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Hamad MIK, Daoud S, Petrova P, Rabaya O, Jbara A, Al Houqani S, BaniYas S, Alblooshi M, Almheiri A, Nakhal MM, Ali BR, Shehab S, Allouh MZ, Emerald BS, Schneider-Lódi M, Bataineh MF, Herz J, Förster E. Reelin differentially shapes dendrite morphology of medial entorhinal cortical ocean and island cells. Development 2024; 151:dev202449. [PMID: 38856043 PMCID: PMC11234379 DOI: 10.1242/dev.202449] [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: 10/18/2023] [Accepted: 06/04/2024] [Indexed: 06/11/2024]
Abstract
The function of medial entorhinal cortex layer II (MECII) excitatory neurons has been recently explored. MECII dysfunction underlies deficits in spatial navigation and working memory. MECII neurons comprise two major excitatory neuronal populations, pyramidal island and stellate ocean cells, in addition to the inhibitory interneurons. Ocean cells express reelin and surround clusters of island cells that lack reelin expression. The influence of reelin expression by ocean cells and interneurons on their own morphological differentiation and that of MECII island cells has remained unknown. To address this, we used a conditional reelin knockout (RelncKO) mouse to induce reelin deficiency postnatally in vitro and in vivo. Reelin deficiency caused dendritic hypertrophy of ocean cells, interneurons and only proximal dendritic compartments of island cells. Ca2+ recording showed that both cell types exhibited an elevation of calcium frequencies in RelncKO, indicating that the hypertrophic effect is related to excessive Ca2+ signalling. Moreover, pharmacological receptor blockade in RelncKO mouse revealed malfunctioning of GABAB, NMDA and AMPA receptors. Collectively, this study emphasizes the significance of reelin in neuronal growth, and its absence results in dendrite hypertrophy of MECII neurons.
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Affiliation(s)
- Mohammad I. K. Hamad
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Solieman Daoud
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Petya Petrova
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Obada Rabaya
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Abdalrahim Jbara
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Shaikha Al Houqani
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Shamsa BaniYas
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Meera Alblooshi
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Ayesha Almheiri
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Mohammed M. Nakhal
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Bassam R. Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Safa Shehab
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Mohammed Z. Allouh
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Mária Schneider-Lódi
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Mo'ath F. Bataineh
- Department of Nutrition and Health, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics; Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eckart Förster
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
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2
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Hamad MIK, Emerald BS, Kumar KK, Ibrahim MF, Ali BR, Bataineh MF. Extracellular molecular signals shaping dendrite architecture during brain development. Front Cell Dev Biol 2023; 11:1254589. [PMID: 38155836 PMCID: PMC10754048 DOI: 10.3389/fcell.2023.1254589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 11/28/2023] [Indexed: 12/30/2023] Open
Abstract
Proper growth and branching of dendrites are crucial for adequate central nervous system (CNS) functioning. The neuronal dendritic geometry determines the mode and quality of information processing. Any defects in dendrite development will disrupt neuronal circuit formation, affecting brain function. Besides cell-intrinsic programmes, extrinsic factors regulate various aspects of dendritic development. Among these extrinsic factors are extracellular molecular signals which can shape the dendrite architecture during early development. This review will focus on extrinsic factors regulating dendritic growth during early neuronal development, including neurotransmitters, neurotrophins, extracellular matrix proteins, contact-mediated ligands, and secreted and diffusible cues. How these extracellular molecular signals contribute to dendritic growth has been investigated in developing nervous systems using different species, different areas within the CNS, and different neuronal types. The response of the dendritic tree to these extracellular molecular signals can result in growth-promoting or growth-limiting effects, and it depends on the receptor subtype, receptor quantity, receptor efficiency, the animal model used, the developmental time windows, and finally, the targeted signal cascade. This article reviews our current understanding of the role of various extracellular signals in the establishment of the architecture of the dendrites.
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Affiliation(s)
- Mohammad I. K. Hamad
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bright Starling Emerald
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Kukkala K. Kumar
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Marwa F. Ibrahim
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Bassam R. Ali
- Department of Genetics and Genomics, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mo’ath F. Bataineh
- Department of Nutrition and Health, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
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3
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Gonda S, Riedel C, Reiner A, Köhler I, Wahle P. Axons of cortical basket cells originating from dendrites develop higher local complexity than axons emerging from basket cell somata. Development 2023; 150:dev202305. [PMID: 37902086 PMCID: PMC10690106 DOI: 10.1242/dev.202305] [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: 08/28/2023] [Accepted: 10/24/2023] [Indexed: 10/31/2023]
Abstract
Neuronal differentiation is regulated by neuronal activity. Here, we analyzed dendritic and axonal growth of Basket cells (BCs) and non-Basket cells (non-BCs) using sparse transfection of channelrhodopsin-YFP and repetitive optogenetic stimulation in slice cultures of rat visual cortex. Neocortical interneurons often display axon-carrying dendrites (AcDs). We found that the AcDs of BCs and non-BCs were, on average, the most complex dendrites. Further, the AcD configuration had an influence on BC axonal development. Axons originating from an AcD formed denser arborizations with more terminal endings within the dendritic field of the parent cell. Intriguingly, this occurred already in unstimulated BCs, and complexity was not increased further by optogenetic stimulation. However, optogenetic stimulation exerted a growth-promoting effect on axons emerging from BC somata. The axons of non-BCs neither responded to the AcD configuration nor to the optogenetic stimulation. The results suggest that the formation of locally dense BC plexuses is regulated by spontaneous activity. Moreover, in the AcD configuration, the AcD and the axon it carries mutually support each other's growth.
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Affiliation(s)
- Steffen Gonda
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Christian Riedel
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Andreas Reiner
- Cellular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Ina Köhler
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, 44801 Bochum, Germany
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4
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Gonda S, Köhler I, Haase A, Czubay K, Räk A, Riedel C, Wahle P. Optogenetic stimulation shapes dendritic trees of infragranular cortical pyramidal cells. Front Cell Neurosci 2023; 17:1212483. [PMID: 37587917 PMCID: PMC10427221 DOI: 10.3389/fncel.2023.1212483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 06/09/2023] [Indexed: 08/18/2023] Open
Abstract
Spontaneous or experimentally evoked activity can lead to changes in length and/or branching of neocortical pyramidal cell dendrites. For instance, an early postnatal overexpression of certain AMPA or kainate glutamate receptor subunits leads to larger amplitudes of depolarizing events driven by spontaneous activity, and this increases apical dendritic complexity. Whether stimulation frequency has a role is less clear. In this study, we report that the expression of channelrhodopsin2-eYFP was followed by a 5-day optogenetic stimulation from DIV 5-10 or 11-15 in organotypic cultures of rat visual cortex-evoked dendritic remodeling. Stimulation at 0.05 Hz, at a frequency range of spontaneous calcium oscillations known to occur in the early postnatal neocortex in vivo until eye opening, had no effect. Stimulation with 0.5 Hz, a frequency at which the cortex in vivo adopts after eye opening, unexpectedly caused shorter and somewhat less branched apical dendrites of infragranular pyramidal neurons. The outcome resembles the remodeling of corticothalamic and callosal projection neurons of layers VI and V, which in the adult have apical dendrites no longer terminating in layer I. Exposure to 2.5 Hz, a frequency not occurring naturally during the time windows, evoked dendritic damage. The results suggested that optogenetic stimulation at a biologically meaningful frequency for the selected developmental stage can influence dendrite growth, but contrary to expectation, the optogenetic stimulation decreased dendritic growth.
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Duan GF, Tang XH, Jia M, Wu D, Shi YS. Kainate receptors GluK1 and GluK2 differentially regulate synapse morphology. Synapse 2023; 77:e22255. [PMID: 36121930 DOI: 10.1002/syn.22255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 09/08/2022] [Accepted: 09/12/2022] [Indexed: 01/29/2023]
Abstract
The regulation of dendritic spine morphology is a critical aspect of neuronal network refinement during development and modulation of neurotransmission. Previous studies revealed that glutamatergic transmission plays a central role in synapse development. AMPA receptors and NMDA receptors regulate spine morphology in an activity dependent manner. However, whether and how Kainate receptors (KARs) regulate synapse development remains poorly understood. In this study, we found that GluK1 and GluK2 may play distinct roles in synapse development. In primary cultured hippocampal neurons, we found overexpression of the calcium-permeable GluK2(Q) receptor variant increased spine length and spine head area compared to overexpression of the calcium-impermeable GluK2(R) variant or EGFP transfected, control neurons, indicating that Q/R editing may play a role in GluK2 regulation of synapse development. Intriguingly, neurons transfected with GluK1(Q) showed decreased spine length and spine head area, while the density of dendritic spines was increased, suggesting that GluK1(Q) and GluK2(Q) have different effects on synaptic development. Swapping the critical domains between GluK2 and GluK1 demonstrated the N-terminal domain (NTD) is responsible for the different effects of GluK1 and GluK2. In conclusion, Kainate receptors GluK1 and GluK2 have distinct roles in regulating spine morphology and development, a process likely relying on the NTD.
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Affiliation(s)
- Gui-Fang Duan
- State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, China
| | - Xiao-Hui Tang
- Department of Anesthesiology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Min Jia
- Department of Anesthesiology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu, China
| | - Dan Wu
- Minister of Education Key Laboratory of Model Animal for Disease Study, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China
| | - Yun Stone Shi
- Minister of Education Key Laboratory of Model Animal for Disease Study, Department of Neurology, Drum Tower Hospital, Medical School, Nanjing University, Nanjing, China
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Gasterstädt I, Schröder M, Cronin L, Kusch J, Rennau LM, Mücher B, Herlitze S, Jack A, Wahle P. Chemogenetic Silencing of Differentiating Cortical Neurons Impairs Dendritic and Axonal Growth. Front Cell Neurosci 2022; 16:941620. [PMID: 35910251 PMCID: PMC9336219 DOI: 10.3389/fncel.2022.941620] [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: 05/11/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022] Open
Abstract
Electrical activity is considered a key driver for the neurochemical and morphological maturation of neurons and the formation of neuronal networks. Designer receptors exclusively activated by designer drugs (DREADDs) are tools for controlling neuronal activity at the single cell level by triggering specific G protein signaling. Our objective was to investigate if prolonged silencing of differentiating cortical neurons can influence dendritic and axonal maturation. The DREADD hM4Di couples to Gi/o signaling and evokes hyperpolarization via GIRK channels. HM4Di was biolistically transfected into neurons in organotypic slice cultures of rat visual cortex, and activated by clozapine-N-oxide (CNO) dissolved in H2O; controls expressed hM4Di, but were mock-stimulated with H2O. Neurons were analyzed after treatment for two postnatal time periods, DIV 5-10 and 10-20. We found that CNO treatment delays the maturation of apical dendrites of L2/3 pyramidal cells. Further, the number of collaterals arising from the main axon was significantly lower, as was the number of bouton terminaux along pyramidal cell and basket cell axons. The dendritic maturation of L5/6 pyramidal cells and of multipolar interneurons (basket cells and bitufted cells) was not altered by CNO treatment. Returning CNO-treated cultures to CNO-free medium for 7 days was sufficient to recover dendritic and axonal complexity. Our findings add to the view that activity is a key driver in particular of postnatal L2/3 pyramidal cell maturation. Our results further suggest that inhibitory G protein signaling may represent a factor balancing the strong driving force of neurotrophic factors, electrical activity and calcium signaling.
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Affiliation(s)
- Ina Gasterstädt
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Max Schröder
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Lukas Cronin
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Julian Kusch
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Lisa-Marie Rennau
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Brix Mücher
- Department of General Zoology and Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Alexander Jack
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
- *Correspondence: Petra Wahle,
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Hamad MIK, Petrova P, Daoud S, Rabaya O, Jbara A, Melliti N, Leifeld J, Jakovčevski I, Reiss G, Herz J, Förster E. Reelin restricts dendritic growth of interneurons in the neocortex. Development 2021; 148:272055. [PMID: 34414407 DOI: 10.1242/dev.199718] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/12/2021] [Indexed: 11/20/2022]
Abstract
Reelin is a large secreted glycoprotein that regulates neuronal migration, lamination and establishment of dendritic architecture in the embryonic brain. Reelin expression switches postnatally from Cajal-Retzius cells to interneurons. However, reelin function in interneuron development is still poorly understood. Here, we have investigated the role of reelin in interneuron development in the postnatal neocortex. To preclude early cortical migration defects caused by reelin deficiency, we employed a conditional reelin knockout (RelncKO) mouse to induce postnatal reelin deficiency. Induced reelin deficiency caused dendritic hypertrophy in distal dendritic segments of neuropeptide Y-positive (NPY+) and calretinin-positive (Calr+) interneurons, and in proximal dendritic segments of parvalbumin-positive (Parv+) interneurons. Chronic recombinant Reelin treatment rescued dendritic hypertrophy in Relncko interneurons. Moreover, we provide evidence that RelncKO interneuron hypertrophy is due to presynaptic GABABR dysfunction. Thus, GABABRs in RelncKO interneurons were unable to block N-type (Cav2.2) Ca2+ channels that control neurotransmitter release. Consequently, the excessive Ca2+ influx through AMPA receptors, but not NMDA receptors, caused interneuron dendritic hypertrophy. These findings suggest that reelin acts as a 'stop-growth-signal' for postnatal interneuron maturation.
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Affiliation(s)
- Mohammad I K Hamad
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, Witten/Herdecke University, Witten 58455, Germany.,Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Petya Petrova
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Solieman Daoud
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Obada Rabaya
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Abdalrahim Jbara
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Nesrine Melliti
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Jennifer Leifeld
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
| | - Igor Jakovčevski
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, Witten/Herdecke University, Witten 58455, Germany
| | - Gebhard Reiss
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, Witten/Herdecke University, Witten 58455, Germany
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics; Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Eckart Förster
- Department of Neuroanatomy and Molecular Brain Research, Medical Faculty, Ruhr University Bochum, Bochum 44801, Germany
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Hamad MIK, Jbara A, Rabaya O, Petrova P, Daoud S, Melliti N, Meseke M, Lutz D, Petrasch-Parwez E, Schwitalla JC, Mark MD, Herlitze S, Reiss G, Herz J, Förster E. Reelin signaling modulates GABA B receptor function in the neocortex. J Neurochem 2021; 156:589-603. [PMID: 32083308 PMCID: PMC7442713 DOI: 10.1111/jnc.14990] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/27/2020] [Accepted: 02/18/2020] [Indexed: 11/27/2022]
Abstract
Reelin is a protein that is best known for its role in controlling neuronal layer formation in the developing cortex. Here, we studied its role for post-natal cortical network function, which is poorly explored. To preclude early cortical migration defects caused by Reelin deficiency, we used a conditional Reelin knock-out (RelncKO ) mouse, and induced Reelin deficiency post-natally. Induced Reelin deficiency caused hyperexcitability of the neocortical network in vitro and ex vivo. Blocking Reelin binding to its receptors ApoER2 and VLDLR resulted in a similar effect. Hyperexcitability in RelncKO organotypic slice cultures could be rescued by co-culture with wild-type organotypic slice cultures. Moreover, the GABAB receptor (GABAB R) agonist baclofen failed to activate and the antagonist CGP35348 failed to block GABAB Rs in RelncKO mice. Immunolabeling of RelncKO cortical slices revealed a reduction in GABAB R1 and GABAB R2 surface expression at the plasma membrane and western blot of RelncKO cortical tissue revealed decreased phosphorylation of the GABAB R2 subunit at serine 892 and increased phosphorylation at serine 783, reflecting receptor deactivation and proteolysis. These data show a role of Reelin in controlling early network activity, by modulating GABAB R function. Cover Image for this issue: https://doi.org/10.1111/jnc.15054.
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Affiliation(s)
- Mohammad I K Hamad
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, Herdecke University, Witten, Witten
| | - Abdalrahim Jbara
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Obada Rabaya
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Petya Petrova
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Solieman Daoud
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Nesrine Melliti
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Maurice Meseke
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - David Lutz
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Elisabeth Petrasch-Parwez
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | | | - Melanie D Mark
- Department of Behavioral Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Stefan Herlitze
- Department of Zoology and Neurobiology, Ruhr University Bochum, Bochum, Germany
| | - Gebhard Reiss
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, Herdecke University, Witten, Witten
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics, Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eckart Förster
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
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9
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Gonda S, Giesen J, Sieberath A, West F, Buchholz R, Klatt O, Ziebarth T, Räk A, Kleinhubbert S, Riedel C, Hollmann M, Hamad MIK, Reiner A, Wahle P. GluN2B but Not GluN2A for Basal Dendritic Growth of Cortical Pyramidal Neurons. Front Neuroanat 2020; 14:571351. [PMID: 33281565 PMCID: PMC7691608 DOI: 10.3389/fnana.2020.571351] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/06/2020] [Indexed: 01/08/2023] Open
Abstract
NMDA receptors are important players for neuronal differentiation. We previously reported that antagonizing NMDA receptors with APV blocked the growth-promoting effects evoked by the overexpression of specific calcium-permeable or flip-spliced AMPA receptor subunits and of type I transmembrane AMPA receptor regulatory proteins which both exclusively modify apical dendritic length and branching of cortical pyramidal neurons. These findings led us to characterize the role of GluN2B and GluN2A for dendritogenesis using organotypic cultures of rat visual cortex. Antagonizing GluN2B with ifenprodil and Ro25-6981 strongly impaired basal dendritic growth of supra- and infragranular pyramidal cells at DIV 5–10, but no longer at DIV 15–20. Growth recovered after washout, and protein blots revealed an increase of synaptic GluN2B-containing receptors as indicated by a enhanced phosphorylation of the tyrosine 1472 residue. Antagonizing GluN2A with TCN201 and NVP-AAM077 was ineffective at both ages. Dendrite growth of non-pyramidal interneurons was not altered. We attempted to overexpress GluN2A and GluN2B. However, although the constructs delivered currents in HEK cells, there were neither effects on dendrite morphology nor an enhanced sensitivity to NMDA. Further, co-expressing GluN1-1a and GluN2B did not alter dendritic growth. Visualization of overexpressed, tagged GluN2 proteins was successful after immunofluorescence for the tag which delivered rather weak staining in HEK cells as well as in neurons. This suggested that the level of overexpression is too weak to modify dendrite growth. In summary, endogenous GluN2B, but not GluN2A is important for pyramidal cell basal dendritic growth during an early postnatal time window.
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Affiliation(s)
- Steffen Gonda
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Jan Giesen
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Alexander Sieberath
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Fabian West
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Raoul Buchholz
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Oliver Klatt
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Tim Ziebarth
- Cellular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Andrea Räk
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Sabine Kleinhubbert
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Christian Riedel
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Michael Hollmann
- Biochemistry I - Receptor Biochemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Mohammad I K Hamad
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Andreas Reiner
- Cellular Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
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10
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Gasterstädt I, Jack A, Stahlhut T, Rennau LM, Gonda S, Wahle P. Genetically Encoded Calcium Indicators Can Impair Dendrite Growth of Cortical Neurons. Front Cell Neurosci 2020; 14:570596. [PMID: 33192315 PMCID: PMC7606991 DOI: 10.3389/fncel.2020.570596] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 08/31/2020] [Indexed: 12/11/2022] Open
Abstract
A battery of genetically encoded calcium indicators (GECIs) with different binding kinetics and calcium affinities was developed over the recent years to permit long-term calcium imaging. GECIs are calcium buffers and therefore, expression of GECIs may interfere with calcium homeostasis and signaling pathways important for neuronal differentiation and survival. Our objective was to investigate if the biolistically induced expression of five commonly used GECIs at two postnatal time points (days 14 and 22–25) could affect the morphological maturation of cortical neurons in organotypic slice cultures of rat visual cortex. Expression of GCaMP3 in both time windows, and of GCaMP5G and TN-XXL in the later time window impaired apical and /or basal dendrite growth of pyramidal neurons. With time, the proportion of GECI transfectants with nuclear filling increased, but an only prolonged expression of TN-XXL caused higher levels of neurodegeneration. In multipolar interneurons, only GCaMP3 evoked a transient growth delay during the early time window. GCaMP6m and GCaMP6m-XC were quite “neuron-friendly.” Since growth-impaired neurons might not have the physiological responses typical of age-matched wildtype neurons the results obtained after prolonged developmental expression of certain GECIs might need to be interpreted with caution.
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Affiliation(s)
- Ina Gasterstädt
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Alexander Jack
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Tobias Stahlhut
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Lisa-Marie Rennau
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Steffen Gonda
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
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Medvedeva VP, Pierani A. How Do Electric Fields Coordinate Neuronal Migration and Maturation in the Developing Cortex? Front Cell Dev Biol 2020; 8:580657. [PMID: 33102486 PMCID: PMC7546860 DOI: 10.3389/fcell.2020.580657] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/04/2020] [Indexed: 12/13/2022] Open
Abstract
During development the vast majority of cells that will later compose the mature cerebral cortex undergo extensive migration to reach their final position. In addition to intrinsically distinct migratory behaviors, cells encounter and respond to vastly different microenvironments. These range from axonal tracts to cell-dense matrices, electrically active regions and extracellular matrix components, which may all change overtime. Furthermore, migrating neurons themselves not only adapt to their microenvironment but also modify the local niche through cell-cell contacts, secreted factors and ions. In the radial dimension, the developing cortex is roughly divided into dense progenitor and cortical plate territories, and a less crowded intermediate zone. The cortical plate is bordered by the subplate and the marginal zone, which are populated by neurons with high electrical activity and characterized by sophisticated neuritic ramifications. Neuronal migration is influenced by these boundaries resulting in dramatic changes in migratory behaviors as well as morphology and electrical activity. Modifications in the levels of any of these parameters can lead to alterations and even arrest of migration. Recent work indicates that morphology and electrical activity of migrating neuron are interconnected and the aim of this review is to explore the extent of this connection. We will discuss on one hand how the response of migrating neurons is altered upon modification of their intrinsic electrical properties and whether, on the other hand, the electrical properties of the cellular environment can modify the morphology and electrical activity of migrating cortical neurons.
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Affiliation(s)
- Vera P Medvedeva
- Imagine Institute of Genetic Diseases, Université de Paris, Paris, France.,Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Université de Paris, Paris, France
| | - Alessandra Pierani
- Imagine Institute of Genetic Diseases, Université de Paris, Paris, France.,Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Université de Paris, Paris, France
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12
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Hamad MIK, Daoud S, Petrova P, Rabaya O, Jbara A, Melliti N, Stichmann S, Reiss G, Herz J, Förster E. Biolistic transfection and expression analysis of acute cortical slices. J Neurosci Methods 2020; 337:108666. [PMID: 32119875 DOI: 10.1016/j.jneumeth.2020.108666] [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: 09/14/2019] [Revised: 02/21/2020] [Accepted: 02/27/2020] [Indexed: 12/28/2022]
Abstract
BACKGROUND Biolistic gene gun transfection has been used to transfect organotypic cultures (OTCs) or dissociated cultures in vitro. Here, we modified this technique to allow successful transfection of acute brain slices, followed by measurement of neuronal activity within a few hours. NEW METHOD We established biolistic transfection of murine acute cortical slices to measure calcium signals. Acute slices are mounted on plasma/thrombin coagulate and transfected with a calcium sensor. Imaging can be performed within 4 h post transfection without affecting cell viability. RESULTS Four hours after GCaMP6s transfection, acute slices display remarkable fluorescent protein expression level allowing to study spontaneous activity and receptor pharmacology. While optimal gas pressure (150 psi) and gold particle size used (1 μm) confirm previously published protocols, the amount of 5 μg DNA was found to be optimal for particle coating. COMPARISON WITH EXISTING METHODS The major advantage of this technique is the rapid disposition of acute slices for calcium imaging. No transgenic GECI expressing animals or OTC for long periods are required. In acute slices, network interaction and connectivity are preserved. The method allows to obtain physiological readouts within 4 h, before functional tissue modifications might come into effect. Limitations of this technique are random transfection, low expression efficiency when using specific promotors, and preclusion or genetic manipulations that require a prolonged time before physiological changes become measurable, such as expression of recombinant proteins that require transport to distant subcellular localizations. CONCLUSION The method is optimal for short-time investigation of calcium signals in acute slices.
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Affiliation(s)
- Mohammad I K Hamad
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, University of Witten/Herdecke, Witten, Germany; Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany.
| | - Solieman Daoud
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Petya Petrova
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Obada Rabaya
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Abdalrahim Jbara
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Nesrine Melliti
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, University of Witten/Herdecke, Witten, Germany
| | - Sarah Stichmann
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
| | - Gebhard Reiss
- Institute for Anatomy and Clinical Morphology, School of Medicine, Faculty of Health, University of Witten/Herdecke, Witten, Germany
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics, Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Eckart Förster
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany
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Abstract
The structure of neuronal circuits that subserve cognitive functions in the brain is shaped and refined throughout development and into adulthood. Evidence from human and animal studies suggests that the cellular and synaptic substrates of these circuits are atypical in neuropsychiatric disorders, indicating that altered structural plasticity may be an important part of the disease biology. Advances in genetics have redefined our understanding of neuropsychiatric disorders and have revealed a spectrum of risk factors that impact pathways known to influence structural plasticity. In this Review, we discuss the importance of recent genetic findings on the different mechanisms of structural plasticity and propose that these converge on shared pathways that can be targeted with novel therapeutics.
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Jack A, Hamad MIK, Gonda S, Gralla S, Pahl S, Hollmann M, Wahle P. Development of Cortical Pyramidal Cell and Interneuronal Dendrites: a Role for Kainate Receptor Subunits and NETO1. Mol Neurobiol 2019; 56:4960-4979. [PMID: 30421168 DOI: 10.1007/s12035-018-1414-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/25/2018] [Indexed: 12/18/2022]
Abstract
During neuronal development, AMPA receptors (AMPARs) and NMDA receptors (NMDARs) are important for neuronal differentiation. Kainate receptors (KARs) are closely related to AMPARs and involved in the regulation of cortical network activity. However, their role for neurite growth and differentiation of cortical neurons is unclear. Here, we used KAR agonists and overexpression of selected KAR subunits and their auxiliary neuropilin and tolloid-like proteins, NETOs, to investigate their influence on dendritic growth and network activity in organotypic cultures of rat visual cortex. Kainate at 500 nM enhanced network activity and promoted development of dendrites in layer II/III pyramidal cells, but not interneurons. GluK2 overexpression promoted dendritic growth in pyramidal cells and interneurons. GluK2 transfectants were highly active and acted as drivers for network activity. GluK1 and NETO1 specifically promoted dendritic growth of interneurons. Our study provides new insights for the roles of KARs and NETOs in the morphological and physiological development of the visual cortex.
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Affiliation(s)
- Alexander Jack
- Faculty for Biology and Biotechnology ND 6/72, Developmental Neurobiology, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Mohammad I K Hamad
- Faculty for Biology and Biotechnology ND 6/72, Developmental Neurobiology, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
- Medical Faculty, Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Steffen Gonda
- Faculty for Biology and Biotechnology ND 6/72, Developmental Neurobiology, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Sebastian Gralla
- Faculty for Biology and Biotechnology ND 6/72, Developmental Neurobiology, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Steffen Pahl
- Faculty of Chemistry and Biochemistry, Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Michael Hollmann
- Faculty of Chemistry and Biochemistry, Biochemistry I-Receptor Biochemistry, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany
| | - Petra Wahle
- Faculty for Biology and Biotechnology ND 6/72, Developmental Neurobiology, Ruhr University Bochum, Universitätsstraße 150, 44801, Bochum, Germany.
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15
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Bissen D, Foss F, Acker-Palmer A. AMPA receptors and their minions: auxiliary proteins in AMPA receptor trafficking. Cell Mol Life Sci 2019; 76:2133-2169. [PMID: 30937469 PMCID: PMC6502786 DOI: 10.1007/s00018-019-03068-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/12/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022]
Abstract
To correctly transfer information, neuronal networks need to continuously adjust their synaptic strength to extrinsic stimuli. This ability, termed synaptic plasticity, is at the heart of their function and is, thus, tightly regulated. In glutamatergic neurons, synaptic strength is controlled by the number and function of AMPA receptors at the postsynapse, which mediate most of the fast excitatory transmission in the central nervous system. Their trafficking to, at, and from the synapse, is, therefore, a key mechanism underlying synaptic plasticity. Intensive research over the last 20 years has revealed the increasing importance of interacting proteins, which accompany AMPA receptors throughout their lifetime and help to refine the temporal and spatial modulation of their trafficking and function. In this review, we discuss the current knowledge about the roles of key partners in regulating AMPA receptor trafficking and focus especially on the movement between the intracellular, extrasynaptic, and synaptic pools. We examine their involvement not only in basal synaptic function, but also in Hebbian and homeostatic plasticity. Included in our review are well-established AMPA receptor interactants such as GRIP1 and PICK1, the classical auxiliary subunits TARP and CNIH, and the newest additions to AMPA receptor native complexes.
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Affiliation(s)
- Diane Bissen
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany
| | - Franziska Foss
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences (BMLS), University of Frankfurt, Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
- Max Planck Institute for Brain Research, Max von Laue Str. 4, 60438, Frankfurt am Main, Germany.
- Cardio-Pulmonary Institute (CPI), Max-von-Laue-Str. 15, 60438, Frankfurt am Main, Germany.
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16
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Eickelbeck D, Karapinar R, Jack A, Suess ST, Barzan R, Azimi Z, Surdin T, Grömmke M, Mark MD, Gerwert K, Jancke D, Wahle P, Spoida K, Herlitze S. CaMello-XR enables visualization and optogenetic control of G q/11 signals and receptor trafficking in GPCR-specific domains. Commun Biol 2019; 2:60. [PMID: 30793039 PMCID: PMC6376006 DOI: 10.1038/s42003-019-0292-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Accepted: 01/09/2019] [Indexed: 12/20/2022] Open
Abstract
The signal specificity of G protein-coupled receptors (GPCRs) including serotonin receptors (5-HT-R) depends on the trafficking and localization of the GPCR within its subcellular signaling domain. Visualizing traffic-dependent GPCR signals in neurons is difficult, but important to understand the contribution of GPCRs to synaptic plasticity. We engineered CaMello (Ca2+-melanopsin-local-sensor) and CaMello-5HT2A for visualization of traffic-dependent Ca2+ signals in 5-HT2A-R domains. These constructs consist of the light-activated Gq/11 coupled melanopsin, mCherry and GCaMP6m for visualization of Ca2+ signals and receptor trafficking, and the 5-HT2A C-terminus for targeting into 5-HT2A-R domains. We show that the specific localization of the GPCR to its receptor domain drastically alters the dynamics and localization of the intracellular Ca2+ signals in different neuronal populations in vitro and in vivo. The CaMello method may be extended to every GPCR coupling to the Gq/11 pathway to help unravel new receptor-specific functions in respect to synaptic plasticity and GPCR localization. Dennis Eickelbeck et al. engineered light-activated constructs, CaMello and CaMello-5HT2A, which are targeted to the 5HT2A-R domains and enable visualization of calcium signals and receptor trafficking in response to activation. The reported CaMello tool could be applied to other GPCRs coupled to the Gq/11 signaling pathways which may shed light on mechanisms of GPCR localization and plasticity.
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Affiliation(s)
- Dennis Eickelbeck
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Raziye Karapinar
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Alexander Jack
- Developmental Neurobiology, ND6/72, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Sandra T Suess
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Ruxandra Barzan
- Optical Imaging Group, Institut für Neuroinformatik, NB 2/27, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Zohre Azimi
- Optical Imaging Group, Institut für Neuroinformatik, NB 2/27, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Tatjana Surdin
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Michelle Grömmke
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Melanie D Mark
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Klaus Gerwert
- Department of Biophysics, ND04/596, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Dirk Jancke
- Optical Imaging Group, Institut für Neuroinformatik, NB 2/27, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Petra Wahle
- Developmental Neurobiology, ND6/72, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Katharina Spoida
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, ND7/31, Ruhr-University Bochum, Universitätsstr. 150, D-44780, Bochum, Germany.
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Höfflin F, Jack A, Riedel C, Mack-Bucher J, Roos J, Corcelli C, Schultz C, Wahle P, Engelhardt M. Heterogeneity of the Axon Initial Segment in Interneurons and Pyramidal Cells of Rodent Visual Cortex. Front Cell Neurosci 2017; 11:332. [PMID: 29170630 PMCID: PMC5684645 DOI: 10.3389/fncel.2017.00332] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 10/09/2017] [Indexed: 11/13/2022] Open
Abstract
The microdomain that orchestrates action potential initiation in neurons is the axon initial segment (AIS). It has long been considered to be a rather homogeneous domain at the very proximal axon hillock with relatively stable length, particularly in cortical pyramidal cells. However, studies in other brain regions paint a different picture. In hippocampal CA1, up to 50% of axons emerge from basal dendrites. Further, in about 30% of thick-tufted layer V pyramidal neurons in rat somatosensory cortex, axons have a dendritic origin. Consequently, the AIS is separated from the soma. Recent in vitro and in vivo studies have shown that cellular excitability is a function of AIS length/position and somatodendritic morphology, undermining a potentially significant impact of AIS heterogeneity for neuronal function. We therefore investigated neocortical axon morphology and AIS composition, hypothesizing that the initial observation of seemingly homogeneous AIS is inadequate and needs to take into account neuronal cell types. Here, we biolistically transfected cortical neurons in organotypic cultures to visualize the entire neuron and classify cell types in combination with immunolabeling against AIS markers. Using confocal microscopy and morphometric analysis, we investigated axon origin, AIS position, length, diameter as well as distance to the soma. We find a substantial AIS heterogeneity in visual cortical neurons, classified into three groups: (I) axons with somatic origin with proximal AIS at the axon hillock; (II) axons with somatic origin with distal AIS, with a discernible gap between the AIS and the soma; and (III) axons with dendritic origin (axon-carrying dendrite cell, AcD cell) and an AIS either starting directly at the axon origin or more distal to that point. Pyramidal cells have significantly longer AIS than interneurons. Interneurons with vertical columnar axonal projections have significantly more distal AIS locations than all other cells with their prevailing phenotype as an AcD cell. In contrast, neurons with perisomatic terminations display most often an axon originating from the soma. Our data contribute to the emerging understanding that AIS morphology is highly variable, and potentially a function of the cell type.
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Affiliation(s)
- Felix Höfflin
- Institute of Neuroanatomy, Medical Faculty Mannheim, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
| | - Alexander Jack
- Developmental Neurobiology, Department of Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Christian Riedel
- Developmental Neurobiology, Department of Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Julia Mack-Bucher
- Live Cell Imaging Core Mannheim (LIMA), Medical Faculty Mannheim, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
| | - Johannes Roos
- Institute of Neuroanatomy, Medical Faculty Mannheim, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
| | - Corinna Corcelli
- Institute of Neuroanatomy, Medical Faculty Mannheim, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
| | - Christian Schultz
- Institute of Neuroanatomy, Medical Faculty Mannheim, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
| | - Petra Wahle
- Developmental Neurobiology, Department of Zoology and Neurobiology, Ruhr-University Bochum, Bochum, Germany
| | - Maren Engelhardt
- Institute of Neuroanatomy, Medical Faculty Mannheim, Center for Biomedicine and Medical Technology Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
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Pratt KG, Hiramoto M, Cline HT. An Evolutionarily Conserved Mechanism for Activity-Dependent Visual Circuit Development. Front Neural Circuits 2016; 10:79. [PMID: 27818623 PMCID: PMC5073143 DOI: 10.3389/fncir.2016.00079] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 09/26/2016] [Indexed: 12/01/2022] Open
Abstract
Neural circuit development is an activity-dependent process. This activity can be spontaneous, such as the retinal waves that course across the mammalian embryonic retina, or it can be sensory-driven, such as the activation of retinal ganglion cells (RGCs) by visual stimuli. Whichever the source, neural activity provides essential instruction to the developing circuit. Indeed, experimentally altering activity has been shown to impact circuit development and function in many different ways and in many different model systems. In this review, we contemplate the idea that retinal waves in amniotes, the animals that develop either in ovo or utero (namely reptiles, birds and mammals) could be an evolutionary adaptation to life on land, and that the anamniotes, animals whose development is entirely external (namely the aquatic amphibians and fish), do not display retinal waves, most likely because they simply don’t need them. We then review what is known about the function of both retinal waves and visual stimuli on their respective downstream targets, and predict that the experience-dependent development of the tadpole visual system is a blueprint of what will be found in future studies of the effects of spontaneous retinal waves on instructing development of retinorecipient targets such as the superior colliculus (SC) and the lateral geniculate nucleus.
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Affiliation(s)
- Kara G Pratt
- Program in Neuroscience, Department of Zoology and Physiology, University of Wyoming Laramie, WY, USA
| | - Masaki Hiramoto
- Department of Molecular and Cellular Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute La Jolla, CA, USA
| | - Hollis T Cline
- Department of Molecular and Cellular Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute La Jolla, CA, USA
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The Emerging Roles of the Calcineurin-Nuclear Factor of Activated T-Lymphocytes Pathway in Nervous System Functions and Diseases. J Aging Res 2016; 2016:5081021. [PMID: 27597899 PMCID: PMC5002468 DOI: 10.1155/2016/5081021] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/21/2016] [Indexed: 12/27/2022] Open
Abstract
The ongoing epidemics of metabolic diseases and increase in the older population have increased the incidences of neurodegenerative diseases. Evidence from murine and cell line models has implicated calcineurin-nuclear factor of activated T-lymphocytes (NFAT) signaling pathway, a Ca2+/calmodulin-dependent major proinflammatory pathway, in the pathogenesis of these diseases. Neurotoxins such as amyloid-β, tau protein, and α-synuclein trigger abnormal calcineurin/NFAT signaling activities. Additionally increased activities of endogenous regulators of calcineurin like plasma membrane Ca2+-ATPase (PMCA) and regulator of calcineurin 1 (RCAN1) also cause neuronal and glial loss and related functional alterations, in neurodegenerative diseases, psychotic disorders, epilepsy, and traumatic brain and spinal cord injuries. Treatment with calcineurin/NFAT inhibitors induces some degree of neuroprotection and decreased reactive gliosis in the central and peripheral nervous system. In this paper, we summarize and discuss the current understanding of the roles of calcineurin/NFAT signaling in physiology and pathologies of the adult and developing nervous system, with an emphasis on recent reports and cutting-edge findings. Calcineurin/NFAT signaling is known for its critical roles in the developing and adult nervous system. Its role in physiological and pathological processes is still controversial. However, available data suggest that its beneficial and detrimental effects are context-dependent. In view of recent reports calcineurin/NFAT signaling is likely to serve as a potential therapeutic target for neurodegenerative diseases and conditions. This review further highlights the need to characterize better all factors determining the outcome of calcineurin/NFAT signaling in diseases and the downstream targets mediating the beneficial and detrimental effects.
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Han J, Zhang H, Wang S, Zhou J, Luo Y, Long LH, Hu ZL, Wang F, Chen JG, Wu PF. Potentiation of Surface Stability of AMPA Receptors by Sulfhydryl Compounds: A Redox-Independent Effect by Disrupting Palmitoylation. Neurochem Res 2016; 41:2890-2903. [PMID: 27426946 DOI: 10.1007/s11064-016-2006-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 07/04/2016] [Accepted: 07/12/2016] [Indexed: 02/07/2023]
Abstract
Sulfhydryl compounds such as dithiothreitol (DTT) and β-mercaptoethanol (β-ME) are widely used as redox agents. Previous studies in our group and other laboratory have reported the effect of sulfhydryl compounds on the function of glutamate receptor, including plasticity. Most of these findings have focused on the N-methyl-D-aspartic acid receptor, in contrast, very little is known about the effect of sulfhydryl compounds on α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR). Here, we observed that DTT (100 μM), β-ME (200 μM) and L-cysteine (200 μM) significantly elevated the surface expression of AMPARs via reducing their palmitoylation in rat hippocampal slices in vitro. Increased surface stability of AMPARs was not be correlated with the altered redox status, because the chemical entities containing mercapto group such as penicillamine (200 μM) and 2-mercapto-1-methylimidazole (200 μM) exhibited little effects on the surface expression of AMPARs. Computing results of Asp-His-His-Cys (DHHC) 3, the main enzyme for palmitoylation of AMPARs, indicated that only the alkyl mercaptans with chain-like configuration, such as DTT and β-ME, can enter the pocket of DHHC3 and disrupt the catalytic activity via inhibiting DHHC3 auto-palmitoylation. Collectively, our findings indicate a novel redox-independent mechanism underlay the multiple effects of thiol reductants on synaptic function.
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Affiliation(s)
- Jun Han
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Hai Zhang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Sheng Wang
- School of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jun Zhou
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Yi Luo
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China
| | - Li-Hong Long
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Zhuang-Li Hu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China.,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China.,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China.,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Peng-Fei Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan, 430030, Hubei, China. .,Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, 430030, Hubei, China. .,The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, 430030, Hubei, China. .,Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China.
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Wang JG, Wang YL, Xu F, Zhao JX, Zhou SY, Yu Y, Chazot PL, Wang XF, Lu CB. Activity- and development-dependent down-regulation of TARPγ8 and GluA1 in cultured rat hippocampal neurons. Acta Pharmacol Sin 2016; 37:303-11. [PMID: 26725511 DOI: 10.1038/aps.2015.112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/26/2015] [Indexed: 01/16/2023] Open
Abstract
AIM Transmembrane AMPA receptor regulatory proteins (TARPs) regulate the trafficking and expression of AMPA receptors that are essential for the fast excitatory synaptic transmission and plasticity in the brain. This study aimed to investigate the activity-dependent regulation of TARPγ8 in cultured rat hippocampal neurons. METHODS Rat hippocampal neurons cultured for 7-8 DIV or 17-18 DIV were exposed to the AMPA receptor agonist AMPA at a non-toxic concentration (100 μmol/L) for 4 h. The protein levels of TARPγ8 and AMPA receptor subunits (GluA1 and GluA2) were measured using Western blotting analysis. AMPA-induced currents were recorded in the neurons using a whole-cell recording method. RESULTS Four-hour exposure to AMPA significantly decreased the protein levels of TARPγ8 and GluA1 in the neurons at 17-18 DIV, but did not change the protein level of TARPγ8 in the neurons cultured at 7-8 DIV. AMPA-induced down-regulation of TARPγ8 and GluA1 was largely blocked by the calpain inhibitor calpeptin (50 μmol/L), but not affected by the caspase inhibitor zVAD (50 μmol/L). Four-hour exposure to AMPA significantly decreased AMPA-induced currents in the neurons at 17-18 DIV, which was blocked by co-exposure to calpeptin (50 μmol/L). CONCLUSION The down-regulation of TARPγ8 and GluA1 protein levels and AMPA-induced currents in cultured rat hippocampal neurons is activity- and development-dependent, and mediated by endogenous calpain.
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Uhlén P, Fritz N, Smedler E, Malmersjö S, Kanatani S. Calcium signaling in neocortical development. Dev Neurobiol 2015; 75:360-8. [DOI: 10.1002/dneu.22273] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 01/16/2015] [Accepted: 01/17/2015] [Indexed: 11/10/2022]
Affiliation(s)
- Per Uhlén
- Department of Medical Biochemistry and Biophysics; Karolinska Institutet; SE-171 77 Stockholm Sweden
| | - Nicolas Fritz
- The Science for Life Laboratory; The Royal Institute of Technology; SE-171 77 Stockholm Sweden
| | - Erik Smedler
- Department of Medical Biochemistry and Biophysics; Karolinska Institutet; SE-171 77 Stockholm Sweden
| | - Seth Malmersjö
- Department of Chemical and Systems Biology; School of Medicine, Stanford University; Stanford California 94305
| | - Shigeaki Kanatani
- Department of Medical Biochemistry and Biophysics; Karolinska Institutet; SE-171 77 Stockholm Sweden
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Domínguez-Alonso A, Valdés-Tovar M, Solís-Chagoyán H, Benítez-King G. Melatonin stimulates dendrite formation and complexity in the hilar zone of the rat hippocampus: participation of the Ca++/Calmodulin complex. Int J Mol Sci 2015; 16:1907-27. [PMID: 25603176 PMCID: PMC4307341 DOI: 10.3390/ijms16011907] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/07/2015] [Indexed: 01/23/2023] Open
Abstract
Melatonin (MEL), the main product synthesized by the pineal gland, stimulates early and late stages of neurodevelopment in the adult brain. MEL increases dendrite length, thickness and complexity in the hilar and mossy neurons of hippocampus. Dendrite formation involves activation of Ca2+/Calmodulin (CaM)-dependent kinase II (CaMKII) by CaM. Previous work showed that MEL increased the synthesis and translocation of CaM, suggesting that MEL activates CaM-dependent enzymes by this pathway. In this work we investigated whether MEL stimulates dendrite formation by CaMKII activation in organotypic cultures from adult rat hippocampus. We found that the CaMKII inhibitor, KN-62, abolished the MEL stimulatory effects on dendritogenesis and that MEL increased the relative amount of CaM in the soluble fraction of hippocampal slices. Also, PKC inhibition abolished dendritogenesis, while luzindole, an antagonist of MEL receptors (MT1/2), partially blocked the effects of MEL. Moreover, autophosphorylation of CaMKII and PKC was increased in presence of MEL, as well as phosphorylation of ERK1/2. Our results indicate that MEL stimulates dendrite formation through CaMKII and the translocation of CaM to the soluble fraction. Dendritogenesis elicited by MEL also required PKC activation, and signaling through MT1/2 receptors was partially involved. Data strongly suggest that MEL could repair the loss of hippocampal dendrites that occur in neuropsychiatric disorders by increasing CaM levels and activation of CaMKII.
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Affiliation(s)
- Aline Domínguez-Alonso
- Laboratorio de Neurofarmacología, Subdirección de Investigaciones Clínicas, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco No. 101, Col. San Lorenzo-Huipulco, CP 14370 Tlalpan, DF, Mexico.
| | - Marcela Valdés-Tovar
- Laboratorio de Neurofarmacología, Subdirección de Investigaciones Clínicas, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco No. 101, Col. San Lorenzo-Huipulco, CP 14370 Tlalpan, DF, Mexico.
| | - Héctor Solís-Chagoyán
- Laboratorio de Neurofarmacología, Subdirección de Investigaciones Clínicas, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco No. 101, Col. San Lorenzo-Huipulco, CP 14370 Tlalpan, DF, Mexico.
| | - Gloria Benítez-King
- Laboratorio de Neurofarmacología, Subdirección de Investigaciones Clínicas, Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz, Calzada México-Xochimilco No. 101, Col. San Lorenzo-Huipulco, CP 14370 Tlalpan, DF, Mexico.
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24
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Hamad MIK, Krause M, Wahle P. Improving AM ester calcium dye loading efficiency. J Neurosci Methods 2014; 240:48-60. [PMID: 25448382 DOI: 10.1016/j.jneumeth.2014.11.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 11/11/2014] [Accepted: 11/12/2014] [Indexed: 11/25/2022]
Abstract
BACKGROUND Calcium imaging has unraveled the calcium-dependent mechanisms underlying neuronal function. Acetoxymethyl ester (AM) dyes are widely employed for calcium imaging. Pluronic F127 (PF127) as a surfactant and dimethyl sulfoxide (DMSO) as a solvent are used to dissolve the dyes, but concentrations vary between protocols. How these substances affect loading efficiency is not well characterized. NEW METHOD We aimed to characterize dye loading in slice cultures. We determined minimum concentrations of surfactant, solvent and dye. The current study shows that the efficiency of AM dye loading depends on the initial stock concentration of PF127. Lowering the PF127 and DMSO concentrations can improve the loading efficiency. RESULTS Both, pluronic and DMSO are required for successful dye loading. However, dissolving the dyes in lower concentrations of PF127 yielded better staining efficiency. Moreover, lowering the DMSO concentration to ∼0.25% improves the efficiency. The strategy allows standard two-photon or confocal microscope monitoring of neuronal activity. The labeled cells display spontaneous and evoked calcium transients, and repetitive measurements for up to 24h after loading indicate that the method is not deleterious to neuronal function. COMPARISON WITH EXISTING METHOD(S) Dissolving the AM dyes in lower concentrations of PF127 combines the advantages of high loading efficiency, preserves cell viability and functional integrity, and allows repetitive measures over hours and days. Moreover, we found that the dye itself can be diluted to a final concentration of 1μM which reduces the experimental costs. CONCLUSION The method is optimal for calcium imaging in slice cultures.
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Affiliation(s)
- Mohammad I K Hamad
- AG Entwicklungsneurobiologie, Fakultät für Biologie, Ruhr Universität Bochum, D-44780 Bochum, Germany.
| | - Martin Krause
- Lehrstuhl für Allgemeine Zoologie und Neurobiologie, Ruhr Universität Bochum, D-44780 Bochum, Germany
| | - Petra Wahle
- AG Entwicklungsneurobiologie, Fakultät für Biologie, Ruhr Universität Bochum, D-44780 Bochum, Germany
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