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Byeon S, Yadav S. Pleiotropic functions of TAO kinases and their dysregulation in neurological disorders. Sci Signal 2024; 17:eadg0876. [PMID: 38166033 DOI: 10.1126/scisignal.adg0876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 12/07/2023] [Indexed: 01/04/2024]
Abstract
Thousand and one amino acid kinases (TAOKs) are relatively understudied and functionally pleiotropic protein kinases that have emerged as important regulators of neurodevelopment. Through their conserved amino-terminal catalytic domain, TAOKs mediate phosphorylation at serine/threonine residues in their substrates, but it is their divergent regulatory carboxyl-terminal domains that confer both exquisite functional specification and cellular localization. In this Review, we discuss the physiological roles of TAOKs and the intricate signaling pathways, molecular interactions, and cellular behaviors they modulate-from cell stress responses, division, and motility to tissue homeostasis, immunity, and neurodevelopment. These insights are then integrated into an analysis of the known and potential impacts of disease-associated variants of TAOKs, with a focus on neurodevelopmental disorders, pain and addiction, and neurodegenerative diseases. Translating this foundation into clinical benefits for patients will require greater structural and functional differentiation of the TAOKs afforded by their individually specialized domains.
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Affiliation(s)
- Sujin Byeon
- Graduate Program in Neuroscience, University of Washington, Seattle, WA 98195, USA
| | - Smita Yadav
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
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2
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Patel AA, Cardona A, Cox DN. Neural substrates of cold nociception in Drosophila larva. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.31.551339. [PMID: 37577520 PMCID: PMC10418107 DOI: 10.1101/2023.07.31.551339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Metazoans detect and differentiate between innocuous (non-painful) and/or noxious (harmful) environmental cues using primary sensory neurons, which serve as the first node in a neural network that computes stimulus specific behaviors to either navigate away from injury-causing conditions or to perform protective behaviors that mitigate extensive injury. The ability of an animal to detect and respond to various sensory stimuli depends upon molecular diversity in the primary sensors and the underlying neural circuitry responsible for the relevant behavioral action selection. Recent studies in Drosophila larvae have revealed that somatosensory class III multidendritic (CIII md) neurons function as multimodal sensors regulating distinct behavioral responses to innocuous mechanical and nociceptive thermal stimuli. Recent advances in circuit bases of behavior have identified and functionally validated Drosophila larval somatosensory circuitry involved in innocuous (mechanical) and noxious (heat and mechanical) cues. However, central processing of cold nociceptive cues remained unexplored. We implicate multisensory integrators (Basins), premotor (Down-and-Back) and projection (A09e and TePns) neurons as neural substrates required for cold-evoked behavioral and calcium responses. Neural silencing of cell types downstream of CIII md neurons led to significant reductions in cold-evoked behaviors and neural co-activation of CIII md neurons plus additional cell types facilitated larval contraction (CT) responses. We further demonstrate that optogenetic activation of CIII md neurons evokes calcium increases in these neurons. Collectively, we demonstrate how Drosophila larvae process cold stimuli through functionally diverse somatosensory circuitry responsible for generating stimulus specific behaviors.
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Affiliation(s)
- Atit A. Patel
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Albert Cardona
- HHMI Janelia Research Campus, Ashburn, VA, USA
- MRC Laboratory of Molecular Biology, Cambridge, UK
- Department of Physiology, Development, and Neuroscience, University of Cambridge, UK
| | - Daniel N. Cox
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
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Roberto GM, Boutet A, Keil S, Emery G. Dual regulation of Misshapen by Tao and Rap2l promotes collective cell migration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.21.550060. [PMID: 37503122 PMCID: PMC10370187 DOI: 10.1101/2023.07.21.550060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Collective cell migration occurs in various biological processes such as development, wound healing and metastasis. During Drosophila oogenesis, border cells (BC) form a cluster that migrates collectively inside the egg chamber. The Ste20-like kinase Misshapen (Msn) is a key regulator of BC migration coordinating the restriction of protrusion formation and contractile forces within the cluster. Here, we demonstrate that the kinase Tao acts as an upstream activator of Msn in BCs. Depletion of Tao significantly impedes BC migration and produces a phenotype similar to Msn loss-of-function. Furthermore, we show that the localization of Msn relies on its CNH domain, which interacts with the small GTPase Rap2l. Our findings indicate that Rap2l promotes the trafficking of Msn to the endolysosomal pathway. When Rap2l is depleted, the levels of Msn increase in the cytoplasm and at cell-cell junctions between BCs. Overall, our data suggest that Rap2l ensures that the levels of Msn are higher at the periphery of the cluster through the targeting of Msn to the degradative pathway. Together, we identified two distinct regulatory mechanisms that ensure the appropriate distribution and activation of Msn in BCs.
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Beeman N, Sapre T, Ong SE, Yadav S. Neurodevelopmental disorder-associated mutations in TAOK1 reveal its function as a plasma membrane remodeling kinase. Sci Signal 2023; 16:eadd3269. [PMID: 36595571 PMCID: PMC9970049 DOI: 10.1126/scisignal.add3269] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Mutations in TAOK1, which encodes a serine-threonine kinase, are associated with both autism spectrum disorder (ASD) and neurodevelopmental delay (NDD). Here, we investigated the molecular function of this evolutionarily conserved kinase and the mechanisms through which TAOK1 mutations may lead to neuropathology. We found that TAOK1 was abundant in neurons in the mammalian brain and remodeled the neuronal plasma membrane through direct association with phosphoinositides. Our characterization of four NDD-associated TAOK1 mutations revealed that these mutants were catalytically inactive and were aberrantly trapped in a membrane-bound state, which induced abnormal membrane protrusions. Expression of these TAOK1 mutants in cultured mouse hippocampal neurons led to abnormal growth of the dendritic arbor. The coiled-coil region carboxyl-terminal to the kinase domain was predicted to fold into a triple helix, and this region directly bound phospholipids and was required for both membrane association and induction of aberrant protrusions. Autophosphorylation of threonine-440 and threonine-443 in the triple-helical region by the kinase domain blocked the plasma membrane association of TAOK1. These findings define TAOK1 as a plasma membrane remodeling kinase and reveal the underlying mechanisms through which TAOK1 dysfunction may lead to neurodevelopmental disorders.
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Affiliation(s)
- Neal Beeman
- Department of Pharmacology, University of Washington, Seattle WA 98195
| | - Tanmay Sapre
- Department of Pharmacology, University of Washington, Seattle WA 98195
| | - Shao-En Ong
- Department of Pharmacology, University of Washington, Seattle WA 98195
| | - Smita Yadav
- Department of Pharmacology, University of Washington, Seattle WA 98195,Corresponding author:
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Ecovoiu AA, Ratiu AC, Micheu MM, Chifiriuc MC. Inter-Species Rescue of Mutant Phenotype-The Standard for Genetic Analysis of Human Genetic Disorders in Drosophila melanogaster Model. Int J Mol Sci 2022; 23:2613. [PMID: 35269756 PMCID: PMC8909942 DOI: 10.3390/ijms23052613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/23/2022] [Accepted: 02/24/2022] [Indexed: 11/16/2022] Open
Abstract
Drosophila melanogaster (the fruit fly) is arguably a superstar of genetics, an astonishing versatile experimental model which fueled no less than six Nobel prizes in medicine. Nowadays, an evolving research endeavor is to simulate and investigate human genetic diseases in the powerful D. melanogaster platform. Such a translational experimental strategy is expected to allow scientists not only to understand the molecular mechanisms of the respective disorders but also to alleviate or even cure them. In this regard, functional gene orthology should be initially confirmed in vivo by transferring human or vertebrate orthologous transgenes in specific mutant backgrounds of D. melanogaster. If such a transgene rescues, at least partially, the mutant phenotype, then it qualifies as a strong candidate for modeling the respective genetic disorder in the fruit fly. Herein, we review various examples of inter-species rescue of relevant mutant phenotypes of the fruit fly and discuss how these results recommend several human genes as candidates to study and validate genetic variants associated with human diseases. We also consider that a wider implementation of this evolutionist exploratory approach as a standard for the medicine of genetic disorders would allow this particular field of human health to advance at a faster pace.
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Affiliation(s)
- Alexandru Al. Ecovoiu
- Department of Genetics, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania;
| | - Attila Cristian Ratiu
- Department of Genetics, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania;
| | - Miruna Mihaela Micheu
- Department of Cardiology, Clinical Emergency Hospital of Bucharest, 014461 Bucharest, Romania;
| | - Mariana Carmen Chifiriuc
- The Research Institute of the University of Bucharest and Faculty of Biology, University of Bucharest, 050095 Bucharest, Romania;
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Heckman EL, Doe CQ. Presynaptic contact and activity opposingly regulate postsynaptic dendrite outgrowth. eLife 2022; 11:82093. [PMID: 36448675 PMCID: PMC9728994 DOI: 10.7554/elife.82093] [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: 07/27/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022] Open
Abstract
The organization of neural circuits determines nervous system function. Variability can arise during neural circuit development (e.g. neurite morphology, axon/dendrite position). To ensure robust nervous system function, mechanisms must exist to accommodate variation in neurite positioning during circuit formation. Previously, we developed a model system in the Drosophila ventral nerve cord to conditionally induce positional variability of a proprioceptive sensory axon terminal, and used this model to show that when we altered the presynaptic position of the sensory neuron, its major postsynaptic interneuron partner modified its dendritic arbor to match the presynaptic contact, resulting in functional synaptic input (Sales et al., 2019). Here, we investigate the cellular mechanisms by which the interneuron dendrites detect and match variation in presynaptic partner location and input strength. We manipulate the presynaptic sensory neuron by (a) ablation; (b) silencing or activation; or (c) altering its location in the neuropil. From these experiments we conclude that there are two opposing mechanisms used to establish functional connectivity in the face of presynaptic variability: presynaptic contact stimulates dendrite outgrowth locally, whereas presynaptic activity inhibits postsynaptic dendrite outgrowth globally. These mechanisms are only active during an early larval critical period for structural plasticity. Collectively, our data provide new insights into dendrite development, identifying mechanisms that allow dendrites to flexibly respond to developmental variability in presynaptic location and input strength.
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Affiliation(s)
- Emily L Heckman
- Institute of Neuroscience, Howard Hughes Medical Institute, University of OregonEugeneUnited States
| | - Chris Q Doe
- Institute of Neuroscience, Howard Hughes Medical Institute, University of OregonEugeneUnited States
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Imambocus BN, Zhou F, Formozov A, Wittich A, Tenedini FM, Hu C, Sauter K, Macarenhas Varela E, Herédia F, Casimiro AP, Macedo A, Schlegel P, Yang CH, Miguel-Aliaga I, Wiegert JS, Pankratz MJ, Gontijo AM, Cardona A, Soba P. A neuropeptidergic circuit gates selective escape behavior of Drosophila larvae. Curr Biol 2021; 32:149-163.e8. [PMID: 34798050 DOI: 10.1016/j.cub.2021.10.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 10/05/2021] [Accepted: 10/29/2021] [Indexed: 12/26/2022]
Abstract
Animals display selective escape behaviors when faced with environmental threats. Selection of the appropriate response by the underlying neuronal network is key to maximizing chances of survival, yet the underlying network mechanisms are so far not fully understood. Using synapse-level reconstruction of the Drosophila larval network paired with physiological and behavioral readouts, we uncovered a circuit that gates selective escape behavior for noxious light through acute and input-specific neuropeptide action. Sensory neurons required for avoidance of noxious light and escape in response to harsh touch, each converge on discrete domains of neuromodulatory hub neurons. We show that acute release of hub neuron-derived insulin-like peptide 7 (Ilp7) and cognate relaxin family receptor (Lgr4) signaling in downstream neurons are required for noxious light avoidance, but not harsh touch responses. Our work highlights a role for compartmentalized circuit organization and neuropeptide release from regulatory hubs, acting as central circuit elements gating escape responses.
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Affiliation(s)
- Bibi Nusreen Imambocus
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany; Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Fangmin Zhou
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany; Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Andrey Formozov
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Annika Wittich
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Federico M Tenedini
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Chun Hu
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Kathrin Sauter
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Ednilson Macarenhas Varela
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - Fabiana Herédia
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - Andreia P Casimiro
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - André Macedo
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal
| | - Philipp Schlegel
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany
| | - Chung-Hui Yang
- Department of Neurobiology, Duke University Medical School, 427E Bryan Research, Durham, NC 27710, USA
| | - Irene Miguel-Aliaga
- MRC London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK
| | - J Simon Wiegert
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany
| | - Michael J Pankratz
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany
| | - Alisson M Gontijo
- Integrative Biomedicine Laboratory, CEDOC, Chronic Diseases Research Center, NOVA Medical School, Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Rua do Instituto Bacteriológico 5, 1150-082 Lisbon, Portugal; The Discoveries Centre for Regenerative and Precision Medicine, Lisbon Campus, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Albert Cardona
- HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK; Department of Physiology, Development, and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Peter Soba
- LIMES Institute, Department of Molecular Brain Physiology and Behavior, University of Bonn, Carl-Troll-Str. 31, 53115 Bonn, Germany; Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Falkenried 94, 20251 Hamburg, Germany.
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Abstract
Critical periods-brief intervals during which neural circuits can be modified by activity-are necessary for proper neural circuit assembly. Extended critical periods are associated with neurodevelopmental disorders; however, the mechanisms that ensure timely critical period closure remain poorly understood1,2. Here we define a critical period in a developing Drosophila motor circuit and identify astrocytes as essential for proper critical period termination. During the critical period, changes in activity regulate dendrite length, complexity and connectivity of motor neurons. Astrocytes invaded the neuropil just before critical period closure3, and astrocyte ablation prolonged the critical period. Finally, we used a genetic screen to identify astrocyte-motor neuron signalling pathways that close the critical period, including Neuroligin-Neurexin signalling. Reduced signalling destabilized dendritic microtubules, increased dendrite dynamicity and impaired locomotor behaviour, underscoring the importance of critical period closure. Previous work defined astroglia as regulators of plasticity at individual synapses4; we show here that astrocytes also regulate motor circuit critical period closure to ensure proper locomotor behaviour.
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Hu C, Feng P, Yang Q, Xiao L. Clinical and Neurobiological Aspects of TAO Kinase Family in Neurodevelopmental Disorders. Front Mol Neurosci 2021; 14:655037. [PMID: 33867937 PMCID: PMC8044823 DOI: 10.3389/fnmol.2021.655037] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/04/2021] [Indexed: 12/20/2022] Open
Abstract
Despite the complexity of neurodevelopmental disorders (NDDs), from their genotype to phenotype, in the last few decades substantial progress has been made in understanding their pathophysiology. Recent accumulating evidence shows the relevance of genetic variants in thousand and one (TAO) kinases as major contributors to several NDDs. Although it is well-known that TAO kinases are a highly conserved family of STE20 kinase and play important roles in multiple biological processes, the emerging roles of TAO kinases in neurodevelopment and NDDs have yet to be intensively discussed. In this review article, we summarize the potential roles of the TAO kinases based on structural and biochemical analyses, present the genetic data from clinical investigations, and assess the mechanistic link between the mutations of TAO kinases, neuropathology, and behavioral impairment in NDDs. We then offer potential perspectives from basic research to clinical therapies, which may contribute to fully understanding how TAO kinases are involved in NDDs.
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Affiliation(s)
- Chun Hu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou, China.,Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
| | - Pan Feng
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou, China.,Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
| | - Qian Yang
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou, China.,Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
| | - Lin Xiao
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, South China Normal University, Guangzhou, China.,Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
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10
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Heckman EL, Doe CQ. Establishment and Maintenance of Neural Circuit Architecture. J Neurosci 2021; 41:1119-1129. [PMID: 33568445 PMCID: PMC7888231 DOI: 10.1523/jneurosci.1143-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 11/29/2020] [Accepted: 12/09/2020] [Indexed: 02/03/2023] Open
Abstract
The ability to sense the world, process information, and navigate the environment depends on the assembly and continuous function of neural circuits in the brain. Within the past two decades, new technologies have rapidly advanced our understanding of how neural circuits are wired during development and how they are stably maintained, often for years. Electron microscopy reconstructions of model organism connectomes have provided a map of the stereotyped (and variable) connections in the brain; advanced light microscopy techniques have enabled direct observation of the cellular dynamics that underlie circuit construction and maintenance; transcriptomic and proteomic surveys of both developing and mature neurons have provided insights into the molecular and genetic programs governing circuit establishment and maintenance; and advanced genetic techniques have allowed for high-throughput discovery of wiring regulators. These tools have empowered scientists to rapidly generate and test hypotheses about how circuits establish and maintain connectivity. Thus, the set of principles governing circuit formation and maintenance have been expanded. These principles are discussed in this review.
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Affiliation(s)
- Emily L Heckman
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon 97403
| | - Chris Q Doe
- Institute of Neuroscience, Institute of Molecular Biology, Howard Hughes Medical Institute, University of Oregon, Eugene, Oregon 97403
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Elkahlah NA, Rogow JA, Ahmed M, Clowney EJ. Presynaptic developmental plasticity allows robust sparse wiring of the Drosophila mushroom body. eLife 2020; 9:e52278. [PMID: 31913123 PMCID: PMC7028369 DOI: 10.7554/elife.52278] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 01/07/2020] [Indexed: 01/29/2023] Open
Abstract
In order to represent complex stimuli, principle neurons of associative learning regions receive combinatorial sensory inputs. Density of combinatorial innervation is theorized to determine the number of distinct stimuli that can be represented and distinguished from one another, with sparse innervation thought to optimize the complexity of representations in networks of limited size. How the convergence of combinatorial inputs to principle neurons of associative brain regions is established during development is unknown. Here, we explore the developmental patterning of sparse olfactory inputs to Kenyon cells of the Drosophila melanogaster mushroom body. By manipulating the ratio between pre- and post-synaptic cells, we find that postsynaptic Kenyon cells set convergence ratio: Kenyon cells produce fixed distributions of dendritic claws while presynaptic processes are plastic. Moreover, we show that sparse odor responses are preserved in mushroom bodies with reduced cellular repertoires, suggesting that developmental specification of convergence ratio allows functional robustness.
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Affiliation(s)
- Najia A Elkahlah
- Department of Molecular, Cellular and Developmental BiologyThe University of MichiganAnn ArborUnited States
| | - Jackson A Rogow
- Laboratory of Neurophysiology and BehaviorThe Rockefeller UniversityNew YorkUnited States
| | - Maria Ahmed
- Department of Molecular, Cellular and Developmental BiologyThe University of MichiganAnn ArborUnited States
| | - E Josephine Clowney
- Department of Molecular, Cellular and Developmental BiologyThe University of MichiganAnn ArborUnited States
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