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Chorghay Z, Li VJ, Schohl A, Ghosh A, Ruthazer ES. The effects of the NMDAR co-agonist D-serine on the structure and function of optic tectal neurons in the developing visual system. Sci Rep 2023; 13:13383. [PMID: 37591903 PMCID: PMC10435543 DOI: 10.1038/s41598-023-39951-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 08/02/2023] [Indexed: 08/19/2023] Open
Abstract
The N-methyl-D-aspartate type glutamate receptor (NMDAR) is a molecular coincidence detector which converts correlated patterns of neuronal activity into cues for the structural and functional refinement of developing circuits in the brain. D-serine is an endogenous co-agonist of the NMDAR. We investigated the effects of potent enhancement of NMDAR-mediated currents by chronic administration of saturating levels of D-serine on the developing Xenopus retinotectal circuit. Chronic exposure to the NMDAR co-agonist D-serine resulted in structural and functional changes in the optic tectum. In immature tectal neurons, D-serine administration led to more compact and less dynamic tectal dendritic arbors, and increased synapse density. Calcium imaging to examine retinotopy of tectal neurons revealed that animals raised in D-serine had more compact visual receptive fields. These findings provide insight into how the availability of endogenous NMDAR co-agonists like D-serine at glutamatergic synapses can regulate the refinement of circuits in the developing brain.
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Affiliation(s)
- Zahraa Chorghay
- Montreal Neurological Institute-Hospital and Department of Neurology and Neurosurgery, McGill University, 3801 Rue University, Montréal, QC, H3A 2B4, Canada
| | - Vanessa J Li
- Montreal Neurological Institute-Hospital and Department of Neurology and Neurosurgery, McGill University, 3801 Rue University, Montréal, QC, H3A 2B4, Canada
| | - Anne Schohl
- Montreal Neurological Institute-Hospital and Department of Neurology and Neurosurgery, McGill University, 3801 Rue University, Montréal, QC, H3A 2B4, Canada
| | - Arna Ghosh
- MILA, 6666 Rue St Urbain, Montréal, QC, H2S 3H1, Canada
| | - Edward S Ruthazer
- Montreal Neurological Institute-Hospital and Department of Neurology and Neurosurgery, McGill University, 3801 Rue University, Montréal, QC, H3A 2B4, Canada.
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2
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Delia J, Gaines-Richardson M, Ludington SC, Akbari N, Vasek C, Shaykevich D, O’Connell LA. Tissue-specific in vivo transformation of plasmid DNA in Neotropical tadpoles using electroporation. PLoS One 2023; 18:e0289361. [PMID: 37590232 PMCID: PMC10434853 DOI: 10.1371/journal.pone.0289361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 07/11/2023] [Indexed: 08/19/2023] Open
Abstract
Electroporation is an increasingly common technique used for exogenous gene expression in live animals, but protocols are largely limited to traditional laboratory organisms. The goal of this protocol is to test in vivo electroporation techniques in a diverse array of tadpole species. We explore electroporation efficiency in tissue-specific cells of five species from across three families of tropical frogs: poison frogs (Dendrobatidae), cryptic forest/poison frogs (Aromobatidae), and glassfrogs (Centrolenidae). These species are well known for their diverse social behaviors and intriguing physiologies that coordinate chemical defenses, aposematism, and/or tissue transparency. Specifically, we examine the effects of electrical pulse and injection parameters on species- and tissue-specific transfection of plasmid DNA in tadpoles. After electroporation of a plasmid encoding green fluorescent protein (GFP), we found strong GFP fluorescence within brain and muscle cells that increased with the amount of DNA injected and electrical pulse number. We discuss species-related challenges, troubleshooting, and outline ideas for improvement. Extending in vivo electroporation to non-model amphibian species could provide new opportunities for exploring topics in genetics, behavior, and organismal biology.
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Affiliation(s)
- Jesse Delia
- Department of Biology, Stanford University, Stanford, CA, United States of America
| | | | - Sarah C. Ludington
- Department of Biology, Stanford University, Stanford, CA, United States of America
| | - Najva Akbari
- Department of Biology, Stanford University, Stanford, CA, United States of America
| | - Cooper Vasek
- Department of Biology, De Anza College, Cupertino, CA, United States of America
| | - Daniel Shaykevich
- Department of Biology, Stanford University, Stanford, CA, United States of America
| | - Lauren A. O’Connell
- Department of Biology, Stanford University, Stanford, CA, United States of America
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3
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Single-Cell Labeling Strategies to Dissect Neuronal Structures and Local Functions. BIOLOGY 2023; 12:biology12020321. [PMID: 36829594 PMCID: PMC9953318 DOI: 10.3390/biology12020321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/09/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023]
Abstract
The brain network consists of ten billion neurons and is the most complex structure in the universe. Understanding the structure of complex brain networks and neuronal functions is one of the main goals of modern neuroscience. Since the seminal invention of Golgi staining, single-cell labeling methods have been among the most potent approaches for dissecting neuronal structures and neural circuits. Furthermore, the development of sparse single-cell transgenic methods has enabled single-cell gene knockout studies to examine the local functions of various genes in neural circuits and synapses. Here, we review non-transgenic single-cell labeling methods and recent advances in transgenic strategies for sparse single neuronal labeling. These methods and strategies will fundamentally contribute to the understanding of brain structure and function.
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Liu L, Zhang J, Teng T, Yang Y, Zhang W, Wu W, Li G, Zheng X. Electroporation of His-Cre fusion protein triggers a specific recombinase-mediated cassette exchange in HEK 293T cells. Protein Expr Purif 2022; 198:106128. [PMID: 35667585 DOI: 10.1016/j.pep.2022.106128] [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: 03/17/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022]
Abstract
Cre recombinase is a widely-used genetic manipulation of genomic DNA. However, the conventional transfection of the DNA vectors expressing the Cre recombinase or viral transduction method yields low transfection efficiencies or insertion mutagenesis. The present paper evaluated whether the direct protein delivery of Cre recombinase through electroporation can induce the Cre-mediated recombination in the HEK 293T cells. Here, the small ubiquitin-related modifier (SUMO) -tagged His-Cre fusion protein was expressed in a soluble pattern in the Eschrichria coli (E.coli) cells, purified using affinity chromatography, and finally electroporated into the HEK 293T cells. These cells were previously transfected with three different Cre reporter vectors. The electroporation of the HEK 293T cells revealed either the activation of EGFP expression, or a decrease in RFP expression, and a concomitant increase in EGFP expression, indicating a desired recombinase-mediated cassette exchange (RMCE) event (conversion of RFP to EGFP), and a biological activity of the purified SUMO-His-Cre protein, which is expected to serve in the Easi-CRISPR-LoxP-mediated genome editing to generate transgenic animal models.
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Affiliation(s)
- Lingkang Liu
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Jiashun Zhang
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Ting Teng
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Yang Yang
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Wanyu Zhang
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Wende Wu
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Gonghe Li
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China
| | - Xibang Zheng
- Department of Animal Medicine, College of Animal Science and Technology, Guangxi University, No. 100 Daxue Road, Nanning, 530004, Guangxi, PR China.
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Yamashiro K, Ikegaya Y, Matsumoto N. In Utero Electroporation for Manipulation of Specific Neuronal Populations. MEMBRANES 2022; 12:membranes12050513. [PMID: 35629839 PMCID: PMC9147339 DOI: 10.3390/membranes12050513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/27/2022] [Accepted: 05/06/2022] [Indexed: 02/05/2023]
Abstract
The complexity of brain functions is supported by the heterogeneity of brain tissue and millisecond-scale information processing. Understanding how complex neural circuits control animal behavior requires the precise manipulation of specific neuronal subtypes at high spatiotemporal resolution. In utero electroporation, when combined with optogenetics, is a powerful method for precisely controlling the activity of specific neurons. Optogenetics allows for the control of cellular membrane potentials through light-sensitive ion channels artificially expressed in the plasma membrane of neurons. Here, we first review the basic mechanisms and characteristics of in utero electroporation. Then, we discuss recent applications of in utero electroporation combined with optogenetics to investigate the functions and characteristics of specific regions, layers, and cell types. These techniques will pave the way for further advances in understanding the complex neuronal and circuit mechanisms that underlie behavioral outputs.
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Affiliation(s)
- Kotaro Yamashiro
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; (K.Y.); (Y.I.)
| | - Yuji Ikegaya
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; (K.Y.); (Y.I.)
- Institute for AI and Beyond, The University of Tokyo, Tokyo 113-0033, Japan
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka 565-0871, Japan
| | - Nobuyoshi Matsumoto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan; (K.Y.); (Y.I.)
- Institute for AI and Beyond, The University of Tokyo, Tokyo 113-0033, Japan
- Correspondence:
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Dab1-deficient deep layer neurons prevent Dab1-deficient superficial layer neurons from entering the cortical plate. Neurosci Res 2022; 180:23-35. [DOI: 10.1016/j.neures.2022.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 02/06/2023]
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7
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Hogg PW, Coleman P, Dellazizzo Toth T, Haas K. Quantifying neuronal structural changes over time using dynamic morphometrics. Trends Neurosci 2021; 45:106-119. [PMID: 34815102 DOI: 10.1016/j.tins.2021.10.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/12/2021] [Accepted: 10/25/2021] [Indexed: 11/29/2022]
Abstract
Brain circuit development involves tremendous structural formation and rearrangement of dendrites, axons, and the synaptic connections between them. Direct studies of neuronal morphogenesis are now possible through recent developments in multiple technologies, including single-neuron labeling, time-lapse imaging in intact tissues, and 4D rendering software capable of tracking neural growth over periods spanning minutes to days. These methods allow detailed quantification of structural changes of neurons over time, called dynamic morphometrics, providing new insights into fundamental growth patterns, underlying molecular mechanisms, and the intertwined influences of external factors, including neural activity, and intrinsic genetic programs. Here, we review the methods of dynamic morphometrics sampling and analyses, focusing on their applications to studies of activity-driven dendritogenesis in vertebrate systems.
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Affiliation(s)
- Peter William Hogg
- Department of Cellular and Physiological Sciences, Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
| | - Patrick Coleman
- Department of Cellular and Physiological Sciences, Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
| | - Tristan Dellazizzo Toth
- Department of Cellular and Physiological Sciences, Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
| | - Kurt Haas
- Department of Cellular and Physiological Sciences, Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, Canada.
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Gore SV, James EJ, Huang LC, Park JJ, Berghella A, Thompson AC, Cline HT, Aizenman CD. Role of matrix metalloproteinase-9 in neurodevelopmental deficits and experience-dependent plasticity in Xenopus laevis. eLife 2021; 10:62147. [PMID: 34282726 PMCID: PMC8315794 DOI: 10.7554/elife.62147] [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: 08/15/2020] [Accepted: 07/18/2021] [Indexed: 02/06/2023] Open
Abstract
Matrix metalloproteinase-9 (MMP-9) is a secreted endopeptidase targeting extracellular matrix proteins, creating permissive environments for neuronal development and plasticity. Developmental dysregulation of MMP-9 may also lead to neurodevelopmental disorders (ND). Here, we test the hypothesis that chronically elevated MMP-9 activity during early neurodevelopment is responsible for neural circuit hyperconnectivity observed in Xenopus tadpoles after early exposure to valproic acid (VPA), a known teratogen associated with ND in humans. In Xenopus tadpoles, VPA exposure results in excess local synaptic connectivity, disrupted social behavior and increased seizure susceptibility. We found that overexpressing MMP-9 in the brain copies effects of VPA on synaptic connectivity, and blocking MMP-9 activity pharmacologically or genetically reverses effects of VPA on physiology and behavior. We further show that during normal neurodevelopment MMP-9 levels are tightly regulated by neuronal activity and required for structural plasticity. These studies show a critical role for MMP-9 in both normal and abnormal development.
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Affiliation(s)
- Sayali V Gore
- Department of Neuroscience, Brown University, Providence, United States
| | - Eric J James
- Department of Neuroscience, Brown University, Providence, United States
| | | | - Jenn J Park
- Department of Neuroscience, Brown University, Providence, United States
| | - Andrea Berghella
- Department of Neuroscience, Brown University, Providence, United States
| | - Adrian C Thompson
- Department of Neuroscience, Brown University, Providence, United States
| | | | - Carlos D Aizenman
- Department of Neuroscience, Brown University, Providence, United States
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Liu K, Garcia A, Park JJ, Toliver AA, Ramos L, Aizenman CD. Early Developmental Exposure to Fluoxetine and Citalopram Results in Different Neurodevelopmental Outcomes. Neuroscience 2021; 467:110-121. [PMID: 34048796 DOI: 10.1016/j.neuroscience.2021.05.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 11/25/2022]
Abstract
Although selective serotonin reuptake inhibitors are commonly prescribed for prenatal depression, there exists controversy over adverse effects of SSRI use on fetal development. Few studies have adequately isolated outcomes due to SSRI exposure and those due to maternal psychiatric conditions. Here, we directly investigated outcomes of exposure to widely-used SSRIs Fluoxetine and Citalopram on the developing nervous system of Xenopus laevis tadpoles, using an integrative experimental approach. We exposed tadpoles to low doses of Citalopram and Fluoxetine during a critical developmental period and found that different experimental groups displayed opposing behavioral effects. While both groups showed reduced schooling behavior, the Fluoxetine group showed increased seizure susceptibility and reduced startle habituation. In contrast, Citalopram treated tadpoles had decreased seizure susceptibility and increased habituation. Both groups had abnormal dendritic morphology in the optic tectum, a brain area important for behaviors tested. Whole-cell electrophysiological recordings of tectal neurons showed no differences in synaptic function; however, tectal cells from Fluoxetine-treated tadpoles had decreased voltage gated K+ currents while cells in the Citalopram group had increased K+ currents. Both behavioral and electrophysiological findings indicate that cells and circuits in the Fluoxetine treated optic tecta are hyperexcitable, while the Citalopram group exhibits decreased excitability. Taken together, these results show that early developmental exposure to SSRIs is sufficient to induce neurodevelopmental effects, however these effects can be complex and vary depending on the SSRI. This may explain some discrepancies across human studies, and further underscores the importance of serotonergic signaling for the developing nervous system.
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Affiliation(s)
- Karine Liu
- Department of Neuroscience, Brown University, United States
| | - Alfonso Garcia
- Department of Neuroscience, Brown University, United States
| | - Jenn J Park
- Department of Neuroscience, Brown University, United States
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