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Tian T, Kim D, Yu K, Hartzell HC, Ward PJ. Regenerative failure of sympathetic axons contributes to deficits in functional recovery after nerve injury. Neurobiol Dis 2025; 209:106893. [PMID: 40164438 DOI: 10.1016/j.nbd.2025.106893] [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: 01/16/2025] [Revised: 03/27/2025] [Accepted: 03/28/2025] [Indexed: 04/02/2025] Open
Abstract
Renewed scientific interest in sympathetic modulation of muscle and neuromuscular junctions has spurred a flurry of new discoveries with major implications for motor diseases. However, the role sympathetic axons play in the persistent dysfunction that occurs after nerve injuries remains to be explored. Peripheral nerve injuries are common and lead to motor, sensory, and autonomic deficits that result in lifelong disabilities. Given the importance of sympathetic signaling in muscle metabolic health and maintaining bodily homeostasis, it is imperative to understand the regenerative capacity of sympathetic axons after injury. Therefore, we tested sympathetic axon regeneration and functional reinnervation of skin and muscle, both acute and long-term, using a battery of anatomical, pharmacological, chemogenetic, cell culture, analytical chemistry, and electrophysiological techniques. We employed several established growth-enhancing interventions, including electrical stimulation and conditioning lesion, as well as an innovative tool called bioluminescent optogenetics. Our results indicate that sympathetic regeneration is not enhanced by any of these treatments and may even be detrimental to sympathetic regeneration. Despite the complete return of motor reinnervation after sciatic nerve injury, gastrocnemius muscle atrophy and deficits in muscle cellular energy charge, as measured by relative ATP, ADP, and AMP concentrations, persisted long after injury, even with electrical stimulation. We suggest that these long-term deficits in muscle energy charge and atrophy are related to the deficiency in sympathetic axon regeneration. New studies are needed to better understand the mechanisms underlying sympathetic regeneration to develop therapeutics that can enhance the regeneration of all axon types.
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Affiliation(s)
- Tina Tian
- Medical Scientist Training Program, Emory University School of Medicine, Atlanta, GA 30307, USA; Neuroscience Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307, USA; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30307, USA.
| | - David Kim
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30307, USA.
| | - Kuai Yu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30307, USA.
| | - H Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30307, USA.
| | - Patricia J Ward
- Neuroscience Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307, USA; Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30307, USA.
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Papatheodoropoulos C. Compensatory Regulation of Excitation/Inhibition Balance in the Ventral Hippocampus: Insights from Fragile X Syndrome. BIOLOGY 2025; 14:363. [PMID: 40282228 PMCID: PMC12025323 DOI: 10.3390/biology14040363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2025] [Revised: 03/20/2025] [Accepted: 03/27/2025] [Indexed: 04/29/2025]
Abstract
The excitation/inhibition (E/I) balance is a critical feature of neural circuits, which is crucial for maintaining optimal brain function by ensuring network stability and preventing neural hyperexcitability. The hippocampus exhibits the particularly interesting characteristics of having different functions and E/I profiles between its dorsal and ventral segments. Furthermore, the hippocampus is particularly vulnerable to epilepsy and implicated in Fragile X Syndrome (FXS), disorders associated with heightened E/I balance and possible deficits in GABA-mediated inhibition. In epilepsy, the ventral hippocampus shows heightened susceptibility to seizures, while in FXS, recent evidence suggests differential alterations in excitability and inhibition between dorsal and ventral regions. This article explores the mechanisms underlying E/I balance regulation, focusing on the hippocampus in epilepsy and FXS, and emphasizing the possible mechanisms that may confer homeostatic flexibility to the ventral hippocampus in maintaining E/I balance. Notably, the ventral hippocampus in adult FXS models shows enhanced GABAergic inhibition, resistance to epileptiform activity, and physiological network pattern (sharp wave-ripples, SWRs), potentially representing a homeostatic adaptation. In contrast, the dorsal hippocampus in these FXS models is more vulnerable to aberrant discharges and displays altered SWRs. These findings highlight the complex, region-specific nature of E/I balance disruptions in neurological disorders and suggest that the ventral hippocampus may possess unique compensatory mechanisms. Specifically, it is proposed that the ventral hippocampus, the brain region most prone to hyperexcitability, may have unique adaptive capabilities at the cellular and network levels that maintain the E/I balance within a normal range to prevent the transition to hyperexcitability and preserve normal function. Investigating the mechanisms underlying these compensatory responses in the ventral hippocampus and their developmental trajectories may offer novel insights into strategies for mitigating E/I imbalances in epilepsy, FXS, and potentially other neuropsychiatric and neurodevelopmental disorders.
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3
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Ikefuama EC, Slaviero AN, Silvagnoli AD, Crespo EL, Schalau R, Gott M, Tree MO, Dunbar GL, Rossignol J, Hochgeschwender U. Presymptomatic targeted circuit manipulation for ameliorating Huntington's disease pathogenesis. iScience 2025; 28:112022. [PMID: 40092615 PMCID: PMC11910118 DOI: 10.1016/j.isci.2025.112022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Revised: 11/23/2024] [Accepted: 02/11/2025] [Indexed: 03/19/2025] Open
Abstract
Early stages of Huntington's disease (HD) before the onset of motor and cognitive symptoms are characterized by imbalanced excitatory and inhibitory output from the cortex to striatal and subcortical structures. The window before the onset of symptoms presents an opportunity to adjust the firing rate within microcircuits with the goal of restoring the impaired E/I balance, thereby preventing or slowing down disease progression. Here, we investigated the effect of presymptomatic cell-type specific manipulation of activity of pyramidal neurons and parvalbumin interneurons in the M1 motor cortex on disease progression in the R6/2 HD mouse model. Our results show that dampening excitation of Emx1 pyramidal neurons or increasing activity of parvalbumin interneurons once daily for 3 weeks during the pre-symptomatic phase alleviated HD-related motor coordination dysfunction. Cell-type-specific modulation to normalize the net output of the cortex is a potential therapeutic avenue for HD and other neurodegenerative disorders.
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Affiliation(s)
- Ebenezer C. Ikefuama
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Ashley N. Slaviero
- Biochemistry, Cell and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI 48859, USA
| | | | - Emmanuel L. Crespo
- Biochemistry, Cell and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Raegan Schalau
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Madison Gott
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Maya O. Tree
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Gary L. Dunbar
- Department of Psychology, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Julien Rossignol
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
- Biochemistry, Cell and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI 48859, USA
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Ute Hochgeschwender
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
- Biochemistry, Cell and Molecular Biology Program, Central Michigan University, Mount Pleasant, MI 48859, USA
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
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4
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Tian T, Kim D, Yu K, Hartzell HC, Ward PJ. Regenerative failure of sympathetic axons contributes to deficits in functional recovery after nerve injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.08.631956. [PMID: 39829867 PMCID: PMC11741411 DOI: 10.1101/2025.01.08.631956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2025]
Abstract
Renewed scientific interest in sympathetic modulation of muscle and neuromuscular junctions has spurred a flurry of new discoveries with major implications for motor diseases. However, the role sympathetic axons play in the persistent dysfunction that occurs after nerve injuries remains to be explored. Peripheral nerve injuries are common and lead to motor, sensory, and autonomic deficits that result in lifelong disabilities. Given the importance of sympathetic signaling in muscle metabolic health and maintaining bodily homeostasis, it is imperative to understand the regenerative capacity of sympathetic axons after injury. Therefore, we tested sympathetic axon regeneration and functional reinnervation of skin and muscle, both acute and long-term, using a battery of anatomical, pharmacological, chemogenetic, cell culture, analytical chemistry, and electrophysiological techniques. We employed several established growth-enhancing interventions, including electrical stimulation and conditioning lesion, as well as an innovative tool called bioluminescent optogenetics. Our results indicate that sympathetic regeneration is not enhanced by any of these treatments and may even be detrimental to sympathetic regeneration. Despite the complete return of motor reinnervation after sciatic nerve injury, gastrocnemius muscle atrophy and deficits in muscle cellular energy charge, as measured by relative ATP, ADP, and AMP concentrations, persisted long after injury, even with electrical stimulation. We suggest that these long-term deficits in muscle energy charge and atrophy are related to the deficiency in sympathetic axon regeneration. New studies are needed to better understand the mechanisms underlying sympathetic regeneration to develop therapeutics that can enhance the regeneration of all axon types.
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5
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Escoubas CC, Dorman LC, Nguyen PT, Lagares-Linares C, Nakajo H, Anderson SR, Barron JJ, Wade SD, Cuevas B, Vainchtein ID, Silva NJ, Guajardo R, Xiao Y, Lidsky PV, Wang EY, Rivera BM, Taloma SE, Kim DK, Kaminskaya E, Nakao-Inoue H, Schwer B, Arnold TD, Molofsky AB, Condello C, Andino R, Nowakowski TJ, Molofsky AV. Type-I-interferon-responsive microglia shape cortical development and behavior. Cell 2024; 187:1936-1954.e24. [PMID: 38490196 PMCID: PMC11015974 DOI: 10.1016/j.cell.2024.02.020] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/31/2023] [Accepted: 02/19/2024] [Indexed: 03/17/2024]
Abstract
Microglia are brain-resident macrophages that shape neural circuit development and are implicated in neurodevelopmental diseases. Multiple microglial transcriptional states have been defined, but their functional significance is unclear. Here, we identify a type I interferon (IFN-I)-responsive microglial state in the developing somatosensory cortex (postnatal day 5) that is actively engulfing whole neurons. This population expands during cortical remodeling induced by partial whisker deprivation. Global or microglial-specific loss of the IFN-I receptor resulted in microglia with phagolysosomal dysfunction and an accumulation of neurons with nuclear DNA damage. IFN-I gain of function increased neuronal engulfment by microglia in both mouse and zebrafish and restricted the accumulation of DNA-damaged neurons. Finally, IFN-I deficiency resulted in excess cortical excitatory neurons and tactile hypersensitivity. These data define a role for neuron-engulfing microglia during a critical window of brain development and reveal homeostatic functions of a canonical antiviral signaling pathway in the brain.
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Affiliation(s)
- Caroline C Escoubas
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Leah C Dorman
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Phi T Nguyen
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Christian Lagares-Linares
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Haruna Nakajo
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sarah R Anderson
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jerika J Barron
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sarah D Wade
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Beatriz Cuevas
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ilia D Vainchtein
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Nicholas J Silva
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ricardo Guajardo
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA; Medical Scientist Training Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yinghong Xiao
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Peter V Lidsky
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ellen Y Wang
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; UCSF SRTP program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Brianna M Rivera
- Institute for Neurodegenerative Diseases/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sunrae E Taloma
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Dong Kyu Kim
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Elizaveta Kaminskaya
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Hiromi Nakao-Inoue
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Bjoern Schwer
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94158, USA; Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Bakar Aging Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Thomas D Arnold
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ari B Molofsky
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Carlo Condello
- Institute for Neurodegenerative Diseases/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tomasz J Nowakowski
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA 94158, USA; Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA; Chan-Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Anna V Molofsky
- Departments of Psychiatry and Behavioral Sciences/Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA 94158, USA; Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94158, USA.
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Björefeldt A, Murphy J, Crespo EL, Lambert GG, Prakash M, Ikefuama EC, Friedman N, Brown TM, Lipscombe D, Moore CI, Hochgeschwender U, Shaner NC. Efficient opto- and chemogenetic control in a single molecule driven by FRET-modified bioluminescence. NEUROPHOTONICS 2024; 11:021005. [PMID: 38450294 PMCID: PMC10917299 DOI: 10.1117/1.nph.11.2.021005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/25/2024] [Accepted: 01/30/2024] [Indexed: 03/08/2024]
Abstract
Significance Bioluminescent optogenetics (BL-OG) offers a unique and powerful approach to manipulate neural activity both opto- and chemogenetically using a single actuator molecule (a LuMinOpsin, LMO). Aim To further enhance the utility of BL-OG by improving the efficacy of chemogenetic (bioluminescence-driven) LMO activation. Approach We developed novel luciferases optimized for Förster resonance energy transfer when fused to the fluorescent protein mNeonGreen, generating bright bioluminescent (BL) emitters spectrally tuned to Volvox Channelrhodopsin 1 (VChR1). Results A new LMO generated from this approach (LMO7) showed significantly stronger BL-driven opsin activation compared to previous and other new variants. We extensively benchmarked LMO7 against LMO3 (current standard) and found significantly stronger neuronal activity modulation ex vivo and in vivo, and efficient modulation of behavior. Conclusions We report a robust new option for achieving multiple modes of control in a single actuator and a promising engineering strategy for continued improvement of BL-OG.
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Affiliation(s)
- Andreas Björefeldt
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Brown University, Department of Neuroscience, Providence, Rhode Island, United States
- University of Gothenburg, Institute of Neuroscience and Physiology, Department of Physiology, Gothenburg, Sweden
| | - Jeremy Murphy
- Brown University, Department of Neuroscience, Providence, Rhode Island, United States
| | - Emmanuel L. Crespo
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cell, and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Gerard G. Lambert
- University of California, San Diego, School of Medicine, Department of Neurosciences, La Jolla, California, United States
| | - Mansi Prakash
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Ebenezer C. Ikefuama
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
| | - Nina Friedman
- Brown University, Department of Neuroscience, Providence, Rhode Island, United States
| | - Tariq M. Brown
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Diane Lipscombe
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Christopher I. Moore
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Ute Hochgeschwender
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cell, and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
| | - Nathan C. Shaner
- University of California, San Diego, School of Medicine, Department of Neurosciences, La Jolla, California, United States
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Slaviero AN, Gorantla N, Simkins J, Crespo EL, Ikefuama EC, Tree MO, Prakash M, Björefeldt A, Barnett LM, Lambert GG, Lipscombe D, Moore CI, Shaner NC, Hochgeschwender U. Engineering luminopsins with improved coupling efficiencies. NEUROPHOTONICS 2024; 11:024208. [PMID: 38559366 PMCID: PMC10980360 DOI: 10.1117/1.nph.11.2.024208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024]
Abstract
Significance Luminopsins (LMOs) are bioluminescent-optogenetic tools with a luciferase fused to an opsin that allow bimodal control of neurons by providing both optogenetic and chemogenetic access. Determining which design features contribute to the efficacy of LMOs will be beneficial for further improving LMOs for use in research. Aim We investigated the relative impact of luciferase brightness, opsin sensitivity, pairing of emission and absorption wavelength, and arrangement of moieties on the function of LMOs. Approach We quantified efficacy of LMOs through whole cell patch clamp recordings in HEK293 cells by determining coupling efficiency, the percentage of maximum LED induced photocurrent achieved with bioluminescent activation of an opsin. We confirmed key results by multielectrode array recordings in primary neurons. Results Luciferase brightness and opsin sensitivity had the most impact on the efficacy of LMOs, and N-terminal fusions of luciferases to opsins performed better than C-terminal and multi-terminal fusions. Precise paring of luciferase emission and opsin absorption spectra appeared to be less critical. Conclusions Whole cell patch clamp recordings allowed us to quantify the impact of different characteristics of LMOs on their function. Our results suggest that coupling brighter bioluminescent sources to more sensitive opsins will improve LMO function. As bioluminescent activation of opsins is most likely based on Förster resonance energy transfer, the most effective strategy for improving LMOs further will be molecular evolution of luciferase-fluorescent protein-opsin fusions.
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Affiliation(s)
- Ashley N. Slaviero
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Nipun Gorantla
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Jacob Simkins
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Emmanuel L. Crespo
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Ebenezer C. Ikefuama
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
| | - Maya O. Tree
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Mansi Prakash
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Andreas Björefeldt
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Lauren M. Barnett
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Gerard G. Lambert
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Diane Lipscombe
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Christopher I. Moore
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Nathan C. Shaner
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Ute Hochgeschwender
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
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8
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Klein E, Marsh S, Becker J, Andermann M, Lehtinen M, Moore CI. BioLuminescent OptoGenetics in the choroid plexus: integrated opto- and chemogenetic control in vivo. NEUROPHOTONICS 2024; 11:024210. [PMID: 38948888 PMCID: PMC11213259 DOI: 10.1117/1.nph.11.2.024210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 07/02/2024]
Abstract
Significance The choroid plexus (ChP) epithelial network displays diverse dynamics, including propagating calcium waves and individuated fluctuations in single cells. These rapid events underscore the possibility that ChP dynamics may reflect behaviorally relevant and clinically important changes in information processing and signaling. Optogenetic and chemogenetic tools provide spatiotemporally precise and sustained approaches for testing such dynamics in vivo. Here, we describe the feasibility of a novel combined opto- and chemogenetic tool, BioLuminescent-OptoGenetics (BL-OG), for the ChP in vivo. In the "LuMinOpsin" (LMO) BL-OG strategy, a luciferase is tethered to an adjacent optogenetic element. This molecule allows chemogenetic activation when the opsin is driven by light produced through luciferase binding a small molecule (luciferin) or by conventional optogenetic light sources and BL-OG report of activation through light production. Aim To test the viability of BL-OG/LMO for ChP control. Approach Using transgenic and Cre-directed targeting to the ChP, we expressed LMO3 (a Gaussia luciferase-VChR1 fusion), a highly effective construct in neural systems. In mice expressing LMO3 in ChP, we directly imaged BL light production following multiple routes of coelenterazine (CTZ: luciferin) administration using an implanted cannula system. We also used home-cage videography with Deep LabCut analysis to test for any impact of repeated CTZ administration on basic health and behavioral indices. Results Multiple routes of CTZ administration drove BL photon production, including intracerebroventricular, intravenous, and intraperitoneal injection. Intravenous administration resulted in fast "flash" kinetics that diminished in seconds to minutes, and intraperitoneal administration resulted in slow rising activity that sustained hours. Mice showed no consistent impact of 1 week of intraperitoneal CTZ administration on weight, drinking, motor behavior, or sleep/wake cycles. Conclusions BL-OG/LMO provides unique advantages for testing the role of ChP dynamics in biological processes.
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Affiliation(s)
- Eric Klein
- Brown University, Providence, Rhode Island, United States
| | - Sophie Marsh
- Brown University, Providence, Rhode Island, United States
| | - Jordan Becker
- Brown University, Providence, Rhode Island, United States
| | - Mark Andermann
- Beth Israel Deaconess Medical Center Harvard, Boston, Massachusetts, United States
| | - Maria Lehtinen
- Brown University, Providence, Rhode Island, United States
- Boston Children’s Hospital, Boston, Massachusetts, United States
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Slaviero A, Gorantla N, Simkins J, Crespo EL, Ikefuama EC, Tree MO, Prakash M, Björefeldt A, Barnett LM, Lambert GG, Lipscombe D, Moore CI, Shaner NC, Hochgeschwender U. Engineering luminopsins with improved coupling efficiencies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.22.568342. [PMID: 38045286 PMCID: PMC10690276 DOI: 10.1101/2023.11.22.568342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Significance Luminopsins (LMOs) are bioluminescent-optogenetic tools with a luciferase fused to an opsin that allow bimodal control of neurons by providing both optogenetic and chemogenetic access. Determining which design features contribute to the efficacy of LMOs will be beneficial for further improving LMOs for use in research. Aim We investigated the relative impact of luciferase brightness, opsin sensitivity, pairing of emission and absorption wavelength, and arrangement of moieties on the function of LMOs. Approach We quantified efficacy of LMOs through whole cell patch clamp recordings in HEK293 cells by determining coupling efficiency, the percentage of maximum LED induced photocurrent achieved with bioluminescent activation of an opsin. We confirmed key results by multielectrode array (MEAs) recordings in primary neurons. Results Luciferase brightness and opsin sensitivity had the most impact on the efficacy of LMOs, and N-terminal fusions of luciferases to opsins performed better than C-terminal and multi-terminal fusions. Precise paring of luciferase emission and opsin absorption spectra appeared to be less critical. Conclusions Whole cell patch clamp recordings allowed us to quantify the impact of different characteristics of LMOs on their function. Our results suggest that coupling brighter bioluminescent sources to more sensitive opsins will improve LMO function. As bioluminescent activation of opsins is most likely based on Förster resonance energy transfer (FRET), the most effective strategy for improving LMOs further will be molecular evolution of luciferase-fluorescent protein-opsin fusions.
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Affiliation(s)
- Ashley Slaviero
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Nipun Gorantla
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Jacob Simkins
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Emmanuel L Crespo
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
| | - Ebenezer C Ikefuama
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
| | - Maya O Tree
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Mansi Prakash
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Andreas Björefeldt
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
| | - Lauren M Barnett
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Gerard G Lambert
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Diane Lipscombe
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Christopher I Moore
- Brown University, Carney Institute for Brain Science, Providence, Rhode Island, United States
| | - Nathan C Shaner
- University of California San Diego, Department of Neurosciences, La Jolla, California, United States
| | - Ute Hochgeschwender
- Central Michigan University, College of Medicine, Mount Pleasant, Michigan, United States
- Central Michigan University, Biochemistry, Cellular and Molecular Biology Graduate Program, Mount Pleasant, Michigan, United States
- Central Michigan University, Neuroscience Graduate Program, Mount Pleasant, Michigan, United States
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10
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Escoubas CC, Dorman LC, Nguyen PT, Lagares-Linares C, Nakajo H, Anderson SR, Cuevas B, Vainchtein ID, Silva NJ, Xiao Y, Lidsky PV, Wang EY, Taloma SE, Nakao-Inoue H, Schwer B, Andino R, Nowakowski TJ, Molofsky AV. Type I interferon responsive microglia shape cortical development and behavior. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2021.04.29.441889. [PMID: 35233577 PMCID: PMC8887080 DOI: 10.1101/2021.04.29.441889] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Microglia are brain resident phagocytes that can engulf synaptic components and extracellular matrix as well as whole neurons. However, whether there are unique molecular mechanisms that regulate these distinct phagocytic states is unknown. Here we define a molecularly distinct microglial subset whose function is to engulf neurons in the developing brain. We transcriptomically identified a cluster of Type I interferon (IFN-I) responsive microglia that expanded 20-fold in the postnatal day 5 somatosensory cortex after partial whisker deprivation, a stressor that accelerates neural circuit remodeling. In situ, IFN-I responsive microglia were highly phagocytic and actively engulfed whole neurons. Conditional deletion of IFN-I signaling (Ifnar1fl/fl) in microglia but not neurons resulted in dysmorphic microglia with stalled phagocytosis and an accumulation of neurons with double strand DNA breaks, a marker of cell stress. Conversely, exogenous IFN-I was sufficient to drive neuronal engulfment by microglia and restrict the accumulation of damaged neurons. IFN-I deficient mice had excess excitatory neurons in the developing somatosensory cortex as well as tactile hypersensitivity to whisker stimulation. These data define a molecular mechanism through which microglia engulf neurons during a critical window of brain development. More broadly, they reveal key homeostatic roles of a canonical antiviral signaling pathway in brain development.
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Affiliation(s)
- Caroline C. Escoubas
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Leah C. Dorman
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- Department of Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA
| | - Phi T. Nguyen
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- Department of Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA
| | - Christian Lagares-Linares
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Haruna Nakajo
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Sarah R. Anderson
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Beatriz Cuevas
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- Department of Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA
| | - Ilia D. Vainchtein
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Nicholas J. Silva
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Yinghong Xiao
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA
| | - Peter V. Lidsky
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA
| | - Ellen Y. Wang
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- UCSF SRTP program, University of California, San Francisco, San Francisco, CA
| | - Sunrae E. Taloma
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- Department of Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA
| | - Hiromi Nakao-Inoue
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
| | - Bjoern Schwer
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA
- Department of Neurosurgery, University of California, San Francisco, San Francisco, CA
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA
| | - Tomasz J. Nowakowski
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA
- Department of Anatomy, University of California, San Francisco, San Francisco, CA
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA
- Chan-Zuckerberg Biohub, San Francisco, CA
| | - Anna V. Molofsky
- Department of Psychiatry and Behavioral Sciences/ Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA
- Eli and Edythe Broad Center for Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA
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11
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Gamma oscillations provide insights into cortical circuit development. Pflugers Arch 2023; 475:561-568. [PMID: 36864347 PMCID: PMC10105678 DOI: 10.1007/s00424-023-02801-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/20/2023] [Accepted: 02/22/2023] [Indexed: 03/04/2023]
Abstract
Rhythmic coordination in gamma oscillations provides temporal structure to neuronal activity. Gamma oscillations are commonly observed in the mammalian cerebral cortex, are altered early on in several neuropsychiatric disorders, and provide insights into the development of underlying cortical networks. However, a lack of knowledge on the developmental trajectory of gamma oscillations prevented the combination of findings from the immature and the adult brain. This review is intended to provide an overview on the development of cortical gamma oscillations, the maturation of the underlying network, and the implications for cortical function and dysfunction. The majority of information is drawn from work in rodents with particular emphasis on the prefrontal cortex, the developmental trajectory of gamma oscillations, and potential implications for neuropsychiatric disorders. Current evidence supports the idea that fast oscillations during development are indeed an immature form of adult gamma oscillations and can help us understand the pathology of neuropsychiatric disorders.
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12
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Banerjee T, Pati S, Tiwari P, Vaidya VA. Chronic hM3Dq-DREADD-mediated chemogenetic activation of parvalbumin-positive inhibitory interneurons in postnatal life alters anxiety and despair-like behavior in adulthood in a task- and sex-dependent manner. J Biosci 2022. [DOI: 10.1007/s12038-022-00308-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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13
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5-HT-dependent synaptic plasticity of the prefrontal cortex in postnatal development. Sci Rep 2022; 12:21015. [PMID: 36470912 PMCID: PMC9723183 DOI: 10.1038/s41598-022-23767-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/04/2022] [Indexed: 12/12/2022] Open
Abstract
Important functions of the prefrontal cortex (PFC) are established during early life, when neurons exhibit enhanced synaptic plasticity and synaptogenesis. This developmental stage drives the organization of cortical connectivity, responsible for establishing behavioral patterns. Serotonin (5-HT) emerges among the most significant factors that modulate brain activity during postnatal development. In the PFC, activated 5-HT receptors modify neuronal excitability and interact with intracellular signaling involved in synaptic modifications, thus suggesting that 5-HT might participate in early postnatal plasticity. To test this hypothesis, we employed intracellular electrophysiological recordings of PFC layer 5 neurons to study the modulatory effects of 5-HT on plasticity induced by theta-burst stimulation (TBS) in two postnatal periods of rats. Our results indicate that 5-HT is essential for TBS to result in synaptic changes during the third postnatal week, but not later. TBS coupled with 5-HT2A or 5-HT1A and 5-HT7 receptors stimulation leads to long-term depression (LTD). On the other hand, TBS and synergic activation of 5-HT1A, 5-HT2A, and 5-HT7 receptors lead to long-term potentiation (LTP). Finally, we also show that 5-HT dependent synaptic plasticity of the PFC is impaired in animals that are exposed to early-life chronic stress.
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14
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Chini M, Pfeffer T, Hanganu-Opatz I. An increase of inhibition drives the developmental decorrelation of neural activity. eLife 2022; 11:78811. [PMID: 35975980 PMCID: PMC9448324 DOI: 10.7554/elife.78811] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 08/16/2022] [Indexed: 11/23/2022] Open
Abstract
Throughout development, the brain transits from early highly synchronous activity patterns to a mature state with sparse and decorrelated neural activity, yet the mechanisms underlying this process are poorly understood. The developmental transition has important functional consequences, as the latter state is thought to allow for more efficient storage, retrieval, and processing of information. Here, we show that, in the mouse medial prefrontal cortex (mPFC), neural activity during the first two postnatal weeks decorrelates following specific spatial patterns. This process is accompanied by a concomitant tilting of excitation-inhibition (E-I) ratio toward inhibition. Using optogenetic manipulations and neural network modeling, we show that the two phenomena are mechanistically linked, and that a relative increase of inhibition drives the decorrelation of neural activity. Accordingly, in mice mimicking the etiology of neurodevelopmental disorders, subtle alterations in E-I ratio are associated with specific impairments in the correlational structure of spike trains. Finally, capitalizing on EEG data from newborn babies, we show that an analogous developmental transition takes place also in the human brain. Thus, changes in E-I ratio control the (de)correlation of neural activity and, by these means, its developmental imbalance might contribute to the pathogenesis of neurodevelopmental disorders.
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Affiliation(s)
- Mattia Chini
- Institute of Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thomas Pfeffer
- Center for Brain and Cognition, Universitat Pompeu Fabra, Barcelona, Spain
| | - Ileana Hanganu-Opatz
- Institute of Developmental Neurophysiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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15
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Jang A, Lehtinen MK. Experimental approaches for manipulating choroid plexus epithelial cells. Fluids Barriers CNS 2022; 19:36. [PMID: 35619113 PMCID: PMC9134666 DOI: 10.1186/s12987-022-00330-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 04/14/2022] [Indexed: 12/26/2022] Open
Abstract
Choroid plexus (ChP) epithelial cells are crucial for the function of the blood-cerebrospinal fluid barrier (BCSFB) in the developing and mature brain. The ChP is considered the primary source and regulator of CSF, secreting many important factors that nourish the brain. It also performs CSF clearance functions including removing Amyloid beta and potassium. As such, the ChP is a promising target for gene and drug therapy for neurodevelopmental and neurological disorders in the central nervous system (CNS). This review describes the current successful and emerging experimental approaches for targeting ChP epithelial cells. We highlight methodological strategies to specifically target these cells for gain or loss of function in vivo. We cover both genetic models and viral gene delivery systems. Additionally, several lines of reporters to access the ChP epithelia are reviewed. Finally, we discuss exciting new approaches, such as chemical activation and transplantation of engineered ChP epithelial cells. We elaborate on fundamental functions of the ChP in secretion and clearance and outline experimental approaches paving the way to clinical applications.
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Affiliation(s)
- Ahram Jang
- Department of Pathology, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Maria K Lehtinen
- Department of Pathology, Boston Children's Hospital, Boston, MA, 02115, USA.
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16
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Keeping Excitation-Inhibition Ratio in Balance. Int J Mol Sci 2022; 23:ijms23105746. [PMID: 35628556 PMCID: PMC9145842 DOI: 10.3390/ijms23105746] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 11/17/2022] Open
Abstract
Unrelated genetic mutations can lead to convergent manifestations of neurological disorders with similar behavioral phenotypes. Experimental data frequently show a lack of dramatic changes in neuroanatomy, indicating that the key cause of symptoms might arise from impairment in the communication between neurons. A transient imbalance between excitatory (glutamatergic) and inhibitory (GABAergic) synaptic transmission (the E/I balance) during early development is generally considered to underlie the development of several neurological disorders in adults. However, the E/I ratio is a multidimensional variable. Synaptic contacts are highly dynamic and the actual strength of synaptic projections is determined from the balance between synaptogenesis and synaptic elimination. During development, relatively slow postsynaptic receptors are replaced by fast ones that allow for fast stimulus-locked excitation/inhibition. Using the binomial model of synaptic transmission allows for the reassessing of experimental data from different mouse models, showing that a transient E/I shift is frequently counterbalanced by additional pre- and/or postsynaptic changes. Such changes—for instance, the slowing down of postsynaptic currents by means of immature postsynaptic receptors—stabilize the average synaptic strength, but impair the timing of information flow. Compensatory processes and/or astrocytic signaling may represent possible targets for medical treatments of different disorders directed to rescue the proper information processing.
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17
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Petersen ED, Sharkey ED, Pal A, Shafau LO, Zenchak-Petersen J, Peña AJ, Aggarwal A, Prakash M, Hochgeschwender U. Restoring Function After Severe Spinal Cord Injury Through BioLuminescent-OptoGenetics. Front Neurol 2022; 12:792643. [PMID: 35126293 PMCID: PMC8811305 DOI: 10.3389/fneur.2021.792643] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 12/09/2021] [Indexed: 02/02/2023] Open
Abstract
The ability to manipulate specific neuronal populations of the spinal cord following spinal cord injury (SCI) could prove highly beneficial for rehabilitation in patients through maintaining and strengthening still existing neuronal connections and/or facilitating the formation of new connections. A non-invasive and highly specific approach to neuronal stimulation is bioluminescent-optogenetics (BL-OG), where genetically expressed light emitting luciferases are tethered to light sensitive channelrhodopsins (luminopsins, LMO); neurons are activated by the addition of the luciferase substrate coelenterazine (CTZ). This approach utilizes ion channels for current conduction while activating the channels through the application of a small chemical compound, thus allowing non-invasive stimulation and recruitment of all targeted neurons. Rats were transduced in the lumbar spinal cord with AAV2/9 to express the excitatory LMO3 under control of a pan-neuronal or motor neuron-specific promoter. A day after contusion injury of the thoracic spine, rats received either CTZ or vehicle every other day for 2 weeks. Activation of either neuron population below the level of injury significantly improved locomotor recovery lasting beyond the treatment window. Utilizing histological and gene expression methods we identified neuronal plasticity as a likely mechanism underlying the functional recovery. These findings provide a foundation for a rational approach to spinal cord injury rehabilitation, thereby advancing approaches for functional recovery after SCI.SummaryBioluminescent optogenetic activation of spinal neurons results in accelerated and enhanced locomotor recovery after spinal cord injury in rats.
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Affiliation(s)
- Eric D. Petersen
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI, United States
- College of Medicine, Central Michigan University, Mount Pleasant, MI, United States
| | - Erik D. Sharkey
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI, United States
- College of Medicine, Central Michigan University, Mount Pleasant, MI, United States
| | - Akash Pal
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI, United States
- College of Medicine, Central Michigan University, Mount Pleasant, MI, United States
| | - Lateef O. Shafau
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI, United States
- College of Medicine, Central Michigan University, Mount Pleasant, MI, United States
| | | | - Alex J. Peña
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI, United States
| | - Anu Aggarwal
- Electrical and Computer Engineering, University of Illinois Urbana Champaign, Urbana, IL, United States
| | - Mansi Prakash
- College of Medicine, Central Michigan University, Mount Pleasant, MI, United States
| | - Ute Hochgeschwender
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI, United States
- College of Medicine, Central Michigan University, Mount Pleasant, MI, United States
- *Correspondence: Ute Hochgeschwender
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18
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Abdelfattah AS, Ahuja S, Akkin T, Allu SR, Brake J, Boas DA, Buckley EM, Campbell RE, Chen AI, Cheng X, Čižmár T, Costantini I, De Vittorio M, Devor A, Doran PR, El Khatib M, Emiliani V, Fomin-Thunemann N, Fainman Y, Fernandez-Alfonso T, Ferri CGL, Gilad A, Han X, Harris A, Hillman EMC, Hochgeschwender U, Holt MG, Ji N, Kılıç K, Lake EMR, Li L, Li T, Mächler P, Miller EW, Mesquita RC, Nadella KMNS, Nägerl UV, Nasu Y, Nimmerjahn A, Ondráčková P, Pavone FS, Perez Campos C, Peterka DS, Pisano F, Pisanello F, Puppo F, Sabatini BL, Sadegh S, Sakadzic S, Shoham S, Shroff SN, Silver RA, Sims RR, Smith SL, Srinivasan VJ, Thunemann M, Tian L, Tian L, Troxler T, Valera A, Vaziri A, Vinogradov SA, Vitale F, Wang LV, Uhlířová H, Xu C, Yang C, Yang MH, Yellen G, Yizhar O, Zhao Y. Neurophotonic tools for microscopic measurements and manipulation: status report. NEUROPHOTONICS 2022; 9:013001. [PMID: 35493335 PMCID: PMC9047450 DOI: 10.1117/1.nph.9.s1.013001] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Neurophotonics was launched in 2014 coinciding with the launch of the BRAIN Initiative focused on development of technologies for advancement of neuroscience. For the last seven years, Neurophotonics' agenda has been well aligned with this focus on neurotechnologies featuring new optical methods and tools applicable to brain studies. While the BRAIN Initiative 2.0 is pivoting towards applications of these novel tools in the quest to understand the brain, this status report reviews an extensive and diverse toolkit of novel methods to explore brain function that have emerged from the BRAIN Initiative and related large-scale efforts for measurement and manipulation of brain structure and function. Here, we focus on neurophotonic tools mostly applicable to animal studies. A companion report, scheduled to appear later this year, will cover diffuse optical imaging methods applicable to noninvasive human studies. For each domain, we outline the current state-of-the-art of the respective technologies, identify the areas where innovation is needed, and provide an outlook for the future directions.
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Affiliation(s)
- Ahmed S. Abdelfattah
- Brown University, Department of Neuroscience, Providence, Rhode Island, United States
| | - Sapna Ahuja
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Taner Akkin
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States
| | - Srinivasa Rao Allu
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Joshua Brake
- Harvey Mudd College, Department of Engineering, Claremont, California, United States
| | - David A. Boas
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Erin M. Buckley
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
- Emory University, Department of Pediatrics, Atlanta, Georgia, United States
| | - Robert E. Campbell
- University of Tokyo, Department of Chemistry, Tokyo, Japan
- University of Alberta, Department of Chemistry, Edmonton, Alberta, Canada
| | - Anderson I. Chen
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Xiaojun Cheng
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Tomáš Čižmár
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Irene Costantini
- University of Florence, European Laboratory for Non-Linear Spectroscopy, Department of Biology, Florence, Italy
- National Institute of Optics, National Research Council, Rome, Italy
| | - Massimo De Vittorio
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Anna Devor
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Patrick R. Doran
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Mirna El Khatib
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | | | - Natalie Fomin-Thunemann
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Yeshaiahu Fainman
- University of California San Diego, Department of Electrical and Computer Engineering, La Jolla, California, United States
| | - Tomas Fernandez-Alfonso
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Christopher G. L. Ferri
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Ariel Gilad
- The Hebrew University of Jerusalem, Institute for Medical Research Israel–Canada, Department of Medical Neurobiology, Faculty of Medicine, Jerusalem, Israel
| | - Xue Han
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Andrew Harris
- Weizmann Institute of Science, Department of Brain Sciences, Rehovot, Israel
| | | | - Ute Hochgeschwender
- Central Michigan University, Department of Neuroscience, Mount Pleasant, Michigan, United States
| | - Matthew G. Holt
- University of Porto, Instituto de Investigação e Inovação em Saúde (i3S), Porto, Portugal
| | - Na Ji
- University of California Berkeley, Department of Physics, Berkeley, California, United States
| | - Kıvılcım Kılıç
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Evelyn M. R. Lake
- Yale School of Medicine, Department of Radiology and Biomedical Imaging, New Haven, Connecticut, United States
| | - Lei Li
- California Institute of Technology, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, Pasadena, California, United States
| | - Tianqi Li
- University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States
| | - Philipp Mächler
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Evan W. Miller
- University of California Berkeley, Departments of Chemistry and Molecular & Cell Biology and Helen Wills Neuroscience Institute, Berkeley, California, United States
| | | | | | - U. Valentin Nägerl
- Interdisciplinary Institute for Neuroscience University of Bordeaux & CNRS, Bordeaux, France
| | - Yusuke Nasu
- University of Tokyo, Department of Chemistry, Tokyo, Japan
| | - Axel Nimmerjahn
- Salk Institute for Biological Studies, Waitt Advanced Biophotonics Center, La Jolla, California, United States
| | - Petra Ondráčková
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Francesco S. Pavone
- National Institute of Optics, National Research Council, Rome, Italy
- University of Florence, European Laboratory for Non-Linear Spectroscopy, Department of Physics, Florence, Italy
| | - Citlali Perez Campos
- Columbia University, Zuckerman Mind Brain Behavior Institute, New York, United States
| | - Darcy S. Peterka
- Columbia University, Zuckerman Mind Brain Behavior Institute, New York, United States
| | - Filippo Pisano
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Ferruccio Pisanello
- Istituto Italiano di Tecnologia, Center for Biomolecular Nanotechnologies, Arnesano, Italy
| | - Francesca Puppo
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Bernardo L. Sabatini
- Harvard Medical School, Howard Hughes Medical Institute, Department of Neurobiology, Boston, Massachusetts, United States
| | - Sanaz Sadegh
- University of California San Diego, Departments of Neurosciences, La Jolla, California, United States
| | - Sava Sakadzic
- Massachusetts General Hospital, Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, Massachusetts, United States
| | - Shy Shoham
- New York University Grossman School of Medicine, Tech4Health and Neuroscience Institutes, New York, New York, United States
| | - Sanaya N. Shroff
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - R. Angus Silver
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Ruth R. Sims
- Sorbonne University, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Spencer L. Smith
- University of California Santa Barbara, Department of Electrical and Computer Engineering, Santa Barbara, California, United States
| | - Vivek J. Srinivasan
- New York University Langone Health, Departments of Ophthalmology and Radiology, New York, New York, United States
| | - Martin Thunemann
- Boston University, Department of Biomedical Engineering, Boston, Massachusetts, United States
| | - Lei Tian
- Boston University, Departments of Electrical Engineering and Biomedical Engineering, Boston, Massachusetts, United States
| | - Lin Tian
- University of California Davis, Department of Biochemistry and Molecular Medicine, Davis, California, United States
| | - Thomas Troxler
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Antoine Valera
- University College London, Department of Neuroscience, Physiology and Pharmacology, London, United Kingdom
| | - Alipasha Vaziri
- Rockefeller University, Laboratory of Neurotechnology and Biophysics, New York, New York, United States
- The Rockefeller University, The Kavli Neural Systems Institute, New York, New York, United States
| | - Sergei A. Vinogradov
- University of Pennsylvania, Perelman School of Medicine, Department of Biochemistry and Biophysics, Philadelphia, Pennsylvania, United States
- University of Pennsylvania, School of Arts and Sciences, Department of Chemistry, Philadelphia, Pennsylvania, United States
| | - Flavia Vitale
- Center for Neuroengineering and Therapeutics, Departments of Neurology, Bioengineering, Physical Medicine and Rehabilitation, Philadelphia, Pennsylvania, United States
| | - Lihong V. Wang
- California Institute of Technology, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, Pasadena, California, United States
| | - Hana Uhlířová
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Chris Xu
- Cornell University, School of Applied and Engineering Physics, Ithaca, New York, United States
| | - Changhuei Yang
- California Institute of Technology, Departments of Electrical Engineering, Bioengineering and Medical Engineering, Pasadena, California, United States
| | - Mu-Han Yang
- University of California San Diego, Department of Electrical and Computer Engineering, La Jolla, California, United States
| | - Gary Yellen
- Harvard Medical School, Department of Neurobiology, Boston, Massachusetts, United States
| | - Ofer Yizhar
- Weizmann Institute of Science, Department of Brain Sciences, Rehovot, Israel
| | - Yongxin Zhao
- Carnegie Mellon University, Department of Biological Sciences, Pittsburgh, Pennsylvania, United States
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19
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Chronic hM4Di-DREADD-Mediated Chemogenetic Inhibition of Forebrain Excitatory Neurons in Postnatal or Juvenile Life Does Not Alter Adult Mood-Related Behavior. eNeuro 2022; 9:ENEURO.0381-21.2021. [PMID: 35115382 PMCID: PMC8856708 DOI: 10.1523/eneuro.0381-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 12/21/2021] [Accepted: 12/25/2021] [Indexed: 11/21/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) coupled to Gi signaling, in particular downstream of monoaminergic neurotransmission, are posited to play a key role during developmental epochs (postnatal and juvenile) in shaping the emergence of adult anxiodepressive behaviors and sensorimotor gating. To address the role of Gi signaling in these developmental windows, we used a CaMKIIα-tTA::TRE hM4Di bigenic mouse line to express the hM4Di-DREADD (designer receptor exclusively activated by designer drugs) in forebrain excitatory neurons and enhanced Gi signaling via chronic administration of the DREADD agonist, clozapine-N-oxide (CNO) in the postnatal window (postnatal days 2–14) or the juvenile window (postnatal days 28–40). We confirmed that the expression of the HA-tagged hM4Di-DREADD was restricted to CaMKIIα-positive neurons in the forebrain, and that the administration of CNO in postnatal or juvenile windows evoked inhibition in forebrain circuits of the hippocampus and cortex, as indicated by a decline in expression of the neuronal activity marker c-Fos. hM4Di-DREADD-mediated inhibition of CaMKIIα-positive forebrain excitatory neurons in postnatal or juvenile life did not impact the weight profile of mouse pups, and also did not influence the normal ontogeny of sensory reflexes. Further, postnatal or juvenile hM4Di-DREADD-mediated inhibition of CaMKIIα-positive forebrain excitatory neurons did not alter anxiety- or despair-like behaviors in adulthood and did not impact sensorimotor gating. Collectively, these results indicate that chemogenetic induction of Gi signaling in CaMKIIα-positive forebrain excitatory neurons in postnatal and juvenile temporal windows does not appear to impinge on the programming of anxiodepressive behaviors in adulthood.
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Stern MA, Skelton H, Fernandez AM, Gutekunst CAN, Gross RE, Berglund K. Applications of Bioluminescence-Optogenetics in Rodent Models. Methods Mol Biol 2022; 2525:347-363. [PMID: 35836082 DOI: 10.1007/978-1-0716-2473-9_27] [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] [Indexed: 06/15/2023]
Abstract
In the preceding chapter, we introduced bioluminescence-optogenetics (BL-OG) and luminopsin fusion proteins (LMOs), an emerging method of molecular neuromodulation. In addition to reviewing the fundamental principles of BL-OG, we provided a discussion of its application in vitro, including with cell lines and primary cells in culture in vitro. BL-OG is mediated by an easily diffusible molecule, luciferin, and when applied systemically in rodents, the substrate can spread throughout the body, including the brain, achieving powerful molecular neuromodulation with convenience even in awake and behaving animals. In this chapter, we provide a practical guide for BL-OG and LMO applications in rodent models of the nervous system, both ex vivo and in vivo.
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Affiliation(s)
- Matthew A Stern
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Henry Skelton
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | | | | | - Robert E Gross
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA
| | - Ken Berglund
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA.
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21
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Crespo EL, Prakash M, Bjorefeldt A, Medendorp WE, Shaner NC, Lipscombe D, Moore CI, Hochgeschwender U. Bioluminescent optogenetic (BL-OG) activation of neurons during mouse postnatal brain development. STAR Protoc 2021; 2:100667. [PMID: 34286295 PMCID: PMC8273415 DOI: 10.1016/j.xpro.2021.100667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Bioluminescent optogenetics (BL-OG) allows activation of photosensory proteins, such as opsins, by either fiberoptics or by administering a luciferin. BL-OG thus confers both optogenetic and chemogenetic access within the same genetically targeted neuron. This bimodality offers a powerful approach for non-invasive chemogenetic manipulation of neural activity during brain development and adult behaviors with standard optogenetic spatiotemporal precision. We detail protocols for bioluminescent stimulation of neurons in postnatally developing brain and its validation through bioluminescence imaging and electrophysiological recording in mice. For complete information on the use and execution of this protocol, please refer to Medendorp et al. (2021).
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Affiliation(s)
- Emmanuel L. Crespo
- Biochemistry, Cellular and Molecular Biology Graduate program, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Mansi Prakash
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Andreas Bjorefeldt
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - William E. Medendorp
- Neuroscience Graduate Program, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Nathan C. Shaner
- Department of Neuroscience, University of California San Diego, La Jolla, CA, USA
| | - Diane Lipscombe
- Carney Institute for Brain Science, Brown University, Providence, RI 02906, USA
| | | | - Ute Hochgeschwender
- Biochemistry, Cellular and Molecular Biology Graduate program, Central Michigan University, Mount Pleasant, MI 48859, USA
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
- Neuroscience Graduate Program, Central Michigan University, Mount Pleasant, MI 48859, USA
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22
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English AW, Berglund K, Carrasco D, Goebel K, Gross RE, Isaacson R, Mistretta OC, Wynans C. Bioluminescent Optogenetics: A Novel Experimental Therapy to Promote Axon Regeneration after Peripheral Nerve Injury. Int J Mol Sci 2021; 22:ijms22137217. [PMID: 34281270 PMCID: PMC8269199 DOI: 10.3390/ijms22137217] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 11/18/2022] Open
Abstract
Functional recovery after peripheral nerve injury (PNI) is poor, mainly due to the slow and incomplete regeneration of injured axons. Experimental therapies that increase the excitability of the injured axons have proven remarkably successful in promoting regeneration, but their clinical applicability has been limited. Bioluminescent optogenetics (BL-OG) uses luminopsins, fusion proteins of light-generating luciferase and light-sensing ion channels that could be used to increase neuronal excitability if exposed to a suitable substrate. Excitatory luminopsins were expressed in motoneurons of transgenic mice and in wildtype mice transduced with adeno-associated viral vectors. Intraperitoneal administration of coelenterazine (CTZ), a known luciferase substrate, generated intense bioluminescence in peripheral axons. This bioluminescence increased motoneuron excitability. A single administration of CTZ immediately after sciatic nerve transection and repair markedly enhanced motor axon regeneration. Compound muscle action potentials were 3–4 times larger than controls by 4 weeks after injury. The results observed with transgenic mice were comparable to those of mice in which the luminopsin was expressed using viral vectors. Significantly more motoneurons had successfully reinnervated muscle targets four weeks after nerve injury in BL-OG treated mice than in controls. Bioluminescent optogenetics is a promising therapeutic approach to enhancing axon regeneration after PNI.
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Affiliation(s)
- Arthur W. English
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (D.C.); (K.G.); (R.I.); (O.C.M.); (C.W.)
- Department of Rehabilitation Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
- Correspondence:
| | - Ken Berglund
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA 30322, USA; (K.B.); (R.E.G.)
| | - Dario Carrasco
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (D.C.); (K.G.); (R.I.); (O.C.M.); (C.W.)
| | - Katharina Goebel
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (D.C.); (K.G.); (R.I.); (O.C.M.); (C.W.)
| | - Robert E. Gross
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA 30322, USA; (K.B.); (R.E.G.)
| | - Robin Isaacson
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (D.C.); (K.G.); (R.I.); (O.C.M.); (C.W.)
| | - Olivia C. Mistretta
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (D.C.); (K.G.); (R.I.); (O.C.M.); (C.W.)
| | - Carly Wynans
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322, USA; (D.C.); (K.G.); (R.I.); (O.C.M.); (C.W.)
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