1
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Lepeu G, van Maren E, Slabeva K, Friedrichs-Maeder C, Fuchs M, Z'Graggen WJ, Pollo C, Schindler KA, Adamantidis A, Proix T, Baud MO. The critical dynamics of hippocampal seizures. Nat Commun 2024; 15:6945. [PMID: 39138153 PMCID: PMC11322644 DOI: 10.1038/s41467-024-50504-9] [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: 07/09/2023] [Accepted: 07/10/2024] [Indexed: 08/15/2024] Open
Abstract
Epilepsy is defined by the abrupt emergence of harmful seizures, but the nature of these regime shifts remains enigmatic. From the perspective of dynamical systems theory, such critical transitions occur upon inconspicuous perturbations in highly interconnected systems and can be modeled as mathematical bifurcations between alternative regimes. The predictability of critical transitions represents a major challenge, but the theory predicts the appearance of subtle dynamical signatures on the verge of instability. Whether such dynamical signatures can be measured before impending seizures remains uncertain. Here, we verified that predictions on bifurcations applied to the onset of hippocampal seizures, providing concordant results from in silico modeling, optogenetics experiments in male mice and intracranial EEG recordings in human patients with epilepsy. Leveraging pharmacological control over neural excitability, we showed that the boundary between physiological excitability and seizures can be inferred from dynamical signatures passively recorded or actively probed in hippocampal circuits. Of importance for the design of future neurotechnologies, active probing surpassed passive recording to decode underlying levels of neural excitability, notably when assessed from a network of propagating neural responses. Our findings provide a promising approach for predicting and preventing seizures, based on a sound understanding of their dynamics.
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Affiliation(s)
- Gregory Lepeu
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Ellen van Maren
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Kristina Slabeva
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Cecilia Friedrichs-Maeder
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Markus Fuchs
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Werner J Z'Graggen
- Department of Neurosurgery, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Claudio Pollo
- Department of Neurosurgery, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Kaspar A Schindler
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Antoine Adamantidis
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland
| | - Timothée Proix
- Department of Fundamental Neuroscience, University of Geneva, Geneva, Switzerland
| | - Maxime O Baud
- Center for experimental neurology, Sleep-wake epilepsy center, NeuroTec, Department of Neurology, Inselspital, University Hospital Bern, University of Bern, Bern, Switzerland.
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2
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Hou JF, Nayeem MOG, Caplan KA, Ruesch EA, Caban-Murillo A, Criado-Hidalgo E, Ornellas SB, Williams B, Pearce AA, Dagdeviren HE, Surets M, White JA, Shapiro MG, Wang F, Ramirez S, Dagdeviren C. An implantable piezoelectric ultrasound stimulator (ImPULS) for deep brain activation. Nat Commun 2024; 15:4601. [PMID: 38834558 PMCID: PMC11150473 DOI: 10.1038/s41467-024-48748-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 05/13/2024] [Indexed: 06/06/2024] Open
Abstract
Precise neurostimulation can revolutionize therapies for neurological disorders. Electrode-based stimulation devices face challenges in achieving precise and consistent targeting due to the immune response and the limited penetration of electrical fields. Ultrasound can aid in energy propagation, but transcranial ultrasound stimulation in the deep brain has limited spatial resolution caused by bone and tissue scattering. Here, we report an implantable piezoelectric ultrasound stimulator (ImPULS) that generates an ultrasonic focal pressure of 100 kPa to modulate the activity of neurons. ImPULS is a fully-encapsulated, flexible piezoelectric micromachined ultrasound transducer that incorporates a biocompatible piezoceramic, potassium sodium niobate [(K,Na)NbO3]. The absence of electrochemically active elements poses a new strategy for achieving long-term stability. We demonstrated that ImPULS can i) excite neurons in a mouse hippocampal slice ex vivo, ii) activate cells in the hippocampus of an anesthetized mouse to induce expression of activity-dependent gene c-Fos, and iii) stimulate dopaminergic neurons in the substantia nigra pars compacta to elicit time-locked modulation of nigrostriatal dopamine release. This work introduces a non-genetic ultrasound platform for spatially-localized neural stimulation and exploration of basic functions in the deep brain.
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Affiliation(s)
- Jason F Hou
- Media Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | | | - Kian A Caplan
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Evan A Ruesch
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
| | - Albit Caban-Murillo
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
| | - Ernesto Criado-Hidalgo
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Sarah B Ornellas
- Media Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Brandon Williams
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA, 02215, USA
| | - Ayeilla A Pearce
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Huseyin E Dagdeviren
- Department of Neurosurgery, Faculty of Medicine, Istanbul University, Istanbul, 34093, Turkey
| | - Michelle Surets
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
| | - John A White
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA, 02215, USA
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Fan Wang
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Steve Ramirez
- Department of Psychological and Brain Sciences, The Center for Systems Neuroscience, Boston University, Boston, 02215, MA, USA
| | - Canan Dagdeviren
- Media Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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3
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Krut' VG, Kalinichenko AL, Maltsev DI, Jappy D, Shevchenko EK, Podgorny OV, Belousov VV. Optogenetic and chemogenetic approaches for modeling neurological disorders in vivo. Prog Neurobiol 2024; 235:102600. [PMID: 38548126 DOI: 10.1016/j.pneurobio.2024.102600] [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: 08/15/2023] [Revised: 02/26/2024] [Accepted: 03/22/2024] [Indexed: 04/01/2024]
Abstract
Animal models of human neurological disorders provide valuable experimental tools which enable us to study various aspects of disorder pathogeneses, ranging from structural abnormalities and disrupted metabolism and signaling to motor and mental deficits, and allow us to test novel therapies in preclinical studies. To be valid, these animal models should recapitulate complex pathological features at the molecular, cellular, tissue, and behavioral levels as closely as possible to those observed in human subjects. Pathological states resembling known human neurological disorders can be induced in animal species by toxins, genetic factors, lesioning, or exposure to extreme conditions. In recent years, novel animal models recapitulating neuropathologies in humans have been introduced. These animal models are based on synthetic biology approaches: opto- and chemogenetics. In this paper, we review recent opto- and chemogenetics-based animal models of human neurological disorders. These models allow for the creation of pathological states by disrupting specific processes at the cellular level. The artificial pathological states mimic a range of human neurological disorders, such as aging-related dementia, Alzheimer's and Parkinson's diseases, amyotrophic lateral sclerosis, epilepsy, and ataxias. Opto- and chemogenetics provide new opportunities unavailable with other animal models of human neurological disorders. These techniques enable researchers to induce neuropathological states varying in severity and ranging from acute to chronic. We also discuss future directions for the development and application of synthetic biology approaches for modeling neurological disorders.
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Affiliation(s)
- Viktoriya G Krut'
- Pirogov Russian National Research Medical University, Moscow 117997, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow 117997, Russia
| | - Andrei L Kalinichenko
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Dmitry I Maltsev
- Pirogov Russian National Research Medical University, Moscow 117997, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow 117997, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - David Jappy
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow 117997, Russia
| | - Evgeny K Shevchenko
- Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow 117997, Russia
| | - Oleg V Podgorny
- Pirogov Russian National Research Medical University, Moscow 117997, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow 117997, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
| | - Vsevolod V Belousov
- Pirogov Russian National Research Medical University, Moscow 117997, Russia; Federal Center of Brain Research and Neurotechnologies, Federal Medical Biological Agency, Moscow 117997, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia; Life Improvement by Future Technologies (LIFT) Center, Skolkovo, Moscow 143025, Russia.
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4
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Li HT, Viskaitis P, Bracey E, Peleg-Raibstein D, Burdakov D. Transient targeting of hypothalamic orexin neurons alleviates seizures in a mouse model of epilepsy. Nat Commun 2024; 15:1249. [PMID: 38341419 PMCID: PMC10858876 DOI: 10.1038/s41467-024-45515-5] [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: 04/16/2023] [Accepted: 01/24/2024] [Indexed: 02/12/2024] Open
Abstract
Lateral hypothalamic (LH) hypocretin/orexin neurons (HONs) control brain-wide electrical excitation. Abnormally high excitation produces epileptic seizures, which affect millions of people and need better treatments. HON population activity spikes from minute to minute, but the role of this in seizures is unknown. Here, we describe correlative and causal links between HON activity spikes and seizures. Applying temporally-targeted HON recordings and optogenetic silencing to a male mouse model of acute epilepsy, we found that pre-seizure HON activity predicts and controls the electrophysiology and behavioral pathology of subsequent seizures. No such links were detected for HON activity during seizures. Having thus defined the time window where HONs influence seizures, we targeted it with LH deep brain stimulation (DBS), which inhibited HON population activity, and produced seizure protection. Collectively, these results uncover a feature of brain activity linked to seizures, and demonstrate a proof-of-concept treatment that controls this feature and alleviates epilepsy.
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Affiliation(s)
- Han-Tao Li
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology | ETH Zurich, 8603, Schwerzenbach, Switzerland
- Section of Epilepsy, Department of Neurology, Chang Gung Memorial Hospital at Linkou Medical Center and Chang Gung University College of Medicine, 333, Taoyuan, Taiwan
| | - Paulius Viskaitis
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology | ETH Zurich, 8603, Schwerzenbach, Switzerland
| | - Eva Bracey
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology | ETH Zurich, 8603, Schwerzenbach, Switzerland
| | - Daria Peleg-Raibstein
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology | ETH Zurich, 8603, Schwerzenbach, Switzerland
| | - Denis Burdakov
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology | ETH Zurich, 8603, Schwerzenbach, Switzerland.
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5
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Wenzel M, Huberfeld G, Grayden DB, de Curtis M, Trevelyan AJ. A debate on the neuronal origin of focal seizures. Epilepsia 2023; 64 Suppl 3:S37-S48. [PMID: 37183507 DOI: 10.1111/epi.17650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/26/2023] [Accepted: 05/12/2023] [Indexed: 05/16/2023]
Abstract
A critical question regarding how focal seizures start is whether we can identify particular cell classes that drive the pathological process. This was the topic for debate at the recent International Conference for Technology and Analysis of Seizures (ICTALS) meeting (July 2022, Bern, CH) that we summarize here. The debate has been fueled in recent times by the introduction of powerful new ways to manipulate subpopulations of cells in relative isolation, mostly using optogenetics. The motivation for resolving the debate is to identify novel targets for therapeutic interventions through a deeper understanding of the etiology of seizures.
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Affiliation(s)
- Michael Wenzel
- Department of Epileptology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Gilles Huberfeld
- Neurology Department, Hopital Fondation Adolphe de Rothschild, Paris, France
- Center for Interdisciplinary Research in Biology (CIRB), College de France, CNRS, INSERM, Université PSL, Paris, France
| | - David B Grayden
- Department of Biomedical Engineering, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Medicine, St Vincent's Hospital, The University of Melbourne, Melbourne, Victoria, Australia
- Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione I.R.C.C.S., Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrew J Trevelyan
- Newcastle University Biosciences Institute, Medical School, Framlington Place, Newcastle upon Tyne, UK
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6
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Mueller JS, Tescarollo FC, Huynh T, Brenner DA, Valdivia DJ, Olagbegi K, Sangappa S, Chen SC, Sun H. Ictogenesis proceeds through discrete phases in hippocampal CA1 seizures in mice. Nat Commun 2023; 14:6010. [PMID: 37752179 PMCID: PMC10522592 DOI: 10.1038/s41467-023-41711-x] [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: 03/07/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
Epilepsy is characterized by spontaneous non-provoked seizures, yet the mechanisms that trigger a seizure and allow its evolution remain underexplored. To dissect out phases of ictogenesis, we evoked hypersynchronous activity with optogenetic stimulation. Focal optogenetic activation of putative excitatory neurons in the mouse hippocampal CA1 reliably evoked convulsive seizures in awake mice. A time-vs-time pulsogram plot characterized the evolution of the EEG pulse response from a light evoked response to induced seizure activity. Our results depict ictogenesis as a stepwise process comprised of three distinctive phases demarcated by two transition points. The induction phase undergoes the first transition to reverberant phase activity, followed by the second transition into the paroxysmal phase or a seizure. Non-seizure responses are confined to either induction or reverberant phases. The pulsogram was then constructed in seizures recorded from a murine model of temporal lobe epilepsy and it depicted a similar reverberance preceding spontaneous seizures. The discovery of these distinct phases of ictogenesis may offer means to abort a seizure before it develops.
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Affiliation(s)
- John-Sebastian Mueller
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Fabio C Tescarollo
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Trong Huynh
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
- Department of Surgery, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Daniel A Brenner
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Daniel J Valdivia
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Kanyin Olagbegi
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Sahana Sangappa
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Spencer C Chen
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA
| | - Hai Sun
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, 08854, USA.
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7
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Haile MT, Khoja S, de Carvalho G, Hunt RF, Chen LY. Conditional deletion of Neurexin-2 alters neuronal network activity in hippocampal circuitries and leads to spontaneous seizures. Transl Psychiatry 2023; 13:97. [PMID: 36941261 PMCID: PMC10027846 DOI: 10.1038/s41398-023-02394-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 02/27/2023] [Accepted: 03/02/2023] [Indexed: 03/23/2023] Open
Abstract
Neurexins (Nrxns) have been extensively studied for their role in synapse organization and have been linked to many neuropsychiatric disorders, including autism spectrum disorder (ASD), and epilepsy. However, no studies have provided direct evidence that Nrxns may be the key regulator in the shared pathogenesis of these conditions largely due to complexities among Nrxns and their non-canonical functions in different synapses. Recent studies identified NRXN2 mutations in ASD and epilepsy, but little is known about Nrxn2's role in a circuit-specific manner. Here, we report that conditional deletion of Nrxn2 from the hippocampus and cortex (Nrxn2 cKO) results in behavioral abnormalities, including reduced social preference and increased nestlet shredding behavior. Electrophysiological recordings identified an overall increase in hippocampal CA3→CA1 network activity in Nrxn2 cKO mice. Using intracranial electroencephalogram recordings, we observed unprovoked spontaneous reoccurring electrographic and behavioral seizures in Nrxn2 cKO mice. This study provides the first evidence that conditional deletion of Nrxn2 induces increased network activity that manifests into spontaneous recurrent seizures and behavioral impairments.
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Affiliation(s)
- Mulatwa T Haile
- Department of Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Sheraz Khoja
- Department of Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Gregory de Carvalho
- Department of Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Robert F Hunt
- Department of Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA
| | - Lulu Y Chen
- Department of Anatomy & Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA.
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8
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Stieve BJ, Smith MM, Krook-Magnuson E. LINCs Are Vulnerable to Epileptic Insult and Fail to Provide Seizure Control via On-Demand Activation. eNeuro 2023; 10:ENEURO.0195-22.2022. [PMID: 36725340 PMCID: PMC9933934 DOI: 10.1523/eneuro.0195-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 12/13/2022] [Accepted: 12/19/2022] [Indexed: 02/03/2023] Open
Abstract
Temporal lobe epilepsy (TLE) is notoriously pharmacoresistant, and identifying novel therapeutic targets for controlling seizures is crucial. Long-range inhibitory neuronal nitric oxide synthase-expressing cells (LINCs), a population of hippocampal neurons, were recently identified as a unique source of widespread inhibition in CA1, able to elicit both GABAA-mediated and GABAB-mediated postsynaptic inhibition. We therefore hypothesized that LINCs could be an effective target for seizure control. LINCs were optogenetically activated for on-demand seizure intervention in the intrahippocampal kainate (KA) mouse model of chronic TLE. Unexpectedly, LINC activation at 1 month post-KA did not substantially reduce seizure duration in either male or female mice. We tested two different sets of stimulation parameters, both previously found to be effective with on-demand optogenetic approaches, but neither was successful. Quantification of LINCs following intervention revealed a substantial reduction of LINC numbers compared with saline-injected controls. We also observed a decreased number of LINCs when the site of initial insult (i.e., KA injection) was moved to the amygdala [basolateral amygdala (BLA)-KA], and correspondingly, no effect of light delivery on BLA-KA seizures. This indicates that LINCs may be a vulnerable population in TLE, regardless of the site of initial insult. To determine whether long-term circuitry changes could influence outcomes, we continued testing once a month for up to 6 months post-KA. However, at no time point did LINC activation provide meaningful seizure suppression. Altogether, our results suggest that LINCs are not a promising target for seizure inhibition in TLE.
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Affiliation(s)
- Bethany J Stieve
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
| | - Madison M Smith
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
| | - Esther Krook-Magnuson
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455
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9
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Belkacem AN, Jamil N, Khalid S, Alnajjar F. On closed-loop brain stimulation systems for improving the quality of life of patients with neurological disorders. Front Hum Neurosci 2023; 17:1085173. [PMID: 37033911 PMCID: PMC10076878 DOI: 10.3389/fnhum.2023.1085173] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Emerging brain technologies have significantly transformed human life in recent decades. For instance, the closed-loop brain-computer interface (BCI) is an advanced software-hardware system that interprets electrical signals from neurons, allowing communication with and control of the environment. The system then transmits these signals as controlled commands and provides feedback to the brain to execute specific tasks. This paper analyzes and presents the latest research on closed-loop BCI that utilizes electric/magnetic stimulation, optogenetic, and sonogenetic techniques. These techniques have demonstrated great potential in improving the quality of life for patients suffering from neurodegenerative or psychiatric diseases. We provide a comprehensive and systematic review of research on the modalities of closed-loop BCI in recent decades. To achieve this, the authors used a set of defined criteria to shortlist studies from well-known research databases into categories of brain stimulation techniques. These categories include deep brain stimulation, transcranial magnetic stimulation, transcranial direct-current stimulation, transcranial alternating-current stimulation, and optogenetics. These techniques have been useful in treating a wide range of disorders, such as Alzheimer's and Parkinson's disease, dementia, and depression. In total, 76 studies were shortlisted and analyzed to illustrate how closed-loop BCI can considerably improve, enhance, and restore specific brain functions. The analysis revealed that literature in the area has not adequately covered closed-loop BCI in the context of cognitive neural prosthetics and implanted neural devices. However, the authors demonstrate that the applications of closed-loop BCI are highly beneficial, and the technology is continually evolving to improve the lives of individuals with various ailments, including those with sensory-motor issues or cognitive deficiencies. By utilizing emerging techniques of stimulation, closed-loop BCI can safely improve patients' cognitive and affective skills, resulting in better healthcare outcomes.
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Affiliation(s)
- Abdelkader Nasreddine Belkacem
- Department of Computer and Network Engineering, College of Information Technology, UAE University, Al-Ain, United Arab Emirates
- *Correspondence: Abdelkader Nasreddine Belkacem
| | - Nuraini Jamil
- Department of Computer Science and Software Engineering, College of Information Technology, UAE University, Al-Ain, United Arab Emirates
| | - Sumayya Khalid
- Department of Computer Science and Software Engineering, College of Information Technology, UAE University, Al-Ain, United Arab Emirates
| | - Fady Alnajjar
- Department of Computer Science and Software Engineering, College of Information Technology, UAE University, Al-Ain, United Arab Emirates
- Center for Brain Science, RIKEN, Saitama, Japan
- Fady Alnajjar
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10
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Abstract
SignificanceAnxiety disorders are among the most prevalent mental illnesses worldwide. Despite significant advances in their treatment, many patients remain treatment resistant. Thus, new treatment modalities and targets are much needed. Therefore, we developed a deep brain stimulation therapy that targets a recently identified anxiety center in the lateral hypothalamus. We show that this therapy rapidly silences anxiety-implicated neurons and immediately relieves diverse anxiety symptoms in a variety of stressful situations. This therapeutic effect occurs without acute or chronic side effects that are typical of many existing treatments, such as physical sedation or memory deficits. These findings identify a clinically applicable new therapeutic strategy for helping patients to manage treatment-resistant anxiety.
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11
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Shimoda Y, Beppu K, Ikoma Y, Morizawa YM, Zuguchi S, Hino U, Yano R, Sugiura Y, Moritoh S, Fukazawa Y, Suematsu M, Mushiake H, Nakasato N, Iwasaki M, Tanaka KF, Tominaga T, Matsui K. Optogenetic stimulus-triggered acquisition of seizure resistance. Neurobiol Dis 2021; 163:105602. [PMID: 34954320 DOI: 10.1016/j.nbd.2021.105602] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 12/21/2021] [Accepted: 12/22/2021] [Indexed: 11/26/2022] Open
Abstract
Unlike an electrical circuit, the hardware of the brain is susceptible to change. Repeated electrical brain stimulation mimics epileptogenesis. After such "kindling" process, a moderate stimulus would become sufficient in triggering a severe seizure. Here, we report that optogenetic neuronal stimulation can also convert the rat brain to a hyperexcitable state. However, continued stimulation once again converted the brain to a state that was strongly resistant to seizure induction. Histochemical examinations showed that moderate astrocyte activation was coincident with resilience acquisition. Administration of an adenosine A1 receptor antagonist instantly reverted the brain back to a hyperexcitable state, suggesting that hyperexcitability was suppressed by adenosine. Furthermore, an increase in basal adenosine was confirmed using in vivo microdialysis. Daily neuron-to-astrocyte signaling likely prompted a homeostatic increase in the endogenous actions of adenosine. Our data suggest that a certain stimulation paradigm could convert the brain circuit resilient to epilepsy without exogenous drug administration.
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Affiliation(s)
- Yoshiteru Shimoda
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kaoru Beppu
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yoko Ikoma
- Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai 980-8577, Japan
| | - Yosuke M Morizawa
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai 980-8577, Japan
| | - Satoshi Zuguchi
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Utaro Hino
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Ryutaro Yano
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Yuki Sugiura
- Department of Biochemistry & Integrative Medical Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Satoru Moritoh
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yugo Fukazawa
- Division of Cell Biology and Neuroscience, University of Fukui Faculty of Medical Sciences, Fukui 910-1193, Japan
| | - Makoto Suematsu
- Department of Biochemistry & Integrative Medical Biology, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Hajime Mushiake
- Department of Physiology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Nobukazu Nakasato
- Department of Epileptology, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Masaki Iwasaki
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Kenji F Tanaka
- Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo 160-8582, Japan
| | - Teiji Tominaga
- Department of Neurosurgery, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Ko Matsui
- Division of Interdisciplinary Medical Science, Center for Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai 980-8577, Japan.
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12
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Repeated hippocampal seizures lead to brain-wide reorganization of circuits and seizure propagation pathways. Neuron 2021; 110:221-236.e4. [PMID: 34706219 PMCID: PMC10402913 DOI: 10.1016/j.neuron.2021.10.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 05/18/2021] [Accepted: 10/05/2021] [Indexed: 11/24/2022]
Abstract
Repeated seizure activity can lead to long-term changes in seizure dynamics and behavior. However, resulting changes in brain-wide dynamics remain poorly understood. This is due partly to technical challenges in precise seizure control and in vivo whole-brain mapping of circuit dynamics. Here, we developed an optogenetic kindling model through repeated stimulation of ventral hippocampal CaMKII neurons in adult rats. We then combined fMRI with electrophysiology to track brain-wide circuit dynamics resulting from non-afterdischarge (AD)-generating stimulations and individual convulsive seizures. Kindling induced widespread increases in non-AD-generating stimulation response and ipsilateral functional connectivity and elevated anxiety. Individual seizures in kindled animals showed more significant increases in brain-wide activity and bilateral functional connectivity. Onset time quantification provided evidence for kindled seizure propagation from the ipsilateral to the contralateral hemisphere. Furthermore, a core of slow-migrating hippocampal activity was identified in both non-kindled and kindled seizures, revealing a novel mechanism of seizure sustainment and propagation.
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13
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Development of an optogenetic gene sensitive to daylight and its implications in vision restoration. NPJ Regen Med 2021; 6:64. [PMID: 34650094 PMCID: PMC8516861 DOI: 10.1038/s41536-021-00177-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 09/29/2021] [Indexed: 11/14/2022] Open
Abstract
Optogenetic gene-mediated therapy for restoring vision is thought to be a useful treatment for blind patients. However, light sensitivity achieved using this gene therapy is inferior to that of daylight vision. To increase light sensitivity, we designed three mutants using a bioinformatics approach. Nucleotide sequences encoding two sites in the extracellular loops (ex1, ex3) of mVChR1 close to simulated ion-conducting pathways were replaced by homologous amino acid-encoding sequences of ChR1 or ChR2. The light sensitivity of ex3mV1 was higher than that of mVChR1 at 405–617 nm. Visual responses were restored in Royal College of Surgeons rats with genetically degenerating photoreceptor cells transfected with ex3mV1Co, wherein transmembrane of sixth (TM6) in ex3mV1 was additionally replaced with the corresponding domain of CoChR; these rats responded to light in the order of μW/mm2. Thus, ex3mV1Co might be useful for the restoration of advanced visual function.
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14
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Ryu B, Nagappan S, Santos-Valencia F, Lee P, Rodriguez E, Lackie M, Takatoh J, Franks KM. Chronic loss of inhibition in piriform cortex following brief, daily optogenetic stimulation. Cell Rep 2021; 35:109001. [PMID: 33882304 PMCID: PMC8102022 DOI: 10.1016/j.celrep.2021.109001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 12/10/2020] [Accepted: 03/24/2021] [Indexed: 12/02/2022] Open
Abstract
It is well established that seizures beget seizures, yet the cellular processes that underlie progressive epileptogenesis remain unclear. Here, we use optogenetics to briefly activate targeted populations of mouse piriform cortex (PCx) principal neurons in vivo. After just 3 or 4 days of stimulation, previously subconvulsive stimuli trigger massive, generalized seizures. Highly recurrent allocortices are especially prone to “optokindling.” Optokindling upsets the balance of recurrent excitation and feedback inhibition. To understand how this balance is disrupted, we then selectively reactivate the same neurons in vitro. Surprisingly, we find no evidence of heterosynaptic potentiation; instead, we observe a marked, pathway-specific decrease in feedback inhibition. We find no loss of inhibitory interneurons; rather, decreased GABA synthesis in feedback inhibitory neurons appears to underlie weakened inhibition. Optokindling will allow precise identification of the molecular processes by which brain activity patterns can progressively and pathologically disrupt the balance of cortical excitation and inhibition. Ryu et al. use optogenetics to briefly activate principal neurons in mouse piriform cortex. After 4 days, previously innocuous stimuli evoke massive, generalized seizures. “Optokindling” does not strengthen recurrent excitation; instead, it weakens feedback inhibition by decreasing synaptic cleft GABA concentrations and slowing vesicle refilling, consistent with decreased GABA synthesis.
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Affiliation(s)
- Brendan Ryu
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | | | | | - Psyche Lee
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Erica Rodriguez
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Meredith Lackie
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Jun Takatoh
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA
| | - Kevin M Franks
- Department of Neurobiology, Duke University Medical School, Durham, NC 27705, USA.
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15
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Duffy BA, Choy M, Lee JH. Predicting Successful Generation and Inhibition of Seizure-like Afterdischarges and Mapping Their Seizure Networks Using fMRI. Cell Rep 2021; 30:2540-2554.e4. [PMID: 32101734 DOI: 10.1016/j.celrep.2020.01.095] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 12/18/2019] [Accepted: 01/27/2020] [Indexed: 11/30/2022] Open
Abstract
To understand the conditions necessary to initiate and terminate seizures, we investigate optogenetically induced hippocampal seizures with LFP, fMRI, and optogenetic inhibition. During afterdischarge induction using optogenetics, LFP recordings show that stimulations with earlier ictal onset times are more likely to result in afterdischarges and are more difficult to curtail with optogenetic inhibition. These results are generalizable across two initiation sites, the dorsal and ventral hippocampus. fMRI shows that afterdischarges initiated from the dorsal or ventral hippocampus exhibit distinct networks. Short-duration seizures initiated in the dorsal and ventral hippocampus are unilateral and bilateral, respectively, while longer-duration afterdischarges recruit broader, bilateral networks. When optogenetic inhibition is ineffective at stopping seizures, the network activity spreads more extensively but largely overlaps with the network activity associated with seizures that could be curtailed. These results provide insights into how seizures can be inhibited, which has implications for targeted seizure interventions.
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Affiliation(s)
- Ben A Duffy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - ManKin Choy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Jin Hyung Lee
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA; Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Neurosurgery, Stanford University, Stanford, CA 94305, USA; Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
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16
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Gao Y, Zheng J, Jiang T, Pi G, Sun F, Xiong R, Wang W, Wu D, Li S, Lei H, Yu H, Zhou Q, Yang Y, Zhang H, Wang JZ. Targeted Reducing of Tauopathy Alleviates Epileptic Seizures and Spatial Memory Impairment in an Optogenetically Inducible Mouse Model of Epilepsy. Front Cell Dev Biol 2021; 8:633725. [PMID: 33681188 PMCID: PMC7930339 DOI: 10.3389/fcell.2020.633725] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 12/29/2020] [Indexed: 11/13/2022] Open
Abstract
Intracellular deposition of hyperphosphorylated tau has been reported in the brain of epilepsy patients, but its contribution to epileptic seizures and the association with spatial cognitive functions remain unclear. Here, we found that repeated optogenetic stimulation of the excitatory neurons in ventral hippocampal CA1 subset could induce a controllable epileptic seizure in mice. Simultaneously, the mice showed spatial learning and memory deficits with a prominently elevated total tau and phospho-tau levels in the brain. Importantly, selective facilitating tau degradation by using a novel designed proteolysis-targeting chimera named C4 could effectively ameliorate the epileptic seizures with remarkable restoration of neuronal firing activities and improvement of spatial learning and memory functions. These results confirm that abnormal tau accumulation plays a pivotal role in the epileptic seizures and the epilepsy-associated spatial memory impairments, which provides new molecular target for the therapeutics.
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Affiliation(s)
- Yang Gao
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jie Zheng
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Pharmacology, Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
| | - Tao Jiang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guilin Pi
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fei Sun
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Xiong
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weijin Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dongqin Wu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shihong Li
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiyang Lei
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiling Yu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qiuzhi Zhou
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Yang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huaqiu Zhang
- Department of Neurosurgery, Key Laboratory of Ministry of Education for Neurological Disorders, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
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17
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Application of Optogenetics in Epilepsy Research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 33398842 DOI: 10.1007/978-981-15-8763-4_39] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Epilepsy is a disease characterized by seizures arising from paroxysmal and self-limited hypersynchrony of neurons. However, the mechanism by which the normal brain develops epilepsy, which involves a chronic process of structural and morphological changes known as epileptogenesis, is not fully understood. Optogenetics involves the use of genetic engineering and optics to monitor or control nerve cell activity. Compared to classical electrophysiological experiments, the application of optogenetics in epilepsy research has many advantages because it allows selective photic stimulation of cell types and electrical observation without introducing artifacts.
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18
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Multimodal Functional Analysis Platform: 4. Optogenetics-Induced Oscillatory Activation to Explore Neural Circuits. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 33398837 DOI: 10.1007/978-981-15-8763-4_34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
To elucidate neural mechanisms underlying oscillatory phenomena in brain function, we have developed optogenetic tools and statistical methods. Specifically, opto-current-clamp induced oscillation reveals intrinsic frequency preferences in the neural circuits by oscillatory resonance. Furthermore, resonance or entrainment to intrinsic frequency is state-dependent. When resonance phenomena go beyond a certain range, it could even induce epileptic seizure in highly reproducible manner. We are able to study how seizures start, develop, and stop in neural circuits. Therefore, the optogenetics-induced oscillatory activation is a powerful tool in neuroscience research.
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19
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Multimodal Functional Analysis Platform: 3. Spherical Treadmill System for Small Animals. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021. [PMID: 33398836 DOI: 10.1007/978-981-15-8763-4_33] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
In the application of advanced neuroscience techniques including optogenetics to small awake animals, it is often necessary to restrict the animal's movements. A spherical treadmill is a beneficial option that enables virtual locomotion of body- or head-restrained small animals. Besides, it has a wide application range, including virtual reality experiments. This chapter describes the fundamentals of a spherical treadmill for researchers who want to start experiments with it. First, we describe the physical aspect of a spherical treadmill based on the simple mechanical analysis. Next, we explain the basics of data logging and preprocessing for behavioral analysis. We also provide simple computer programs that work for the purpose.
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20
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Guo Y, Werner CF, Handa S, Wang M, Ohshiro T, Mushiake H, Yoshinobu T. Miniature multiplexed label-free pH probe in vivo. Biosens Bioelectron 2021; 174:112870. [PMID: 33334636 DOI: 10.1016/j.bios.2020.112870] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 10/27/2020] [Accepted: 11/26/2020] [Indexed: 11/19/2022]
Abstract
Correlating in-brain pH fluctuations with the pathophysiology has been impeded by the lack of in vivo techniques to precisely determine local pH changes. Here, we developed an all-in-one pH probe for spatially-resolved and label-free pH sensing in vivo, based on a field-effect pH sensor, i.e., a light-addressable potentiometric sensor (LAPS), coupled to a flexible multimodal fiber. A readout photocurrent from the LAPS, elicited from a modulated light source, registers the localized surface potential change, proportional to the pH change. Upon simultaneous illuminations at multi-spot by a plurality of light sources with different modulation frequencies, pH changes at multiple designated spots are obtained via demultiplexing this photocurrent. To enable its in vivo applications, we combined the LAPS with a multimodal fiber fabricated by the convergence thermal drawing. Such fiber seamlessly integrates a multicore optical waveguide in the center for the light delivery, surrounded by electrodes for leading out photocurrent and serving as a pseudo-reference electrode, respectively. Such hybrid all-in-one pH probes can measure pH changes at 14 pixels simultaneously with a spatial resolution of 250 μm and a temporal resolution of 30 Hz. The pH sensitivity was characterized as 57.5 ± 2.2 mV/pH homogeneously across all measurable pixels. Such probes have been implanted into the hippocampal formation of rats and their capabilities to capture pH changes at multiple pixels were evaluated at both physiological and pathological conditions. Technologies developed here represents a new class of in vivo chemical sensing technologies enabling the spatially-resolved investigation of intrinsic chemical signals in deep brain structures with high spatial and temporal resolutions.
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Affiliation(s)
- Yuanyuan Guo
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai, Miyagi 9800845, Japan; Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, 9808575, Japan; Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan.
| | - Carl Frederik Werner
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Shoma Handa
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Mengyun Wang
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Tomokazu Ohshiro
- Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, 9808575, Japan
| | - Hajime Mushiake
- Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, 9808575, Japan
| | - Tatsuo Yoshinobu
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan; Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
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21
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Paschen E, Elgueta C, Heining K, Vieira DM, Kleis P, Orcinha C, Häussler U, Bartos M, Egert U, Janz P, Haas CA. Hippocampal low-frequency stimulation prevents seizure generation in a mouse model of mesial temporal lobe epilepsy. eLife 2020; 9:54518. [PMID: 33349333 PMCID: PMC7800381 DOI: 10.7554/elife.54518] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 12/13/2020] [Indexed: 12/18/2022] Open
Abstract
Mesial temporal lobe epilepsy (MTLE) is the most common form of focal, pharmacoresistant epilepsy in adults and is often associated with hippocampal sclerosis. Here, we established the efficacy of optogenetic and electrical low-frequency stimulation (LFS) in interfering with seizure generation in a mouse model of MTLE. Specifically, we applied LFS in the sclerotic hippocampus to study the effects on spontaneous subclinical and evoked generalized seizures. We found that stimulation at 1 Hz for 1 hr resulted in an almost complete suppression of spontaneous seizures in both hippocampi. This seizure-suppressive action during daily stimulation remained stable over several weeks. Furthermore, LFS for 30 min before a pro-convulsive stimulus successfully prevented seizure generalization. Finally, acute slice experiments revealed a reduced efficacy of perforant path transmission onto granule cells upon LFS. Taken together, our results suggest that hippocampal LFS constitutes a promising approach for seizure control in MTLE.
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Affiliation(s)
- Enya Paschen
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Claudio Elgueta
- Systemic and Cellular Neurophysiology, Institute for Physiology I, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katharina Heining
- Biomicrotechnology, Department of Microsystems Engineering - IMTEK, Faculty of Engineering, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Diego M Vieira
- Biomicrotechnology, Department of Microsystems Engineering - IMTEK, Faculty of Engineering, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Piret Kleis
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Catarina Orcinha
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Ute Häussler
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marlene Bartos
- Systemic and Cellular Neurophysiology, Institute for Physiology I, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ulrich Egert
- Biomicrotechnology, Department of Microsystems Engineering - IMTEK, Faculty of Engineering, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Philipp Janz
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center - University of Freiburg, Faculty of Medicine, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.,Center for Basics in NeuroModulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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22
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Hannan S, Faulkner M, Aristovich K, Avery J, Walker MC, Holder DS. Optimised induction of on-demand focal hippocampal and neocortical seizures by electrical stimulation. J Neurosci Methods 2020; 346:108911. [DOI: 10.1016/j.jneumeth.2020.108911] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/10/2020] [Accepted: 08/12/2020] [Indexed: 11/25/2022]
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23
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Spatially expandable fiber-based probes as a multifunctional deep brain interface. Nat Commun 2020; 11:6115. [PMID: 33257708 PMCID: PMC7704647 DOI: 10.1038/s41467-020-19946-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 10/29/2020] [Indexed: 11/28/2022] Open
Abstract
Understanding the cytoarchitecture and wiring of the brain requires improved methods to record and stimulate large groups of neurons with cellular specificity. This requires miniaturized neural interfaces that integrate into brain tissue without altering its properties. Existing neural interface technologies have been shown to provide high-resolution electrophysiological recording with high signal-to-noise ratio. However, with single implantation, the physical properties of these devices limit their access to one, small brain region. To overcome this limitation, we developed a platform that provides three-dimensional coverage of brain tissue through multisite multifunctional fiber-based neural probes guided in a helical scaffold. Chronic recordings from the spatially expandable fiber probes demonstrate the ability of these fiber probes capturing brain activities with a single-unit resolution for long observation times. Furthermore, using Thy1-ChR2-YFP mice we demonstrate the application of our probes in simultaneous recording and optical/chemical modulation of brain activities across distant regions. Similarly, varying electrographic brain activities from different brain regions were detected by our customizable probes in a mouse model of epilepsy, suggesting the potential of using these probes for the investigation of brain disorders such as epilepsy. Ultimately, this technique enables three-dimensional manipulation and mapping of brain activities across distant regions in the deep brain with minimal tissue damage, which can bring new insights for deciphering complex brain functions and dynamics in the near future. Existing neural interfaces are limited in accessing one, small brain region. Here, the authors introduce a scaffold with helix hollow channels, which direct multisite multifunctional fibre probes into the brain at different angles, allowing for simultaneous recording and stimulation across distant regions.
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24
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Wang GH, Chou P, Hsueh SW, Yang YC, Kuo CC. Glutamate transmission rather than cellular pacemaking propels excitatory-inhibitory resonance for ictogenesis in amygdala. Neurobiol Dis 2020; 148:105188. [PMID: 33221531 DOI: 10.1016/j.nbd.2020.105188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 10/20/2020] [Accepted: 11/17/2020] [Indexed: 12/16/2022] Open
Abstract
Epileptic seizures are automatic, excessive, and synchronized neuronal activities originating from many brain regions especially the amygdala, the allocortices and neocortices. This may reflect a shared principle for network organization and signaling in these telencephalic structures. In theory, the automaticity of epileptic discharges may stem from spontaneously active "oscillator" neurons equipped with intrinsic pacemaking conductances, or from a group of synaptically-connected collaborating "resonator" neurons. In the basolateral amygdalar (BLA) network of pyramidal-inhibitory (PN-IN) neuronal resonators, we demonstrated that rhythmogenic currents are provided by glutamatergic rather than the classic intrinsic or cellular pacemaking conductances (namely the h currents). The excitatory output of glutamatergic neurons such as PNs presumably propels a novel network-based "relay burst mode" of discharges especially in INs, which precondition PNs into a state prone to burst discharges and thus further glutamate release. Also, selective activation of unilateral PNs, but never INs, readily drives bilateral BLA networks into reverberating discharges which are fully synchronized with the behavioral manifestations of seizures (e.g. muscle contractions). Seizures originating in BLA and/or the other structures with similar PN-IN networks thus could be viewed as glutamate-triggered erroneous network oscillations that are normally responsible for information relay.
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Affiliation(s)
- Guan-Hsun Wang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; School of Medicine, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Department of Medical Education, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan
| | - Ping Chou
- Department of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shu-Wei Hsueh
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Ya-Chin Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan; Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan.
| | - Chung-Chin Kuo
- Department of Physiology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan.
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25
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Yang YC, Wang GH, Chuang AY, Hsueh SW. Perampanel reduces paroxysmal depolarizing shift and inhibitory synaptic input in excitatory neurons to inhibit epileptic network oscillations. Br J Pharmacol 2020; 177:5177-5194. [PMID: 32901915 DOI: 10.1111/bph.15253] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 08/10/2020] [Accepted: 08/28/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Perampanel is a newly approved anticonvulsant uniquely targeting AMPA receptors, which mediate the most abundant form of excitatory synaptic transmission in the brain. However, the network mechanism underlying the anti-epileptic effect of the AMPAergic inhibition remains to be explored. EXPERIMENTAL APPROACH The mechanism of perampanel action was studied with the basolateral amygdala network containing pyramidal-inhibitory neuronal resonators in seizure models of 4-aminopyridine (4-AP) and electrical kindling. KEY RESULTS Application of either 4-AP or electrical kindling to the basolateral amygdala readily induces AMPAergic transmission-dependent reverberating activities between pyramidal-inhibitory neuronal resonators, which are chiefly characterized by burst discharges in inhibitory neurons and corresponding recurrent inhibitory postsynaptic potentials in pyramidal neurons. Perampanel reduces post-kindling "paroxysmal depolarizing shift" especially in pyramidal neurons and, counterintuitively, eliminates burst activities in inhibitory neurons and inhibitory synaptic inputs onto excitatory pyramidal neurons to result in prevention of epileptiform discharges and seizure behaviours. Intriguingly, similar effects can be obtained with not only the AMPA receptor antagonist CNQX but also the GABAA receptor antagonist bicuculline, which is usually considered as a proconvulsant. CONCLUSION AND IMPLICATIONS Ictogenesis depends on the AMPA receptor-dependent recruitment of pyramidal-inhibitory neuronal network oscillations tuned by dynamic glutamatergic and GABAergic transmission. The anticonvulsant effect of perampanel then stems from disruption of the coordinated network activities rather than simply decreased neuronal excitability or excitatory transmission. Positive or negative modulation of epileptic network reverberations may be pro-ictogenic or anti-ictogenic, respectively, constituting a more applicable rationale for the therapy against seizures.
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Affiliation(s)
- Ya-Chin Yang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Guan-Hsun Wang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,School of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medical Education, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
| | - Ai-Yu Chuang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Shu-Wei Hsueh
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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Lab-Scale Production of Recombinant Adeno-Associated Viruses (AAV) for Expression of Optogenetic Elements. Methods Mol Biol 2020; 2173:83-100. [PMID: 32651911 DOI: 10.1007/978-1-0716-0755-8_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Optogenetics, that is, the use of photoswitchable/-activatable moieties to precisely control or monitor the activity of cells and genes at unprecedented spatiotemporal resolution, holds tremendous promise for a wide array of applications in fundamental and clinical research. To fully realize and harness this potential, the availability of gene transfer vehicles ("vectors") that are easily produced and that allow to deliver the essential components to desired target cells in an efficient manner is key. For in vivo applications, it is, moreover, important that these vectors exhibit a high degree of cell specificity in order to reduce the risk of adverse side effects in off-targets and to minimize manufacturing costs. Here, we describe a set of basic protocols for the cloning, production, purification, and quality control of a particular vector that can fulfill all these requirements, that is, recombinant adeno-associated viruses (AAV). The latter are very attractive owing to their apathogenicity, their compatibility with the lowest biosafety level 1 conditions, their occurrence in multiple natural variants with distinct properties, and their exceptional amenability to engineering of the viral capsid and genome. The specific procedures reported here complement alternative protocols for AAV production described by others and us before, and, together, should enable any laboratory to generate these vectors on a small-to-medium scale for ex vivo or in vivo expression of optogenetic elements.
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Chen X, Sobczak F, Chen Y, Jiang Y, Qian C, Lu Z, Ayata C, Logothetis NK, Yu X. Mapping optogenetically-driven single-vessel fMRI with concurrent neuronal calcium recordings in the rat hippocampus. Nat Commun 2019; 10:5239. [PMID: 31748553 PMCID: PMC6868210 DOI: 10.1038/s41467-019-12850-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/01/2019] [Indexed: 01/07/2023] Open
Abstract
Extensive in vivo imaging studies investigate the hippocampal neural network function, mainly focusing on the dorsal CA1 region given its optical accessibility. Multi-modality fMRI with simultaneous hippocampal electrophysiological recording reveal broad cortical correlation patterns, but the detailed spatial hippocampal functional map remains lacking given the limited fMRI resolution. In particular, hemodynamic responses linked to specific neural activity are unclear at the single-vessel level across hippocampal vasculature, which hinders the deciphering of the hippocampal malfunction in animal models and the translation to critical neurovascular coupling (NVC) patterns for human fMRI. We simultaneously acquired optogenetically-driven neuronal Ca2+ signals with single-vessel blood-oxygen-level-dependent (BOLD) and cerebral-blood-volume (CBV)-fMRI from individual venules and arterioles. Distinct spatiotemporal patterns of hippocampal hemodynamic responses were correlated to optogenetically evoked and spreading depression-like calcium events. The calcium event-related single-vessel hemodynamic modeling revealed significantly reduced NVC efficiency upon spreading depression-like (SDL) events, providing a direct measure of the NVC function at various hippocampal states.
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Affiliation(s)
- Xuming Chen
- Research Group of Translational Neuroimaging and Neural Control, High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, 72076, Tuebingen, Germany
- University of Tuebingen, 72074, Tuebingen, Germany
- Department of Neurology, Wuhan University, Renmin Hospital, Wuhan, 430060, China
| | - Filip Sobczak
- Research Group of Translational Neuroimaging and Neural Control, High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, 72076, Tuebingen, Germany
- Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, 72074, Tuebingen, Germany
| | - Yi Chen
- Research Group of Translational Neuroimaging and Neural Control, High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, 72076, Tuebingen, Germany
- Graduate Training Centre of Neuroscience, International Max Planck Research School, University of Tuebingen, 72074, Tuebingen, Germany
| | - Yuanyuan Jiang
- Research Group of Translational Neuroimaging and Neural Control, High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, 72076, Tuebingen, Germany
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, 02129, MA, USA
| | - Chunqi Qian
- Department of Radiology, Michigan State University, East Lansing, 48824, MI, USA
| | - Zuneng Lu
- Department of Neurology, Wuhan University, Renmin Hospital, Wuhan, 430060, China
| | - Cenk Ayata
- Neurovascular Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, 02129, MA, USA
- Stroke Service and Neuroscience Intensive Care Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 02129, Boston, USA
| | - Nikos K Logothetis
- Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tuebingen, 72076, Germany
- Department of Imaging Science and Biomedical Engineering, University of Manchester, Manchester, M13 9PT, UK
| | - Xin Yu
- Research Group of Translational Neuroimaging and Neural Control, High-Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, 72076, Tuebingen, Germany.
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, 02129, MA, USA.
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Gao F, Cai X, Xiao G, Song Y, Wang M, Li Z, Zhang Y, Xu S, Xie J, Yin H. Recording of Neural Activity With Modulation of Photolysis of Caged Compounds Using Microelectrode Arrays in Rats With Seizures. IEEE Trans Biomed Eng 2019; 66:3080-3087. [DOI: 10.1109/tbme.2019.2900251] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Bortel A, Yao ZS, Shmuel A. A rat model of somatosensory-evoked reflex seizures induced by peripheral stimulation. Epilepsy Res 2019; 157:106209. [PMID: 31629247 DOI: 10.1016/j.eplepsyres.2019.106209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/31/2019] [Accepted: 09/19/2019] [Indexed: 01/14/2023]
Abstract
OBJECTIVE We introduce a novel animal model of somatosensory stimulation-induced reflex seizures which generates focal seizures without causing damage to the brain. METHODS Specifically, we electrically stimulated digits or forepaws of adult rats sedated with dexmedetomidine while imaging cerebral blood volume and recording neurophysiological activity in cortical area S1FL. For the recordings, we either inserted a linear probe into the D3 digit representation or we performed surface electrocorticography (ECoG) recordings. RESULTS Peripheral stimulation of a digit or the forepaw elicited seizures that were followed by a refractory period with decreased neuronal activity, or another seizure or normal response. LFP amplitudes in response to electrical pulses during the seizures (0.28 ± 0.03 mV) were higher than during normal evoked responses (0.25 ± 0.05 mV) and refractory periods (0.2 ± 0.08 mV). Seizures generated during the stimulation period showed prolonged after-discharges that were sustained for 20.9 ± 1.9 s following the cessation of the stimulus. High-frequency oscillations were observed prior to and during the seizures, with amplitudes higher than those associated with normal evoked responses. The seizures were initially focal. Optical imaging of the cerebral blood volume response showed that they propagated from the onset zone to adjacent cortical areas, beyond the S1FL representation of the stimulated digit or forepaw. The spatial extent during seizures was on average 1.74 times larger during the stimulation and 4.1 times following its cessation relative to normal evoked responses. Seizures were recorded not only by probes inserted into cortex but also with ECoG arrays (24.1 ± 5.8 seizures per rat) placed over the dura matter, indicating that the seizures were not induced by damage caused by inserting the probes to the cortex. Stimulation of the forepaw elicited more seizures (18.8 ± 8.5 seizures per rat) than stimulation of a digit (1.7 ± 0.7). Unlike rats sedated with dexmedetomidine, rats anesthetized with urethane showed no seizures, indicating that the seizures may depend on the use of the mild sedative dexmedetomidine. SIGNIFICANCE Our proposed animal model generates seizures induced by electrical sensory stimulation free of artifacts and brain damage. It can be used for studying the mechanisms underlying the generation and propagation of reflex seizures and for evaluating antiepileptic drugs.
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Affiliation(s)
- Aleksandra Bortel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada.
| | - Ze Shan Yao
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Biomedical Engineering, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Amir Shmuel
- Montreal Neurological Institute, McConnell Brain Imaging Centre, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Physiology, McGill University, Montreal, QC, H3A 2B4, Canada; Department of Biomedical Engineering, McGill University, Montreal, QC, H3A 2B4, Canada.
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Cela E, Sjöström PJ. Novel Optogenetic Approaches in Epilepsy Research. Front Neurosci 2019; 13:947. [PMID: 31551699 PMCID: PMC6743373 DOI: 10.3389/fnins.2019.00947] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/22/2019] [Indexed: 11/13/2022] Open
Abstract
Epilepsy is a major neurological disorder characterized by repeated seizures afflicting 1% of the global population. The emergence of seizures is associated with several comorbidities and severely decreases the quality of life of patients. Unfortunately, around 30% of patients do not respond to first-line treatment using anti-seizure drugs (ASDs). Furthermore, it is still unclear how seizures arise in the healthy brain. Therefore, it is critical to have well developed models where a causal understanding of epilepsy can be investigated. While the development of seizures has been studied in several animal models, using chemical or electrical induction, deciphering the results of such studies has been difficult due to the uncertainty of the cell population being targeted as well as potential confounds such as brain damage from the procedure itself. Here we describe novel approaches using combinations of optical and genetic methods for studying epileptogenesis. These approaches can circumvent some shortcomings associated with the classical animal models and may thus increase the likelihood of developing new treatment options.
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Affiliation(s)
- Elvis Cela
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada
| | - Per Jesper Sjöström
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Department of Medicine, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, QC, Canada
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31
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Wang Y, Chen Z. An update for epilepsy research and antiepileptic drug development: Toward precise circuit therapy. Pharmacol Ther 2019; 201:77-93. [PMID: 31128154 DOI: 10.1016/j.pharmthera.2019.05.010] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 05/07/2019] [Indexed: 12/14/2022]
Abstract
Epilepsy involves neuronal dysfunction at molecular, cellular, and circuit levels. The understanding of the mechanism of the epilepsies has advanced greatly in the last three decades, especially in terms of their cellular and molecular basis. However, despite the availability of ~30 anti-epileptic drugs (AEDs) with diverse molecular targets, there are still many challenges (e.g. drug resistance, side effects) in pharmacological treatment of epilepsies today. Because molecular mechanisms are integrated at the level of neuronal circuits, we suggest a shift in epilepsy treatment and research strategies from the "molecular" level to the "circuit" level. Recent technological advances have facilitated circuit mechanistic discovery at each level and have paved the way for many opportunities of novel therapeutic strategies and AED development toward precise circuit therapy.
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Affiliation(s)
- Yi Wang
- Institute of Pharmacology and Toxicology, Department of Pharmacology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, Department of Pharmacology, NHC and CAMS Key Laboratory of Medical Neurobiology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058, China; Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009, China.
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32
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Cela E, McFarlan AR, Chung AJ, Wang T, Chierzi S, Murai KK, Sjöström PJ. An Optogenetic Kindling Model of Neocortical Epilepsy. Sci Rep 2019; 9:5236. [PMID: 30918286 PMCID: PMC6437216 DOI: 10.1038/s41598-019-41533-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/11/2019] [Indexed: 01/26/2023] Open
Abstract
Epileptogenesis is the gradual process by which the healthy brain develops epilepsy. However, the neuronal circuit changes that underlie epileptogenesis are not well understood. Unfortunately, current chemically or electrically induced epilepsy models suffer from lack of cell specificity, so it is seldom known which cells were activated during epileptogenesis. We therefore sought to develop an optogenetic variant of the classical kindling model of epilepsy in which activatable cells are both genetically defined and fluorescently tagged. We briefly optogenetically activated pyramidal cells (PCs) in awake behaving mice every two days and conducted a series of experiments to validate the effectiveness of the model. Although initially inert, brief optogenetic stimuli eventually elicited seizures that increased in number and severity with additional stimulation sessions. Seizures were associated with long-lasting plasticity, but not with tissue damage or astrocyte reactivity. Once optokindled, mice retained an elevated seizure susceptibility for several weeks in the absence of additional stimulation, indicating a form of long-term sensitization. We conclude that optokindling shares many features with classical kindling, with the added benefit that the role of specific neuronal populations in epileptogenesis can be studied. Links between long-term plasticity and epilepsy can thus be elucidated.
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Affiliation(s)
- Elvis Cela
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada.,Integrated Program in Neuroscience, McGill University, 3801 University Street, Montreal, Quebec, H3A 2B4, Canada
| | - Amanda R McFarlan
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada.,Integrated Program in Neuroscience, McGill University, 3801 University Street, Montreal, Quebec, H3A 2B4, Canada
| | - Andrew J Chung
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada
| | - Taiji Wang
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada
| | - Sabrina Chierzi
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada
| | - Keith K Murai
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada
| | - P Jesper Sjöström
- Brain Repair and Integrative Neuroscience Program, Centre for Research in Neuroscience, Departments of Medicine, and Neurology & Neurosurgery, The Research Institute of the McGill University Health Centre, Montreal General Hospital, Montreal, Quebec, H3G 1A4, Canada.
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Camporeze B, Manica BA, Bonafé GA, Ferreira JJC, Diniz AL, de Oliveira CTP, Mathias Junior LR, de Aguiar PHP, Ortega MM. Optogenetics: the new molecular approach to control functions of neural cells in epilepsy, depression and tumors of the central nervous system. Am J Cancer Res 2018; 8:1900-1918. [PMID: 30416844 PMCID: PMC6220144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 09/14/2018] [Indexed: 06/09/2023] Open
Abstract
The optogenetic tools have been described as valuable techniques to study neural activity through light stimulation, as well as potential neuromodulator approaches in the management of several central nervous system (CNS) diseases. Since the first bacteriorhodopsin protein described as a single-component light-activated regulator of transmembrane ion flow description, in 1980's, the focus has been on channel proteins for neurobiology; however, the advances in engineering techniques showed involvement changes in cellular biological behavior in several types of proteins involved in cell cytoskeleton regulation, motility and gene expression. Although the use of this technology has been published in many papers, a question still remains regarding real results and potential clinical applicability in CNS diseases, as well as the publications scarcity that systematically analyses the published results. Lastly, the aim of this review is to discuss the experimental results, molecular mechanisms and potential clinical applications of optogenetic tools in epilepsy and depression treatment, as well as its applicability in the treatment of CNS tumors.
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Affiliation(s)
- Bruno Camporeze
- Postgraduate Program in Health Science, Laboratory of Cellular and Molecular Biology and Bioactive Compounds, São Francisco University (USF)Bragança Paulista-SP, Brazil
- Postgraduate Program in Health Science, Department of Neurosurgery, Institute of Medical Assistance of The State Public Servant (IAMSPE)São Paulo-SP, Brazil
| | - Bruno Alcântara Manica
- Departament of Neurology, Medical School University Pontifical University Catholic of São Paulo (PUCSP)Sorocaba-SP, Brazil
| | - Gabriel Alves Bonafé
- Postgraduate Program in Health Science, Laboratory of Cellular and Molecular Biology and Bioactive Compounds, São Francisco University (USF)Bragança Paulista-SP, Brazil
| | | | - Aurélio Lourenço Diniz
- Departament of Neurology, Medical School University Pontifical University Catholic of São Paulo (PUCSP)Sorocaba-SP, Brazil
| | | | | | - Paulo Henrique Pires de Aguiar
- Postgraduate Program in Health Science, Department of Neurosurgery, Institute of Medical Assistance of The State Public Servant (IAMSPE)São Paulo-SP, Brazil
- Departament of Neurology, Medical School University Pontifical University Catholic of São Paulo (PUCSP)Sorocaba-SP, Brazil
- Departament of Neurosurgery, Hospital Santa PaulaSão Paulo-SP, Brazil
- Department of Research and Innovation, Laboratory of Cellular and Molecular Biology, Medical School of ABC (FMABC)Santo André-SP, Brazil
| | - Manoela Marques Ortega
- Postgraduate Program in Health Science, Laboratory of Cellular and Molecular Biology and Bioactive Compounds, São Francisco University (USF)Bragança Paulista-SP, Brazil
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Kilias A, Canales A, Froriep UP, Park S, Egert U, Anikeeva P. Optogenetic entrainment of neural oscillations with hybrid fiber probes. J Neural Eng 2018; 15:056006. [PMID: 29923505 PMCID: PMC6125198 DOI: 10.1088/1741-2552/aacdb9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVE Optogenetic modulation of neural activity is a ubiquitous tool for basic investigation of brain circuits. While the majority of optogenetic paradigms rely on short light pulses to evoke synchronized activity of optically sensitized cells, many neurobiological processes are associated with slow local field potential (LFP) oscillations. Therefore, we developed a hybrid fiber probe capable of simultaneous electrophysiological recording and optical stimulation and used it to investigate the utility of sinusoidal light stimulation for evoking oscillatory neural activity in vivo across a broad frequency range. APPROACH We fabricated hybrid fiber probes comprising a hollow cylindrical array of 9 electrodes and a flexible optical waveguide integrated within the core. We implanted these probes in the hippocampus of transgenic Thy1-ChR2-YFP mice that broadly express the blue-light sensitive cation channel channelrhodopsin 2 (ChR2) in excitatory neurons across the brain. The effects of the sinusoidal light stimulation were characterized and contrasted with those corresponding to pulsed stimulation in the frequency range of physiological LFP rhythms (3-128 Hz). MAIN RESULTS Within hybrid probes, metal electrode surfaces were vertically aligned with the waveguide tip, which minimized optical stimulation artifacts in neurophysiological recordings. Sinusoidal stimulation resulted in reliable and coherent entrainment of LFP oscillations up to 70 Hz, the cutoff frequency of ChR2, with response amplitudes inversely scaling with the stimulation frequencies. Effectiveness of the stimulation was maintained for two months following implantation. SIGNIFICANCE Alternative stimulation patterns complementing existing pulsed protocols, in particular sinusoidal light stimulation, are a prerequisite for investigating the physiological mechanisms underlying brain rhythms. So far, studies applying sinusoidal stimulation in vivo were limited to single stimulation frequencies. We show the feasibility of sinusoidal stimulation in vivo to induce coherent LFP oscillations across the entire frequency spectrum supported by the gating dynamics of ChR2 and introduce a hybrid fiber probe tailored to continuous light stimulation.
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Affiliation(s)
- Antje Kilias
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Biomicrotechnology, Institute for Microsystems Engineering, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Andres Canales
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ulrich P. Froriep
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Simons Center for the Social Brain, Massachusetts Institute of Technology, Hannover, Germany
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
| | - Seongjun Park
- Department of Electrical Engineering and Computer Science, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ulrich Egert
- Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
- Biomicrotechnology, Institute for Microsystems Engineering, University of Freiburg, Freiburg, Germany
| | - Polina Anikeeva
- Department of Materials Science and Engineering, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
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Janz P, Hauser P, Heining K, Nestel S, Kirsch M, Egert U, Haas CA. Position- and Time-Dependent Arc Expression Links Neuronal Activity to Synaptic Plasticity During Epileptogenesis. Front Cell Neurosci 2018; 12:244. [PMID: 30154698 PMCID: PMC6102356 DOI: 10.3389/fncel.2018.00244] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/18/2018] [Indexed: 12/14/2022] Open
Abstract
In mesial temporal lobe epilepsy (mTLE) an initial precipitating injury can trigger aberrant wiring of neuronal circuits causing seizure activity. While circuit reorganization is known to be largely activity-dependent, the interactions between neuronal activity and synaptic plasticity during the development of mTLE remain poorly understood. Therefore, the present study aimed at delineating the spatiotemporal relationship between epileptic activity, activity-dependent gene expression and synaptic plasticity during kainic acid-induced epileptogenesis in mice. We show that during epileptogenesis the sclerotic hippocampus differed from non-sclerotic regions by displaying a consistently lower power of paroxysmal discharges. However, the power of these discharges steadily increased during epileptogenesis. This increase was paralleled by the upregulation of the activity-related cytoskeleton protein (Arc) gene expression in dentate granule cells (DGCs) of the sclerotic hippocampus. Importantly, we found that Arc mRNA-upregulating DGCs exhibited increased spine densities and spine sizes, but at the same time decreased AMPA-type glutamate receptor (AMPAR) densities. Finally, we show that in vivo optogenetic stimulation of DGC synapses evoked robust seizure activity in epileptic mice, but failed to induce dendritic translocation of Arc mRNA as under healthy conditions, supporting the theory of a breakdown of the dentate gate in mTLE. We conclude that during epileptogenesis epileptic activity emerges early and persists in the whole hippocampus, however, only the sclerotic part shows modulation of discharge amplitudes accompanied by plasticity of DGCs. In this context, we identified Arc as a putative mediator between seizure activity and synaptic plasticity.
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Affiliation(s)
- Philipp Janz
- Experimental Epilepsy Research, Department of Neurosurgery, University Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Pascal Hauser
- Experimental Epilepsy Research, Department of Neurosurgery, University Medical Center, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Katharina Heining
- Faculty of Biology, University of Freiburg, Freiburg, Germany.,Laboratory for Biomicrotechnology, Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Sigrun Nestel
- Institute for Anatomy and Cell Biology, Department of Neuroanatomy, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Kirsch
- Institute for Anatomy and Cell Biology, Department of Neuroanatomy, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany
| | - Ulrich Egert
- Laboratory for Biomicrotechnology, Department of Microsystems Engineering, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, University Medical Center, University of Freiburg, Freiburg, Germany.,Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BrainLinks-BrainTools Cluster of Excellence, University of Freiburg, Freiburg, Germany
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Christenson Wick Z, Krook-Magnuson E. Specificity, Versatility, and Continual Development: The Power of Optogenetics for Epilepsy Research. Front Cell Neurosci 2018; 12:151. [PMID: 29962936 PMCID: PMC6010559 DOI: 10.3389/fncel.2018.00151] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Accepted: 05/15/2018] [Indexed: 12/19/2022] Open
Abstract
Optogenetics is a powerful and rapidly expanding set of techniques that use genetically encoded light sensitive proteins such as opsins. Through the selective expression of these exogenous light-sensitive proteins, researchers gain the ability to modulate neuronal activity, intracellular signaling pathways, or gene expression with spatial, directional, temporal, and cell-type specificity. Optogenetics provides a versatile toolbox and has significantly advanced a variety of neuroscience fields. In this review, using recent epilepsy research as a focal point, we highlight how the specificity, versatility, and continual development of new optogenetic related tools advances our understanding of neuronal circuits and neurological disorders. We additionally provide a brief overview of some currently available optogenetic tools including for the selective expression of opsins.
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Affiliation(s)
- Zoé Christenson Wick
- Graduate Program in Neuroscience and Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States
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37
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Berglind F, Andersson M, Kokaia M. Dynamic interaction of local and transhemispheric networks is necessary for progressive intensification of hippocampal seizures. Sci Rep 2018; 8:5669. [PMID: 29618778 PMCID: PMC5884800 DOI: 10.1038/s41598-018-23659-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 03/02/2018] [Indexed: 12/02/2022] Open
Abstract
The detailed mechanisms of progressive intensification of seizures often occurring in epilepsy are not well understood. Animal models of kindling, with progressive intensification of stimulation-induced seizures, have been previously used to investigate alterations in neuronal networks, but has been obscured by limited recording capabilities during electrical stimulations. Remote networks in kindling have been studied by physical deletions of the connected structures or pathways, inevitably leading to structural reorganisations and related adverse effects. We used optogenetics to circumvent the above-mentioned problems inherent to electrical kindling, and chemogenetics to temporarily inhibit rather than ablate the remote interconnected networks. Progressively intensifying afterdischarges (ADs) were induced by repetitive photoactivation of principal neurons in the hippocampus of anaesthetized transgenic mice expressing ChR2. This allowed, during the stimulation, to reveal dynamic increases in local field potentials (LFPs), which coincided with the start of AD intensification. Furthermore, chemogenetic functional inhibition of contralateral hippocampal neurons via hM4D(Gi) receptors abrogated AD progression. These findings demonstrate that, during repeated activation, local circuits undergo acute plastic changes with appearance of additional network discharges (LFPs), leading to transhemispheric recruitment of contralateral dentate gyrus, which seems to be necessary for progressive intensification of ADs.
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Affiliation(s)
- Fredrik Berglind
- Epilepsy Centre, Department of Clinical Sciences, Lund University Hospital, Lund, Sweden
| | - My Andersson
- Epilepsy Centre, Department of Clinical Sciences, Lund University Hospital, Lund, Sweden
| | - Merab Kokaia
- Epilepsy Centre, Department of Clinical Sciences, Lund University Hospital, Lund, Sweden.
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Igarashi H, Ikeda K, Onimaru H, Kaneko R, Koizumi K, Beppu K, Nishizawa K, Takahashi Y, Kato F, Matsui K, Kobayashi K, Yanagawa Y, Muramatsu SI, Ishizuka T, Yawo H. Targeted expression of step-function opsins in transgenic rats for optogenetic studies. Sci Rep 2018; 8:5435. [PMID: 29615713 PMCID: PMC5882906 DOI: 10.1038/s41598-018-23810-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 03/20/2018] [Indexed: 12/12/2022] Open
Abstract
Rats are excellent animal models for experimental neuroscience. However, the application of optogenetics in rats has been hindered because of the limited number of established transgenic rat strains. To accomplish cell-type specific targeting of an optimized optogenetic molecular tool, we generated ROSA26/CAG-floxed STOP-ChRFR(C167A)-Venus BAC rats that conditionally express the step-function mutant channelrhodopsin ChRFR(C167A) under the control of extrinsic Cre recombinase. In primary cultured cortical neurons derived from this reporter rat, only Cre-positive cells expressing ChRFR(C167A) became bi-stable, that is, their excitability was enhanced by blue light and returned to the baseline by yellow~red light. In bigenic pups carrying the Phox2B-Cre driver, ChRFR(C167A) was specifically expressed in the rostral parafacial respiratory group (pFRG) in the medulla, where endogenous Phox2b immunoreactivity was detected. These neurons were sensitive to blue light with an increase in the firing frequency. Thus, this transgenic rat actuator/reporter system should facilitate optogenetic studies involving the effective in vivo manipulation of the activities of specific cell fractions using light of minimal intensity.
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Affiliation(s)
- Hiroyuki Igarashi
- Department of Physiology and Pharmacology, Tohoku University Graduate school of Medicine, Sendai, Japan. .,Research Fellow of the Japan Society for the Promotion of Science (JSPS Research Fellow), Tokyo, Japan.
| | - Keiko Ikeda
- Department of Physiology, International University of Health and Welfare, Narita, Chiba, Japan.,Division of Biology, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Shinagawa, Tokyo, Japan
| | - Ryosuke Kaneko
- Department of Genetic and Behavioural Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Kyo Koizumi
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Kaoru Beppu
- Department of Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Kayo Nishizawa
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Yukari Takahashi
- Department of Neuroscience, The Jikei University School of Medicine, Tokyo, Japan
| | - Fusao Kato
- Department of Neuroscience, The Jikei University School of Medicine, Tokyo, Japan
| | - Ko Matsui
- Department of Super-network Brain Physiology, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Kazuto Kobayashi
- Department of Molecular Genetics, Institute of Biomedical Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioural Neuroscience, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shin-Ichi Muramatsu
- Division of Neurology, Jichi Medical School, Tochigi, Japan.,Center for Gene & Cell Therapy, The Institute of Medical Science, University of Tokyo, Tokyo, Japan
| | - Toru Ishizuka
- Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Hiromu Yawo
- Department of Physiology and Pharmacology, Tohoku University Graduate school of Medicine, Sendai, Japan. .,Department of Developmental Biology and Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan.
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39
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Komatsu M, Sugano E, Tomita H, Fujii N. A Chronically Implantable Bidirectional Neural Interface for Non-human Primates. Front Neurosci 2017; 11:514. [PMID: 28966573 PMCID: PMC5605616 DOI: 10.3389/fnins.2017.00514] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 08/31/2017] [Indexed: 11/17/2022] Open
Abstract
Optogenetics has potential applications in the study of epilepsy and neuroprostheses, and for studies on neural circuit dynamics. However, to achieve translation to clinical usage, optogenetic interfaces that are capable of chronic stimulation and monitoring with minimal brain trauma are required. We aimed to develop a chronically implantable device for photostimulation of the brain of non-human primates. We used a micro-light-emitting diode (LED) array with a flexible polyimide film. The array was combined with a whole-cortex electrocorticographic (ECoG) electrode array for simultaneous photostimulation and recording. Channelrhodopsin-2 (ChR2) was virally transduced into the cerebral cortex of common marmosets, and then the device was epidurally implanted into their brains. We recorded the neural activity during photostimulation of the awake monkeys for 4 months. The neural responses gradually increased after the virus injection for ~8 weeks and remained constant for another 8 weeks. The micro-LED and ECoG arrays allowed semi-invasive simultaneous stimulation and recording during long-term implantation in the brains of non-human primates. The development of this device represents substantial progress in the field of optogenetic applications.
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Affiliation(s)
- Misako Komatsu
- Ichinohe Group, Laboratory for Molecular Analysis of Higher Brain Function, RIKEN Brain Science InstituteSaitama, Japan
| | - Eriko Sugano
- Department of Chemistry and Biological Sciences, Iwate UniversityIwate, Japan
| | - Hiroshi Tomita
- Department of Chemistry and Biological Sciences, Iwate UniversityIwate, Japan
| | - Naotaka Fujii
- Laboratory for Adaptive Intelligence, RIKEN Brain Science InstituteSaitama, Japan
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40
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Investigation of Seizure-Susceptibility in a Drosophila melanogaster Model of Human Epilepsy with Optogenetic Stimulation. Genetics 2017. [PMID: 28630111 DOI: 10.1534/genetics.116.194779] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We examined seizure-susceptibility in a Drosophila model of human epilepsy using optogenetic stimulation of ReaChR (red-activatable channelrhodopsin). Photostimulation of the seizure-sensitive mutant parabss1 causes behavioral paralysis that resembles paralysis caused by mechanical stimulation, in many aspects. Electrophysiology shows that photostimulation evokes abnormal seizure-like neuronal firing in parabss1 followed by a quiescent period resembling synaptic failure and apparently responsible for paralysis. The pattern of neuronal activity concludes with seizure-like activity just prior to recovery. We tentatively identify the mushroom body as one apparent locus of optogenetic seizure initiation. The α/β lobes may be primarily responsible for mushroom body seizure induction.
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41
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Houben T, Loonen IC, Baca SM, Schenke M, Meijer JH, Ferrari MD, Terwindt GM, Voskuyl RA, Charles A, van den Maagdenberg AM, Tolner EA. Optogenetic induction of cortical spreading depression in anesthetized and freely behaving mice. J Cereb Blood Flow Metab 2017; 37:1641-1655. [PMID: 27107026 PMCID: PMC5435281 DOI: 10.1177/0271678x16645113] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cortical spreading depression, which plays an important role in multiple neurological disorders, has been studied primarily with experimental models that use highly invasive methods. We developed a relatively non-invasive optogenetic model to induce cortical spreading depression by transcranial stimulation of channelrhodopsin-2 ion channels expressed in cortical layer 5 neurons. Light-evoked cortical spreading depression in anesthetized and freely behaving mice was studied with intracortical DC-potentials, multi-unit activity and/or non-invasive laser Doppler flowmetry, and optical intrinsic signal imaging. In anesthetized mice, cortical spreading depression induction thresholds and propagation rates were similar for invasive (DC-potential) and non-invasive (laser Doppler flowmetry) recording paradigms. Cortical spreading depression-related vascular and parenchymal optical intrinsic signal changes were similar to those evoked with KCl. In freely behaving mice, DC-potential and multi-unit activity recordings combined with laser Doppler flowmetry revealed cortical spreading depression characteristics comparable to those under anesthesia, except for a shorter cortical spreading depression duration. Cortical spreading depression resulted in a short increase followed by prolonged reduction of spontaneous active behavior. Motor function, as assessed by wire grip tests, was transiently and unilaterally suppressed following a cortical spreading depression. Optogenetic cortical spreading depression induction has significant advantages over current models in that multiple cortical spreading depression events can be elicited in a non-invasive and cell type-selective fashion.
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Affiliation(s)
- Thijs Houben
- 1 Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Inge Cm Loonen
- 2 Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Serapio M Baca
- 3 Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, USA
| | - Maarten Schenke
- 2 Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Johanna H Meijer
- 4 Laboratory for Neurophysiology, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michel D Ferrari
- 1 Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Gisela M Terwindt
- 1 Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands
| | - Rob A Voskuyl
- 2 Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Andrew Charles
- 3 Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, USA
| | - Arn Mjm van den Maagdenberg
- 1 Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.,2 Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Else A Tolner
- 1 Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.,2 Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
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42
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Sato M, Sugano E, Tabata K, Sannohe K, Watanabe Y, Ozaki T, Tamai M, Tomita H. Visual Responses of Photoreceptor-Degenerated Rats Expressing Two Different Types of Channelrhodopsin Genes. Sci Rep 2017; 7:41210. [PMID: 28112267 PMCID: PMC5255552 DOI: 10.1038/srep41210] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/16/2016] [Indexed: 12/02/2022] Open
Abstract
Optogenetic technologies are expected to be applicable for clinical use in restoring vision. However, the degree of recovered visual function is highly dependent on the function of the chosen optogenetic gene. To investigate the effect on visual function of dual expression of genes with different wavelength sensitivities, we transduced a modified Volvox-derived channelrhodopsin gene (mVChR1) via an adeno-associated virus vector into transgenic rats harbouring the ChR2 gene in retinal ganglion cells. These transgenic rats were given an intraperitoneal injection of N-methyl-N-nitrosourea to induce the degeneration of native photoreceptor cells prior to transduction of mVChR1. Optical coherence tomography images indicated the degeneration of the native photoreceptor cells after the N-methyl-N-nitrosourea injection. Complete loss of function of the native photoreceptor cells was confirmed using electroretinograms. In the ChR2 transgenic rats, visually evoked potentials were clearly detectable in spite of native photoreceptor function abolishment; however the responses were limited to within blue wavelengths. In contrast, the limited wavelength sensitivities were improved by the additional transduction of mVChR1, which exhibited sensitivities to green and red. Thus, the transductions of dual genes encoding channelrhodopsins that exhibit different wavelength sensitivities represents a promising candidate method to expand and to enhance rescued wavelength sensitivities in blind subjects.
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Affiliation(s)
- Masatoshi Sato
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Eriko Sugano
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan.,Soft-Path Engineering Research Center (SPERC), Iwate University Division of Science and Engineering, Morioka 020-8551, Japan
| | - Kitako Tabata
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Kei Sannohe
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Yoshito Watanabe
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan
| | - Taku Ozaki
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan.,Soft-Path Engineering Research Center (SPERC), Iwate University Division of Science and Engineering, Morioka 020-8551, Japan
| | - Makoto Tamai
- Tohoku University Graduate School of Medicine, 1-1 Seiryo, Aoba, Sendai, Miyagi 980-8574, Japan
| | - Hiroshi Tomita
- Laboratory of Visual Neuroscience, Graduate Course in Biological Sciences, Iwate University Division of Science and Engineering, 4-3-5 Ueda, Morioka, Iwate 020-8551, Japan.,Soft-Path Engineering Research Center (SPERC), Iwate University Division of Science and Engineering, Morioka 020-8551, Japan.,Clinical Research, Innovation and Education Center, Tohoku University Hospital, 1-1 Seiryo, Aoba, Sendai, Miyagi 980-8574, Japan
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43
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Abstract
Optogenetic methods have been highly effective for suppressing neural activity and modulating behavior in rodents, but effects have been much smaller in primates, which have much larger brains. Here, we present a suite of technologies to use optogenetics effectively in primates and apply these tools to a classic question in oculomotor control. First, we measured light absorption and heat propagation in vivo, optimized the conditions for using the red-light-shifted halorhodopsin Jaws in primates, and developed a large-volume illuminator to maximize light delivery with minimal heating and tissue displacement. Together, these advances allowed for nearly universal neuronal inactivation across more than 10 mm3 of the cortex. Using these tools, we demonstrated large behavioral changes (i.e., up to several fold increases in error rate) with relatively low light power densities (≤100 mW/mm2) in the frontal eye field (FEF). Pharmacological inactivation studies have shown that the FEF is critical for executing saccades to remembered locations. FEF neurons increase their firing rate during the three epochs of the memory-guided saccade task: visual stimulus presentation, the delay interval, and motor preparation. It is unclear from earlier work, however, whether FEF activity during each epoch is necessary for memory-guided saccade execution. By harnessing the temporal specificity of optogenetics, we found that FEF contributes to memory-guided eye movements during every epoch of the memory-guided saccade task (the visual, delay, and motor periods).
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44
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Tung JK, Berglund K, Gross RE. Optogenetic Approaches for Controlling Seizure Activity. Brain Stimul 2016; 9:801-810. [PMID: 27496002 PMCID: PMC5143193 DOI: 10.1016/j.brs.2016.06.055] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 06/21/2016] [Accepted: 06/28/2016] [Indexed: 01/01/2023] Open
Abstract
Optogenetics, a technique that utilizes light-sensitive ion channels or pumps to activate or inhibit neurons, has allowed scientists unprecedented precision and control for manipulating neuronal activity. With the clinical need to develop more precise and effective therapies for patients with drug-resistant epilepsy, these tools have recently been explored as a novel treatment for halting seizure activity in various animal models. In this review, we provide a detailed and current summary of these optogenetic approaches and provide a perspective on their future clinical application as a potential neuromodulatory therapy.
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Affiliation(s)
- Jack K Tung
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA; Department of Neurosurgery, Emory University, Atlanta, GA
| | - Ken Berglund
- Department of Neurosurgery, Emory University, Atlanta, GA
| | - Robert E Gross
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA; Department of Neurosurgery, Emory University, Atlanta, GA.
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45
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Propagating Neural Source Revealed by Doppler Shift of Population Spiking Frequency. J Neurosci 2016; 36:3495-505. [PMID: 27013678 DOI: 10.1523/jneurosci.3525-15.2016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/28/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Electrical activity in the brain during normal and abnormal function is associated with propagating waves of various speeds and directions. It is unclear how both fast and slow traveling waves with sometime opposite directions can coexist in the same neural tissue. By recording population spikes simultaneously throughout the unfolded rodent hippocampus with a penetrating microelectrode array, we have shown that fast and slow waves are causally related, so a slowly moving neural source generates fast-propagating waves at ∼0.12 m/s. The source of the fast population spikes is limited in space and moving at ∼0.016 m/s based on both direct and Doppler measurements among 36 different spiking trains among eight different hippocampi. The fact that the source is itself moving can account for the surprising direction reversal of the wave. Therefore, these results indicate that a small neural focus can move and that this phenomenon could explain the apparent wave reflection at tissue edges or multiple foci observed at different locations in neural tissue. SIGNIFICANCE STATEMENT The use of novel techniques with an unfolded hippocampus and penetrating microelectrode array to record and analyze neural activity has revealed the existence of a source of neural signals that propagates throughout the hippocampus. The source itself is electrically silent, but its location can be inferred by building isochrone maps of population spikes that the source generates. The movement of the source can also be tracked by observing the Doppler frequency shift of these spikes. These results have general implications for how neural signals are generated and propagated in the hippocampus; moreover, they have important implications for the understanding of seizure generation and foci localization.
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46
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Choy M, Duffy BA, Lee JH. Optogenetic study of networks in epilepsy. J Neurosci Res 2016; 95:2325-2335. [PMID: 27413006 PMCID: PMC5548626 DOI: 10.1002/jnr.23767] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 01/23/2023]
Abstract
Currently, approximately 30% of patients with epilepsy do not have adequate seizure control. A greater understanding of the underlying mechanisms by which seizures start or propagate could lead to new therapeutic strategies. The recent development of optogenetics, because of its unprecedented precision for controlling activity within distinct neuronal populations, has revolutionized neuroscience, including epilepsy research. This Review discusses recent breakthroughs made with optogenetics in epilepsy research. These breakthroughs include new insights into the key roles that different cell types play in mediating seizures as well as in the development of epilepsy. Subsequently, we discuss how targeting different brain regions and cell populations has opened up the possibility of highly specific therapies that can stop seizures on demand. Finally, we illustrate how combining newly available neuroscience tools with whole-brain imaging techniques will allow researchers to understand better the spread of seizures on a network level. © 2016 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc.
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Affiliation(s)
- ManKin Choy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California
| | - Ben A Duffy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California
| | - Jin Hyung Lee
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California.,Department of Bioengineering, Stanford University, Stanford, California.,Department of Neurosurgery, Stanford University, Stanford, California.,Department of Electrical Engineering, Stanford University, Stanford, California
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47
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Bui AD, Alexander A, Soltesz I. Seizing Control: From Current Treatments to Optogenetic Interventions in Epilepsy. Neuroscientist 2016; 23:68-81. [PMID: 26700888 DOI: 10.1177/1073858415619600] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The unpredictability and severity of seizures contribute to the debilitating nature of epilepsy. These factors also render the condition particularly challenging to treat, as an ideal treatment would need to detect and halt the pathological bursts of hyperactivity without disrupting normal brain activity. Optogenetic techniques offer promising tools to study and perhaps eventually treat this episodic disorder by controlling specific brain circuits in epileptic animals with great temporal precision. Here, we briefly review the current treatment options for patients with epilepsy. We then describe the many ways optogenetics has allowed us to untangle the microcircuits involved in seizure activity, and how it has, in some cases, changed our perception of previous theories of seizure generation. Control of seizures with light is no longer a dream, and has been achieved in numerous different animal models of epilepsy. Beyond its application as a seizure suppressor, we highlight another facet of optogenetics in epilepsy, namely the ability to create "on-demand" seizures, as a tool to systematically probe the dynamics of networks during seizure initiation and propagation. Finally, we look into the future to discuss the possibilities and challenges of translating optogenetic techniques to clinical use.
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Affiliation(s)
- Anh D Bui
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA.,2 Department of Anatomy and Neurobiology, University of California, Irvine, CA, USA
| | - Allyson Alexander
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Ivan Soltesz
- 1 Department of Neurosurgery, Stanford University, Stanford, CA, USA
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48
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Bazan NG, Musto AE. What is the therapeutic potential of neuroprotectin D1 for epilepsy? FUTURE NEUROLOGY 2015. [DOI: 10.2217/fnl.15.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Nicolas G. Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, 2020 Gravier Street, New Orleans, LA 70112, USA
| | - Alberto E. Musto
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health Sciences Center, 2020 Gravier Street, New Orleans, LA 70112, USA
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49
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Local and systemic responses following intravitreous injection of AAV2-encoded modified Volvox channelrhodopsin-1 in a genetically blind rat model. Gene Ther 2015; 23:158-66. [PMID: 26440056 DOI: 10.1038/gt.2015.99] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/11/2015] [Accepted: 09/04/2015] [Indexed: 01/22/2023]
Abstract
We previously designed a modified channelrhodopsin-1 (mVChR1) protein chimera with a broader action than that of Chlamydomonas channelrhodopsin-2 and reported that its transduction into retinal ganglion cells can restore visual function in genetically blind, dystrophic Royal College of Surgeons (RCS) rats, with photostimuli ranging from 486 to 640 nm. In the current study, we sought to investigate the safety and influence of mVChR1 transgene expression. Adeno-associated virus type 2 encoding mVChR1 was administered by intravitreous injection into dystrophic RCS rats. Reverse-transcription PCR was used to monitor virus and transgene dissemination and the results demonstrated that their expression was restricted specifically within the eye tissues, and not in non-target organs. Moreover, examination of the blood, plasma and serum revealed that no excess immunoreactivity was present, as determined using standard clinical hematological parameters. Serum antibodies targeting the recombinant adeno-associated virus (rAAV) capsid increased after the injection; however, no increase in mVChR1 antibody was detected during the observation period. In addition, retinal histological examination showed no signs of inflammation in rAAV-injected rats. In conclusion, our results demonstrate that mVChR1 can be exogenously expressed without harmful immunological reactions in vivo. These findings will aid in studies of AAV gene transfer to restore vision in late-stage retinitis pigmentosa.
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50
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Zhao M, Alleva R, Ma H, Daniel AGS, Schwartz TH. Optogenetic tools for modulating and probing the epileptic network. Epilepsy Res 2015; 116:15-26. [PMID: 26354163 PMCID: PMC4567692 DOI: 10.1016/j.eplepsyres.2015.06.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/29/2015] [Accepted: 06/14/2015] [Indexed: 12/01/2022]
Abstract
Epilepsy affects roughly 1% of the population worldwide. Although effective treatments with antiepileptic drugs are available, more than 20% of patients have seizures that are refractory to medical therapy and many patients experience adverse effects. Hence, there is a continued need for novel therapies for those patients. A new technique called "optogenetics" may offer a new hope for these refractory patients. Optogenetics is a technology based on the combination of optics and genetics, which can control or record neural activity with light. Following delivery of light-sensitive opsin genes such as channelrhodopsin-2 (ChR2), halorhodopsin (NpHR), and others into brain, excitation or inhibition of specific neurons in precise brain areas can be controlled by illumination at different wavelengths with very high temporal and spatial resolution. Neuromodulation with the optogenetics toolbox have already been shown to be effective at treating seizures in animal models of epilepsy. This review will outline the most recent advances in epilepsy research with optogenetic techniques and discuss how this technology can contribute to our understanding and treatment of epilepsy in the future.
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Affiliation(s)
- Mingrui Zhao
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Rose Alleva
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Hongtao Ma
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Andy G S Daniel
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
| | - Theodore H Schwartz
- Department of Neurological Surgery, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA; Department of Otolaryngology, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA; Department of Neuroscience, Weill Medical College of Cornell University, New York Presbyterian Hospital, New York, NY 10021, USA.
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