1
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Wickham J, Ledri M, Andersson M, Kokaia M. Cell-specific switch for epileptiform activity: critical role of interneurons in the mouse subicular network. Cereb Cortex 2023; 33:6171-6183. [PMID: 36611229 PMCID: PMC10183737 DOI: 10.1093/cercor/bhac493] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 01/09/2023] Open
Abstract
During epileptic seizures, neuronal network activity is hyper synchronized whereby GABAergic parvalbumin-interneurons may have a key role. Previous studies have mostly utilized 4-aminopyridine to induce epileptiform discharges in brain slices from healthy animals. However, it is not clear if the seizure-triggering ability of parvalbumin-interneurons also holds true without the use of external convulsive agents. Here, we investigate whether synchronized activation of parvalbumin-interneurons or principal cells can elicit epileptiform discharges in subiculum slices of epileptic mice. We found that selective synchronized activation of parvalbumin-interneurons or principal cells with optogenetics do not result in light-induced epileptiform discharges (LIEDs) neither in epileptic nor in normal brain slices. Adding 4-aminopyridine to slices, activation of parvalbumin-interneurons still failed to trigger LIEDs. In contrast, such activation of principal neurons readily generated LIEDs with features resembling afterdischarges. When GABAA receptor blocker was added to the perfusion medium, the LIEDs were abolished. These results demonstrate that in subiculum, selective synchronized activation of principal excitatory neurons can trigger epileptiform discharges by recruiting a large pool of downstream interneurons. This study also suggests region-specific role of principal neurons and interneurons in ictogenesis, opening towards differential targeting of specific brain areas for future treatment strategies tailored for individual patients with epilepsy.
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Affiliation(s)
- J Wickham
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Ledri
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Andersson
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
| | - M Kokaia
- Epilepsy Center, Department of Clinical Sciences, Lund University, Sölvegatan 17, 223 62 Lund, Sweden
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2
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Fei F, Wang X, Xu C, Shi J, Gong Y, Cheng H, Lai N, Ruan Y, Ding Y, Wang S, Chen Z, Wang Y. Discrete subicular circuits control generalization of hippocampal seizures. Nat Commun 2022; 13:5010. [PMID: 36008421 PMCID: PMC9411516 DOI: 10.1038/s41467-022-32742-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 08/15/2022] [Indexed: 11/09/2022] Open
Abstract
Epilepsy is considered a circuit-level dysfunction associated with imbalanced excitation-inhibition, it is therapeutically necessary to identify key brain regions and related circuits in epilepsy. The subiculum is an essential participant in epileptic seizures, but the circuit mechanism underlying its role remains largely elusive. Here we deconstruct the diversity of subicular circuits in a mouse model of epilepsy. We find that excitatory subicular pyramidal neurons heterogeneously control the generalization of hippocampal seizures by projecting to different downstream regions. Notably, anterior thalamus-projecting subicular neurons bidirectionally mediate seizures, while entorhinal cortex-projecting subicular neurons act oppositely in seizure modulation. These two subpopulations are structurally and functionally dissociable. An intrinsically enhanced hyperpolarization-activated current and robust bursting intensity in anterior thalamus-projecting neurons facilitate synaptic transmission, thus contributing to the generalization of hippocampal seizures. These results demonstrate that subicular circuits have diverse roles in epilepsy, suggesting the necessity to precisely target specific subicular circuits for effective treatment of epilepsy.
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Affiliation(s)
- Fan Fei
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Xia Wang
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Cenglin Xu
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China.
| | - Jiaying Shi
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yiwei Gong
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China.,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Heming Cheng
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Nanxi Lai
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yeping Ruan
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yao Ding
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shuang Wang
- Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhong Chen
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. .,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China. .,Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Yi Wang
- Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. .,Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, School of Pharmaceutical Sciences, Zhejiang Chinese Medical University, Hangzhou, China. .,Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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3
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Nadel JA, Pawelko SS, Scott JR, McLaughlin R, Fox M, Ghanem M, van der Merwe R, Hollon NG, Ramsson ES, Howard CD. Optogenetic stimulation of striatal patches modifies habit formation and inhibits dopamine release. Sci Rep 2021; 11:19847. [PMID: 34615966 PMCID: PMC8494762 DOI: 10.1038/s41598-021-99350-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 09/23/2021] [Indexed: 11/12/2022] Open
Abstract
Habits are inflexible behaviors that develop after extensive repetition, and overreliance on habits is a hallmark of many pathological states. The striatum is involved in the transition from flexible to inflexible responding, and interspersed throughout the striatum are patches, or striosomes, which make up ~15% of the volume of the striatum relative to the surrounding matrix compartment. Previous studies have suggested that patches are necessary for normal habit formation, but it remains unknown exactly how patches contribute to habit formation and expression. Here, using optogenetics, we stimulated striatal patches in Sepw1-NP67 mice during variable interval training (VI60), which is used to establish habitual responding. We found that activation of patches at reward retrieval resulted in elevated responding during VI60 training by modifying the pattern of head entry and pressing. Further, this optogenetic manipulation reduced subsequent responding following reinforcer devaluation, suggesting modified habit formation. However, patch stimulation did not generally increase extinction rates during a subsequent extinction probe, but did result in a small 'extinction burst', further suggesting goal-directed behavior. On the other hand, this manipulation had no effect in omission trials, where mice had to withhold responses to obtain rewards. Finally, we utilized fast-scan cyclic voltammetry to investigate how patch activation modifies evoked striatal dopamine release and found that optogenetic activation of patch projections to the substantia nigra pars compacta (SNc) is sufficient to suppress dopamine release in the dorsal striatum. Overall, this work provides novel insight into the role of the patch compartment in habit formation, and provides a potential mechanism for how patches modify habitual behavior by exerting control over dopamine signaling.
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Affiliation(s)
- J A Nadel
- Neuroscience Department, Oberlin College, Oberlin, OH, USA
| | - S S Pawelko
- Neuroscience Department, Oberlin College, Oberlin, OH, USA
| | - J R Scott
- Neuroscience Department, Oberlin College, Oberlin, OH, USA
| | - R McLaughlin
- Neuroscience Department, Oberlin College, Oberlin, OH, USA
| | - M Fox
- Neuroscience Department, Oberlin College, Oberlin, OH, USA
| | - M Ghanem
- Neuroscience Department, Oberlin College, Oberlin, OH, USA
| | | | - N G Hollon
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - E S Ramsson
- Department of Biomedical Science, Grand Valley State University, Allendale, MI, USA
| | - C D Howard
- Neuroscience Department, Oberlin College, Oberlin, OH, USA.
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4
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Gordon-Fennell A, Stuber GD. Illuminating subcortical GABAergic and glutamatergic circuits for reward and aversion. Neuropharmacology 2021; 198:108725. [PMID: 34375625 DOI: 10.1016/j.neuropharm.2021.108725] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/13/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
Reinforcement, reward, and aversion are fundamental processes for guiding appropriate behaviors. Longstanding theories have pointed to dopaminergic neurons of the ventral tegmental area (VTA) and the limbic systems' descending pathways as crucial systems for modulating these behaviors. The application of optogenetic techniques in neurotransmitter- and projection-specific circuits has supported and enhanced many preexisting theories but has also revealed many unexpected results. Here, we review the past decade of optogenetic experiments to study the neural circuitry of reinforcement and reward/aversion with a focus on the mesolimbic dopamine system and brain areas along the medial forebrain bundle (MFB). The cumulation of these studies to date has revealed generalizable findings across molecularly defined cell types in areas of the basal forebrain and anterior hypothalamus. Optogenetic stimulation of GABAergic neurons in these brain regions drives reward and can support positive reinforcement and optogenetic stimulation of glutamatergic neurons in these regions drives aversion. We also review studies of the activity dynamics of neurotransmitter defined populations in these areas which have revealed varied response patterns associated with motivated behaviors.
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Affiliation(s)
- Adam Gordon-Fennell
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, 98195, Seattle, WA, USA
| | - Garret D Stuber
- Center for the Neurobiology of Addiction, Pain, and Emotion, Department of Anesthesiology and Pain Medicine, Department of Pharmacology, University of Washington, 98195, Seattle, WA, USA.
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Shiri Z, Simorgh S, Naderi S, Baharvand H. Optogenetics in the Era of Cerebral Organoids. Trends Biotechnol 2019; 37:1282-1294. [PMID: 31227305 DOI: 10.1016/j.tibtech.2019.05.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 05/18/2019] [Accepted: 05/23/2019] [Indexed: 02/08/2023]
Abstract
The human brain has been deemed the most complex organ and has captivated neuroscientists for decades. Most studies of this organ have relied on reductionist model systems. Although all model systems are essentially wrong, cerebral organoids so far represent the closest recapitulation of human brain development and disease both in terms of cell diversity and organization. The optogenetic technique can be used in this context to study the functional neuroanatomy of the brain, to examine the neural circuits, and to determine the etiology of neurological disorders. In this opinion article, we suggest ways in which optogenetics can be combined with cerebral organoids to allow unprecedented precision and accuracy in studying normal and aberrant neurodevelopmental processes and, as well, neurodegenerative diseases.
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Affiliation(s)
- Zahra Shiri
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Susan Simorgh
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Somayeh Naderi
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Hossein Baharvand
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran; Department of Developmental Biology, University of Science and Culture, Tehran, Iran.
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6
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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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7
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Zestos AG, Luna-Munguia H, Stacey WC, Kennedy RT. Use and Future Prospects of in Vivo Microdialysis for Epilepsy Studies. ACS Chem Neurosci 2019; 10:1875-1883. [PMID: 30001105 DOI: 10.1021/acschemneuro.8b00271] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epilepsy is a common neurological disease characterized by recurrent unpredictable seizures. For the last 30 years, microdialysis sampling has been used to measure changes in excitatory and inhibitory neurotransmitter concentrations before, during, and after seizures. These advances have fostered breakthroughs in epilepsy research by identifying neurochemical changes associated with seizures and correlating them to electrophysiological data. Recent advances in methodology may be useful in further delineating the chemical underpinnings of seizures. A new model of ictogenesis has been developed that allows greater control over the timing of seizures that are similar to spontaneous seizures. This model will facilitate making chemical measurements before and during a seizure. Recent advancements in microdialysis sampling, including the use of segmented flow, "fast" liquid chromatography (LC), and capillary electrophoresis with laser-induced fluorescence (CE-LIF) have significantly improved temporal resolution to better than 1 min, which could be used to measure transient, spontaneous neurochemical changes associated with seizures. Microfabricated sampling probes that are markedly smaller than conventional probes and allow for a much greater spatial resolution have been developed. They may allow the targeting of specific brain regions important to epilepsy studies. Coupling microdialysis sampling to optogenetics and light-stimulated release of neurotransmitters may also prove useful for studying epileptic seizures.
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Affiliation(s)
- Alexander G. Zestos
- Department of Chemistry, Center for Behavioral Neuroscience, American University, Washington, D.C. 20016, United States
| | - Hiram Luna-Munguia
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Campus UNAM-Juriquilla, Queretaro 76230, Mexico
| | - William C. Stacey
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Neurology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Robert T. Kennedy
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
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8
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Delbeke J, Hoffman L, Mols K, Braeken D, Prodanov D. And Then There Was Light: Perspectives of Optogenetics for Deep Brain Stimulation and Neuromodulation. Front Neurosci 2017; 11:663. [PMID: 29311765 PMCID: PMC5732983 DOI: 10.3389/fnins.2017.00663] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 11/14/2017] [Indexed: 12/12/2022] Open
Abstract
Deep Brain Stimulation (DBS) has evolved into a well-accepted add-on treatment for patients with severe Parkinsons disease as well as for other chronic neurological conditions. The focal action of electrical stimulation can yield better responses and it exposes the patient to fewer side effects compared to pharmaceuticals distributed throughout the body toward the brain. On the other hand, the current practice of DBS is hampered by the relatively coarse level of neuromodulation achieved. Optogenetics, in contrast, offers the perspective of much more selective actions on the various physiological structures, provided that the stimulated cells are rendered sensitive to the action of light. Optogenetics has experienced tremendous progress since its first in vivo applications about 10 years ago. Recent advancements of viral vector technology for gene transfer substantially reduce vector-associated cytotoxicity and immune responses. This brings about the possibility to transfer this technology into the clinic as a possible alternative to DBS and neuromodulation. New paths could be opened toward a rich panel of clinical applications. Some technical issues still limit the long term use in humans but realistic perspectives quickly emerge. Despite a rapid accumulation of observations about patho-physiological mechanisms, it is still mostly serendipity and empiric adjustments that dictate clinical practice while more efficient logically designed interventions remain rather exceptional. Interestingly, it is also very much the neuro technology developed around optogenetics that offers the most promising tools to fill in the existing knowledge gaps about brain function in health and disease. The present review examines Parkinson's disease and refractory epilepsy as use cases for possible optogenetic stimulation therapies.
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Affiliation(s)
- Jean Delbeke
- LCEN3, Department of Neurology, Institute of Neuroscience, Ghent University, Ghent, Belgium
| | | | - Katrien Mols
- Neuroscience Research Flanders, Leuven, Belgium.,Life Science and Imaging, Imec, Leuven, Belgium
| | | | - Dimiter Prodanov
- Neuroscience Research Flanders, Leuven, Belgium.,Environment, Health and Safety, Imec, Leuven, Belgium
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