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Pasquini L, Jenabi M, Graham M, Peck KK, Schöder H, Holodny AI, Krebs S. Tumors Affect the Metabolic Connectivity of the Human Brain Measured by 18 F-FDG PET. Clin Nucl Med 2024; 49:822-829. [PMID: 38693648 PMCID: PMC11300165 DOI: 10.1097/rlu.0000000000005227] [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: 05/03/2024]
Abstract
PURPOSE 18 F-FDG PET captures the relationship between glucose metabolism and synaptic activity, allowing for modeling brain function through metabolic connectivity. We investigated tumor-induced modifications of brain metabolic connectivity. PATIENTS AND METHODS Forty-three patients with left hemispheric tumors and 18 F-FDG PET/MRI were retrospectively recruited. We included 37 healthy controls (HCs) from the database CERMEP-IDB-MRXFDG. We analyzed the whole brain and right versus left hemispheres connectivity in patients and HC, frontal versus temporal tumors, active tumors versus radiation necrosis, and patients with high Karnofsky performance score (KPS = 100) versus low KPS (KPS < 70). Results were compared with 2-sided t test ( P < 0.05). RESULTS Twenty high-grade glioma, 4 low-grade glioma, and 19 metastases were included. The patients' whole-brain network displayed lower connectivity metrics compared with HC ( P < 0.001), except assortativity and betweenness centrality ( P = 0.001). The patients' left hemispheres showed decreased similarity, and lower connectivity metrics compared with the right ( P < 0.01), with the exception of betweenness centrality ( P = 0.002). HC did not show significant hemispheric differences. Frontal tumors showed higher connectivity metrics ( P < 0.001) than temporal tumors, but lower betweenness centrality ( P = 4.5 -7 ). Patients with high KPS showed higher distance local efficiency ( P = 0.01), rich club coefficient ( P = 0.0048), clustering coefficient ( P = 0.00032), betweenness centrality ( P = 0.008), and similarity ( P = 0.0027) compared with low KPS. Patients with active tumor(s) (14/43) demonstrated significantly lower connectivity metrics compared with necroses. CONCLUSIONS Tumors cause reorganization of metabolic brain networks, characterized by formation of new connections and decreased centrality. Patients with frontal tumors retained a more efficient, centralized, and segregated network than patients with temporal tumors. Stronger metabolic connectivity was associated with higher KPS.
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Affiliation(s)
- Luca Pasquini
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Mehrnaz Jenabi
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Maya Graham
- Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, NY
- The Brain Tumor Center, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Kyung K. Peck
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Heiko Schöder
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Andrei I. Holodny
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
| | - Simone Krebs
- Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
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Yee C, Xiao Y, Chen H, Reddy AR, Xu B, Medwig-Kinney TN, Zhang W, Boyle AP, Herbst WA, Xiang YK, Matus DQ, Shen K. An activity-regulated transcriptional program directly drives synaptogenesis. Nat Neurosci 2024:10.1038/s41593-024-01728-x. [PMID: 39103556 DOI: 10.1038/s41593-024-01728-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 07/11/2024] [Indexed: 08/07/2024]
Abstract
Although the molecular composition and architecture of synapses have been widely explored, much less is known about what genetic programs directly activate synaptic gene expression and how they are modulated. Here, using Caenorhabditis elegans dopaminergic neurons, we reveal that EGL-43/MECOM and FOS-1/FOS control an activity-dependent synaptogenesis program. Loss of either factor severely reduces presynaptic protein expression. Both factors bind directly to promoters of synaptic genes and act together with CUT homeobox transcription factors to activate transcription. egl-43 and fos-1 mutually promote each other's expression, and increasing the binding affinity of FOS-1 to the egl-43 locus results in increased presynaptic protein expression and synaptic function. EGL-43 regulates the expression of multiple transcription factors, including activity-regulated factors and developmental factors that define multiple aspects of dopaminergic identity. Together, we describe a robust genetic program underlying activity-regulated synapse formation during development.
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Affiliation(s)
- Callista Yee
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Yutong Xiao
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA
| | - Hongwen Chen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Anay R Reddy
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Bing Xu
- Department of Pharmacology, University of California, Davis, Davis, CA, USA
- VA Northern California Healthcare System, Mather, CA, USA
| | - Taylor N Medwig-Kinney
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wan Zhang
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Alan P Boyle
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Wendy A Herbst
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Yang Kevin Xiang
- Department of Pharmacology, University of California, Davis, Davis, CA, USA
- VA Northern California Healthcare System, Mather, CA, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA.
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA.
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Savage JT, Ramirez J, Risher WC, Wang Y, Irala D, Eroglu C. SynBot: An open-source image analysis software for automated quantification of synapses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.26.546578. [PMID: 37425715 PMCID: PMC10327002 DOI: 10.1101/2023.06.26.546578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The formation of precise numbers of neuronal connections, known as synapses, is crucial for brain function. Therefore, synaptogenesis mechanisms have been one of the main focuses of neuroscience. Immunohistochemistry is a common tool for visualizing synapses. Thus, quantifying the numbers of synapses from light microscopy images enables screening the impacts of experimental manipulations on synapse development. Despite its utility, this approach is paired with low throughput analysis methods that are challenging to learn and results are variable between experimenters, especially when analyzing noisy images of brain tissue. We developed an open-source ImageJ-based software, SynBot, to address these technical bottlenecks by automating the analysis. SynBot incorporates the advanced algorithms ilastik and SynQuant for accurate thresholding for synaptic puncta identification, and the code can easily be modified by users. The use of this software will allow for rapid and reproducible screening of synaptic phenotypes in healthy and diseased nervous systems.
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Affiliation(s)
- Justin T. Savage
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Juan Ramirez
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - W. Christopher Risher
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University,Huntington, WV 25755, USA
| | - Yizhi Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Arlington, VA 22203, USA
| | - Dolores Irala
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
| | - Cagla Eroglu
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA
- Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA
- Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815
- Lead contact
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Pasquini L, Tao A, Ferraro GD, Jenabi M, Peck KK, Napolitano A, Fahy TA, Brennan C, Moss NS, Tabar V, Makse H, Holodny AI. Association of Lack of Speech Arrest During Cortical Stimulation With Interhemispheric Reorganization of the Functional Language Network in Patients With Brain Tumors. AJR Am J Roentgenol 2023; 221:806-816. [PMID: 37377358 DOI: 10.2214/ajr.23.29434] [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] [Indexed: 06/29/2023]
Abstract
BACKGROUND. Brain tumors induce language reorganization, which may influence the extent of resection in surgical planning. Direct cortical stimulation (DCS) allows definitive language mapping during awake surgery by locating areas of speech arrest (SA) surrounding the tumor. Although functional MRI (fMRI) combined with graph theory analysis can illustrate whole-brain network reorganization, few studies have corroborated these findings with DCS intraoperative mapping and clinical language performance. OBJECTIVE. We evaluated whether patients with low-grade gliomas (LGGs) without SA during DCS show increased right-hemispheric connections and better speech performance compared with patients with SA. METHODS. We retrospectively recruited 44 consecutive patients with left perisylvian LGG, preoperative language task-based fMRI, speech performance evaluation, and awake surgery with DCS. We generated language networks from ROIs corresponding to known language areas (i.e., language core) on fMRI using optimal percolation. Language core connectivity in the left and right hemispheres was quantified as fMRI laterality index (LI) and connectivity LI on the basis of fMRI activation maps and connectivity matrices. We compared fMRI LI and connectivity LI between patients with SA and without SA and used multivariable logistic regression (p < .05) to assess associations between DCS and connectivity LI, fMRI LI, tumor location, Broca area and Wernicke area involvement, prior treatments, age, handedness, sex, tumor size, and speech deficit before surgery, within 1 week after surgery, and 3-6 months after surgery. RESULTS. Patients with SA showed left-dominant connectivity; patients without SA lateralized more to the right hemisphere (p < .001). Between patients with SA and those without, fMRI LI was not significantly different. Patients without SA showed right-greater-than-left connectivity of Broca area and premotor area compared with patients with SA. Regression analysis showed significant association between no SA and right-lateralized connectivity LI (p < .001) and fewer speech deficits before (p < .001) and 1 week after (p = .02) surgery. CONCLUSION. Patients without SA had increased right-hemispheric connections and right translocation of the language core, suggesting language reorganization. Lack of interoperative SA was associated with fewer speech deficits both before and immediately after surgery. CLINICAL IMPACT. These findings support tumor-induced language plasticity as a compensatory mechanism, which may lead to fewer postsurgical deficits and allow extended resection.
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Affiliation(s)
- Luca Pasquini
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065
- Department of Radiology, Molecular Imaging and Therapy Service, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Alice Tao
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065
| | | | - Mehrnaz Jenabi
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065
| | - Kyung K Peck
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Antonio Napolitano
- Medical Physics Department, Bambino Gesù Children's Hospital, Rome, Italy
| | - Tara A Fahy
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065
| | - Cameron Brennan
- Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Nelson S Moss
- Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Vivian Tabar
- Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, NY
| | - Hernan Makse
- Levich Institute and Physics Department, City College of New York, New York, NY
| | - Andrei I Holodny
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, 1275 York Ave, New York, NY 10065
- Department of Neuroscience, Weill Cornell Medicine Graduate School of the Medical Sciences, New York, NY
- Department of Radiology, Weill Medical College of Cornell University, New York, NY
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Kim H, Skuba A, Xia J, Han SB, Zhai J, Hu H, Kang SH, Son YJ. Oligodendrocyte precursor cells stop sensory axons regenerating into the spinal cord. Cell Rep 2023; 42:113068. [PMID: 37656624 DOI: 10.1016/j.celrep.2023.113068] [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: 11/01/2022] [Revised: 07/17/2023] [Accepted: 08/18/2023] [Indexed: 09/03/2023] Open
Abstract
Primary somatosensory axons stop regenerating as they re-enter the spinal cord, resulting in incurable sensory loss. What arrests them has remained unclear. We previously showed that axons stop by forming synaptic contacts with unknown non-neuronal cells. Here, we identified these cells in adult mice as oligodendrocyte precursor cells (OPCs). We also found that only a few axons stop regenerating by forming dystrophic endings, exclusively at the CNS:peripheral nervous system (PNS) borderline where OPCs are absent. Most axons stop in contact with a dense network of OPC processes. Live imaging, immuno-electron microscopy (immuno-EM), and OPC-dorsal root ganglia (DRG) co-culture additionally suggest that axons are rapidly immobilized by forming synapses with OPCs. Genetic OPC ablation enables many axons to continue regenerating deep into the spinal cord. We propose that sensory axons stop regenerating by encountering OPCs that induce presynaptic differentiation. Our findings identify OPCs as a major regenerative barrier that prevents intraspinal restoration of sensory circuits following spinal root injury.
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Affiliation(s)
- Hyukmin Kim
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Andy Skuba
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Jingsheng Xia
- Department of Medicine, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Sung Baek Han
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Jinbin Zhai
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Huijuan Hu
- Department of Medicine, New Jersey Medical School, Rutgers University, Newark, NJ, USA
| | - Shin H Kang
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Young-Jin Son
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA.
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Pasquini L, Yildirim O, Silveira P, Tamer C, Napolitano A, Lucignani M, Jenabi M, Peck KK, Holodny A. Effect of tumor genetics, pathology, and location on fMRI of language reorganization in brain tumor patients. Eur Radiol 2023; 33:6069-6078. [PMID: 37074422 PMCID: PMC10415458 DOI: 10.1007/s00330-023-09610-3] [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: 08/17/2022] [Revised: 01/27/2023] [Accepted: 02/20/2023] [Indexed: 04/20/2023]
Abstract
OBJECTIVES Language reorganization may follow tumor invasion of the dominant hemisphere. Tumor location, grade, and genetics influence the communication between eloquent areas and tumor growth dynamics, which are drivers of language plasticity. We evaluated tumor-induced language reorganization studying the relationship of fMRI language laterality to tumor-related variables (grade, genetics, location), and patient-related variables (age, sex, handedness). METHODS The study was retrospective cross-sectional. We included patients with left-hemispheric tumors (study group) and right-hemispheric tumors (controls). We calculated five fMRI laterality indexes (LI): hemispheric, temporal lobe, frontal lobe, Broca's area (BA), Wernicke's area (WA). We defined LI ≥ 0.2 as left-lateralized (LL) and LI < 0.2 as atypical lateralized (AL). Chi-square test (p < 0.05) was employed to identify the relationship between LI and tumor/patient variables in the study group. For those variables having significant results, confounding factors were evaluated in a multinomial logistic regression model. RESULTS We included 405 patients (235 M, mean age: 51 years old) and 49 controls (36 M, mean age: 51 years old). Contralateral language reorganization was more common in patients than controls. The statistical analysis demonstrated significant association between BA LI and patient sex (p = 0.005); frontal LI, BA LI, and tumor location in BA (p < 0.001); hemispheric LI and fibroblast growth factor receptor (FGFR) mutation (p = 0.019); WA LI and O6-methylguanine-DNA methyltransferase promoter (MGMT) methylation in high-grade gliomas (p = 0.016). CONCLUSIONS Tumor genetics, pathology, and location influence language laterality, possibly due to cortical plasticity. Increased fMRI activation in the right hemisphere was seen in patients with tumors in the frontal lobe, BA and WA, FGFR mutation, and MGMT promoter methylation. KEY POINTS • Patients harboring left-hemispheric tumors present with contralateral translocation of language function. Influential variables for this phenomenon included frontal tumor location, BA location, WA location, sex, MGMT promoter methylation, and FGFR mutation. • Tumor location, grade, and genetics may influence language plasticity, thereby affecting both communication between eloquent areas and tumor growth dynamics. • In this retrospective cross-sectional study, we evaluated language reorganization in 405 brain tumor patients by studying the relationship of fMRI language laterality to tumor-related variables (grade, genetics, location), and patient-related variables (age, sex, handedness).
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Affiliation(s)
- Luca Pasquini
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
- NESMOS Department, Neuroradiology Unit, Sant'Andrea Hospital, La Sapienza University, 00189, Rome, Italy.
| | - Onur Yildirim
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Patrick Silveira
- Molecular Imaging and Therapy Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Christel Tamer
- Diagnostic Radiology Department, American University of Beirut Medical Center, Beirut, 1107 2020, Lebanon
| | - Antonio Napolitano
- Medical Physics Department, Bambino Gesù Children's Hospital, 00165, Rome, Italy
| | - Martina Lucignani
- Medical Physics Department, Bambino Gesù Children's Hospital, 00165, Rome, Italy
| | - Mehrnaz Jenabi
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
| | - Kyung K Peck
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Department of Radiology, Weill Medical College of Cornell University, New York, NY, 10065, USA
| | - Andrei Holodny
- Department of Radiology, Neuroradiology Service, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Brain Tumor Center, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA
- Department of Radiology, Weill Medical College of Cornell University, New York, NY, 10065, USA
- Department of Neuroscience, Weill Cornell Graduate School of the Medical Sciences, New York, NY, 10065, USA
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Soutschek M, Schratt G. Non-coding RNA in the wiring and remodeling of neural circuits. Neuron 2023:S0896-6273(23)00341-0. [PMID: 37230080 DOI: 10.1016/j.neuron.2023.04.031] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/25/2023] [Accepted: 04/26/2023] [Indexed: 05/27/2023]
Abstract
The brain constantly adapts to changes in the environment, a capability that underlies memory and behavior. Long-term adaptations require the remodeling of neural circuits that are mediated by activity-dependent alterations in gene expression. Over the last two decades, it has been shown that the expression of protein-coding genes is significantly regulated by a complex layer of non-coding RNA (ncRNA) interactions. The aim of this review is to summarize recent discoveries regarding the functional involvement of ncRNAs during different stages of neural circuit development, activity-dependent circuit remodeling, and circuit maladapations underlying neurological and neuropsychiatric disorders. In addition to the intensively studied microRNA (miRNA) family, we focus on more recently added ncRNA classes, such as long ncRNAs (lncRNAs) and circular RNAs (circRNAs), and discuss the complex regulatory interactions between these different RNAs. We conclude by discussing the potential relevance of ncRNAs for cell-type and -state-specific regulation in the context of memory formation, the evolution of human cognitive abilities, and the development of new diagnostic and therapeutic tools in brain disorders.
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Affiliation(s)
- Michael Soutschek
- Laboratory of Systems Neuroscience, Institute for Neuroscience, Department of Health Science and Technology, Swiss Federal Institute of Technology ETH, 8057 Zurich, Switzerland
| | - Gerhard Schratt
- Laboratory of Systems Neuroscience, Institute for Neuroscience, Department of Health Science and Technology, Swiss Federal Institute of Technology ETH, 8057 Zurich, Switzerland.
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Arshad MN, Pinto A, van Praag H, Naegele JR. Altered connectomes of adult-born granule cells following engraftment of GABAergic progenitors in the mouse hippocampus. Prog Neurobiol 2023; 226:102450. [PMID: 37061022 DOI: 10.1016/j.pneurobio.2023.102450] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 03/25/2023] [Accepted: 04/12/2023] [Indexed: 04/17/2023]
Abstract
Adult neurogenesis occurs in the dentate gyrus (DG) of the rodent hippocampus throughout life, producing new granule cells (GCs) that migrate from a stem cell niche called the subgranular zone (SGZ) into the adjacent granule cell layer (GCL). Seizures associated with temporal lobe epilepsy alter adult neurogenesis and promote the formation of hyperexcitable circuits. Stem cell therapies for treating intractable seizure disorders are based on the premise that transplantation of GABAergic interneurons will strengthen inhibitory connections within the hippocampus and reduce hyperexcitability. Grafts of medial ganglionic eminence (MGE)-derived fetal GABAergic progenitors into the DG of adult mice with pilocarpine-induced TLE have been shown to suppress spontaneous recurrent seizures. In addition, the transplanted cells formed functional inhibitory synaptic connections with hippocampal neurons, including adult-born GCs. However, it is unknown whether MGE grafts change adult-born GC connectivity. To address this question, we compared the first-order monosynaptic inputs to adult-born GCs in TLE mice with or without MGE-derived interneuron grafts. Here we show that TLE increased excitatory inputs from endogenous hippocampal, entorhinal cortex, and medial septum/diagonal band neurons onto adult-born GCs. In contrast, in TLE mice with grafts, these excitatory inputs were reduced, coinciding with transplanted GABAergic interneuron innervation of adult-born GCs. These findings indicate that GABAergic interneuron transplantation into the dentate gyrus may prevent epilepsy-associated alterations in the connectivity of adult-born GCs.
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Affiliation(s)
- Muhammad N Arshad
- Hall-Atwater Laboratory, Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT 06459-0170, USA.
| | - Alejandro Pinto
- Stiles-Nicholson Brain Institute and Charles E. Schmidt College of Biomedical Sciences, Florida Atlantic University, Jupiter, FL, 33458, USA.
| | - Henriette van Praag
- Stiles-Nicholson Brain Institute and Charles E. Schmidt College of Biomedical Sciences, Florida Atlantic University, Jupiter, FL, 33458, USA.
| | - Janice R Naegele
- Hall-Atwater Laboratory, Wesleyan University, Department of Biology, Program in Neuroscience and Behavior, Middletown, CT 06459-0170, USA.
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Majumdar S. Role of glutamate in the development of visual pathways. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1147769. [PMID: 38983097 PMCID: PMC11182277 DOI: 10.3389/fopht.2023.1147769] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 02/20/2023] [Indexed: 07/11/2024]
Abstract
Glutamate is an important amino acid, metabolite and excitatory neurotransmitter, which is found in its free form in the extracellular spaces of the central nervous system (CNS). More than half of all synapses in CNS release glutamate. It is the main neurotransmitter driving the light responses in the retina. All types of photoreceptors, bipolar, ganglion and one type of glycinergic amacrine cells express specific subtypes of vesicular glutamate transporters and are the main source of endogenous glutamate in retina, besides Müller glia that are responsible for glutamate homeostasis, release and reuptake. Reduced or excessive extracellular glutamate was detected in the synaptic clefts of several naturally occurring or transgenic eye disease models, in which network rewiring and altered functions were observed. These led to the hypothesis that glutamate is one of the extrinsic signals for visual pathway development. This minireview examines experimental evidences supporting, or refuting, the influence of glutamate on prenatal and postnatal retinal development.
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Affiliation(s)
- Sriparna Majumdar
- Department of Psychology, Santa Clara University, Santa Clara, CA, United States
- Computer Science Department, City College of San Francisco, San Francisco, CA, United States
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10
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Jorratt P, Ricny J, Leibold C, Ovsepian SV. Endogenous Modulators of NMDA Receptor Control Dendritic Field Expansion of Cortical Neurons. Mol Neurobiol 2023; 60:1440-1452. [PMID: 36462136 PMCID: PMC9899188 DOI: 10.1007/s12035-022-03147-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 11/21/2022] [Indexed: 12/05/2022]
Abstract
Impairments of N-methyl-D-aspartate receptor (NMDAR) activity have been implicated in several neuropsychiatric disorders, with pharmacological inhibition of NMDAR-mediated currents and associated neurobehavioral changes considered as a model of schizophrenia. We analyzed the effects of brief and long-term exposure of rat cortical cultures to the most prevalent endogenous modulators of NMDAR (kynurenic acid, pregnenolone sulfate, spermidine, and zinc) on neuronal viability, stimulation-induced release of glutamate, and dendritic morphology with synaptic density. Both, glutamate release and neuronal viability studies revealed no difference between the test and control groups. No differences were also observed in the number of dendritic branching and length, or density of synaptic connections and neuronal soma size. Comparison of the extent of dendritic projections and branching patterns, however, revealed enhanced distal arborization with the expansion of the dendritic area under prolonged treatment of cultures with physiological concentrations of NMDAR modulators, with differences reaching significance in spermidine and pregnenolone sulfate tests. Measurements of the density of glutamatergic synapses showed consistency across all neuronal groups, except those treated with pregnenolone sulfate, which showed a reduction of PSD-95-positive elements. Overall, our data suggest that constitutive glutamatergic activity mediated by NMDAR controls the dendritic field expansion and can influence the integrative properties of cortical neurons.
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Affiliation(s)
- Pascal Jorratt
- grid.447902.cNational Institute of Mental Health, Klecany, Czech Republic ,grid.4491.80000 0004 1937 116XThird Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Ricny
- grid.447902.cNational Institute of Mental Health, Klecany, Czech Republic
| | - Christian Leibold
- grid.5963.9Faculty of Biology and Bernstein Center Freiburg, University of Freiburg, Freiburg, Germany
| | - Saak V. Ovsepian
- grid.36316.310000 0001 0806 5472Faculty of Science and Engineering, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB UK
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11
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Ortuño-Sahagún D, Riesgo-Escovar JR. Editorial: Emerging frontiers in developmental biology in Latin America. Front Neurosci 2023; 17:1129291. [PMID: 37152601 PMCID: PMC10159055 DOI: 10.3389/fnins.2023.1129291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Affiliation(s)
- Daniel Ortuño-Sahagún
- Laboratorio de Neuroinmunobiología Molecular, Instituto de Investigación en Ciencias Biomédicas, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Jalisco, Mexico
- *Correspondence: Daniel Ortuño-Sahagún
| | - Juan Rafael Riesgo-Escovar
- Developmental Neurobiology and Neurophysiology, Instituto de Neurobiología, Campus UNAM Juriquilla, Universidad Nacional Autónoma de Mexico, Santiago de Querétaro, Mexico
- Juan Rafael Riesgo-Escovar
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12
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Pasquini L, Jenabi M, Peck KK, Holodny AI. Language reorganization in patients with left-hemispheric gliomas is associated with increased cortical volume in language-related areas and in the default mode network. Cortex 2022; 157:245-255. [PMID: 36356409 PMCID: PMC10201933 DOI: 10.1016/j.cortex.2022.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 08/02/2022] [Accepted: 09/19/2022] [Indexed: 12/15/2022]
Abstract
BACKGROUND Language function may reorganize to overcome focal impairment; however, the relation between functional and structural changes in patients with brain tumors remains unclear. We investigated the cortical volume of atypical language dominant (AD) patients with left frontal-insular high-grade (HGG) and low-grade glioma (LGG). We hypothesized atypical language being associated with areas of increased cortical volume in the right hemisphere, including language areas homologues. METHODS Patient were recruited following the criteria: left frontal-insular glioma; functional MRI and 3DT1-weighted images; no artifacts. We calculated an hemispheric language laterality index (LI), defined as: AD if LI < .2; left-dominant (LD) if LI ≥ .2. We measured cortical volume in three voxel-based morphometry (VBM) analyses: total AD vs. LD patients; AD vs. LD in HGG; AD vs. LD in LGG. We repeated the analysis in AD vs. LD healthy controls (HC). A minimum threshold of t > 2 and corrected p < .025 (Bonferroni) was employed. RESULTS We recruited 119 patients (44LGG, 75HGG). Hemispheric LI demonstrated 64/119AD and 55/119LD patients. The first VBM analysis demonstrated significantly increased cortical volume in AD patients in the right inferior frontal gyrus (IFG), right superior temporal gyrus (STG), right insula, right fusiform gyrus (FG), right precentral gyrus, right temporal-parietal junction, right posterior cingulate cortex (PCC), right hippocampus, right- and left cerebellum. AD patients with HGG showed the same areas of significantly increased cortical volume. AD patients with LGG displayed significantly increased cortical volume in right IFG, right STG, right insula, right FG, right anterior cingulate cortex, right PCC, right dorsal-lateral prefrontal cortex. HC showed no significant results. CONCLUSION Right-sided (atypical) language activations in patients with left-hemispheric gliomas are associated with areas of increased cortical volume. Additionally, default mode network nodes showed greater cortical volume in AD patients regardless of the tumor grade, supporting the idea of these cortices participating in the development of language plasticity.
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Affiliation(s)
- Luca Pasquini
- Neuroradiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Neuroradiology Unit, NESMOS Department, Sant'Andrea Hospital, La Sapienza University, Rome 00189, Italy.
| | - Mehrnaz Jenabi
- Neuroradiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Kyung K Peck
- Neuroradiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Andrei I Holodny
- Neuroradiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Brain Tumor Center, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Department of Radiology, Weill Medical College of Cornell University, New York, NY 10065, USA; Department of Neuroscience, Weill-Cornell Graduate School of the Medical Sciences, New York, NY 10065, USA
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13
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Davison A, Gierke K, Brandstätter JH, Babai N. Synaptic vesicle release during ribbon synapse formation of cone photoreceptors. Front Cell Neurosci 2022; 16:1022419. [PMID: 36406751 PMCID: PMC9672513 DOI: 10.3389/fncel.2022.1022419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/20/2022] [Indexed: 08/14/2023] Open
Abstract
Mammalian cone photoreceptors enable through their sophisticated synapse the high-fidelity transfer of visual information to second-order neurons in the retina. The synapse contains a proteinaceous organelle, called the synaptic ribbon, which tethers synaptic vesicles (SVs) at the active zone (AZ) close to voltage-gated Ca2+ channels. However, the exact contribution of the synaptic ribbon to neurotransmission is not fully understood, yet. In mice, precursors to synaptic ribbons appear within photoreceptor terminals shortly after birth as free-floating spherical structures, which progressively elongate and then attach to the AZ during the following days. Here, we took advantage of the process of synaptic ribbon maturation to study their contribution to SV release. We performed whole-cell patch-clamp recordings from cone photoreceptors at three postnatal (P) development stages (P8-9, P12-13, >P30) and measured evoked SV release, SV replenishment rate, recovery from synaptic depression, domain organization of voltage-sensitive Ca2+ channels, and Ca2+-sensitivity of exocytosis. Additionally, we performed electron microscopy to determine the density of SVs at ribbon-free and ribbon-occupied AZs. Our results suggest that ribbon attachment does not organize the voltage-sensitive Ca2+ channels into nanodomains or control SV release probability. However, ribbon attachment increases SV density at the AZ, increases the pool size of readily releasable SVs available for evoked SV release, facilitates SV replenishment without changing the SV pool refilling time, and increases the Ca2+- sensitivity of glutamate release.
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Affiliation(s)
| | | | | | - Norbert Babai
- Division of Animal Physiology/Neurobiology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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14
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Anastasiades PG, de Vivo L, Bellesi M, Jones MW. Adolescent sleep and the foundations of prefrontal cortical development and dysfunction. Prog Neurobiol 2022; 218:102338. [PMID: 35963360 PMCID: PMC7616212 DOI: 10.1016/j.pneurobio.2022.102338] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/04/2022] [Accepted: 08/08/2022] [Indexed: 11/17/2022]
Abstract
Modern life poses many threats to good-quality sleep, challenging brain health across the lifespan. Curtailed or fragmented sleep may be particularly damaging during adolescence, when sleep disruption by delayed chronotypes and societal pressures coincides with our brains preparing for adult life via intense refinement of neural connectivity. These vulnerabilities converge on the prefrontal cortex, one of the last brain regions to mature and a central hub of the limbic-cortical circuits underpinning decision-making, reward processing, social interactions and emotion. Even subtle disruption of prefrontal cortical development during adolescence may therefore have enduring impact. In this review, we integrate synaptic and circuit mechanisms, glial biology, sleep neurophysiology and epidemiology, to frame a hypothesis highlighting the implications of adolescent sleep disruption for the neural circuitry of the prefrontal cortex. Convergent evidence underscores the importance of acknowledging, quantifying and optimizing adolescent sleep's contributions to normative brain development and to lifelong mental health.
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Affiliation(s)
- Paul G Anastasiades
- University of Bristol, Translational Health Sciences, Dorothy Hodgkin Building, Whitson Street, Bristol BS1 3NY, UK
| | - Luisa de Vivo
- University of Bristol, School of Physiology, Pharmacology & Neuroscience, University Walk, Bristol BS8 1TD, UK; University of Camerino, School of Pharmacy, via Gentile III Da Varano, Camerino 62032, Italy
| | - Michele Bellesi
- University of Bristol, School of Physiology, Pharmacology & Neuroscience, University Walk, Bristol BS8 1TD, UK; University of Camerino, School of Bioscience and Veterinary Medicine, via Gentile III Da Varano, Camerino 62032, Italy
| | - Matt W Jones
- University of Bristol, School of Physiology, Pharmacology & Neuroscience, University Walk, Bristol BS8 1TD, UK
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15
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Masoli S, Rizza MF, Tognolina M, Prestori F, D’Angelo E. Computational models of neurotransmission at cerebellar synapses unveil the impact on network computation. Front Comput Neurosci 2022; 16:1006989. [PMID: 36387305 PMCID: PMC9649760 DOI: 10.3389/fncom.2022.1006989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022] Open
Abstract
The neuroscientific field benefits from the conjoint evolution of experimental and computational techniques, allowing for the reconstruction and simulation of complex models of neurons and synapses. Chemical synapses are characterized by presynaptic vesicle cycling, neurotransmitter diffusion, and postsynaptic receptor activation, which eventually lead to postsynaptic currents and subsequent membrane potential changes. These mechanisms have been accurately modeled for different synapses and receptor types (AMPA, NMDA, and GABA) of the cerebellar cortical network, allowing simulation of their impact on computation. Of special relevance is short-term synaptic plasticity, which generates spatiotemporal filtering in local microcircuits and controls burst transmission and information flow through the network. Here, we present how data-driven computational models recapitulate the properties of neurotransmission at cerebellar synapses. The simulation of microcircuit models is starting to reveal how diverse synaptic mechanisms shape the spatiotemporal profiles of circuit activity and computation.
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Affiliation(s)
- Stefano Masoli
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | | | | | - Francesca Prestori
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- *Correspondence: Francesca Prestori,
| | - Egidio D’Angelo
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- IRCCS Mondino Foundation, Brain Connectivity Center, Pavia, Italy
- Egidio D’Angelo,
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16
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Sharma G, Banerjee S. Activity-regulated E3 ubiquitin ligase TRIM47 modulates excitatory synapse development. Front Mol Neurosci 2022; 15:943980. [PMID: 36211980 PMCID: PMC9532517 DOI: 10.3389/fnmol.2022.943980] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022] Open
Abstract
The Ubiquitin Proteasome System (UPS) has been shown to regulate neuronal development and synapse formation. Activity-dependent regulation of E3 ligase, a component of the UPS that targets specific proteins for proteasome-mediated degradation, is emerging as a pivotal player for the establishment of functional synapses. Here, we identified TRIM47 as a developmentally regulated E3 ligase that is expressed in rat hippocampus during the temporal window of synapse formation. We have demonstrated that the expression of TRIM47 is regulated by the glutamate-induced synaptic activity of hippocampal neurons in culture. In addition, the activity-dependent enhancement of TRIM47 expression is recapitulated following the object location test, a hippocampus-dependent spatial memory paradigm. We observed that this enhancement of TRIM47 expression requires NMDA receptor activation. The knockdown of TRIM47 leads to an enhancement of spine density without affecting dendritic complexity. Furthermore, we observed an increase in excitatory synapse development upon loss of TRIM47 function. Comprehensively, our study identified an activity-regulated E3 ligase that drives excitatory synapse formation in hippocampal neurons.
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17
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Qi C, Luo LD, Feng I, Ma S. Molecular mechanisms of synaptogenesis. Front Synaptic Neurosci 2022; 14:939793. [PMID: 36176941 PMCID: PMC9513053 DOI: 10.3389/fnsyn.2022.939793] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
Synapses are the basic units for information processing and storage in the nervous system. It is only when the synaptic connection is established, that it becomes meaningful to discuss the structure and function of a circuit. In humans, our unparalleled cognitive abilities are correlated with an increase in the number of synapses. Additionally, genes involved in synaptogenesis are also frequently associated with neurological or psychiatric disorders, suggesting a relationship between synaptogenesis and brain physiology and pathology. Thus, understanding the molecular mechanisms of synaptogenesis is the key to the mystery of circuit assembly and neural computation. Furthermore, it would provide therapeutic insights for the treatment of neurological and psychiatric disorders. Multiple molecular events must be precisely coordinated to generate a synapse. To understand the molecular mechanisms underlying synaptogenesis, we need to know the molecular components of synapses, how these molecular components are held together, and how the molecular networks are refined in response to neural activity to generate new synapses. Thanks to the intensive investigations in this field, our understanding of the process of synaptogenesis has progressed significantly. Here, we will review the molecular mechanisms of synaptogenesis by going over the studies on the identification of molecular components in synapses and their functions in synaptogenesis, how cell adhesion molecules connect these synaptic molecules together, and how neural activity mobilizes these molecules to generate new synapses. Finally, we will summarize the human-specific regulatory mechanisms in synaptogenesis and results from human genetics studies on synaptogenesis and brain disorders.
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Affiliation(s)
- Cai Qi
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- *Correspondence: Cai Qi,
| | - Li-Da Luo
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
- Department of Cellular and Molecular Physiology, Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, United States
| | - Irena Feng
- Boston University School of Medicine, Boston, MA, United States
| | - Shaojie Ma
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, United States
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18
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Dean CA, Metzbower SR, Dessain SK, Blanpied TA, Benavides DR. Regulation of NMDA Receptor Signaling at Single Synapses by Human Anti-NMDA Receptor Antibodies. Front Mol Neurosci 2022; 15:940005. [PMID: 35966009 PMCID: PMC9371948 DOI: 10.3389/fnmol.2022.940005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
The NMDA receptor (NMDAR) subunit GluN1 is critical for receptor function and plays a pivotal role in synaptic plasticity. Mounting evidence has shown that pathogenic autoantibody targeting of the GluN1 subunit of NMDARs, as in anti-NMDAR encephalitis, leads to altered NMDAR trafficking and synaptic localization. However, the underlying signaling pathways affected by antibodies targeting the NMDAR remain to be fully delineated. It remains unclear whether patient antibodies influence synaptic transmission via direct effects on NMDAR channel function. Here, we show using short-term incubation that GluN1 antibodies derived from patients with anti-NMDAR encephalitis label synapses in mature hippocampal primary neuron culture. Miniature spontaneous calcium transients (mSCaTs) mediated via NMDARs at synaptic spines are not altered in pathogenic GluN1 antibody exposed conditions. Unexpectedly, spine-based and cell-based analyses yielded distinct results. In addition, we show that calcium does not accumulate in neuronal spines following brief exposure to pathogenic GluN1 antibodies. Together, these findings show that pathogenic antibodies targeting NMDARs, under these specific conditions, do not alter synaptic calcium influx following neurotransmitter release. This represents a novel investigation of the molecular effects of anti-NMDAR antibodies associated with autoimmune encephalitis.
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Affiliation(s)
- Charles A. Dean
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Sarah R. Metzbower
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Scott K. Dessain
- Lankenau Institute for Medical Research, Wynnewood, PA, United States
| | - Thomas A. Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, United States
| | - David R. Benavides
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: David R. Benavides,
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19
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Plata ALD, Robles E. NMDA Receptor Antagonist MK801 Reduces Dendritic Spine Density and Stability in Zebrafish Pyramidal Neurons. Neuroscience 2022; 498:50-63. [PMID: 35718218 DOI: 10.1016/j.neuroscience.2022.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/02/2022] [Accepted: 06/10/2022] [Indexed: 11/25/2022]
Abstract
NMDA-type glutamate receptors play a critical role in activity-dependent neurite growth. We employed cell type-specific genetic labeling in zebrafish to examine the effects of NMDA receptor antagonism on the morphological development of tectal pyramidal neurons (PyrNs). Our data demonstrate that the NMDA receptor antagonist MK801 reduces PyrN spine density and stability without significantly altering dendritic growth and branching. However, the axons that synapse onto PyrN dendritic spines do exhibit reduced arbor growth and branching in response to MK801 treatment. Axons that synapse with PyrNs, but not on spines, are unaffected by MK801 treatment. These findings may reflect different roles for NMDARs during the development of spiny and aspiny dendrites.
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Affiliation(s)
- Amanda Lamarca Dela Plata
- Department of Biological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA
| | - Estuardo Robles
- Department of Biological Sciences and Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, USA.
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20
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Pasquini L, Di Napoli A, Rossi-Espagnet MC, Visconti E, Napolitano A, Romano A, Bozzao A, Peck KK, Holodny AI. Understanding Language Reorganization With Neuroimaging: How Language Adapts to Different Focal Lesions and Insights Into Clinical Applications. Front Hum Neurosci 2022; 16:747215. [PMID: 35250510 PMCID: PMC8895248 DOI: 10.3389/fnhum.2022.747215] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 01/18/2022] [Indexed: 12/13/2022] Open
Abstract
When the language-dominant hemisphere is damaged by a focal lesion, the brain may reorganize the language network through functional and structural changes known as adaptive plasticity. Adaptive plasticity is documented for triggers including ischemic, tumoral, and epileptic focal lesions, with effects in clinical practice. Many questions remain regarding language plasticity. Different lesions may induce different patterns of reorganization depending on pathologic features, location in the brain, and timing of onset. Neuroimaging provides insights into language plasticity due to its non-invasiveness, ability to image the whole brain, and large-scale implementation. This review provides an overview of language plasticity on MRI with insights for patient care. First, we describe the structural and functional language network as depicted by neuroimaging. Second, we explore language reorganization triggered by stroke, brain tumors, and epileptic lesions and analyze applications in clinical diagnosis and treatment planning. By comparing different focal lesions, we investigate determinants of language plasticity including lesion location and timing of onset, longitudinal evolution of reorganization, and the relationship between structural and functional changes.
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Affiliation(s)
- Luca Pasquini
- Neuroradiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States
- Neuroradiology Unit, NESMOS Department, Sant’Andrea Hospital, La Sapienza University, Rome, Italy
| | - Alberto Di Napoli
- Neuroradiology Unit, NESMOS Department, Sant’Andrea Hospital, La Sapienza University, Rome, Italy
- Radiology Department, Castelli Hospital, Rome, Italy
- IRCCS Fondazione Santa Lucia, Rome, Italy
| | | | - Emiliano Visconti
- Neuroradiology Unit, Cesena Surgery and Trauma Department, M. Bufalini Hospital, AUSL Romagna, Cesena, Italy
| | - Antonio Napolitano
- Medical Physics Department, Bambino Gesù Children’s Hospital, Rome, Italy
| | - Andrea Romano
- Neuroradiology Unit, NESMOS Department, Sant’Andrea Hospital, La Sapienza University, Rome, Italy
| | - Alessandro Bozzao
- Neuroradiology Unit, NESMOS Department, Sant’Andrea Hospital, La Sapienza University, Rome, Italy
| | - Kyung K. Peck
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, United States
| | - Andrei I. Holodny
- Neuroradiology Service, Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, United States
- Department of Radiology, Weill Medical College of Cornell University, New York, NY, United States
- Department of Neuroscience, Weill-Cornell Graduate School of the Medical Sciences, New York, NY, United States
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21
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Kawai M, Imaizumi K, Ishikawa M, Shibata S, Shinozaki M, Shibata T, Hashimoto S, Kitagawa T, Ago K, Kajikawa K, Shibata R, Kamata Y, Ushiba J, Koga K, Furue H, Matsumoto M, Nakamura M, Nagoshi N, Okano H. Long-term selective stimulation of transplanted neural stem/progenitor cells for spinal cord injury improves locomotor function. Cell Rep 2021; 37:110019. [PMID: 34818559 DOI: 10.1016/j.celrep.2021.110019] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/06/2021] [Accepted: 10/28/2021] [Indexed: 02/07/2023] Open
Abstract
In cell transplantation therapy for spinal cord injury (SCI), grafted human induced pluripotent stem cell-derived neural stem/progenitor cells (hiPSC-NS/PCs) mainly differentiate into neurons, forming synapses in a process similar to neurodevelopment. In the developing nervous system, the activity of immature neurons has an important role in constructing and maintaining new synapses. Thus, we investigate how enhancing the activity of transplanted hiPSC-NS/PCs affects both the transplanted cells themselves and the host tissue. We find that chemogenetic stimulation of hiPSC-derived neural cells enhances cell activity and neuron-to-neuron interactions in vitro. In a rodent model of SCI, consecutive and selective chemogenetic stimulation of transplanted hiPSC-NS/PCs also enhances the expression of synapse-related genes and proteins in surrounding host tissues and prevents atrophy of the injured spinal cord, thereby improving locomotor function. These findings provide a strategy for enhancing activity within the graft to improve the efficacy of cell transplantation therapy for SCI.
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Affiliation(s)
- Momotaro Kawai
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Kent Imaizumi
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Mitsuru Ishikawa
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Shinsuke Shibata
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Division of Microscopic Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata City, Niigata 951-8510, Japan
| | - Munehisa Shinozaki
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Takahiro Shibata
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Shogo Hashimoto
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Takahiro Kitagawa
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Kentaro Ago
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Keita Kajikawa
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Reo Shibata
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Yasuhiro Kamata
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan; Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Junichi Ushiba
- Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku, Yokohama 223-8522, Japan
| | - Keisuke Koga
- Department of Neurophysiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan
| | - Hidemasa Furue
- Department of Neurophysiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan
| | - Morio Matsumoto
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Masaya Nakamura
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Narihito Nagoshi
- Department of Orthopaedic Surgery, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
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22
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Periods of synchronized myelin changes shape brain function and plasticity. Nat Neurosci 2021; 24:1508-1521. [PMID: 34711959 DOI: 10.1038/s41593-021-00917-2] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 07/30/2021] [Indexed: 12/11/2022]
Abstract
Myelin, a lipid membrane that wraps axons, enabling fast neurotransmission and metabolic support to axons, is conventionally thought of as a static structure that is set early in development. However, recent evidence indicates that in the central nervous system (CNS), myelination is a protracted and plastic process, ongoing throughout adulthood. Importantly, myelin is emerging as a potential modulator of neuronal networks, and evidence from human studies has highlighted myelin as a major player in shaping human behavior and learning. Here we review how myelin changes throughout life and with learning. We discuss potential mechanisms of myelination at different life stages, explore whether myelin plasticity provides the regenerative potential of the CNS white matter, and question whether changes in myelin may underlie neurological disorders.
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23
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Camargo WL, Kushmerick C, Pinto E, Souza N, Cavalcante W, Souza-Neto FP, Guatimosim S, Prado M, Guatimosim C, Naves LA. Homeostatic plasticity induced by increased acetylcholine release at the mouse neuromuscular junction. Neurobiol Aging 2021; 110:13-26. [PMID: 34844076 DOI: 10.1016/j.neurobiolaging.2021.10.010] [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: 07/07/2020] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 02/07/2023]
Abstract
At the neuromuscular junction (NMJ), changes to the size of the postsynaptic potential induce homeostatic compensation. At the Drosophila NMJ, increased glutamate release causes a compensatory decrease in quantal content, but it is unknown if this mechanism operates at the cholinergic mammalian NMJ. We addressed this question by recording endplate potentials (EPP) and muscle contraction in 3-month and 24-month ChAT-ChR2-EYFP mice that overexpress vesicular acetylcholine transporter and release more acetylcholine per vesicle. At 3 months, the quantal content of EPPs from ChAT-ChR2-EYFP mice were not different from WT controls, however tetanic depression was greater, and quantal size during high-frequency stimulation and the size of the readily releasable pool (RRP) were decreased. At 24 months of age, quantal content was reduced in ChAT-ChR2-EYFP mice, which normalized synaptic depression despite smaller RRP. The effect of pancuronium on indirect evoked muscle twitch was not different between groups. These results indicate that an increase in the amount of acetylcholine per vesicle induces two distinct age-dependent homeostatic mechanisms compensating excessive acetylcholine release.
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Affiliation(s)
| | | | | | | | | | | | | | - Mam Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell Biology, University of Western Ontario, London, ON, Canada
| | | | - L A Naves
- Departments of Physiology and biophysics
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24
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Secreted Reporter Assay Enables Quantitative and Longitudinal Monitoring of Neuronal Activity. eNeuro 2021; 8:ENEURO.0518-20.2021. [PMID: 34531280 PMCID: PMC8489021 DOI: 10.1523/eneuro.0518-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 08/23/2021] [Accepted: 09/08/2021] [Indexed: 11/21/2022] Open
Abstract
The ability to measure changes in neuronal activity in a quantifiable and precise manner is of fundamental importance to understand neuron development and function. Repeated monitoring of neuronal activity of the same population of neurons over several days is challenging and, typically, low-throughput. Here, we describe a new biochemical reporter assay that allows for repeated measurements of neuronal activity in a cell type-specific manner. We coupled activity-dependent elements from the Arc/Arg3.1 gene with a secreted reporter, Gaussia luciferase (Gluc), to quantify neuronal activity without sacrificing the neurons. The reporter predominantly senses calcium and NMDA receptor (NMDAR)-dependent activity. By repeatedly measuring the accumulation of the reporter in cell media, we can profile the developmental dynamics of neuronal activity in cultured neurons from male and female mice. The assay also allows for longitudinal analysis of pharmacological treatments, thus distinguishing acute from delayed responses. Moreover, conditional expression of the reporter allows for monitoring cell type-specific changes. This simple, quantitative, cost-effective, automatable, and cell type-specific activity reporter is a valuable tool to study the development of neuronal activity in normal and disease-model conditions, and to identify small molecules or protein factors that selectively modulate the activity of a specific population of neurons.
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25
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Winlow W, Johnson AS. Nerve Impulses Have Three Interdependent Functions: Communication, Modulation, and Computation. Bioelectricity 2021. [DOI: 10.1089/bioe.2021.0001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- William Winlow
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, Napoli, Italia
- Institute of Ageing and Chronic Diseases, University of Liverpool, Liverpool, United Kingdom
| | - Andrew S. Johnson
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, Napoli, Italia
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26
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Kasai H, Ziv NE, Okazaki H, Yagishita S, Toyoizumi T. Spine dynamics in the brain, mental disorders and artificial neural networks. Nat Rev Neurosci 2021; 22:407-422. [PMID: 34050339 DOI: 10.1038/s41583-021-00467-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/14/2021] [Indexed: 12/15/2022]
Abstract
In the brain, most synapses are formed on minute protrusions known as dendritic spines. Unlike their artificial intelligence counterparts, spines are not merely tuneable memory elements: they also embody algorithms that implement the brain's ability to learn from experience and cope with new challenges. Importantly, they exhibit structural dynamics that depend on activity, excitatory input and inhibitory input (synaptic plasticity or 'extrinsic' dynamics) and dynamics independent of activity ('intrinsic' dynamics), both of which are subject to neuromodulatory influences and reinforcers such as dopamine. Here we succinctly review extrinsic and intrinsic dynamics, compare these with parallels in machine learning where they exist, describe the importance of intrinsic dynamics for memory management and adaptation, and speculate on how disruption of extrinsic and intrinsic dynamics may give rise to mental disorders. Throughout, we also highlight algorithmic features of spine dynamics that may be relevant to future artificial intelligence developments.
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Affiliation(s)
- Haruo Kasai
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan. .,International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
| | - Noam E Ziv
- Technion Faculty of Medicine and Network Biology Research Labs, Technion City, Haifa, Israel
| | - Hitoshi Okazaki
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Sho Yagishita
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.,International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Taro Toyoizumi
- Laboratory for Neural Computation and Adaptation, RIKEN Center for Brain Science, Saitama, Japan.,Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo, Tokyo, Japan
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27
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Johnson AS, Winlow W. Does the Brain Function as a Quantum Phase Computer Using Phase Ternary Computation? Front Physiol 2021; 12:572041. [PMID: 33959034 PMCID: PMC8093521 DOI: 10.3389/fphys.2021.572041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 03/16/2021] [Indexed: 11/13/2022] Open
Abstract
Here we provide evidence that the fundamental basis of nervous communication is derived from a pressure pulse/soliton capable of computation with sufficient temporal precision to overcome any processing errors. Signalling and computing within the nervous system are complex and different phenomena. Action potentials are plastic and this makes the action potential peak an inappropriate fixed point for neural computation, but the action potential threshold is suitable for this purpose. Furthermore, neural models timed by spiking neurons operate below the rate necessary to overcome processing error. Using retinal processing as our example, we demonstrate that the contemporary theory of nerve conduction based on cable theory is inappropriate to account for the short computational time necessary for the full functioning of the retina and by implication the rest of the brain. Moreover, cable theory cannot be instrumental in the propagation of the action potential because at the activation-threshold there is insufficient charge at the activation site for successive ion channels to be electrostatically opened. Deconstruction of the brain neural network suggests that it is a member of a group of Quantum phase computers of which the Turing machine is the simplest: the brain is another based upon phase ternary computation. However, attempts to use Turing based mechanisms cannot resolve the coding of the retina or the computation of intelligence, as the technology of Turing based computers is fundamentally different. We demonstrate that that coding in the brain neural network is quantum based, where the quanta have a temporal variable and a phase-base variable enabling phase ternary computation as previously demonstrated in the retina.
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Affiliation(s)
- Andrew S. Johnson
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, Napoli, Italy
| | - William Winlow
- Dipartimento di Biologia, Università degli Studi di Napoli, Federico II, Napoli, Italy
- Institute of Ageing and Chronic Diseases, University of Liverpool, Liverpool, United Kingdom
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28
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Kuhlmann N, Wagner Valladolid M, Quesada-Ramírez L, Farrer MJ, Milnerwood AJ. Chronic and Acute Manipulation of Cortical Glutamate Transmission Induces Structural and Synaptic Changes in Co-cultured Striatal Neurons. Front Cell Neurosci 2021; 15:569031. [PMID: 33679324 PMCID: PMC7930618 DOI: 10.3389/fncel.2021.569031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
In contrast to the prenatal topographic development of sensory cortices, striatal circuit organization is slow and requires the functional maturation of cortical and thalamic excitatory inputs throughout the first postnatal month. While mechanisms regulating synapse development and plasticity are quite well described at excitatory synapses of glutamatergic neurons in the neocortex, comparatively little is known of how this translates to glutamate synapses onto GABAergic neurons in the striatum. Here we investigate excitatory striatal synapse plasticity in an in vitro system, where glutamate can be studied in isolation from dopamine and other neuromodulators. We examined pre-and post-synaptic structural and functional plasticity in GABAergic striatal spiny projection neurons (SPNs), co-cultured with glutamatergic cortical neurons. After synapse formation, medium-term (24 h) TTX silencing increased the density of filopodia, and modestly decreased dendritic spine density, when assayed at 21 days in vitro (DIV). Spine reductions appeared to require residual spontaneous activation of ionotropic glutamate receptors. Conversely, chronic (14 days) TTX silencing markedly reduced spine density without any observed increase in filopodia density. Time-dependent, biphasic changes to the presynaptic marker Synapsin-1 were also observed, independent of residual spontaneous activity. Acute silencing (3 h) did not affect presynaptic markers or postsynaptic structures. To induce rapid, activity-dependent plasticity in striatal neurons, a chemical NMDA receptor-dependent “long-term potentiation (LTP)” paradigm was employed. Within 30 min, this increased spine and GluA1 cluster densities, and the percentage of spines containing GluA1 clusters, without altering the presynaptic signal. The results demonstrate that the growth and pruning of dendritic protrusions is an active process, requiring glutamate receptor activity in striatal projection neurons. Furthermore, NMDA receptor activation is sufficient to drive glutamatergic structural plasticity in SPNs, in the absence of dopamine or other neuromodulators.
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Affiliation(s)
- Naila Kuhlmann
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada.,Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | | | - Lucía Quesada-Ramírez
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada
| | - Matthew J Farrer
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada.,McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Austen J Milnerwood
- Centre for Applied Neurogenetics (CAN), University of British Columbia, Vancouver, BC, Canada.,Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
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29
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Selective postnatal excitation of neocortical pyramidal neurons results in distinctive behavioral and circuit deficits in adulthood. iScience 2021; 24:102157. [PMID: 33665575 PMCID: PMC7907816 DOI: 10.1016/j.isci.2021.102157] [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: 03/03/2020] [Revised: 10/03/2020] [Accepted: 02/03/2021] [Indexed: 01/08/2023] Open
Abstract
In genetic and pharmacological models of neurodevelopmental disorders, and human data, neural activity is altered within the developing neocortical network. This commonality begs the question of whether early enhancement in excitation might be a common driver, across etiologies, of characteristic behaviors. We tested this concept by chemogenetically driving cortical pyramidal neurons during postnatal days 4–14. Hyperexcitation of Emx1-, but not dopamine transporter-, parvalbumin-, or Dlx5/6-expressing neurons, led to decreased social interaction and increased grooming activity in adult animals. In vivo optogenetic interrogation in adults revealed decreased baseline but increased stimulus-evoked firing rates of pyramidal neurons and impaired recruitment of inhibitory neurons. Slice recordings in adults from prefrontal cortex layer 5 pyramidal neurons revealed decreased intrinsic excitability and increased synaptic E/I ratio. Together these results support the prediction that enhanced pyramidal firing during development, in otherwise normal cortex, can selectively drive altered adult circuit function and maladaptive changes in behavior. BL-OG allows chemogenetic activation and optogenetic interrogation in the same animal Developmental hyperexcitation in normal mice leads to neurodevelopmental disorders In these mice adult neurons show reduced baseline activity and increased excitability Reduced activity-triggered coherence and altered oscillations in cortex and striatum
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30
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A computational framework for optimal control of a self-adjustive neural system with activity-dependent and homeostatic plasticity. Neuroimage 2021; 230:117805. [PMID: 33524581 DOI: 10.1016/j.neuroimage.2021.117805] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Revised: 01/20/2021] [Accepted: 01/24/2021] [Indexed: 12/13/2022] Open
Abstract
The control of the brain system has received increasing attention in the domain of brain science. Most brain control studies have been conducted to explore the brain network's graph-theoretic properties or to produce the desired state based on neural state dynamics, regarding the brain as a passively responding system. However, the self-adjusting nature of neural system after treatment has not been fully considered in the brain control. In the present study, we propose a computational framework for optimal control of the brain with a self-adjustment process in the effective connectivity after treatment. The neural system is modeled to adjust its outgoing effective connectivity as activity-dependent plasticity after treatment, followed by synaptic rescaling of incoming effective connectivity. To control this neural system to induce the desired function, the system's self-adjustment parameter is first estimated, based on which the treatment is optimized. Utilizing this framework, we conducted simulations of optimal control over a functional hippocampal circuitry, estimated using dynamic causal modeling of voltage-sensitive dye imaging from the wild type and mutant mice, responding to consecutive electrical stimuli. Simulation results for optimal control of the abnormal circuit toward a healthy circuit using a single node treatment, neural-type specific treatment as an analogy of medication, and combined treatments of medication and nodal treatment suggest the plausibility of the current framework in controlling the self-adjusting neural system within a restricted treatment setting. We believe the proposed computational framework of the self-adjustment system would help optimal control of the dynamic brain after treatment.
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31
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Espírito-Santo SA, Nunes-Tavares N, Mendonça HR, Serfaty CA, Sholl-Franco A, Campello-Costa P. Intravitreal Interleukin-2 modifies retinal excitatory circuits and retinocollicular innervation. Exp Eye Res 2021; 204:108442. [PMID: 33460624 DOI: 10.1016/j.exer.2021.108442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 12/14/2020] [Accepted: 01/08/2021] [Indexed: 10/22/2022]
Abstract
Interleukin-2 is a classical immune cytokine whose neural functions have received little attention. Its levels have been found to be increased in some neuropathologies, such as Alzheimer's disease, multiple sclerosis and uveitis. Mechanistically, it has been demonstrated the role of IL-2 in regulating glutamate and acetylcholine transmission, thus being relevant for CNS physiology. In fact, our previous work showed that an acute intravitreal IL-2 injection during retinotectal development promoted contralateral eye axonal plasticity in the superior colliculus, but the involved mechanisms were not explored. So, our present study aimed to investigate the effect of increased intravitreal IL-2 levels on the retinal glutamatergic and cholinergic signalling required for retinotectal normal development. We showed through HRP neuronal tracing that intravitreal IL-2 also induces ipsilateral eye axonal sprouting. Protein level and/or immunolocalization analysis in the retina confirmed IL-2 pathway activation by increased expression of phospho-STAT-3, coupled to transient (24h) reduced levels of Egr1, PSD-95 and nicotinic acetylcholine receptor β2 subunit, suggesting reduced neural activity and synaptic sites. Also, AChE activity and GluN2B and GluA2 contents were reduced within 96h after IL-2 treatment. Therefore, IL-2-induced retinotectal plasticity might be driven by changes in cholinergic and glutamatergic pathways of the retina.
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Affiliation(s)
- S A Espírito-Santo
- Instituto de Biologia, Programa de Pós-Graduação Em Neurociências, Universidade Federal Fluminense, Niterói, Brazil; Instituto de Biofísica, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil; Universidade Do Estado de Minas Gerais, Departamento de Ciências Biológicas, Minas Gerais, Brazil
| | - N Nunes-Tavares
- Instituto de Biofísica, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - H R Mendonça
- Instituto de Biologia, Programa de Pós-Graduação Em Neurociências, Universidade Federal Fluminense, Niterói, Brazil; Laboratório Integrado de Morfologia, Instituto de Biodiversidade e Sustentabilidade NUPEM, Universidade Federal Do Rio de Janeiro, Campus Macaé, Brazil
| | - C A Serfaty
- Instituto de Biologia, Programa de Pós-Graduação Em Neurociências, Universidade Federal Fluminense, Niterói, Brazil
| | - A Sholl-Franco
- Instituto de Biofísica, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - P Campello-Costa
- Instituto de Biologia, Programa de Pós-Graduação Em Neurociências, Universidade Federal Fluminense, Niterói, Brazil.
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32
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Wu D, Jin Y, Shapiro TM, Hinduja A, Baas PW, Tom VJ. Chronic neuronal activation increases dynamic microtubules to enhance functional axon regeneration after dorsal root crush injury. Nat Commun 2020; 11:6131. [PMID: 33257677 PMCID: PMC7705672 DOI: 10.1038/s41467-020-19914-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 11/05/2020] [Indexed: 12/26/2022] Open
Abstract
After a dorsal root crush injury, centrally-projecting sensory axons fail to regenerate across the dorsal root entry zone (DREZ) to extend into the spinal cord. We find that chemogenetic activation of adult dorsal root ganglion (DRG) neurons improves axon growth on an in vitro model of the inhibitory environment after injury. Moreover, repeated bouts of daily chemogenetic activation of adult DRG neurons for 12 weeks post-crush in vivo enhances axon regeneration across a chondroitinase-digested DREZ into spinal gray matter, where the regenerating axons form functional synapses and mediate behavioral recovery in a sensorimotor task. Neuronal activation-mediated axon extension is dependent upon changes in the status of tubulin post-translational modifications indicative of highly dynamic microtubules (as opposed to stable microtubules) within the distal axon, illuminating a novel mechanism underlying stimulation-mediated axon growth. We have identified an effective combinatory strategy to promote functionally-relevant axon regeneration of adult neurons into the CNS after injury.
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Affiliation(s)
- Di Wu
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Ying Jin
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Tatiana M Shapiro
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Abhishek Hinduja
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Peter W Baas
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Veronica J Tom
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, USA.
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33
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Singh L, Kaur A, Garg S, Singh AP, Bhatti R. Protective Effect of Esculetin, Natural Coumarin in Mice Model of Fibromyalgia: Targeting Pro-Inflammatory Cytokines and MAO-A. Neurochem Res 2020; 45:2364-2374. [DOI: 10.1007/s11064-020-03095-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/04/2020] [Accepted: 07/09/2020] [Indexed: 10/23/2022]
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Chemogenetic Suppression of GnRH Neurons during Pubertal Development Can Alter Adult GnRH Neuron Firing Rate and Reproductive Parameters in Female Mice. eNeuro 2020; 7:ENEURO.0223-20.2020. [PMID: 32513661 PMCID: PMC7363480 DOI: 10.1523/eneuro.0223-20.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 12/02/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) neurons control anterior pituitary, and thereby gonadal, function. GnRH neurons are active before outward indicators of puberty appear. Prenatal androgen (PNA) exposure mimics reproductive dysfunction of the common fertility disorder polycystic ovary syndrome (PCOS) and reduces prepubertal GnRH neuron activity. Early neuron activity can play a critical role in establishing circuitry and adult function. We tested the hypothesis that changing prepubertal GnRH neuron activity programs adult GnRH neuron activity and reproduction independent of androgen exposure in female mice. Activating (3Dq) or inhibitory (4Di) designer receptors exclusively activated by designer drugs (DREADDs) were targeted to GnRH neurons using Cre-lox technology. In control studies, the DREADD ligand clozapine n-oxide (CNO) produced the expected changes in GnRH neuron activity in vitro and luteinizing hormone (LH) release in vivo. CNO was administered to control or PNA mice between two and three weeks of age, when GnRH neuron firing rate is reduced in PNA mice. In controls, reducing prepubertal GnRH neuron activity with 4Di increased adult GnRH neuron firing rate and days in diestrus but did not change puberty onset or GABA transmission to these cells. In contrast, activating GnRH neurons had no effect on reproductive parameters or firing rate and did not rescue reproductive phenotypes in PNA mice. These studies support the hypothesis that prepubertal neuronal activity sculpts elements of the adult reproductive neuroendocrine axis and cyclicity but indicate that other PNA-induced programming actions are required for full reproductive phenotypes and/or that compensatory mechanisms overcome activity-mediated changes to mitigate reproductive changes in adults.
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35
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Refinement of Cerebellar Network Organization by Extracellular Signaling During Development. Neuroscience 2020; 462:44-55. [PMID: 32502568 DOI: 10.1016/j.neuroscience.2020.05.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/21/2022]
Abstract
The cerebellum forms regular neural network structures consisting of a few major types of neurons, such as Purkinje cells, granule cells, and molecular layer interneurons, and receives two major inputs from climbing fibers and mossy fibers. Its regular structures consist of three well-defined layers, with each type of neuron designated to a specific location and forming specific synaptic connections. During the first few weeks of postnatal development in rodents, the cerebellum goes through dynamic changes via proliferation, migration, differentiation, synaptogenesis, and maturation, to create such a network structure. The development of this organized network structure presumably relies on the communication between developing elements in the network, including not only individual neurons, but also their dendrites, axons, and synapses. Therefore, it is reasonable that extracellular signaling via synaptic transmission, secreted molecules, and cell adhesion molecules, plays important roles in cerebellar network development. Although it is not yet clear as to how overall cerebellar development is orchestrated, there is indeed accumulating lines of evidence that extracellular signaling acts toward the development of individual elements in the cerebellar networks. In this article, we introduce what we have learned from many studies regarding the extracellular signaling required for cerebellar network development, including our recent study suggesting the importance of unbiased synaptic inputs from parallel fibers.
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36
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Burger CA, Alevy J, Casasent AK, Jiang D, Albrecht NE, Liang JH, Hirano AA, Brecha NC, Samuel MA. LKB1 coordinates neurite remodeling to drive synapse layer emergence in the outer retina. eLife 2020; 9:e56931. [PMID: 32378514 PMCID: PMC7237215 DOI: 10.7554/elife.56931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/11/2020] [Indexed: 12/04/2022] Open
Abstract
Structural changes in pre and postsynaptic neurons that accompany synapse formation often temporally and spatially overlap. Thus, it has been difficult to resolve which processes drive patterned connectivity. To overcome this, we use the laminated outer murine retina. We identify the serine/threonine kinase LKB1 as a key driver of synapse layer emergence. The absence of LKB1 in the retina caused a marked mislocalization and delay in synapse layer formation. In parallel, LKB1 modulated postsynaptic horizontal cell refinement and presynaptic photoreceptor axon growth. Mislocalized horizontal cell processes contacted aberrant cone axons in LKB1 mutants. These defects coincided with altered synapse protein organization, and horizontal cell neurites were misdirected to ectopic synapse protein regions. Together, these data suggest that LKB1 instructs the timing and location of connectivity in the outer retina via coordinate regulation of pre and postsynaptic neuron structure and the localization of synapse-associated proteins.
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Affiliation(s)
- Courtney A Burger
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Jonathan Alevy
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Anna K Casasent
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Danye Jiang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Nicholas E Albrecht
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Justine H Liang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Arlene A Hirano
- Department of Neurobiology, David Geffen School of Medicine at UCLALos AngelesUnited States
- United States Veterans Administration Greater Los Angeles Healthcare SystemLos AngelesUnited States
| | - Nicholas C Brecha
- Department of Neurobiology, David Geffen School of Medicine at UCLALos AngelesUnited States
- United States Veterans Administration Greater Los Angeles Healthcare SystemLos AngelesUnited States
| | - Melanie A Samuel
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
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37
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Pan-Vazquez A, Wefelmeyer W, Gonzalez Sabater V, Neves G, Burrone J. Activity-Dependent Plasticity of Axo-axonic Synapses at the Axon Initial Segment. Neuron 2020; 106:265-276.e6. [PMID: 32109363 PMCID: PMC7181187 DOI: 10.1016/j.neuron.2020.01.037] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 12/06/2019] [Accepted: 01/27/2020] [Indexed: 12/20/2022]
Abstract
The activity-dependent rules that govern the wiring of GABAergic interneurons are not well understood. Chandelier cells (ChCs) are a type of GABAergic interneuron that control pyramidal cell output through axo-axonic synapses that target the axon initial segment. In vivo imaging of ChCs during development uncovered a narrow window (P12-P18) over which axons arborized and formed connections. We found that increases in the activity of either pyramidal cells or individual ChCs during this temporal window result in a reversible decrease in axo-axonic connections. Voltage imaging of GABAergic transmission at the axon initial segment (AIS) showed that axo-axonic synapses were depolarizing during this period. Identical manipulations of network activity in older mice (P40-P46), when ChC synapses are inhibitory, resulted instead in an increase in axo-axonic synapses. We propose that the direction of ChC synaptic plasticity follows homeostatic rules that depend on the polarity of axo-axonic synapses.
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Affiliation(s)
- Alejandro Pan-Vazquez
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Winnie Wefelmeyer
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Victoria Gonzalez Sabater
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK
| | - Guilherme Neves
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; The Rosalind Franklin Institute, Harwell Campus, Didcot OX11 0FA, UK
| | - Juan Burrone
- MRC Centre for Neurodevelopmental Disorders, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK; Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, UK.
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Activity Dependent and Independent Determinants of Synaptic Size Diversity. J Neurosci 2020; 40:2828-2848. [PMID: 32127494 DOI: 10.1523/jneurosci.2181-19.2020] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 02/04/2020] [Accepted: 02/13/2020] [Indexed: 11/21/2022] Open
Abstract
The extraordinary diversity of excitatory synapse sizes is commonly attributed to activity-dependent processes that drive synaptic growth and diminution. Recent studies also point to activity-independent size fluctuations, possibly driven by innate synaptic molecule dynamics, as important generators of size diversity. To examine the contributions of activity-dependent and independent processes to excitatory synapse size diversity, we studied glutamatergic synapse size dynamics and diversification in cultured rat cortical neurons (both sexes), silenced from plating. We found that in networks with no history of activity whatsoever, synaptic size diversity was no less extensive than that observed in spontaneously active networks. Synapses in silenced networks were larger, size distributions were broader, yet these were rightward-skewed and similar in shape when scaled by mean synaptic size. Silencing reduced the magnitude of size fluctuations and weakened constraints on size distributions, yet these were sufficient to explain synaptic size diversity in silenced networks. Model-based exploration followed by experimental testing indicated that silencing-associated changes in innate molecular dynamics and fluctuation characteristics might negatively impact synaptic persistence, resulting in reduced synaptic numbers. This, in turn, would increase synaptic molecule availability, promote synaptic enlargement, and ultimately alter fluctuation characteristics. These findings suggest that activity-independent size fluctuations are sufficient to fully diversify glutamatergic synaptic sizes, with activity-dependent processes primarily setting the scale rather than the shape of size distributions. Moreover, they point to reciprocal relationships between synaptic size fluctuations, size distributions, and synaptic numbers mediated by the innate dynamics of synaptic molecules as they move in, out, and between synapses.SIGNIFICANCE STATEMENT Sizes of glutamatergic synapses vary tremendously, even when formed on the same neuron. This diversity is commonly thought to reflect the outcome of activity-dependent forms of synaptic plasticity, yet activity-independent processes might also play some part. Here we show that in neurons with no history of activity whatsoever, synaptic sizes are no less diverse. We show that this diversity is the product of activity-independent size fluctuations, which are sufficient to generate a full repertoire of synaptic sizes at correct proportions. By combining modeling and experimentation we expose reciprocal relationships between size fluctuations, synaptic sizes and synaptic counts, and show how these phenomena might be connected through the dynamics of synaptic molecules as they move in, out, and between synapses.
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Keihani S, Kluever V, Mandad S, Bansal V, Rahman R, Fritsch E, Gomes LC, Gärtner A, Kügler S, Urlaub H, Wren JD, Bonn S, Rizzoli SO, Fornasiero EF. The long noncoding RNA neuroLNC regulates presynaptic activity by interacting with the neurodegeneration-associated protein TDP-43. SCIENCE ADVANCES 2019; 5:eaay2670. [PMID: 31897430 PMCID: PMC6920028 DOI: 10.1126/sciadv.aay2670] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 10/23/2019] [Indexed: 05/26/2023]
Abstract
The cellular and the molecular mechanisms by which long noncoding RNAs (lncRNAs) may regulate presynaptic function and neuronal activity are largely unexplored. Here, we established an integrated screening strategy to discover lncRNAs implicated in neurotransmitter and synaptic vesicle release. With this approach, we identified neuroLNC, a neuron-specific nuclear lncRNA conserved from rodents to humans. NeuroLNC is tuned by synaptic activity and influences several other essential aspects of neuronal development including calcium influx, neuritogenesis, and neuronal migration in vivo. We defined the molecular interactors of neuroLNC in detail using chromatin isolation by RNA purification, RNA interactome analysis, and protein mass spectrometry. We found that the effects of neuroLNC on synaptic vesicle release require interaction with the RNA-binding protein TDP-43 (TAR DNA binding protein-43) and the selective stabilization of mRNAs encoding for presynaptic proteins. These results provide the first proof of an lncRNA that orchestrates neuronal excitability by influencing presynaptic function.
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Affiliation(s)
- S. Keihani
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073 Göttingen, Germany
| | - V. Kluever
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073 Göttingen, Germany
| | - S. Mandad
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073 Göttingen, Germany
- Department of Clinical Chemistry, University Medical Center Göttingen, 37077 Göttingen, Germany
| | - V. Bansal
- Institute of Medical Systems Biology, Center for Molecular Neurobiology (ZMNH), UKE, 20246 Hamburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - R. Rahman
- Institute of Medical Systems Biology, Center for Molecular Neurobiology (ZMNH), UKE, 20246 Hamburg, Germany
| | - E. Fritsch
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073 Göttingen, Germany
| | - L. Caldi Gomes
- Department of Neurology, University Medical Center Göttingen, 37073 Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), 37075 Göttingen, Germany
| | - A. Gärtner
- VIB Center for the Biology of Disease and Center for Human Genetics, KU Leuven, Leuven, Belgium
| | - S. Kügler
- Department of Neurology, University Medical Center Göttingen, 37073 Göttingen, Germany
| | - H. Urlaub
- Department of Clinical Chemistry, University Medical Center Göttingen, 37077 Göttingen, Germany
- Bioanalytical Mass Spectrometry Group, Max Planck Institute of Biophysical Chemistry, 37077 Göttingen, Germany
| | - J. D. Wren
- Department of Genes and Human Disease, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - S. Bonn
- Institute of Medical Systems Biology, Center for Molecular Neurobiology (ZMNH), UKE, 20246 Hamburg, Germany
- German Center for Neurodegenerative Diseases (DZNE), 72076 Tübingen, Germany
| | - S. O. Rizzoli
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073 Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), 37075 Göttingen, Germany
| | - E. F. Fornasiero
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073 Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), 37075 Göttingen, Germany
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Batty NJ, Torres-Espín A, Vavrek R, Raposo P, Fouad K. Single-session cortical electrical stimulation enhances the efficacy of rehabilitative motor training after spinal cord injury in rats. Exp Neurol 2019; 324:113136. [PMID: 31786212 DOI: 10.1016/j.expneurol.2019.113136] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 10/28/2019] [Accepted: 11/27/2019] [Indexed: 12/13/2022]
Abstract
Low neuronal cAMP levels in adults and a further decline following traumatic central nervous system (CNS) injury has been associated with the limited ability of neurons to regenerate. An approach to increase neuronal cAMP levels post injury is electrical stimulation. Stimulation as a tool to promote neuronal growth has largely been studied in the peripheral nervous system or in spared fibers of the CNS and this research suggests that a single session of electrical stimulation is sufficient to initiate a long-lasting axonal growth program. Here, we sought to promote plasticity and growth of the injured corticospinal tract with electrical cortical stimulation immediately after its spinal injury. Moreover, given the importance of rehabilitative motor training in the clinical setting and in translating plasticity into functional recovery, we applied training as a standard treatment to all rats (i.e., with or without electrical stimulation). Our findings show that electrical cortical stimulation did improve recovery in forelimb function compared to the recovery in unstimulated animals. This recovery is likely linked to increased corticospinal tract plasticity as evidenced by a significant increase in sprouting of collaterals above the lesion site, but not to increased regenerative growth through the lesion itself.
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Affiliation(s)
- Nicholas J Batty
- Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Abel Torres-Espín
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Romana Vavrek
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Pamela Raposo
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Karim Fouad
- Neuroscience and Mental Health Institute, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
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Park H, Kim T, Kim J, Yamamoto Y, Tanaka-Yamamoto K. Inputs from Sequentially Developed Parallel Fibers Are Required for Cerebellar Organization. Cell Rep 2019; 28:2939-2954.e5. [DOI: 10.1016/j.celrep.2019.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/10/2019] [Accepted: 07/30/2019] [Indexed: 11/15/2022] Open
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Machado CB, Pluchon P, Harley P, Rigby M, Gonzalez Sabater V, Stevenson DC, Hynes S, Lowe A, Burrone J, Viasnoff V, Lieberam I. In Vitro Modelling of Nerve-Muscle Connectivity in a Compartmentalised Tissue Culture Device. ADVANCED BIOSYSTEMS 2019; 3:1800307. [PMID: 31428672 PMCID: PMC6699992 DOI: 10.1002/adbi.201800307] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Indexed: 01/02/2023]
Abstract
Motor neurons project axons from the hindbrain and spinal cord to muscle, where they induce myofibre contractions through neurotransmitter release at neuromuscular junctions. Studies of neuromuscular junction formation and homeostasis have been largely confined to in vivo models. In this study we have merged three powerful tools - pluripotent stem cells, optogenetics and microfabrication - and designed an open microdevice in which motor axons grow from a neural compartment containing embryonic stem cell-derived motor neurons and astrocytes through microchannels to form functional neuromuscular junctions with contractile myofibers in a separate compartment. Optogenetic entrainment of motor neurons in this reductionist neuromuscular circuit enhanced neuromuscular junction formation more than two-fold, mirroring the activity-dependence of synapse development in vivo. We incorporated an established motor neuron disease model into our system and found that coculture of motor neurons with SOD1G93A astrocytes resulted in denervation of the central compartment and diminished myofiber contractions, a phenotype which was rescued by the Receptor Interacting Serine/Threonine Kinase 1 (RIPK1) inhibitor Necrostatin. This coculture system replicates key aspects of nerve-muscle connectivity in vivo and represents a rapid and scalable alternative to animal models of neuromuscular function and disease.
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Affiliation(s)
- Carolina Barcellos Machado
- Centre for Stem Cells and Regenerative Medicine, King’s
College London, London SE1 9RT, UK; Centre for Developmental
Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s
College London, London SE1 1UL, UK
| | - Perrine Pluchon
- Centre for Stem Cells and Regenerative Medicine, King’s
College London, London SE1 9RT, UK; Centre for Developmental
Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s
College London, London SE1 1UL, UK; Mechanobiology Institute, National
University of Singapore, Singapore 117411
| | - Peter Harley
- Centre for Stem Cells and Regenerative Medicine, King’s College London, London SE1 9RT, UK; Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | | | - Victoria Gonzalez Sabater
- Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | | | - Stephanie Hynes
- Centre for Stem Cells and Regenerative Medicine, King’s College London, London SE1 9RT, UK; Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | - Andrew Lowe
- Centre for Developmental Neurobiology, King’s College London, London SE1 1UL, UK
| | - Juan Burrone
- Centre for Developmental Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s College London, London SE1 1UL, UK
| | - Virgile Viasnoff
- Mechanobiology Institute, National University of Singapore,
Singapore 117411
| | - Ivo Lieberam
- Centre for Stem Cells and Regenerative Medicine, King’s
College London, London SE1 9RT, UK; Centre for Developmental
Neurobiology/MRC Centre for Neurodevelopmental Disorders, King’s
College London, London SE1 1UL, UK
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Song ZJ, Yang SJ, Han L, Wang B, Zhu G. Postnatal calpeptin treatment causes hippocampal neurodevelopmental defects in neonatal rats. Neural Regen Res 2019; 14:834-840. [PMID: 30688269 PMCID: PMC6375038 DOI: 10.4103/1673-5374.249231] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Our previous studies showed that the early use of calpain inhibitors reduces calpain activity in multiple brain regions, and that postnatal treatment with calpeptin may lead to cerebellar motor dysfunction. However, it remains unclear whether postnatal calpeptin application affects hippocampus-related behaviors. In this study, Sprague-Dawley rats were purchased from the Animal Center of Anhui Medical University of China. For the experiments in the adult stage, rats were intraperitoneally injected with calpeptin, 2 mg/kg, once a day, on postnatal days 7-14. Then on postnatal day 60, the Morris water maze test was used to evaluate spatial learning and memory abilities. The open field test was carried out to assess anxiety-like activities. Phalloidin staining was performed to observe synaptic morphology in the hippocampus. Immunohistochemistry was used to count the number of NeuN-positive cells in the hippocampal CA1 region. DiI was applied to label dendritic spines. Calpeptin administration impaired spatial memory, caused anxiety-like behavior in adulthood, reduced the number and area of apical dendritic spines, and decreased actin polymerization in the hippocampus, but did not affect the number of NeuN-positive cells in the hippocampal CA1 region. For the neonatal experiments, neonatal rats were intraperitoneally injected with calpeptin, 2 mg/kg, on postnatal days 7 and 8. Western blot assay was performed to analyze the protein levels of Akt, Erk, p-Akt, p-Erk1/2, Erk1/2, SCOP, PTEN, mTOR, p-mTOR, CREB and p-CREB in the hippocampus. SCOP expression was increased, and the phosphorylation levels of Akt, mTOR and CREB were reduced in the hippocampus. These findings show that calpeptin administration after birth affects synaptic development in neonatal rats by inhibiting the Akt/mTOR signaling pathway, thereby perturbing hippocampal function. Therefore, calpeptin administration after birth is a risk factor for neurodevelopmental defects.
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Affiliation(s)
- Zhu-Jin Song
- Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - San-Juan Yang
- Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Lan Han
- School of Pharmacy, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Bin Wang
- Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
| | - Guoqi Zhu
- Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei, Anhui Province, China
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Rhythmogenesis evolves as a consequence of long-term plasticity of inhibitory synapses. Sci Rep 2018; 8:13050. [PMID: 30158555 PMCID: PMC6115462 DOI: 10.1038/s41598-018-31412-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/07/2018] [Indexed: 11/08/2022] Open
Abstract
Brain rhythms are widely believed to reflect numerous cognitive processes. Changes in rhythmicity have been associated with pathological states. However, the mechanism underlying these rhythms remains unknown. Here, we present a theoretical analysis of the evolvement of rhythm generating capabilities in neuronal circuits. We tested the hypothesis that brain rhythms can be acquired via an intrinsic unsupervised learning process of activity dependent plasticity. Specifically, we focused on spike timing dependent plasticity (STDP) of inhibitory synapses. We detail how rhythmicity can develop via STDP under certain conditions that serve as a natural prediction of the hypothesis. We show how global features of the STDP rule govern and stabilize the resultant rhythmic activity. Finally, we demonstrate how rhythmicity is retained even in the face of synaptic variability. This study suggests a role for inhibitory plasticity that is beyond homeostatic processes.
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45
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Böhme MA, Grasskamp AT, Walter AM. Regulation of synaptic release-site Ca 2+ channel coupling as a mechanism to control release probability and short-term plasticity. FEBS Lett 2018; 592:3516-3531. [PMID: 29993122 DOI: 10.1002/1873-3468.13188] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/26/2018] [Accepted: 07/06/2018] [Indexed: 12/31/2022]
Abstract
Synaptic transmission relies on the rapid fusion of neurotransmitter-containing synaptic vesicles (SVs), which happens in response to action potential (AP)-induced Ca2+ influx at active zones (AZs). A highly conserved molecular machinery cooperates at SV-release sites to mediate SV plasma membrane attachment and maturation, Ca2+ sensing, and membrane fusion. Despite this high degree of conservation, synapses - even within the same organism, organ or neuron - are highly diverse regarding the probability of APs to trigger SV fusion. Additionally, repetitive activation can lead to either strengthening or weakening of transmission. In this review, we discuss mechanisms controlling release probability and this short-term plasticity. We argue that an important layer of control is exerted by evolutionarily conserved AZ scaffolding proteins, which determine the coupling distance between SV fusion sites and voltage-gated Ca2+ channels (VGCC) and, thereby, shape synapse-specific input/output behaviors. We propose that AZ-scaffold modifications may occur to adapt the coupling distance during synapse maturation and plastic regulation of synapse strength.
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Affiliation(s)
- Mathias A Böhme
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
| | | | - Alexander M Walter
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany
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46
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Soteros BM, Cong Q, Palmer CR, Sia GM. Sociability and synapse subtype-specific defects in mice lacking SRPX2, a language-associated gene. PLoS One 2018; 13:e0199399. [PMID: 29920554 PMCID: PMC6007900 DOI: 10.1371/journal.pone.0199399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/06/2018] [Indexed: 01/05/2023] Open
Abstract
The FoxP2 transcription factor and its target genes have been implicated in developmental brain diseases with a prominent language component, such as developmental verbal dyspraxia and specific language impairment. How FoxP2 affects neural circuitry development remains poorly understood. The sushi domain protein SRPX2 is a target of FoxP2, and mutations in SRPX2 are associated with language defects in humans. We have previously shown that SRPX2 is a synaptogenic protein that increases excitatory synapse density. Here we provide the first characterization of mice lacking the SRPX2 gene, and show that these mice exhibit defects in both neural circuitry and communication and social behaviors. Specifically, we show that mice lacking SRPX2 show a specific reduction in excitatory VGlut2 synapses in the cerebral cortex, while VGlut1 and inhibitory synapses were largely unaffected. SRPX2 KO mice also exhibit an abnormal ultrasonic vocalization ontogenetic profile in neonatal pups, and reduced preference for social novelty. These data demonstrate a functional role for SRPX2 during brain development, and further implicate FoxP2 and its targets in regulating the development of vocalization and social circuits.
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Affiliation(s)
- Breeanne M. Soteros
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Qifei Cong
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
| | - Christian R. Palmer
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, United States of America
| | - Gek-Ming Sia
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States of America
- * E-mail:
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47
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Tao CL, Liu YT, Zhou ZH, Lau PM, Bi GQ. Accumulation of Dense Core Vesicles in Hippocampal Synapses Following Chronic Inactivity. Front Neuroanat 2018; 12:48. [PMID: 29942253 PMCID: PMC6004418 DOI: 10.3389/fnana.2018.00048] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/23/2018] [Indexed: 01/03/2023] Open
Abstract
The morphology and function of neuronal synapses are regulated by neural activity, as manifested in activity-dependent synapse maturation and various forms of synaptic plasticity. Here we employed cryo-electron tomography (cryo-ET) to visualize synaptic ultrastructure in cultured hippocampal neurons and investigated changes in subcellular features in response to chronic inactivity, a paradigm often used for the induction of homeostatic synaptic plasticity. We observed a more than 2-fold increase in the mean number of dense core vesicles (DCVs) in the presynaptic compartment of excitatory synapses and an almost 20-fold increase in the number of DCVs in the presynaptic compartment of inhibitory synapses after 2 days treatment with the voltage-gated sodium channel blocker tetrodotoxin (TTX). Short-term treatment with TTX and the N-methyl-D-aspartate receptor (NMDAR) antagonist amino-5-phosphonovaleric acid (AP5) caused a 3-fold increase in the number of DCVs within 100 nm of the active zone area in excitatory synapses but had no significant effects on the overall number of DCVs. In contrast, there were very few DCVs in the postsynaptic compartments of both synapse types under all conditions. These results are consistent with a role for presynaptic DCVs in activity-dependent synapse maturation. We speculate that these accumulated DCVs can be released upon reactivation and may contribute to homeostatic metaplasticity.
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Affiliation(s)
- Chang-Lu Tao
- Center for Integrative Imaging, National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.,School of Life Sciences, University of Science and Technology of China, Hefei, China.,CAS Key Laboratory of Brain Function and Disease, University of Science and Technology of China, Hefei, China
| | - Yun-Tao Liu
- Center for Integrative Imaging, National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.,School of Life Sciences, University of Science and Technology of China, Hefei, China.,CAS Key Laboratory of Brain Function and Disease, University of Science and Technology of China, Hefei, China
| | - Z Hong Zhou
- Center for Integrative Imaging, National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.,School of Life Sciences, University of Science and Technology of China, Hefei, China.,The California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA, United States
| | - Pak-Ming Lau
- Center for Integrative Imaging, National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.,School of Life Sciences, University of Science and Technology of China, Hefei, China.,CAS Key Laboratory of Brain Function and Disease, University of Science and Technology of China, Hefei, China
| | - Guo-Qiang Bi
- Center for Integrative Imaging, National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China.,School of Life Sciences, University of Science and Technology of China, Hefei, China.,CAS Key Laboratory of Brain Function and Disease, University of Science and Technology of China, Hefei, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, University of Science and Technology of China, Hefei, China
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48
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Winters BD, Golding NL. Glycinergic Inhibitory Plasticity in Binaural Neurons Is Cumulative and Gated by Developmental Changes in Action Potential Backpropagation. Neuron 2018; 98:166-178.e2. [PMID: 29576388 PMCID: PMC5886803 DOI: 10.1016/j.neuron.2018.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 01/09/2018] [Accepted: 02/28/2018] [Indexed: 11/20/2022]
Abstract
Utilization of timing-based sound localization cues by neurons in the medial superior olive (MSO) depends critically on glycinergic inhibitory inputs. After hearing onset, the strength and subcellular location of these inhibitory inputs are dramatically altered, but the cellular processes underlying this experience-dependent refinement are unknown. Here we reveal a form of inhibitory long-term potentiation (iLTP) in MSO neurons that is dependent on spiking and synaptic activation but is not affected by their fine-scale relative timing at higher frequencies prevalent in auditory circuits. We find that iLTP reinforces inhibitory inputs coactive with binaural excitation in a cumulative manner, likely well suited for networks featuring persistent high-frequency activity. We also show that a steep drop in action potential size and backpropagation limits induction of iLTP to the first 2 weeks of hearing. These intrinsic changes would deprive more distal inhibitory synapses of reinforcement, conceivably establishing the mature, soma-biased pattern of inhibition.
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Affiliation(s)
- Bradley D Winters
- The University of Texas at Austin, Department of Neuroscience and Center for Learning and Memory, 1 University Station C7000, Austin TX 78712-0248, USA
| | - Nace L Golding
- The University of Texas at Austin, Department of Neuroscience and Center for Learning and Memory, 1 University Station C7000, Austin TX 78712-0248, USA.
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Prepubertal Development of GABAergic Transmission to Gonadotropin-Releasing Hormone (GnRH) Neurons and Postsynaptic Response Are Altered by Prenatal Androgenization. J Neurosci 2018; 38:2283-2293. [PMID: 29374136 DOI: 10.1523/jneurosci.2304-17.2018] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/29/2017] [Accepted: 01/20/2018] [Indexed: 11/21/2022] Open
Abstract
Gonadotropin-releasing hormone (GnRH) neurons regulate reproduction through pulsatile GnRH release. Women with polycystic ovary syndrome (PCOS) have persistently elevated luteinizing hormone release frequency, reflecting GnRH release; this exacerbates hyperandrogenemia and disrupted reproductive cycles that are characteristic of this disorder. Clinical evidence suggests that neuroendocrine features of PCOS may manifest peripubertally. Adult mice prenatally exposed to androgens (PNA) mimic several reproductive features of PCOS. GnRH neurons from these mice have increased firing activity and receive increased GABAergic transmission, which is excitatory. When changes emerge during development is unknown. To study the typical postnatal development of GABAergic transmission and the effects of PNA treatment and sex, whole-cell voltage-clamp recordings were made of GABAergic postsynaptic currents (PSCs) in GnRH neurons in brain slices from prepubertal through adult control and PNA female and male mice. GABAergic transmission was present by 1 week of age in females and males and increased in frequency, reaching adult levels at 3 and 4 weeks, respectively. GABAergic PSC frequency was elevated in 3-week-old PNA versus control females. PSC frequency in both controls and PNA mice was activity independent, suggesting that PNA induces changes in synapse organization. PNA also alters the functional response of GnRH neurons to GABA. GABA induced firing in fewer neurons from 3-week-old PNA than control females; membrane potential depolarization induced by GABA was also reduced in cells from PNA mice at this age. PNA thus induces changes during development in the presynaptic organization of the GABAergic network afferent to GnRH neurons as well as the postsynaptic GnRH neuron response, both of which may contribute to adult reproductive dysfunction.SIGNIFICANCE STATEMENT The central neuronal network that regulates reproduction is overactive in polycystic ovary syndrome (PCOS), a leading cause of infertility. Recent evidence of neuroendocrine dysfunction in midpubertal girls suggests that the pathophysiological mechanisms underlying PCOS may arise before pubertal maturation. Prenatal exposure to androgens (PNA) in mice mimics several neuroendocrine features of PCOS. GABAergic transmission to gonadotropin-releasing hormone (GnRH) neurons is important for reproduction and is increased in adult PNA mice. The typical development of this network and when changes with PNA and sex arise relative to puberty are unknown. These studies provide evidence that PNA alters prepubertal development of the GABAergic network afferent to GnRH neurons, including both the presynaptic organization and postsynaptic response. These changes may contribute to reproductive dysfunction in adults.
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Dulka EA, Moenter SM. Prepubertal Development of Gonadotropin-Releasing Hormone Neuron Activity Is Altered by Sex, Age, and Prenatal Androgen Exposure. Endocrinology 2017; 158:3943-3953. [PMID: 28938422 PMCID: PMC5695838 DOI: 10.1210/en.2017-00768] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 09/12/2017] [Indexed: 11/19/2022]
Abstract
Gonadotropin-releasing hormone (GnRH) neurons regulate reproduction though pulsatile hormone release. Disruption of GnRH release as measured via luteinizing hormone (LH) pulses occurs in polycystic ovary syndrome (PCOS), and in young hyperandrogenemic girls. In adult prenatally androgenized (PNA) mice, which exhibit many aspects of PCOS, increased LH is associated with increased GnRH neuron action potential firing. How GnRH neuron activity develops over the prepubertal period and whether this is altered by sex or prenatal androgen treatment are unknown. We hypothesized GnRH neurons are active before puberty and that this activity is sexually differentiated and altered by PNA. Dams were injected with dihydrotestosterone (DHT) on days 16 to 18 post copulation to generate PNA mice. Action potential firing of GFP-identified GnRH neurons in brain slices from 1-, 2-, 3-, and 4-week-old and adult mice was monitored. GnRH neurons were active at all ages tested. In control females, activity increased with age through 3 weeks, then decreased to adult levels. In contrast, activity did not change in PNA females and was reduced at 3 weeks. Activity was higher in control females than males from 2 to 3 weeks. PNA did not affect GnRH neuron firing rate in males at any age. Short-term action potential patterns were also affected by age and PNA treatment. GnRH neurons are thus typically more active during the prepubertal period than adulthood, and PNA reduces prepubertal activity in females. Prepubertal activity may play a role in establishing sexually differentiated neuronal networks upstream of GnRH neurons; androgen-induced changes during this time may contribute to the adult PNA, and possibly PCOS, phenotype.
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Affiliation(s)
- Eden A. Dulka
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109
| | - Suzanne M. Moenter
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan 48109
- Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, Michigan 48109
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