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Celinskis D, Black CJ, Murphy J, Barrios-Anderson A, Friedman N, Shaner NC, Saab C, Gomez-Ramirez M, Lipscombe D, Borton DA, Moore CI. Towards a Brighter Constellation: Multi-Organ Neuroimaging of Neural and Vascular Dynamics in the Spinal Cord and Brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.25.573323. [PMID: 38234789 PMCID: PMC10793404 DOI: 10.1101/2023.12.25.573323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Significance Pain is comprised of a complex interaction between motor action and somatosensation that is dependent on dynamic interactions between the brain and spinal cord. This makes understanding pain particularly challenging as it involves rich interactions between many circuits (e.g., neural and vascular) and signaling cascades throughout the body. As such, experimentation on a single region may lead to an incomplete and potentially incorrect understanding of crucial underlying mechanisms. Aim Here, we aimed to develop and validate new tools to enable detailed and extended observation of neural and vascular activity in the brain and spinal cord. The first key set of innovations were targeted to developing novel imaging hardware that addresses the many challenges of multi-site imaging. The second key set of innovations were targeted to enabling bioluminescent imaging, as this approach can address limitations of fluorescent microscopy including photobleaching, phototoxicity and decreased resolution due to scattering of excitation signals. Approach We designed 3D-printed brain and spinal cord implants to enable effective surgical implantations and optical access with wearable miniscopes or an open window (e.g., for one- or two-photon microscopy or optogenetic stimulation). We also tested the viability for bioluminescent imaging, and developed a novel modified miniscope optimized for these signals (BLmini). Results Here, we describe novel 'universal' implants for acute and chronic simultaneous brain-spinal cord imaging and optical stimulation. We further describe successful imaging of bioluminescent signals in both foci, and a new miniscope, the 'BLmini,' which has reduced weight, cost and form-factor relative to standard wearable miniscopes. Conclusions The combination of 3D printed implants, advanced imaging tools, and bioluminescence imaging techniques offers a new coalition of methods for understanding spinal cord-brain interactions. This work has the potential for use in future research into neuropathic pain and other sensory disorders and motor behavior.
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Affiliation(s)
| | | | - Jeremy Murphy
- Carney Institute for Brain Science, Providence, RI, USA
| | | | - Nina Friedman
- Carney Institute for Brain Science, Providence, RI, USA
| | - Nathan C. Shaner
- University of California San Diego School of Medicine, La Jolla, CA, USA
| | - Carl Saab
- Cleveland Clinic Lerner Research Institute, Department of Biomedical Engineering and Neurological Institute, Cleveland, OH, USA
| | | | | | - David A. Borton
- Carney Institute for Brain Science, Providence, RI, USA
- School of Engineering, Brown University, RI, USA
- Center for Neurorestoration and Neurotechnology, Providence VA Medical Center, RI, USA
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Bjorefeldt A, Murphy J, Crespo EL, Lambert GG, Prakash M, Ikefuama EC, Friedman N, Brown TM, Lipscombe D, Moore CI, Hochgeschwender U, Shaner NC. A New Highly Efficient Molecule for Both Optogenetic and Chemogenetic Control Driven by FRET Amplification of BioLuminescence. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.26.545546. [PMID: 37425735 PMCID: PMC10327108 DOI: 10.1101/2023.06.26.545546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
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 Forster resonance energy transfer (FRET) 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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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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Crespo EL, Pal A, Prakash M, Silvagnoli AD, Zaidi Z, Gomez-Ramirez M, Tree MO, Shaner NC, Lipscombe D, Moore C, Hochgeschwender U. A Bioluminescent Activity Dependent (BLADe) Platform for Converting Neuronal Activity to Photoreceptor Activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.25.546469. [PMID: 37425742 PMCID: PMC10327117 DOI: 10.1101/2023.06.25.546469] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
We developed a platform that utilizes a calcium-dependent luciferase to convert neuronal activity into activation of light sensing domains within the same cell. The platform is based on a Gaussia luciferase variant with high light emission split by calmodulin-M13 sequences that depends on influx of calcium ions (Ca2+) for functional reconstitution. In the presence of its luciferin, coelenterazine (CTZ), Ca2+ influx results in light emission that drives activation of photoreceptors, including optogenetic channels and LOV domains. Critical features of the converter luciferase are light emission low enough to not activate photoreceptors under baseline condition and high enough to activate photosensing elements in the presence of Ca2+ and luciferin. We demonstrate performance of this activity-dependent sensor and integrator for changing membrane potential and driving transcription in individual and populations of neurons in vitro and in vivo.
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Affiliation(s)
- Emmanuel L. Crespo
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
- Biochemistry, Cell and Molecular Biology Graduate Program, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Akash Pal
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Mansi Prakash
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Alexander D. Silvagnoli
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Zohair Zaidi
- Duke University, Undergraduate Neuroscience Program, Durham, NC 27710
| | | | - Maya O. Tree
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
| | - Nathan C. Shaner
- University of California, San Diego, School of Medicine, Department of Neuroscience, 9500 Gilman Drive La Jolla, CA 92093-0662, USA
| | - Diane Lipscombe
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, RI 02906, USA
| | - Christopher Moore
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
- Carney Institute for Brain Science, Brown University, Providence, RI 02906, USA
| | - Ute Hochgeschwender
- College of Medicine, Central Michigan University, Mount Pleasant, MI 48859, USA
- Biochemistry, Cell and Molecular Biology Graduate Program, Central Michigan University, Mount Pleasant, MI 48859, USA
- Program in Neuroscience, Central Michigan University, Mount Pleasant, MI 48859, USA
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