Niespodziany I. Intrinsic Inflammation Is a Potential Anti-Epileptogenic Target in the Organotypic Hippocampal Slice Model. Neurotherapeutics 2018; 15:470-488. [PMID: 29464573 DOI: 10.1007/s13311-018-0607-6/figures/7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023] Open
Abstract
Understanding the mechanisms of epileptogenesis is essential to develop novel drugs that could prevent or modify the disease. Neuroinflammation has been proposed as a promising target for therapeutic interventions to inhibit the epileptogenic process that evolves from traumatic brain injury. However, it remains unclear whether cytokine-related pathways, particularly TNFα signaling, have a critical role in the development of epilepsy. In this study, we investigated the role of innate inflammation in an in vitro model of post-traumatic epileptogenesis. We combined organotypic hippocampal slice cultures, representing an in vitro model of post-traumatic epilepsy, with multi-electrode array recordings to directly monitor the development of epileptiform activity and to examine the concomitant changes in cytokine release, cell death, and glial cell activation. We report that synchronized ictal- and interictal-like activities spontaneously evolve in this culture. Dynamic changes in the release of the pro-inflammatory cytokines IL-1β, TNFα, and IL-6 were observed throughout the culture period (3 to 21 days in vitro) with persistent activation of microglia and astrocytes. We found that neutralizing TNFα with a polyclonal antibody significantly reduced ictal discharges, and this effect lasted for 1 week after antibody washout. Neither phenytoin nor an anti-IL-6 polyclonal antibody was efficacious in inhibiting the development of epileptiform activity. Our data show a sustained effect of the anti-TNFα antibody on the ictal progression in organotypic hippocampal slice cultures supporting the critical role of inflammatory mediators in epilepsy and establishing a proof-of-principle evidence for the utility of this preparation to test the therapeutic effects of anti-inflammatory treatments.
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Affiliation(s)
- Seon-Ah Chong
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium.
| | - Silvia Balosso
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, 20156, Italy
| | | | - Gregory Szczesny
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Etienne Hanon
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Kasper Claes
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Xavier Van Damme
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Bénédicte Danis
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Jonathan Van Eyll
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Christian Wolff
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
| | - Annamaria Vezzani
- Department of Neuroscience, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milan, 20156, Italy
| | - Rafal M Kaminski
- UCB Biopharma SPRL, Chemin du Foriest, B-1420, Braine l'Alleud, Belgium
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Raimondo JV, Heinemann U, de Curtis M, Goodkin HP, Dulla CG, Janigro D, Ikeda A, Lin CCK, Jiruska P, Galanopoulou AS, Bernard C. Methodological standards for in vitro models of epilepsy and epileptic seizures. A TASK1-WG4 report of the AES/ILAE Translational Task Force of the ILAE. Epilepsia 2017; 58 Suppl 4:40-52. [PMID: 29105075 DOI: 10.1111/epi.13901] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2017] [Indexed: 01/02/2023]
Abstract
In vitro preparations are a powerful tool to explore the mechanisms and processes underlying epileptogenesis and ictogenesis. In this review, we critically review the numerous in vitro methodologies utilized in epilepsy research. We provide support for the inclusion of detailed descriptions of techniques, including often ignored parameters with unpredictable yet significant effects on study reproducibility and outcomes. In addition, we explore how recent developments in brain slice preparation relate to their use as models of epileptic activity.
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Affiliation(s)
- Joseph V Raimondo
- Division of Cell Biology, Department of Human Biology, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Uwe Heinemann
- Neuroscience Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Marco de Curtis
- Epilepsy and Experimental Neurophysiology Unit, The Foundation of the Carlo Besta Neurological Institute, Milan, Italy
| | - Howard P Goodkin
- Departments of Neurology and Pediatrics, University of Virginia, Charlottesville, Virginia, U.S.A
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, U.S.A
| | - Damir Janigro
- Flocel Inc., Cleveland, Ohio, U.S.A.,Case Western Reserve University, Cleveland, Ohio, U.S.A
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders, and Physiology, Kyoto University Graduate School of Medicine, Sakyo-ku, Kyoto, Japan
| | - Chou-Ching K Lin
- Department of Neurology, College of Medicine and Hospital, National Cheng Kung University, Tainan, Taiwan
| | - Premysl Jiruska
- Department of Developmental Epileptology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Aristea S Galanopoulou
- Laboratory of Developmental Epilepsy, Saul R. Korey Department of Neurology, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Einstein/Montefiore Epilepsy Center, Montefiore Medical Center, Bronx, New York, U.S.A
| | - Christophe Bernard
- Inserm, Institut de Neurosciences des Systemes UMRS 1106, Aix Marseille University, Marseille, France
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Lara-Valderrábano L, Galván EJ, Rocha L. Propylparaben suppresses epileptiform activity in hippocampal CA1 pyramidal cells in vitro. Epilepsy Res 2017; 136:126-129. [PMID: 28843182 DOI: 10.1016/j.eplepsyres.2017.08.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 07/18/2017] [Accepted: 08/13/2017] [Indexed: 11/18/2022]
Abstract
Epilepsy is a highly prevalent neurological disorder. Additionally, a percentage of patients do not respond to conventional antiepileptic drugs. Therefore, drugs for epilepsy control are still being developed. In the present study, the effect of propylparaben (PPB) in the epileptiform activity induced by 4-aminopyridine in hippocampal CA1 pyramidal neurons was evaluated using individual recordings in current-clamp mode. Results indicated that PPB suppressed the epileptiform activity in registered neurons. This effect disappeared when PPB was removed from the solution of incubation. In contrast, phenytoin only reduced the firing frequency without abolishing epileptiform activity. Our results indicate that PPB exerts an antiepileptic effect on CA1 pyramidal neurons in vitro. Therefore, PPB may represent an effective antiepileptic compound.
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Affiliation(s)
| | - Emilio J Galván
- Pharmacobiology Department, Center of Research and Advanced Studies, México City, Mexico
| | - Luisa Rocha
- Pharmacobiology Department, Center of Research and Advanced Studies, México City, Mexico.
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Uchida T, Lossin C, Ihara Y, Deshimaru M, Yanagawa Y, Koyama S, Hirose S. Abnormal γ-aminobutyric acid neurotransmission in aKcnq2model of early onset epilepsy. Epilepsia 2017; 58:1430-1439. [DOI: 10.1111/epi.13807] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2015] [Indexed: 12/01/2022]
Affiliation(s)
- Taku Uchida
- Central Research Institute for the Pathomechanisms of Epilepsy; Fukuoka University; Fukuoka Japan
- Department of Neuroscience; Section of Integrative Physiology; Faculty of Medicine; University of Miyazaki; Miyazaki Japan
| | - Christoph Lossin
- Department of Neurology; University of California, Davis; Sacramento California U.S.A
| | - Yukiko Ihara
- Department of Pediatrics; Fukuoka University School of Medicine; Fukuoka Japan
| | - Masanobu Deshimaru
- Department of Chemistry; Faculty of Science; Fukuoka University; Fukuoka Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience; Gunma University Graduate School of Medicine; Maebashi Japan
| | - Susumu Koyama
- Department of Advanced Pharmacology; Daiichi University of Pharmacy; Fukuoka Japan
| | - Shinichi Hirose
- Central Research Institute for the Pathomechanisms of Epilepsy; Fukuoka University; Fukuoka Japan
- Department of Pediatrics; Fukuoka University School of Medicine; Fukuoka Japan
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Berdichevsky Y, Saponjian Y, Park K, Roach B, Pouliot W, Lu K, Swiercz W, Dudek FE, Staley KJ. Staged anticonvulsant screening for chronic epilepsy. Ann Clin Transl Neurol 2016; 3:908-923. [PMID: 28097203 PMCID: PMC5224819 DOI: 10.1002/acn3.364] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/15/2016] [Accepted: 09/15/2016] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE Current anticonvulsant screening programs are based on seizures evoked in normal animals. One-third of epileptic patients do not respond to the anticonvulsants discovered with these models. We evaluated a tiered program based on chronic epilepsy and spontaneous seizures, with compounds advancing from high-throughput in vitro models to low-throughput in vivo models. METHODS Epileptogenesis in organotypic hippocampal slice cultures was quantified by lactate production and lactate dehydrogenase release into culture media as rapid assays for seizure-like activity and cell death, respectively. Compounds that reduced these biochemical measures were retested with in vitro electrophysiological confirmation (i.e., second stage). The third stage involved crossover testing in the kainate model of chronic epilepsy, with blinded analysis of spontaneous seizures after continuous electrographic recordings. RESULTS We screened 407 compound-concentration combinations. The cyclooxygenase inhibitor, celecoxib, had no effect on seizures evoked in normal brain tissue but demonstrated robust antiseizure activity in all tested models of chronic epilepsy. INTERPRETATION The use of organotypic hippocampal cultures, where epileptogenesis occurs on a compressed time scale, and where seizure-like activity and seizure-induced cell death can be easily quantified with biomarker assays, allowed us to circumvent the throughput limitations of in vivo chronic epilepsy models. Ability to rapidly screen compounds in a chronic model of epilepsy allowed us to find an anticonvulsant that would be missed by screening in acute models.
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Affiliation(s)
- Yevgeny Berdichevsky
- Department of Electrical and Computer Engineering and Bioengineering ProgramLehigh UniversityBethlehemPennsylvania18015
| | - Yero Saponjian
- Department of NeurologyMassachusetts General HospitalBostonMassachusetts02129
- Harvard Medical SchoolBostonMassachusetts02129
| | - Kyung‐Il Park
- Department of NeurologySeoul National University Hospital Healthcare System Gangnam CenterSeoulSouth Korea06236
| | - Bonnie Roach
- Department of NeurosurgeryUniversity of Utah School of MedicineSalt Lake CityUtah84108
| | - Wendy Pouliot
- Department of NeurosurgeryUniversity of Utah School of MedicineSalt Lake CityUtah84108
| | - Kimberly Lu
- Boston University School of MedicineBostonMassachusetts02119
| | - Waldemar Swiercz
- Department of NeurologyMassachusetts General HospitalBostonMassachusetts02129
- Harvard Medical SchoolBostonMassachusetts02129
| | - F. Edward Dudek
- Department of NeurosurgeryUniversity of Utah School of MedicineSalt Lake CityUtah84108
| | - Kevin J. Staley
- Department of NeurologyMassachusetts General HospitalBostonMassachusetts02129
- Harvard Medical SchoolBostonMassachusetts02129
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Liu J, Pan L, Cheng X, Berdichevsky Y. Perfused drop microfluidic device for brain slice culture-based drug discovery. Biomed Microdevices 2016; 18:46. [PMID: 27194028 PMCID: PMC5563980 DOI: 10.1007/s10544-016-0073-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Living slices of brain tissue are widely used to model brain processes in vitro. In addition to basic neurophysiology studies, brain slices are also extensively used for pharmacology, toxicology, and drug discovery research. In these experiments, high parallelism and throughput are critical. Capability to conduct long-term electrical recording experiments may also be necessary to address disease processes that require protein synthesis and neural circuit rewiring. We developed a novel perfused drop microfluidic device for use with long term cultures of brain slices (organotypic cultures). Slices of hippocampus were placed into wells cut in polydimethylsiloxane (PDMS) film. Fluid level in the wells was hydrostatically controlled such that a drop was formed around each slice. The drops were continuously perfused with culture medium through microchannels. We found that viable organotypic hippocampal slice cultures could be maintained for at least 9 days in vitro. PDMS microfluidic network could be readily integrated with substrate-printed microelectrodes for parallel electrical recordings of multiple perfused organotypic cultures on a single MEA chip. We expect that this highly scalable perfused drop microfluidic device will facilitate high-throughput drug discovery and toxicology.
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Affiliation(s)
- Jing Liu
- Department of Electrical and Computer Engineering, Lehigh University, 111 Research Dr. D-320, Bethlehem, PA, 18015, USA
| | - Liping Pan
- Materials Science and Engineering Department, Lehigh University, Bethlehem, PA, 18015, USA
| | - Xuanhong Cheng
- Materials Science and Engineering Department, Lehigh University, Bethlehem, PA, 18015, USA
- Bioengineering Program, Lehigh University, Bethlehem, PA, 18015, USA
| | - Yevgeny Berdichevsky
- Department of Electrical and Computer Engineering, Lehigh University, 111 Research Dr. D-320, Bethlehem, PA, 18015, USA.
- Bioengineering Program, Lehigh University, Bethlehem, PA, 18015, USA.
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11
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Human brain slices for epilepsy research: Pitfalls, solutions and future challenges. J Neurosci Methods 2015; 260:221-32. [PMID: 26434706 DOI: 10.1016/j.jneumeth.2015.09.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/21/2015] [Accepted: 09/23/2015] [Indexed: 12/17/2022]
Abstract
Increasingly, neuroscientists are taking the opportunity to use live human tissue obtained from elective neurosurgical procedures for electrophysiological studies in vitro. Access to this valuable resource permits unique studies into the network dynamics that contribute to the generation of pathological electrical activity in the human epileptic brain. Whilst this approach has provided insights into the mechanistic features of electrophysiological patterns associated with human epilepsy, it is not without technical and methodological challenges. This review outlines the main difficulties associated with working with epileptic human brain slices from the point of collection, through the stages of preparation, storage and recording. Moreover, it outlines the limitations, in terms of the nature of epileptic activity that can be observed in such tissue, in particular, the rarity of spontaneous ictal discharges, we discuss manipulations that can be utilised to induce such activity. In addition to discussing conventional electrophysiological techniques that are routinely employed in epileptic human brain slices, we review how imaging and multielectrode array recordings could provide novel insights into the network dynamics of human epileptogenesis. Acute studies in human brain slices are ultimately limited by the lifetime of the tissue so overcoming this issue provides increased opportunity for information gain. We review the literature with respect to organotypic culture techniques that may hold the key to prolonging the viability of this material. A combination of long-term culture techniques, viral transduction approaches and electrophysiology in human brain slices promotes the possibility of large scale monitoring and manipulation of neuronal activity in epileptic microcircuits.
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Abstract
Epileptogenesis is a chronic process that can be triggered by genetic or acquired factors, and that can continue long after epilepsy diagnosis. In 2015, epileptogenesis is not a treatment indication, and there are no therapies available in clinic to treat individuals at risk of epileptogenesis. However, thanks to active research, a large number of animal models have become available for search of molecular mechanisms of epileptogenesis. The first glimpses of treatment targets and biomarkers that could be developed to become useful in clinic are in sight. However, the heterogeneity of the epilepsy condition, and the dynamics of molecular changes over the course of epileptogenesis remain as challenges to overcome.
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Affiliation(s)
- Asla Pitkänen
- Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211 Kuopio, Finland Department of Neurology, Kuopio University Hospital, FI-70211 Kuopio, Finland
| | - Katarzyna Lukasiuk
- The Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland
| | - F Edward Dudek
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah 84108
| | - Kevin J Staley
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts 02114
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13
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In vitro seizure like events and changes in ionic concentration. J Neurosci Methods 2015; 260:33-44. [PMID: 26300181 DOI: 10.1016/j.jneumeth.2015.08.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 08/06/2015] [Accepted: 08/12/2015] [Indexed: 11/20/2022]
Abstract
BACKGROUND In vivo, seizure like events are associated with increases in extracellular K(+) concentration, decreases in extracellular Ca(2+) concentration, diphasic changes in extracellular sodium, chloride, and proton concentration, as well as changes of extracellular space size. These changes point to mechanisms underlying the induction, spread and termination of seizure like events. METHODS We investigated the potential role of alterations of the ionic environment on the induction of seizure like events-considering a review of the literature and own experimental work in animal and human slices. RESULTS Increasing extracellular K(+) concentration, lowering extracellular Mg(2+) concentration, or lowering extracellular Ca(2+) concentration can induce seizure like events. In human tissue from epileptic patients, elevation of K(+) concentration induces seizure like events in the dentate gyrus and subiculum. A combination of elevated K(+) concentration and 4-AP or bicuculline can induce seizure like events in neocortical tissue. CONCLUSIONS These protocols provide insight into the mechanisms involved in seizure initiation, spread and termination. Moreover, pharmacological studies as well as studies on mechanisms underlying pharmacoresistance are feasible.
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