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Komo L, Charabidze D. Balance between larval and pupal development time in carrion blowflies. JOURNAL OF INSECT PHYSIOLOGY 2021; 133:104292. [PMID: 34371061 DOI: 10.1016/j.jinsphys.2021.104292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/25/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
Several studies have highlighted the impact of environmental factors such as food type or larval density on the development of blowfly larvae. We investigated how changes in development speed (due to larval density and group composition) are divided among feeding and post-feeding stages. Even if these parameters impinge only on feeding larvae, they may ultimately also affect their subsequent development, and especially metamorphosis duration. Therefore, this study analysed the effect of larval density and group composition on the rhythm of necrophagous blowfly development. Based on laboratory studies, we highlighted that Calliphora vicina individuals with a fast development during their feeding phase developed slower in the later post-feeding phase (i.e., they had a compensatory effect). Lucilia sericata, a calliphorid species also frequently found on carrion at the same time as C. vicina, showed a different developmental strategy by not making its post-larval development speed dependent on the larval development speed. Finally, while a compensatory effect may exist, variations in the development rate more often accumulate through life-stages and resulted in a larger variability for later development instars. In this respect, the inclusion of detailed development duration covering all life stages, including post-feeding, is recommended in future studies, especially those dedicated to forensic entomology.
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Affiliation(s)
- Larissa Komo
- CHU Lille, EA 7367 - UTML - Unite de Taphonomie Medico-Legale, University of Lille, Rue André Verhaeghe, 59000 Lille, France.
| | - Damien Charabidze
- UMR 8025, Centre d'Histoire Judiciaire, Université de Lille, F-59000 Lille, France; Unit of Social Ecology (USE), Université Libre de Bruxelles (ULB), 1050 Bruxelles, Belgium
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2
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Galbraith A, Leone S, Stuart K, Emery J, Renkemeyer MK, Pritchett N, Galbraith L, Stuckmeyer H, Berke B. Reducing the expression of the Numb adaptor protein in neurons increases the searching behavior of Drosophila larvae. MICROPUBLICATION BIOLOGY 2021; 2021:10.17912/micropub.biology.000426. [PMID: 34327314 PMCID: PMC8314082 DOI: 10.17912/micropub.biology.000426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/23/2022]
Abstract
Drosophila larval crawling is easily-observable and relatively stereotyped. Crawling consists of linear locomotion interrupted by periods when the larvae pause, swing their heads, and change direction (a 'search'). Here we identify Numb, a peripheral membrane adaptor protein, as an important regulator of searching behavior. When Numb RNAi transgenes were expressed in all neurons, searching frequency increased while linear movement appeared normal. Numb's role in suppressing searching behavior was verified by rescuing this phenotype with a Numb homologue from mice. Such behavioral specificity suggests that further analysis of searching might help identify additional, evolutionarily-conserved interactors of the Numb protein.
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Affiliation(s)
- Andrew Galbraith
- Department of Biology, Truman State University, Kirksville, MO USA
| | - Samuel Leone
- Department of Biology, Truman State University, Kirksville, MO USA
| | - Katherine Stuart
- Department of Biology, Truman State University, Kirksville, MO USA
| | - Josie Emery
- Department of Biology, Truman State University, Kirksville, MO USA
| | | | | | - Lauren Galbraith
- Department of Biology, Truman State University, Kirksville, MO USA
| | - Haley Stuckmeyer
- Department of Biology, Truman State University, Kirksville, MO USA
| | - Brett Berke
- Department of Biology, Truman State University, Kirksville, MO USA,
Correspondence to: Brett Berke ()
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3
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Abstract
Diabetes and obesity are the two notorious metabolic disorders in today's world. Both diabetes and obesity are interlinked with each other and often referred to as 'Diabesity'. It is a complex and multi-organ failure disorder. Thus, many researches and tremendous efforts have been made toward prevention, treatment as well as early detection of diabesity. However, and still, there is a large gap in understanding the etiology as well as treatment of diabesity. Various animal models are also used to decipher the mechanism underlying diabesity. Among all the model organism, recently Drosophila melanogaster is gaining its importance to study diabetes, obesity, and other metabolic disorder. Various experimental methods like histological, biochemical, developmental, and behavioral assays are described in this study to detect diabetes as well as obesity in the fly model.
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Affiliation(s)
- Nibedita Nayak
- Neural Developmental Biology Lab, Department of Life Science, National Institute of Technology , Rourkela , India
| | - Monalisa Mishra
- Neural Developmental Biology Lab, Department of Life Science, National Institute of Technology , Rourkela , India
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4
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Scaplen KM, Mei NJ, Bounds HA, Song SL, Azanchi R, Kaun KR. Automated real-time quantification of group locomotor activity in Drosophila melanogaster. Sci Rep 2019; 9:4427. [PMID: 30872709 PMCID: PMC6418093 DOI: 10.1038/s41598-019-40952-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 02/25/2019] [Indexed: 11/09/2022] Open
Abstract
Recent advances in neurogenetics have highlighted Drosophila melanogaster as an exciting model to study neural circuit dynamics and complex behavior. Automated tracking methods have facilitated the study of complex behaviors via high throughput behavioral screening. Here we describe a newly developed low-cost assay capable of real-time monitoring and quantifying Drosophila group activity. This platform offers reliable real-time quantification with open source software and a user-friendly interface for data acquisition and analysis. We demonstrate the utility of this platform by characterizing ethanol-induced locomotor activity in a dose-dependent manner as well as the effects of thermo and optogenetic manipulation of ellipsoid body neurons important for ethanol-induced locomotor activity. As expected, low doses of ethanol induced an initial startle and slow ramping of group activity, whereas high doses of ethanol induced sustained group activity followed by sedation. Advanced offline processing revealed discrete behavioral features characteristic of intoxication. Thermogenetic inactivation of ellipsoid body ring neurons reduced group activity whereas optogenetic activation increased activity. Together, these data establish the fly Group Activity Monitor (flyGrAM) platform as a robust means of obtaining an online read out of group activity in response to manipulations to the environment or neural activity, with an opportunity for more advanced post-processing offline.
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Affiliation(s)
- Kristin M Scaplen
- Department of Neuroscience, Brown University Providence, Providence, USA
| | - Nicholas J Mei
- Department of Neuroscience, Brown University Providence, Providence, USA
| | - Hayley A Bounds
- Department of Neuroscience, Brown University Providence, Providence, USA
| | - Sophia L Song
- Department of Neuroscience, Brown University Providence, Providence, USA
| | - Reza Azanchi
- Department of Neuroscience, Brown University Providence, Providence, USA
| | - Karla R Kaun
- Department of Neuroscience, Brown University Providence, Providence, USA.
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5
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Tyramine action on motoneuron excitability and adaptable tyramine/octopamine ratios adjust Drosophila locomotion to nutritional state. Proc Natl Acad Sci U S A 2019; 116:3805-3810. [PMID: 30808766 DOI: 10.1073/pnas.1813554116] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Adrenergic signaling profoundly modulates animal behavior. For example, the invertebrate counterpart of norepinephrine, octopamine, and its biological precursor and functional antagonist, tyramine, adjust motor behavior to different nutritional states. In Drosophila larvae, food deprivation increases locomotor speed via octopamine-mediated structural plasticity of neuromuscular synapses, whereas tyramine reduces locomotor speed, but the underlying cellular and molecular mechanisms remain unknown. We show that tyramine is released into the CNS to reduce motoneuron intrinsic excitability and responses to excitatory cholinergic input, both by tyraminehonoka receptor activation and by downstream decrease of L-type calcium current. This central effect of tyramine on motoneurons is required for the adaptive reduction of locomotor activity after feeding. Similarly, peripheral octopamine action on motoneurons has been reported to be required for increasing locomotion upon starvation. We further show that the level of tyramine-β-hydroxylase (TBH), the enzyme that converts tyramine into octopamine in aminergic neurons, is increased by food deprivation, thus selecting between antagonistic amine actions on motoneurons. Therefore, octopamine and tyramine provide global but distinctly different mechanisms to regulate motoneuron excitability and behavioral plasticity, and their antagonistic actions are balanced within a dynamic range by nutritional effects on TBH.
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Syed A, Lukacsovich T, Pomeroy M, Bardwell AJ, Decker GT, Waymire KG, Purcell J, Huang W, Gui J, Padilla EM, Park C, Paul A, Pham TBT, Rodriguez Y, Wei S, Worthge S, Zebarjedi R, Zhang B, Bardwell L, Marsh JL, MacGregor GR. Miles to go (mtgo) encodes FNDC3 proteins that interact with the chaperonin subunit CCT3 and are required for NMJ branching and growth in Drosophila. Dev Biol 2018; 445:37-53. [PMID: 30539716 DOI: 10.1016/j.ydbio.2018.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 09/01/2018] [Accepted: 10/17/2018] [Indexed: 11/17/2022]
Abstract
Analysis of mutants that affect formation and function of the Drosophila larval neuromuscular junction (NMJ) has provided valuable insight into genes required for neuronal branching and synaptic growth. We report that NMJ development in Drosophila requires both the Drosophila ortholog of FNDC3 genes; CG42389 (herein referred to as miles to go; mtgo), and CCT3, which encodes a chaperonin complex subunit. Loss of mtgo function causes late pupal lethality with most animals unable to escape the pupal case, while rare escapers exhibit an ataxic gait and reduced lifespan. NMJs in mtgo mutant larvae have dramatically reduced branching and growth and fewer synaptic boutons compared with control animals. Mutant larvae show normal locomotion but display an abnormal self-righting response and chemosensory deficits that suggest additional functions of mtgo within the nervous system. The pharate lethality in mtgo mutants can be rescued by both low-level pan- and neuronal-, but not muscle-specific expression of a mtgo transgene, supporting a neuronal-intrinsic requirement for mtgo in NMJ development. Mtgo encodes three similar proteins whose domain structure is most closely related to the vertebrate intracellular cytosolic membrane-anchored fibronectin type-III domain-containing protein 3 (FNDC3) protein family. Mtgo physically and genetically interacts with Drosophila CCT3, which encodes a subunit of the TRiC/CCT chaperonin complex required for maturation of actin, tubulin and other substrates. Drosophila larvae heterozygous for a mutation in CCT3 that reduces binding between CCT3 and MTGO also show abnormal NMJ development similar to that observed in mtgo null mutants. Hence, the intracellular FNDC3-ortholog MTGO and CCT3 can form a macromolecular complex, and are both required for NMJ development in Drosophila.
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Affiliation(s)
- Adeela Syed
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Tamás Lukacsovich
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Miles Pomeroy
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - A Jane Bardwell
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Gentry Thomas Decker
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211-7400, USA
| | - Katrina G Waymire
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Judith Purcell
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Weijian Huang
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - James Gui
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Emily M Padilla
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Cindy Park
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Antor Paul
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Thai Bin T Pham
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Yanete Rodriguez
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Stephen Wei
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Shane Worthge
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Ronak Zebarjedi
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - Bing Zhang
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211-7400, USA
| | - Lee Bardwell
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA
| | - J Lawrence Marsh
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA.
| | - Grant R MacGregor
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California, Irvine, Irvine, CA 92697-2300, USA.
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7
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Kinold JC, Pfarr C, Aberle H. Sidestep-induced neuromuscular miswiring causes severe locomotion defects in Drosophila larvae. Development 2018; 145:145/17/dev163279. [DOI: 10.1242/dev.163279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 07/17/2018] [Indexed: 01/12/2023]
Abstract
ABSTRACT
Mutations in motor axon guidance molecules cause aberrant projection patterns of motor nerves. As most studies in Drosophila have analysed these molecules in fixed embryos, the consequences for larval locomotion are entirely unexplored. Here, we took advantage of sidestep (side)-mutant larvae that display severe locomotion defects because of irreparable innervation errors. Mutations in side affected all motor nerve branches and all body wall regions. Innervation defects were non-stereotypical, showing unique innervation patterns in each hemisegment. Premature activation of Side in muscle precursors abrogated dorsal migration of motor nerves, resulting in larvae with a complete loss of neuromuscular junctions on dorsal-most muscles. High-speed videography showed that these larvae failed to maintain substrate contact and inappropriately raised both head and tail segments above the substrate, resulting in unique ‘arching’ and ‘lifting’ phenotypes. These results show that guidance errors in side mutants are maintained throughout larval life and are asymmetrical with respect to the bilateral body axis. Together with similar findings in mice, this study also suggests that miswiring could be an underlying cause of inherited movement disorders.
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Affiliation(s)
- Jaqueline C. Kinold
- Heinrich Heine University Düsseldorf, Functional Cell Morphology Lab, Building 26-12-00, Universitaetsstrasse 1, 40225 Düsseldorf, Germany
| | - Carsten Pfarr
- Heinrich Heine University Düsseldorf, Functional Cell Morphology Lab, Building 26-12-00, Universitaetsstrasse 1, 40225 Düsseldorf, Germany
| | - Hermann Aberle
- Heinrich Heine University Düsseldorf, Functional Cell Morphology Lab, Building 26-12-00, Universitaetsstrasse 1, 40225 Düsseldorf, Germany
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Aleman-Meza B, Loeza-Cabrera M, Peña-Ramos O, Stern M, Zhong W. High-content behavioral profiling reveals neuronal genetic network modulating Drosophila larval locomotor program. BMC Genet 2017; 18:40. [PMID: 28499390 PMCID: PMC5429570 DOI: 10.1186/s12863-017-0513-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/09/2017] [Indexed: 12/04/2022] Open
Abstract
Background Two key questions in understanding the genetic control of behaviors are: what genes are involved and how these genes interact. To answer these questions at a systems level, we conducted high-content profiling of Drosophila larval locomotor behaviors for over 100 genotypes. Results We studied 69 genes whose C. elegans orthologs were neuronal signalling genes with significant locomotor phenotypes, and conducted RNAi with ubiquitous, pan-neuronal, or motor-neuronal Gal4 drivers. Inactivation of 42 genes, including the nicotinic acetylcholine receptors nAChRα1 and nAChRα3, in the neurons caused significant movement defects. Bioinformatic analysis suggested 81 interactions among these genes based on phenotypic pattern similarities. Comparing the worm and fly data sets, we found that these genes were highly conserved in having neuronal expressions and locomotor phenotypes. However, the genetic interactions were not conserved for ubiquitous profiles, and may be mildly conserved for the neuronal profiles. Unexpectedly, our data also revealed a possible motor-neuronal control of body size, because inactivation of Rdl and Gαo in the motor neurons reduced the larval body size. Overall, these data established a framework for further exploring the genetic control of Drosophila larval locomotion. Conclusions High content, quantitative phenotyping of larval locomotor behaviours provides a framework for system-level understanding of the gene networks underlying such behaviours. Electronic supplementary material The online version of this article (doi:10.1186/s12863-017-0513-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | - Omar Peña-Ramos
- Department of BioSciences, Rice University, Houston, TX, 77005, USA
| | - Michael Stern
- Department of BioSciences, Rice University, Houston, TX, 77005, USA
| | - Weiwei Zhong
- Department of BioSciences, Rice University, Houston, TX, 77005, USA.
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Kohsaka H, Guertin PA, Nose A. Neural Circuits Underlying Fly Larval Locomotion. Curr Pharm Des 2017; 23:1722-1733. [PMID: 27928962 PMCID: PMC5470056 DOI: 10.2174/1381612822666161208120835] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/01/2016] [Indexed: 12/17/2022]
Abstract
Locomotion is a complex motor behavior that may be expressed in different ways using a variety of strategies depending upon species and pathological or environmental conditions. Quadrupedal or bipedal walking, running, swimming, flying and gliding constitute some of the locomotor modes enabling the body, in all cases, to move from one place to another. Despite these apparent differences in modes of locomotion, both vertebrate and invertebrate species share, at least in part, comparable neural control mechanisms for locomotor rhythm and pattern generation and modulation. Significant advances have been made in recent years in studies of the genetic aspects of these control systems. Findings made specifically using Drosophila (fruit fly) models and preparations have contributed to further understanding of the key role of genes in locomotion. This review focuses on some of the main findings made in larval fruit flies while briefly summarizing the basic advantages of using this powerful animal model for studying the neural locomotor system.
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Affiliation(s)
- Hiroshi Kohsaka
- Department of Complexity Science and Engineering, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
| | - Pierre A. Guertin
- Department of Psychiatry & Neurosciences, Laval University, Québec City, QC, Canada
| | - Akinao Nose
- Department of Complexity Science and Engineering, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8561, Japan
- Department of Physics, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Transmembrane channel-like (tmc) gene regulates Drosophila larval locomotion. Proc Natl Acad Sci U S A 2016; 113:7243-8. [PMID: 27298354 DOI: 10.1073/pnas.1606537113] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Drosophila larval locomotion, which entails rhythmic body contractions, is controlled by sensory feedback from proprioceptors. The molecular mechanisms mediating this feedback are little understood. By using genetic knock-in and immunostaining, we found that the Drosophila melanogaster transmembrane channel-like (tmc) gene is expressed in the larval class I and class II dendritic arborization (da) neurons and bipolar dendrite (bd) neurons, both of which are known to provide sensory feedback for larval locomotion. Larvae with knockdown or loss of tmc function displayed reduced crawling speeds, increased head cast frequencies, and enhanced backward locomotion. Expressing Drosophila TMC or mammalian TMC1 and/or TMC2 in the tmc-positive neurons rescued these mutant phenotypes. Bending of the larval body activated the tmc-positive neurons, and in tmc mutants this bending response was impaired. This implicates TMC's roles in Drosophila proprioception and the sensory control of larval locomotion. It also provides evidence for a functional conservation between Drosophila and mammalian TMCs.
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Seada MA, Elkholy SE, Meshrif WS. Does the cellphone radio-frequency electromagnetic radiation during ringing or talking modes induce locomotor disturbance inDrosophila melanogaster? AFRICAN ZOOLOGY 2016. [DOI: 10.1080/15627020.2016.1151828] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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12
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An automated system for quantitative analysis of Drosophila larval locomotion. BMC DEVELOPMENTAL BIOLOGY 2015; 15:11. [PMID: 25881248 PMCID: PMC4345013 DOI: 10.1186/s12861-015-0062-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 02/16/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Drosophila larvae have been used as a model to study to genetic and cellular circuitries modulating behaviors. One of the challenges in behavioral study is the quantification of complex phenotypes such as locomotive behaviors. Experimental capability can be greatly enhanced by an automatic single-animal tracker that records an animal at a high resolution for an extended period, and analyzes multiple behavioral parameters. RESULTS Here we present MaggotTracker, a single-animal tracking system for Drosophila larval locomotion analysis. This system controls the motorized microscope stage while taking a video, so that the animal remains in the viewing center. It then reduces the animal to 13 evenly distributed points along the midline, and computes over 20 parameters evaluating the shape, peristalsis movement, stamina, and track of the animal. To demonstrate its utility, we applied MaggotTracker to analyze both wild-type and mutant animals to identify factors affecting locomotive behaviors. Each animal was tracked for four minutes. Our analysis on Canton-S third-instar larvae revealed that the distance an animal travelled was correlated to its striding speed rather than the percentage of time the animal spent striding, and that the striding speed was correlated to both the distance and the duration of one stride. Sexual dimorphism was observed in body length but not in locomotive parameters such as speed. Locomotive parameters were affected by animal developmental stage and the crawling surface. No significant changes in movement speed were detected in mutants of circadian genes such as period (per), timeout, and timeless (tim). The MaggotTracker analysis showed that ether a go-go (eag), Shaker (Sh), slowpoke (slo), and dunce (dnc) mutant larvae had severe phenotypes in multiple locomotive parameters such as stride distance and speed, consistent with their function in neuromuscular junctions. Further, the phenotypic patterns of the K(+) channel genes eag, Sh and slo are highly similar. CONCLUSIONS These results showed that MaggotTracker is an efficient tool for automatic phenotyping. The MaggotTracker software as well as the data presented here can be downloaded from our open-access site www.WormLoco.org/Mag.
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13
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Breda C, Nugent ML, Estranero JG, Kyriacou CP, Outeiro TF, Steinert JR, Giorgini F. Rab11 modulates α-synuclein-mediated defects in synaptic transmission and behaviour. Hum Mol Genet 2015; 24:1077-91. [PMID: 25305083 PMCID: PMC4986550 DOI: 10.1093/hmg/ddu521] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 09/17/2014] [Accepted: 10/07/2014] [Indexed: 01/03/2023] Open
Abstract
A central pathological hallmark of Parkinson's disease (PD) is the presence of proteinaceous depositions known as Lewy bodies, which consist largely of the protein α-synuclein (aSyn). Mutations, multiplications and polymorphisms in the gene encoding aSyn are associated with familial forms of PD and susceptibility to idiopathic PD. Alterations in aSyn impair neuronal vesicle formation/transport, and likely contribute to PD pathogenesis by neuronal dysfunction and degeneration. aSyn is functionally associated with several Rab family GTPases, which perform various roles in vesicle trafficking. Here, we explore the role of the endosomal recycling factor Rab11 in the pathogenesis of PD using Drosophila models of aSyn toxicity. We find that aSyn induces synaptic potentiation at the larval neuromuscular junction by increasing synaptic vesicle (SV) size, and that these alterations are reversed by Rab11 overexpression. Furthermore, Rab11 decreases aSyn aggregation and ameliorates several aSyn-dependent phenotypes in both larvae and adult fruit flies, including locomotor activity, degeneration of dopaminergic neurons and shortened lifespan. This work emphasizes the importance of Rab11 in the modulation of SV size and consequent enhancement of synaptic function. Our results suggest that targeting Rab11 activity could have a therapeutic value in PD.
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Affiliation(s)
- Carlo Breda
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Marie L Nugent
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK, MRC Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Jasper G Estranero
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
| | | | - Tiago F Outeiro
- Department of NeuroDegeneration and Restorative Research, Center for Nanoscale Microscopy and Molecular Physiology of the Brain, University Medical Center Goettingen, Göttingen, Germany and Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
| | - Joern R Steinert
- MRC Toxicology Unit, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Flaviano Giorgini
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK,
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14
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Risse B, Berh D, Otto N, Jiang X, Klämbt C. Quantifying subtle locomotion phenotypes of Drosophila larvae using internal structures based on FIM images. Comput Biol Med 2014; 63:269-76. [PMID: 25280919 DOI: 10.1016/j.compbiomed.2014.08.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 08/26/2014] [Accepted: 08/26/2014] [Indexed: 11/25/2022]
Abstract
Quantitative analysis of behavioral traits requires precise image acquisition and sophisticated image analysis to detect subtle locomotion phenotypes. In the past, we have established Frustrated Total Internal Reflection (FTIR) to improve the measurability of small animals like insects. This FTIR-based Imaging Method (FIM) results in an excellent foreground/background contrast and even internal organs and other structures are visible without any complicated imaging or labeling techniques. For example, the trachea and muscle organizations are detectable in FIM images. Here these morphological details are incorporated into phenotyping by performing cluster analysis using histogram-based statistics for the first time. We demonstrate that FIM enables the precise quantification of locomotion features namely rolling behavior or muscle contractions. Both were impossible to quantify automatically before. This approach extends the range of FIM applications by enabling advanced automatic phenotyping for particular locomotion patterns.
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Affiliation(s)
- Benjamin Risse
- Department of Computer Science, University of Münster, Einsteinstr. 62, 48149 Münster, Germany; Institute of Neuro and Behavioural Biology, University of Münster, Badestr. 9, 48149 Münster, Germany
| | - Dimitri Berh
- Department of Computer Science, University of Münster, Einsteinstr. 62, 48149 Münster, Germany; Institute of Neuro and Behavioural Biology, University of Münster, Badestr. 9, 48149 Münster, Germany
| | - Nils Otto
- Institute of Neuro and Behavioural Biology, University of Münster, Badestr. 9, 48149 Münster, Germany
| | - Xiaoyi Jiang
- Department of Computer Science, University of Münster, Einsteinstr. 62, 48149 Münster, Germany; Cluster of Excellence EXC 1003, Cells in Motion, CiM, Münster, Germany.
| | - Christian Klämbt
- Institute of Neuro and Behavioural Biology, University of Münster, Badestr. 9, 48149 Münster, Germany; Cluster of Excellence EXC 1003, Cells in Motion, CiM, Münster, Germany
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15
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Iyengar A, Wu CF. Flight and seizure motor patterns in Drosophila mutants: simultaneous acoustic and electrophysiological recordings of wing beats and flight muscle activity. J Neurogenet 2014; 28:316-28. [PMID: 25159538 PMCID: PMC5555410 DOI: 10.3109/01677063.2014.957827] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Abstract Tethered flies allow studies of biomechanics and electrophysiology of flight control. We performed microelectrode recordings of spikes in an indirect flight muscle (the dorsal longitudinal muscle, DLMa) coupled with acoustic analysis of wing beat frequency (WBF) via microphone signals. Simultaneous electrophysiological recording of direct and indirect flight muscles has been technically challenging; however, the WBF is thought to reflect in a one-to-one relationship with spiking activity in a subset of direct flight muscles, including muscle m1b. Therefore, our approach enables systematic mutational analysis for changes in temporal features of electrical activity of motor neurons innervating subsets of direct and indirect flight muscles. Here, we report the consequences of specific ion channel disruptions on the spiking activity of myogenic DLMs (firing at ∼5 Hz) and the corresponding WBF (∼200 Hz). We examined mutants of the genes enconding: 1) voltage-gated Ca(2+) channels (cacophony, cac), 2) Ca(2+)-activated K(+) channels (slowpoke, slo), and 3) voltage-gated K(+) channels (Shaker, Sh) and their auxiliary subunits (Hyperkinetic, Hk and quiver, qvr). We found flight initiation in response to an air puff was severely disrupted in both cac and slo mutants. However, once initiated, slo flight was largely unaltered, whereas cac displayed disrupted DLM firing rates and WBF. Sh, Hk, and qvr mutants were able to maintain normal DLM firing rates, despite increased WBF. Notably, defects in the auxiliary subunits encoded by Hk and qvr could lead to distinct consequences, that is, disrupted DLM firing rhythmicity, not observed in Sh. Our mutant analysis of direct and indirect flight muscle activities indicates that the two motor activity patterns may be independently modified by specific ion channel mutations, and that this approach can be extended to other dipteran species and additional motor programs, such as electroconvulsive stimulation-induced seizures.
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Affiliation(s)
- Atulya Iyengar
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Chun-Fang Wu
- Interdisciplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
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16
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Serotonin receptors expressed in Drosophila mushroom bodies differentially modulate larval locomotion. PLoS One 2014; 9:e89641. [PMID: 24586928 PMCID: PMC3934909 DOI: 10.1371/journal.pone.0089641] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 01/25/2014] [Indexed: 12/20/2022] Open
Abstract
Drosophila melanogaster has been successfully used as a simple model to study the cellular and molecular mechanisms underlying behaviors, including the generation of motor programs. Thus, it has been shown that, as in vertebrates, CNS biogenic amines (BA) including serotonin (5HT) participate in motor control in Drosophila. Several evidence show that BA systems innervate an important association area in the insect brain previously associated to the planning and/or execution of motor programs, the Mushroom Bodies (MB). The main objective of this work is to evaluate the contribution of 5HT and its receptors expressed in MB to motor behavior in fly larva. Locomotion was evaluated using an automated tracking system, in Drosophila larvae (3rd-instar) exposed to drugs that affect the serotonergic neuronal transmission: alpha-methyl-L-dopa, MDMA and fluoxetine. In addition, animals expressing mutations in the 5HT biosynthetic enzymes or in any of the previously identified receptors for this amine (5HT1AR, 5HT1BR, 5HT2R and 5HT7R) were evaluated in their locomotion. Finally, RNAi directed to the Drosophila 5HT receptor transcripts were expressed in MB and the effect of this manipulation on motor behavior was assessed. Data obtained in the mutants and in animals exposed to the serotonergic drugs, suggest that 5HT systems are important regulators of motor programs in fly larvae. Studies carried out in animals pan-neuronally expressing the RNAi for each of the serotonergic receptors, support this idea and further suggest that CNS 5HT pathways play a role in motor control. Moreover, animals expressing an RNAi for 5HT1BR, 5HT2R and 5HT7R in MB show increased motor behavior, while no effect is observed when the RNAi for 5HT1AR is expressed in this region. Thus, our data suggest that CNS 5HT systems are involved in motor control, and that 5HT receptors expressed in MB differentially modulate motor programs in fly larvae.
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17
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Aby E, Gumps K, Roth A, Sigmon S, Jenkins SE, Kim JJ, Kramer NJ, Parfitt KD, Korey CA. Mutations in palmitoyl-protein thioesterase 1 alter exocytosis and endocytosis at synapses in Drosophila larvae. Fly (Austin) 2013; 7:267-79. [PMID: 24091420 PMCID: PMC3896500 DOI: 10.4161/fly.26630] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 09/14/2013] [Accepted: 09/26/2013] [Indexed: 11/19/2022] Open
Abstract
Infantile-onset neuronal ceroid lipofuscinosis (INCL) is a severe pediatric neurodegenerative disorder produced by mutations in the gene encoding palmitoyl-protein thioesterase 1 (Ppt1). This enzyme is responsible for the removal of a palmitate group from its substrate proteins, which may include presynaptic proteins like SNAP-25, cysteine string protein (CSP), dynamin, and synaptotagmin. The fruit fly, Drosophila melanogaster, has been a powerful model system for studying the functions of these proteins and the molecular basis of neurological disorders like the NCLs. Genetic modifier screens and tracer uptake studies in Ppt1 mutant larval garland cells have suggested that Ppt1 plays a role in endocytic trafficking. We have extended this analysis to examine the involvement of Ppt1 in synaptic function at the Drosophila larval neuromuscular junction (NMJ). Mutations in Ppt1 genetically interact with temperature sensitive mutations in the Drosophila dynamin gene shibire, accelerating the paralytic behavior of shibire mutants at 27 °C. Electrophysiological work in NMJs of Ppt1-deficient larvae has revealed an increase in miniature excitatory junctional potentials (EJPs) and a significant depression of evoked EJPs in response to repetitive (10 hz) stimulation. Endocytosis was further examined in Ppt1-mutant larvae using FM1-43 uptake assays, demonstrating a significant decrease in FM1-43 uptake at the mutant NMJs. Finally, Ppt1-deficient and Ppt1 point mutant larvae display defects in locomotion that are consistent with alterations in synaptic function. Taken together, our genetic, cellular, and electrophysiological analyses suggest a direct role for Ppt1 in synaptic vesicle exo- and endocytosis at motor nerve terminals of the Drosophila NMJ.
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Affiliation(s)
- Elizabeth Aby
- Department of Biology; Pomona College; Claremont, CA USA
| | - Katherine Gumps
- Department of Biology; The College of Charleston; Charleston, SC USA
| | - Amalia Roth
- Department of Biology; Pomona College; Claremont, CA USA
| | - Stacey Sigmon
- Department of Biology; The College of Charleston; Charleston, SC USA
| | | | - Joyce J Kim
- Department of Biology; Pomona College; Claremont, CA USA
| | | | - Karen D Parfitt
- Department of Biology; Pomona College; Claremont, CA USA
- Program in Molecular Biology ; Pomona College; Claremont, CA USA
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18
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Characterization of Drosophila larval crawling at the level of organism, segment, and somatic body wall musculature. J Neurosci 2012; 32:12460-71. [PMID: 22956837 DOI: 10.1523/jneurosci.0222-12.2012] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Understanding rhythmic behavior at the developmental and genetic levels has important implications for neurobiology, medicine, evolution, and robotics. We studied rhythmic behavior--larval crawling--in the genetically and developmentally tractable organism, Drosophila melanogaster. We used narrow-diameter channels to constrain behavior to simple, rhythmic crawling. We quantified crawling at the organism, segment, and muscle levels. We showed that Drosophila larval crawling is made up of a series of periodic strides. Each stride consists of two phases. First, while most abdominal segments remain planted on the substrate, the head, tail, and gut translocate; this "visceral pistoning" moves the center of mass. The movement of the center of mass is likely powered by muscle contractions in the head and tail. Second, the head and tail anchor while a body wall wave moves each abdominal segment in the direction of the crawl. These two phases can be observed occurring independently in embryonic stages before becoming coordinated at hatching. During forward crawls, abdominal body wall movements are powered by simultaneous contraction of dorsal and ventral muscle groups, which occur concurrently with contraction of lateral muscles of the adjacent posterior segment. During reverse crawls, abdominal body wall movements are powered by phase-shifted contractions of dorsal and ventral muscles; and ventral muscle contractions occur concurrently with contraction of lateral muscles in the adjacent anterior segment. This work lays a foundation for use of Drosophila larva as a model system for studying the genetics and development of rhythmic behavior.
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19
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Jakubowski BR, Longoria RA, Shubeita GT. A high throughput and sensitive method correlates neuronal disorder genotypes to Drosophila larvae crawling phenotypes. Fly (Austin) 2012; 6:303-8. [PMID: 22992470 DOI: 10.4161/fly.21582] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Drosophila melanogaster is widely used as a model system for development and disease. Due to the homology between Drosophila and human genes, as well as the tractable genetics of the fly, its use as a model for neurologic disorders, in particular, has been rising. Locomotive impairment is a commonly used diagnostic for screening and characterization of these models, yet a fast, sensitive and model-free method to compare behavior is lacking. Here, we present a high throughput method to quantify the crawling behavior of larvae. We use the mean squared displacement as well as the direction autocorrelation of the crawling larvae as descriptors of their motion. By tracking larvae from wild-type strains and models of the Fragile X mental retardation as well as Alzheimer disease, we show these mutants exhibit impaired crawling. We further show that the magnitude of impairment correlates with the severity of the mutation, demonstrating the sensitivity and the dynamic range of the method. Finally, we study larvae with altered expression of the shaggy gene, a homolog of Glycogen Synthase Kinase-3 (GSK-3), which has been implicated in Alzheimer disease. Surprisingly, we find that both increased and decreased expression of dGSK-3 lead to similar larval crawling impairment. These findings have implications for the use of GSK-3 inhibitors recently proposed for Alzheimer treatment.
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Affiliation(s)
- Brandon R Jakubowski
- Center for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Austin, TX, USA
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20
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Selcho M, Pauls D, el Jundi B, Stocker RF, Thum AS. The Role of octopamine and tyramine in Drosophila larval locomotion. J Comp Neurol 2012; 520:3764-85. [DOI: 10.1002/cne.23152] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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21
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Iyengar A, Imoehl J, Ueda A, Nirschl J, Wu CF. Automated quantification of locomotion, social interaction, and mate preference in Drosophila mutants. J Neurogenet 2012; 26:306-16. [PMID: 23106154 PMCID: PMC3613147 DOI: 10.3109/01677063.2012.729626] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Automated tracking methods facilitate screening for and characterization of abnormal locomotion or more complex behaviors in Drosophila. We developed the Iowa Fly Locomotion and Interaction Tracker (IowaFLI Tracker), a MATLAB-based video analysis system, to identify and track multiple flies in a small arena. We report altered motor activity in the K(+) and Na(+) channel mutants, Hk(1) and para(ts1), which had previously been shown to display abnormal larval locomotion. Environmental factors influencing individual behavior, such as available "social space," were studied by using IowaFLI Tracker to simultaneously track multiple flies in the same arena. We found that crowding levels affect individual fly activity, with the total movement of individual flies attenuated around a particular density. This observation may have important implications in the design of activity chambers for studying particular kinds of social interactions. IowaFLI Tracker also directly quantifies social interactions by tracking the amount of time individuals are in proximity to one another-visualized as an "interactogram." This feature enables the development of a "target-preference" assay to study male courtship behavior where males are presented with a choice between two immobilized, decapitated females, and their locomotion and interactions quantified. We used this assay to study the chemosensory mutants olf D (para(olfD), sbl(2)) and Gr32a and their preferences towards virgin or mated females. Male olf D flies showed reduced courtship levels, with no clear preference towards either, whereas Gr32a males preferentially courted with virgin females over mated females in this assay. These initial results demonstrate that IowaFLI Tracker can be employed to explore motor coordination and social interaction phenomena in behavioral mutants of Drosophila.
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Affiliation(s)
- Atulya Iyengar
- Interdisiplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
| | - Jordan Imoehl
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Atsushi Ueda
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
| | - Jeffery Nirschl
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
| | - Chun-Fang Wu
- Interdisiplinary Graduate Program in Neuroscience, University of Iowa, Iowa City, IA 52242, USA
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
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22
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Brierley DJ, Rathore K, VijayRaghavan K, Williams DW. Developmental origins and architecture of Drosophila leg motoneurons. J Comp Neurol 2012; 520:1629-49. [PMID: 22120935 DOI: 10.1002/cne.23003] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Motoneurons are key points of convergence within motor networks, acting as the "output channels" that directly control sets of muscles to maintain posture and generate movement. Here we use genetic mosaic techniques to reveal the origins and architecture of the leg motoneurons of Drosophila. We show that a small number of leg motoneurons are born in the embryo but most are generated during larval life. These postembryonic leg motoneurons are produced by five neuroblasts per hemineuromere, and each lineage generates stereotyped lineage-specific projection patterns. Two of these postembryonic neuroblasts generate solely motoneurons that are the bulk of the leg motoneurons. Within the largest lineage, lineage 15, we see distinct birth-order differences in projection patterns. A comparison of the central projections of leg motoneurons and the muscles they innervate reveals a stereotyped architecture and the existence of a myotopic map. Timeline analysis of axonal outgrowth reveals that leg motoneurons reach their sites of terminal arborization in the leg at the time when their dendrites are elaborating their subtype-specific shapes. Our findings provide a comprehensive description of the origin, development, and architecture of leg motoneurons that will aid future studies exploring the link between the assembly and organization of connectivity within the leg motor system of Drosophila.
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Affiliation(s)
- D J Brierley
- MRC Centre for Developmental Neurobiology, King's College London, London, SE1 1UL, UK
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23
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Steinert JR, Campesan S, Richards P, Kyriacou CP, Forsythe ID, Giorgini F. Rab11 rescues synaptic dysfunction and behavioural deficits in a Drosophila model of Huntington's disease. Hum Mol Genet 2012; 21:2912-22. [PMID: 22466800 PMCID: PMC3373239 DOI: 10.1093/hmg/dds117] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Synapse abnormalities in Huntington's disease (HD) patients can precede clinical diagnosis and neuron loss by decades. The polyglutamine expansion in the huntingtin (htt) protein that underlies this disorder leads to perturbations in many cellular pathways, including the disruption of Rab11-dependent endosomal recycling. Impairment of the small GTPase Rab11 leads to the defective formation of vesicles in HD models and may thus contribute to the early stages of the synaptic dysfunction in this disorder. Here, we employ transgenic Drosophila melanogaster models of HD to investigate anomalies at the synapse and the role of Rab11 in this pathology. We find that the expression of mutant htt in the larval neuromuscular junction decreases the presynaptic vesicle size, reduces quantal amplitudes and evoked synaptic transmission and alters larval crawling behaviour. Furthermore, these indicators of early synaptic dysfunction are reversed by the overexpression of Rab11. This work highlights a potential novel HD therapeutic strategy for early intervention, prior to neuronal loss and clinical manifestation of disease.
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Affiliation(s)
- Joern R Steinert
- MRC Toxicology Unit, University of Leicester, Hodgkin Building, Lancaster Road, Leicester, UK
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24
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Sinadinos C, Cowan C, Wyttenbach A, Mudher A. Increased throughput assays of locomotor dysfunction in Drosophila larvae. J Neurosci Methods 2012; 203:325-34. [DOI: 10.1016/j.jneumeth.2011.08.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 08/23/2011] [Accepted: 08/23/2011] [Indexed: 10/17/2022]
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25
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Wang JW, Wu CF. Modulation of the frequency response of Shaker potassium channels by the quiver peptide suggesting a novel extracellular interaction mechanism. J Neurogenet 2011; 24:67-74. [PMID: 20429677 DOI: 10.3109/01677061003746341] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Recent studies have indicated that the Shaker potassium channel regulates sleep in Drosophila. The Drosophila quiver (qvr) gene encodes a novel potassium channel subunit that modulates the Shaker potassium channel. The Qvr peptide contains a signal sequence for extracellular localization and may regulate a unique feature of the Shaker I(A) current that confers special neuronal excitability patterns. Thus, studies of the Shaker channel properties in the qvr mutant background should provide an opportunity to uncover a new form of physiologic modulation of potassium channels. We have begun to investigate the impact of qvr protein on the Shaker channel properties and its implications in synaptic function in vivo. We studied synaptic transmission at the larval neuromuscular junction and characterized the transient potassium current I(A) in larval muscles. We identified two different functional states of I(A) in qvr larval muscles, as reflected by two distinct components, I(AF) and I(AS), differing in their kinetics of recovery from inactivation and sensitivity to a K(+) channel blocker. Correspondingly, qvr mutant larvae exhibit multiple synaptic discharges following individual nerve stimuli during repetitive activity.
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Affiliation(s)
- Jing W Wang
- Department of Biological Sciences, University of Iowa, Iowa City, Iowa, USA.
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26
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Cheng LE, Song W, Looger LL, Jan LY, Jan YN. The role of the TRP channel NompC in Drosophila larval and adult locomotion. Neuron 2010; 67:373-80. [PMID: 20696376 DOI: 10.1016/j.neuron.2010.07.004] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2010] [Indexed: 01/15/2023]
Abstract
The generation of coordinated body movements relies on sensory feedback from mechanosensitive proprioceptors. We have found that the proper function of NompC, a putative mechanosensitive TRP channel, is not only required for fly locomotion, but also crucial for larval crawling. Calcium imaging revealed that NompC is required for the activation of two subtypes of sensory neurons during peristaltic muscle contractions. Having isolated a full-length nompC cDNA with a protein coding sequence larger than previously predicted, we demonstrate its function by rescuing locomotion defects in nompC mutants, and further show that antibodies against the extended C terminus recognize NompC in chordotonal ciliary tips. Moreover, we show that the ankyrin repeats in NompC are required for proper localization and function of NompC in vivo and are required for association of NompC with microtubules. Taken together, our findings suggest that NompC mediates proprioception in locomotion and support its role as a mechanosensitive channel.
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Affiliation(s)
- Li E Cheng
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
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27
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Abstract
In vertebrates, sialylated glycans participate in a wide range of biological processes and affect the development and function of the nervous system. While the complexity of glycosylation and the functional redundancy among sialyltransferases provide obstacles for revealing biological roles of sialylation in mammals, Drosophila possesses a sole vertebrate-type sialyltransferase, Drosophila sialyltransferase (DSiaT), with significant homology to its mammalian counterparts, suggesting that Drosophila could be a suitable model to investigate the function of sialylation. To explore this possibility and investigate the role of sialylation in Drosophila, we inactivated DSiaT in vivo by gene targeting and analyzed phenotypes of DSiaT mutants using a combination of behavioral, immunolabeling, electrophysiological, and pharmacological approaches. Our experiments demonstrated that DSiaT expression is restricted to a subset of CNS neurons throughout development. We found that DSiaT mutations result in significantly decreased life span, locomotor abnormalities, temperature-sensitive paralysis, and defects of neuromuscular junctions. Our results indicate that DSiaT regulates neuronal excitability and affects the function of a voltage-gated sodium channel. Finally, we showed that sialyltransferase activity is required for DSiaT function in vivo, which suggests that DSiaT mutant phenotypes result from a defect in sialylation of N-glycans. This work provided the first evidence that sialylation has an important biological function in protostomes, while also revealing a novel, nervous system-specific function of alpha2,6-sialylation. Thus, our data shed light on one of the most ancient functions of sialic acids in metazoan organisms and suggest a possibility that this function is evolutionarily conserved between flies and mammals.
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28
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Scantlebury N, Zhao XL, Rodriguez Moncalvo VG, Camiletti A, Zahanova S, Dineen A, Xin JH, Campos AR. The Drosophila gene RanBPM functions in the mushroom body to regulate larval behavior. PLoS One 2010; 5:e10652. [PMID: 20498842 PMCID: PMC2871054 DOI: 10.1371/journal.pone.0010652] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Accepted: 04/12/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In vertebrates, Ran-Binding Protein in the Microtubule Organizing Center (RanBPM) appears to function as a scaffolding protein in a variety of signal transduction pathways. In Drosophila, RanBPM is implicated in the regulation of germ line stem cell (GSC) niche organization in the ovary. Here, we addressed the role of RanBPM in nervous system function in the context of Drosophila larval behavior. METHODOLOGY/PRINCIPAL FINDINGS We report that in Drosophila, RanBPM is required for larval feeding, light-induced changes in locomotion, and viability. RanBPM is highly expressed in the Kenyon cells of the larval mushroom body (MB), a structure well studied for its role in associative learning in Drosophila and other insects. RanBPM mutants do not display major disruption in nervous system morphology besides reduced proliferation. Expression of the RanBPM gene in the Kenyon cells is sufficient to rescue all behavioral phenotypes. Through genetic epistasis experiments, we demonstrate that RanBPM participates with the Drosophila orthologue of the Fragile X Mental Retardation Protein (FMRP) in the development of neuromuscular junction (NMJ). CONCLUSIONS/SIGNIFICANCE We demonstrate that the RanBPM gene functions in the MB neurons for larval behavior. Our results suggest a role for this gene in an FMRP-dependent process. Taken together our findings point to a novel role for the MB in larval behavior.
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Affiliation(s)
- Nadia Scantlebury
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Xiao Li Zhao
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | | | - Alison Camiletti
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Stacy Zahanova
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Aidan Dineen
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Ji-Hou Xin
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Ana Regina Campos
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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29
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Rodriguez Moncalvo VG, Campos AR. Role of serotonergic neurons in the Drosophila larval response to light. BMC Neurosci 2009; 10:66. [PMID: 19549295 PMCID: PMC2711092 DOI: 10.1186/1471-2202-10-66] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 06/23/2009] [Indexed: 11/24/2022] Open
Abstract
Background Drosophila larval locomotion consists of forward peristalsis interrupted by episodes of pausing, turning and exploratory behavior (head swinging). This behavior can be regulated by visual input as seen by light-induced increase in pausing, head swinging and direction change as well as reduction of linear speed that characterizes the larval photophobic response. During 3rd instar stage, Drosophila larvae gradually cease to be repelled by light and are photoneutral by the time they wander in search for a place to undergo metamorphosis. Thus, Drosophila larval photobehavior can be used to study control of locomotion. Results We used targeted neuronal silencing to assess the role of candidate neurons in the regulation of larval photobehavior. Inactivation of DOPA decarboxylase (Ddc) neurons increases the response to light throughout larval development, including during the later stages of the 3rd instar characterized by photoneutral response. Increased response to light is characterized by increase in light-induced direction change and associated pause, and reduction of linear movement. Amongst Ddc neurons, suppression of the activity of corazonergic and serotonergic but not dopaminergic neurons increases the photophobic response observed during 3rd instar stage. Silencing of serotonergic neurons does not disrupt larval locomotion or the response to mechanical stimuli. Reduced serotonin (5-hydroxytryptamine, 5-HT) signaling within serotonergic neurons recapitulates the results obtained with targeted neuronal silencing. Ablation of serotonergic cells in the ventral nerve cord (VNC) does not affect the larval response to light. Similarly, disruption of serotonergic projections that contact the photoreceptor termini in the brain hemispheres does not impact the larval response to light. Finally, pan-neural over-expression of 5-HT1ADro receptors, but not of any other 5-HT receptor subtype, causes a significant decrease in the response to light of 3rd instar larvae. Conclusion Our data demonstrate that activity of serotonergic and corazonergic neurons contribute to the control of larval locomotion by light. We conclude that this control is carried out by 5-HT neurons located in the brain hemispheres, but does not appear to occur at the photoreceptor level and may be mediated by 5-HT1ADro receptors. These findings provide new insights into the function of 5-HT neurons in Drosophila larval behavior as well as into the mechanisms underlying regulation of larval response to light.
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Peron S, Zordan MA, Magnabosco A, Reggiani C, Megighian A. From action potential to contraction: neural control and excitation-contraction coupling in larval muscles of Drosophila. Comp Biochem Physiol A Mol Integr Physiol 2009; 154:173-83. [PMID: 19427393 DOI: 10.1016/j.cbpa.2009.04.626] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 04/16/2009] [Accepted: 04/22/2009] [Indexed: 11/17/2022]
Abstract
The neuromuscular system of Drosophila melanogaster has been studied for many years for its relative simplicity and because of the genetic and molecular versatilities. Three main types of striated muscles are present in this dipteran: fibrillar muscles, tubular muscles and supercontractile muscles. The visceral muscles in adult flies and the body wall segmental muscles in embryos and larvae belong to the group of supercontractile muscles. Larval body wall muscles have been the object of detailed studies as a model for neuromuscular junction function but have received much less attention with respect to their mechanical properties and to the control of contraction. In this review we wish to assess available information on the physiology of the Drosophila larval muscular system. Our aim is to establish whether this system has the requisites to be considered a good model in which to perform a functional characterization of Drosophila genes, with a known muscular expression, as well as Drosophila homologs of human genes, the dysfunction of which, is known to be associated with human hereditary muscle pathologies.
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Affiliation(s)
- Samantha Peron
- Department of Anatomy and Physiology, University of Padua, Italy
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Hughes CL, Thomas JB. A sensory feedback circuit coordinates muscle activity in Drosophila. Mol Cell Neurosci 2007; 35:383-96. [PMID: 17498969 PMCID: PMC1978164 DOI: 10.1016/j.mcn.2007.04.001] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 04/01/2007] [Accepted: 04/03/2007] [Indexed: 11/17/2022] Open
Abstract
Drosophila larval crawling is a simple behavior that allows us to dissect the functions of specific neurons in the intact animal and explore the roles of genes in the specification of those neurons. By inhibiting subsets of neurons in the PNS, we have found that two classes of multidendritic neurons play a major role in larval crawling. The bipolar dendrites and class I mds send a feedback signal to the CNS that keeps the contraction wave progressing quickly, allowing smooth forward movement. Genetic manipulation of the sensory neurons suggests that this feedback depends on proper dendritic morphology and axon pathfinding to appropriate synaptic target areas in the CNS. Our data suggest that coordination of muscle activity in larval crawling requires feedback from neurons acting as proprioceptors, sending a "mission accomplished" signal in response to segment contraction, and resulting in rapid relaxation of the segment and propagation of the wave.
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Affiliation(s)
- Cynthia L Hughes
- Molecular Neurobiology Laboratory, The Salk Institute, 10010 N. Torrey Pines Rd, La Jolla, CA 92037, USA.
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32
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Song W, Onishi M, Jan LY, Jan YN. Peripheral multidendritic sensory neurons are necessary for rhythmic locomotion behavior in Drosophila larvae. Proc Natl Acad Sci U S A 2007; 104:5199-204. [PMID: 17360325 PMCID: PMC1820883 DOI: 10.1073/pnas.0700895104] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
From breathing to walking, rhythmic movements encompass physiological processes important across the entire animal kingdom. It is thought by many that the generation of rhythmic behavior is operated by a central pattern generator (CPG) and does not require peripheral sensory input. Sensory feedback is, however, required to modify or coordinate the motor activity in response to the circumstances of actual movement. In contrast to this notion, we report here that sensory input is necessary for the generation of Drosophila larval locomotion, a form of rhythmic behavior. Blockage of all peripheral sensory inputs resulted in cessation of larval crawling. By conditionally silencing various subsets of larval peripheral sensory neurons, we identified the multiple dendritic (MD) neurons as the neurons essential for the generation of rhythmic peristaltic locomotion. By recording the locomotive motor activities, we further demonstrate that removal of MD neuron input disrupted rhythmic motor firing pattern in a way that prolonged the stereotyped segmental motor firing duration and prevented the propagation of posterior to anterior segmental motor firing. These findings reveal that MD sensory neuron input is a necessary component in the neural circuitry that generates larval locomotion.
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Affiliation(s)
- Wei Song
- Departments of Physiology and Biochemistry, Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
| | - Maika Onishi
- Departments of Physiology and Biochemistry, Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
| | - Lily Yeh Jan
- Departments of Physiology and Biochemistry, Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
| | - Yuh Nung Jan
- Departments of Physiology and Biochemistry, Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
- *To whom correspondence should be addressed. E-mail:
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Scantlebury N, Sajic R, Campos AR. Kinematic analysis of Drosophila larval locomotion in response to intermittent light pulses. Behav Genet 2007; 37:513-24. [PMID: 17318369 DOI: 10.1007/s10519-007-9146-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 01/30/2007] [Indexed: 12/01/2022]
Abstract
We report a quantitative analysis of the modulation of locomotion by light in the Drosophila larva. The photobehavior of wild type larvae and of larvae carrying mutations altering various aspects of locomotion was evaluated in an assay that exposes individual animals to intermittent pulses of dark and light (ON/OFF assay). The application of the Dynamic Image Analysis System for the analysis of larval movement in the ON/OFF assay allowed a detailed description of the behavioral repertoire underlying the modulation of larval motion by light. We established that the larval response to light is characterized by decreased frequency of peristaltic contractions in addition to increased direction change and pausing. Moreover, using various mutant strains we show that this approach allows the detection of a response to light in mutant larvae whose locomotion is severely reduced and uncoordinated, mutants that would otherwise have been considered non-responders in this assay.
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Affiliation(s)
- Nadia Scantlebury
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada L8S 4K1
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Schuster CM. Experience-dependent potentiation of larval neuromuscular synapses. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2006; 75:307-22. [PMID: 17137934 DOI: 10.1016/s0074-7742(06)75014-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Christoph M Schuster
- Department of Neurobiology, Interdisciplinary Center for Neurosciences University of Heidelberg, 69120 Heidelberg, Germany
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35
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Gerber B, Stocker RF. The Drosophila larva as a model for studying chemosensation and chemosensory learning: a review. Chem Senses 2006; 32:65-89. [PMID: 17071942 DOI: 10.1093/chemse/bjl030] [Citation(s) in RCA: 170] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Understanding the relationship between brain and behavior is the fundamental challenge in neuroscience. We focus on chemosensation and chemosensory learning in larval Drosophila and review what is known about its molecular and cellular bases. Detailed analyses suggest that the larval olfactory system, albeit much reduced in cell number, shares the basic architecture, both in terms of receptor gene expression and neuronal circuitry, of its adult counterpart as well as of mammals. With respect to the gustatory system, less is known in particular with respect to processing of gustatory information in the central nervous system, leaving generalizations premature. On the behavioral level, a learning paradigm for the association of odors with food reinforcement has been introduced. Capitalizing on the knowledge of the chemosensory pathways, we review the first steps to reveal the genetic and cellular bases of olfactory learning in larval Drosophila. We argue that the simplicity of the larval chemosensory system, combined with the experimental accessibility of Drosophila on the genetic, electrophysiological, cellular, and behavioral level, makes this system suitable for an integrated understanding of chemosensation and chemosensory learning.
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Affiliation(s)
- Bertram Gerber
- Universität Würzburg, Biozentrum, Am Hubland, Lehrstuhl für Genetik und Neurobiologie, D-97074 Würzburg, Germany.
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36
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Schuster CM. Glutamatergic synapses of Drosophila neuromuscular junctions: a high-resolution model for the analysis of experience-dependent potentiation. Cell Tissue Res 2006; 326:287-99. [PMID: 16896945 DOI: 10.1007/s00441-006-0290-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Accepted: 06/16/2006] [Indexed: 10/24/2022]
Abstract
The glutamatergic synapses of developing neuromuscular junctions (NMJ) of Drosophila larvae are readily accessible, morphologically simple, and physiologically well-characterized. They therefore have a long and highly successful tradition as a model system for the discovery of genetic and molecular mechanisms of target recognition, synaptogenesis, NMJ development, and synaptic plasticity. However, since the development and the activity-dependent refinement of NMJs are concurrent processes, they cannot easily be separated by the widely applied genetic manipulations that mostly have chronic effects. Recent studies have therefore begun systematically to incorporate larval foraging behavior into the physiological and genetic analysis of NMJ function in order to analyze potential experience-dependent changes of glutamatergic transmission. These studies have revealed that recent crawling experience is a potent modulator of glutamatergic transmission at NMJs, because high crawling activities result after an initial lag-phase in several subsequent phases of experience-dependent synaptic potentiation. Depending on the time window of occurrence, four distinct phases of experience-dependent potentiation have been defined. These phases of potentiation can be followed from their initial induction (phase-I) up to the morphological consolidation (phase-III/IV) of previously established functional changes (phase-II). This therefore establishes, for the first time, a temporal hierarchy of mechanisms involved in the use-dependent modification of glutamatergic synapses.
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Affiliation(s)
- Christoph M Schuster
- Interdisciplinary Center for Neurosciences (ICN), Department of Neurobiology, University of Heidelberg, 69120 Heidelberg, Germany.
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37
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Ueda A, Wu CF. Distinct frequency-dependent regulation of nerve terminal excitability and synaptic transmission by IA and IK potassium channels revealed by Drosophila Shaker and Shab mutations. J Neurosci 2006; 26:6238-48. [PMID: 16763031 PMCID: PMC6675186 DOI: 10.1523/jneurosci.0862-06.2006] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Regulation of synaptic efficacy by nerve terminal excitability has not been extensively studied. We performed genetic and pharmacological dissections for presynaptic actions of K+ channels in Drosophila neuromuscular transmission by using electrophysiological and optical imaging techniques. Current understanding of the roles of the Shab IK channel and its mammalian Kv2 counterparts is relatively poor, as compared with that for Shaker IA channels and their Kv1 homologues. Our results revealed the striking effect of Shab mutations during high-frequency synaptic activity, as well as a functional division in synaptic regulation between the Shaker and Shab channels. Shaker channels control the basal level of release, indicated by a response to single nerve stimulation, whereas Shab channels regulate repetitive synaptic activities. These observations highlight the crucial control of nerve terminal excitability by Shaker and Shab channels to confer temporal patterns of synaptic transmission and suggest the potential participation of these channels, along with the transmitter release machinery, in activity-dependent synaptic plasticity.
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38
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Fox LE, Soll DR, Wu CF. Coordination and modulation of locomotion pattern generators in Drosophila larvae: effects of altered biogenic amine levels by the tyramine beta hydroxlyase mutation. J Neurosci 2006; 26:1486-98. [PMID: 16452672 PMCID: PMC2673197 DOI: 10.1523/jneurosci.4749-05.2006] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Forward locomotion of Drosophila melanogaster larvae is composed of rhythmic waves of contractions that are thought to be produced by segmentally organized central pattern generators. We present a systematic description of spike activity patterns during locomotive contraction waves in semi-intact wild-type and mutant larval preparations. We have shown previously that Tbetah(nM18) mutants, with altered levels of octopamine and tyramine, have a locomotion deficit. By recording en passant from the segmental nerves, we investigated the coordination of the neuronal activity driving contraction waves of the abdominal body-wall muscles. Rhythmic bursts of activity that occurred concurrently with locomotive waves were frequently observed in wild-type larvae but were rarely seen in Tbetah(nM18) mutants. These centrally generated patterned activities were eliminated in the distal stumps of both wild-type and Tbetah(nM18) larvae after severing the segmental nerve from the CNS. Patterned activities persisted in the proximal stumps deprived of sensory feedback from the periphery. Simultaneous recordings demonstrated a delay in the bursting activity between different segments, with greater delay for segments that were farther apart. In contrast, bilateral recordings within a single segment revealed a well synchronized activity pattern in nerves innervating each hemisegment in both wild-type and Tbetah(nM18) larvae. Significantly, rhythmic patterns of bursts and waves could be evoked in Tbetah(nM18) mutants by head or tail stimulation despite their highly irregular spontaneous activities. These observations suggest a role of the biogenic amines in the initiation and modulation of motor pattern generation. The technique presented here can be readily extended to examine the locomotion motor program of other mutants.
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Affiliation(s)
- Lyle E Fox
- Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242, USA.
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Mosca TJ, Carrillo RA, White BH, Keshishian H. Dissection of synaptic excitability phenotypes by using a dominant-negative Shaker K+ channel subunit. Proc Natl Acad Sci U S A 2005; 102:3477-82. [PMID: 15728380 PMCID: PMC552910 DOI: 10.1073/pnas.0406164102] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During nervous system development, synapses undergo morphological change as a function of electrical activity. In Drosophila, enhanced activity results in the expansion of larval neuromuscular junctions. We have examined whether these structural changes involve the pre- or postsynaptic partner by selectively enhancing electrical excitability with a Shaker dominant-negative (SDN) potassium channel subunit. We find that the SDN enhances neurotransmitter release when expressed in motoneurons, postsynaptic potential broadening when expressed in muscles and neurons, and selectively suppresses fast-inactivating, Shaker-mediated IA currents in muscles. SDN expression also phenocopies the canonical behavioral phenotypes of the Sh mutation. At the neuromuscular junction, we find that activity-dependent changes in arbor size occur only when SDN is expressed presynaptically. This finding indicates that elevated postsynaptic membrane excitability is by itself insufficient to enhance presynaptic arbor growth. Such changes must minimally involve increased neuronal excitability.
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Affiliation(s)
- Timothy J Mosca
- Department of Molecular, Cellular, and Developmental Biology, Yale University, P.O. Box 208103, New Haven, CT 06520-8103, USA
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40
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Suster ML, Karunanithi S, Atwood HL, Sokolowski MB. Turning behavior in Drosophila larvae: a role for the small scribbler transcript. GENES BRAIN AND BEHAVIOR 2004; 3:273-86. [PMID: 15344921 DOI: 10.1111/j.1601-183x.2004.00082.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Drosophila larva is extensively used for studies of neural development and function, yet the mechanisms underlying the appropriate development of its stereotypic motor behaviors remain largely unknown. We have previously shown that mutations in scribbler (sbb), a gene encoding two transcripts widely expressed in the nervous system, cause abnormally frequent episodes of turning in the third instar larva. Here we report that hypomorphic sbb mutant larvae display aberrant turning from the second instar stage onwards. We focus on the smaller of the two sbb transcripts and show that its pan-neural expression during early larval life, but not in later larval life, restores wild type turning behavior. To identify the classes of neurons in which this sbb transcript is involved, we carried out transgenic rescue experiments. Targeted expression of the small sbb transcript using the cha-GAL4 driver was sufficient to restore wild type turning behavior. In contrast, expression of this sbb transcript in motoneurons, sensory neurons or large numbers of unidentified interneurons was not sufficient. Our data suggest that the expression of the smaller sbb transcript may be needed in a subset of neurons for the maintenance of normal turning behavior in Drosophila larvae.
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Affiliation(s)
- M L Suster
- Department of Zoology, University of Toronto, Mississauga L5L 1C6, Ontario, Canada
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41
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Abstract
The RNA-binding protein, Boule is conserved across species and is required for male fertility. Boule and the DAZ homologues in mice and humans appear specific to the testis. Boule functions in spermatogenesis by controlling the translation of the meiotic cell division cycle 25 (Cdc25) phosphatase, Twine. Here we show, for the first time, a function for the DAZ protein, Boule, outside of meiosis. We found that an isoform of Boule is expressed in the nervous system and when its expression is increased we observe mutant phenotypes in neural communication between the receptor and laminar cells of the fly eye, altered larval locomotion and when further overexpressed, viability. As in the germ line, genetic studies indicate that Boule functions in the Cdc25 phosphatase pathway in the nervous system. In a sensitized genetic background of Boule overexpression, we added a loss-of-function mutation of twine and demonstrated a role for Twine Cdc25, in the adult nervous system. Our results indicate that isoforms of boule are expressed outside of the male germ line and that these isoforms have a role in neural function, unlike the boule testis-specific isoform.
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Affiliation(s)
- Mei-Ling Joiner
- Department of Biological Sciences, University of Iowa, Iowa City, IA 52242, USA.
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42
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Wang P, Saraswati S, Guan Z, Watkins CJ, Wurtman RJ, Littleton JT. A Drosophila temperature-sensitive seizure mutant in phosphoglycerate kinase disrupts ATP generation and alters synaptic function. J Neurosci 2004; 24:4518-29. [PMID: 15140922 PMCID: PMC6729406 DOI: 10.1523/jneurosci.0542-04.2004] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A novel paralytic mutant, nubian, was identified in a behavioral screen for conditional temperature-sensitive seizure mutants in Drosophila melanogaster. nubian mutants display reduced lifespan, abnormal motor behavior, altered synaptic structure, and defective neurotransmitter release. The nubian mutant disrupts phosphoglycerate kinase (PGK), an enzyme required for ATP generation in the terminal stage of the glycolytic pathway. Consistent with altered ATP generation in nubian animals, brain extracts show a threefold reduction in resting ATP levels compared with controls. Microarray analysis of nubian mutants reveals altered transcription of genes implicated in glucose and lipid metabolism. Disruption of ATP generation in nubian animals is accompanied by temperature-dependent defects in neuronal activity, with initial seizure activity, followed by an activity-dependent loss of synaptic transmission. nubian mutants also display structural defects at the synapse, with larger varicosity size but normal varicosity number, indicating that these synaptic parameters are regulated independently. Both exocytotic (NSF) and endocytotic (dynamin) ATPase/GTPase activity are required for normal synaptic transmission. Biochemical and physiological analyses indicate that synaptic defects in nubian animals are secondary to defective endocytosis, suggesting that endocytotic pathways may be generally more sensitive to altered ATP levels than those used for exocytosis. Alterations in ATP metabolism likely disrupt similar pathways in humans, because PGK deficiency is associated with mental retardation, seizures, and exercise intolerance. Given the behavioral similarities between disruptions of PGK function in Drosophila and humans, the analysis of nubian animals may reveal conserved neuronal responses associated with altered ATP generation within the brain.
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Affiliation(s)
- Ping Wang
- The Picower Center for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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43
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Xu K, Bogert BA, Li W, Su K, Lee A, Gao FB. The fragile X-related Gene Affects the Crawling Behavior of Drosophila Larvae by Regulating the mRNA Level of the DEG/ENaC Protein Pickpocket1. Curr Biol 2004; 14:1025-34. [PMID: 15202995 DOI: 10.1016/j.cub.2004.05.055] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Revised: 04/07/2004] [Accepted: 04/07/2004] [Indexed: 11/19/2022]
Abstract
BACKGROUND Fragile X syndrome is caused by loss-of-function mutations in the fragile X mental retardation 1 (FMR1) gene. How FMR1 affects the function of the central and peripheral nervous systems is still unclear. FMR1 is an RNA binding protein that associates with a small percentage of total mRNAs in vivo. It remains largely unknown what proteins encoded by mRNAs in the FMR1-messenger ribonuclear protein (mRNP) complex are most relevant to the affected physiological processes. RESULTS Loss-of-function mutations in the Drosophila fragile X-related (dfmr1) gene, which is highly homologous to the human fmr1 gene, decrease the duration and percentage of time that crawling larvae spend on linear locomotion. Overexpression of DFMR1 in multiple dendritic (MD) sensory neurons increases the time percentage and duration of linear locomotion; this phenotype is similar to that caused by reduced expression of the MD neuron subtype-specific degenerin/epithelial sodium channel (DEG/ENaC) family protein Pickpocket1 (PPK1). Genetic analyses indicate that PPK1 is a key component downstream of DFMR1 in controlling the crawling behavior of Drosophila larvae. DFMR1 and ppk1 mRNA are present in the same mRNP complex in vivo and can directly bind to each other in vitro. DFMR1 downregulates the level of ppk1 mRNA in vivo, and this regulatory process also involves Argonaute2 (Ago2), a key component in the RNA interference pathway. CONCLUSIONS These studies identify ppk1 mRNA as a physiologically relevant in vivo target of DFMR1. Our finding that the level of ppk1 mRNA is regulated by DFMR1 and Ago2 reveals a genetic pathway that controls sensory input-modulated locomotion behavior.
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Affiliation(s)
- Kanyan Xu
- Gladstone Institute of Neurological Disease, University of California, San Francisco, San Francisco, CA 94103 USA
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44
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Sandstrom DJ. Isoflurane depresses glutamate release by reducing neuronal excitability at the Drosophila neuromuscular junction. J Physiol 2004; 558:489-502. [PMID: 15169847 PMCID: PMC1664974 DOI: 10.1113/jphysiol.2004.065748] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The mechanisms through which volatile general anaesthetics exert their behavioural effects remain unclear. The accessibility of the Drosophila larval neuromuscular junction to genetic and neurophysiological analysis has made it an attractive model system for identification of anaesthetic targets. This study provides a mechanistic basis for the genetic analysis of anaesthetic action, by analysing the neurophysiological effects of the volatile anaesthetic isoflurane on axonal and synaptic function in the Drosophila larva. The most robust effect of isoflurane was a reversible decrease in the amplitude and area of glutamatergic excitatory junctional currents (EJCs) evoked at the neuromuscular junction. Isoflurane did not affect postsynaptic glutamate receptor function detectably, in that the amplitudes, areas and decay times of spontaneous miniature EJCs were unchanged at any concentration. Therefore, decreased EJC amplitude resulted from reduction of neurotransmitter release. Reduced neurotransmitter release was associated with decreased presynaptic excitability, measured as increased delay to EJC onset and reduced axonal conduction velocity. EJC amplitude was rescued to control levels by direct electrotonic stimulation of the synapse in the presence of tetrodotoxin, indicating that isoflurane inhibits neurotransmitter release by reducing presynaptic excitability. In addition, isoflurane reduced release probability, measured as increased paired-pulse facilitation. The EC(50) for suppression of larval locomotion was similar to that for reduction of transmitter release, indicating that the axonal and synaptic effects were occurring in a behaviourally relevant range. These results provide a cellular context for ongoing genetic and neurophysiological analyses of volatile anaesthetic action in Drosophila, and suggest candidate anaesthetic target molecules.
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Affiliation(s)
- David J Sandstrom
- Laboratory of Molecular Biology, National Institute of Mental Health, National Institutes of Health MSC 4034, Bethesda, MD 20892, USA.
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45
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Saraswati S, Fox LE, Soll DR, Wu CF. Tyramine and octopamine have opposite effects on the locomotion of Drosophila larvae. ACTA ACUST UNITED AC 2004; 58:425-41. [PMID: 14978721 DOI: 10.1002/neu.10298] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Biogenic amines are believed to play important roles in producing behaviors. Although some biogenic amines have been extensively studied in both vertebrates and invertebrates, little is known about the effects of trace amines like tyramine and octopamine. We investigated how trace amines affect behaviors using quantitative morphometric methods on Drosophila Tbetah(nM18) and iav(N) mutants that have altered levels of tyramine and octopamine. Locomotion of wild-type and mutant third instar larvae was analyzed using Dynamic Image Analysis System (DIAS) software. We found that Tbetah(nM18) mutants, with elevated tyramine levels and reduced octopamine levels, had a severe locomotion phenotype. Mutant larvae spent much more time in pausing episodes than wild-type larvae and displayed a reduction in speed and linear translocation. The locomotion phenotype was partially rescued by feeding Tbetah(nM18) larvae octopamine, an effect that could be nullified with simultaneous feeding of tyramine. Feeding Tbetah(nM18) larvae yohimbine, an agent that inhibits the activity of Drosophila tyramine receptors, also improved some locomotion parameters. Feeding both octopamine and yohimbine further improved rescue efficiency. Simultaneously reducing the octopamine and tyramine levels as in iav(N) larvae, in contrast, led to a less severe behavioral phenotype than that of Tbetah(nM18) mutants. Feeding iav(N) larvae either tyramine or octopamine exerted only a minor improvement in locomotion. These results suggest that tyramine and octopamine have opposite effects on Drosophila larval locomotion regulation and that a balance between the two is important in producing normal behavior.
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Affiliation(s)
- Sudipta Saraswati
- Department of Biological Sciences, University of Iowa, Iowa City, Iowa 52242, USA
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46
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Caldwell JC, Miller MM, Wing S, Soll DR, Eberl DF. Dynamic analysis of larval locomotion in Drosophila chordotonal organ mutants. Proc Natl Acad Sci U S A 2003; 100:16053-8. [PMID: 14673076 PMCID: PMC307691 DOI: 10.1073/pnas.2535546100] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2003] [Accepted: 10/09/2003] [Indexed: 11/18/2022] Open
Abstract
Rhythmic movements, such as peristaltic contraction, are initiated by output from central pattern generator (CPG) networks in the CNS. These oscillatory networks elicit locomotion in the absence of external sensory or descending inputs, but CPG circuits produce more directed and behaviorally relevant movement via peripheral nervous system (PNS) input. Drosophila melanogaster larval locomotion results from patterned muscle contractions moving stereotypically along the body segments, but without PNS feedback, contraction of body segments is uncoordinated. We have dissected the role of a subset of mechanosensory neurons in the larval PNS, the chordotonal organs (chos), in providing sensory feedback to the locomotor CPG circuit with dias (Dynamic Image Analysis System) software. We analyzed mutants carrying cho mutations including atonal, a cho proneural gene, beethoven, a cho cilia class mutant, smetana and touch-insensitive larva B, two axonemal mutants, and 5D10, a weak cho mutant. All cho mutants have defects in gross path morphology compared to controls. These mutants exhibit increased frequency and duration of turning (decision-making) and reduced duration of linear locomotion. Furthermore, cho mutants affect locomotor parameters, including reduced average speed, direction change, and persistence. Dias analysis of peristaltic waves indicates that mutants exhibit reduced average speed, positive flow and negative flow, and increased stride period. Thus, cho sensilla are major proprioceptive components that underlie touch sensitivity, locomotion, and peristaltic contraction by providing sensory feedback to the locomotor CPG circuit in larvae.
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Affiliation(s)
- Jason C Caldwell
- Department of Biological Sciences, University of Iowa, Iowa City, IA 52242, USA
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47
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Abstract
The genetic analysis of larval neuromuscular junctions (NMJs) of Drosophila has provided detailed insights into molecular mechanisms that control the morphological and physiological development of these glutamatergic synapses. However, because of the chronic defects caused by mutations, a time-resolved analysis of these mechanisms and their functional relationships has been difficult so far. In this study we provide a first temporal map of some of the molecular and cellular key processes, which are triggered in wild-type animals by natural larval locomotor activity and then mediate experience-dependent strengthening of larval NMJs. Larval locomotor activity was increased either by chronically rearing a larval culture at 29 degrees C instead of 18 or 25 degrees C or by acutely transferring larvae from a culture vial onto agar plates. Within 2 hr of enhanced locomotor activity, NMJs showed a significant potentiation of signal transmission that was rapidly reversed by an induced paralysis of the temperature-sensitive mutant parats1. Enhanced locomotor activity was also associated with a significant increase in the number of large subsynaptic translation aggregates. After 4 hr, postsynaptic DGluR-IIA glutamate receptor subunits started to transiently accumulate in ring-shaped areas around synapses, and they condensed later on, after chronic locomotor stimulation at 29 degrees C, into typical postsynaptic patches. These NMJs showed a reduced perisynaptic expression of the cell adhesion molecule Fasciclin II, an increased number of junctional boutons, and significantly more active zones. Such temporal mapping of experience-dependent adaptations at developing wild-type and mutant NMJs will provide detailed insights into the dynamic control of glutamatergic signal transmission.
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48
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Ainsley JA, Pettus JM, Bosenko D, Gerstein CE, Zinkevich N, Anderson MG, Adams CM, Welsh MJ, Johnson WA. Enhanced locomotion caused by loss of the Drosophila DEG/ENaC protein Pickpocket1. Curr Biol 2003; 13:1557-63. [PMID: 12956960 DOI: 10.1016/s0960-9822(03)00596-7] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Coordination of rhythmic locomotion depends upon a precisely balanced interplay between central and peripheral control mechanisms. Although poorly understood, peripheral proprioceptive mechanosensory input is thought to provide information about body position for moment-to-moment modifications of central mechanisms mediating rhythmic motor output. Pickpocket1 (PPK1) is a Drosophila subunit of the epithelial sodium channel (ENaC) family displaying limited expression in multiple dendritic (md) sensory neurons tiling the larval body wall and a small number of bipolar neurons in the upper brain. ppk1 null mutant larvae had normal external touch sensation and md neuron morphology but displayed striking alterations in crawling behavior. Loss of PPK1 function caused an increase in crawling speed and an unusual straight path with decreased stops and turns relative to wild-type. This enhanced locomotion resulted from sustained peristaltic contraction wave cycling at higher frequency with a significant decrease in pause period between contraction cycles. The mutant phenotype was rescued by a wild-type PPK1 transgene and duplicated by expressing a ppk1RNAi transgene or a dominant-negative PPK1 isoform. These results demonstrate that the PPK1 channel plays an essential role in controlling rhythmic locomotion and provide a powerful genetic model system for further analysis of central and peripheral control mechanisms and their role in movement disorders.
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Affiliation(s)
- Joshua A Ainsley
- Department of Physiology and Biophysics, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
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Abstract
Locomotor activity in Drosophila, as in other organisms, is an important trait since it is at the basis of almost all behaviours. Indeed, the locomotor centre is implicated in all complex behaviours consisting of a change in the position of the animal with respect to its environment. Despite its importance, locomotor activity itself has received sparse attention for the following two reasons: first, until recently, the study of locomotor activity has lacked a well automated and standardised paradigm which is necessary for a detailed description. Second, locomotor activity is complicated by many factors (genetic, feeding, temperature), and as such is rather difficult to study. With recent technological developments, locomotor activity is now more accessible to automated paradigms. These have permitted us to reveal that locomotor activity is a very complex and rich behaviour that follows strict rules, harbours an organised (fractal-like) structure, and consequently might adhere to highly organised neurophysiological processes. Undoubtedly, locomotor activity has now reached a scientific maturity that allows it to be studied with the panoply of neuroethological approaches, in particular genetic, to unravel its mechanisms and neural circuitry. Consequently, we propose that locomotor activity can now represent a relevant biomarker to study various model diseases such as addiction, Parkinson, Alzheimer, Huntington, and diabetes.
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Affiliation(s)
- Jean René Martin
- Equipe ATIPE: Bases Neurales du Mouvement chez la Drosophile, NAMC, CNRS, UMR-8620, Université Paris-Sud, Bâtiment 446, F-91405, Orsay, France
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Scherer S, Stocker RF, Gerber B. Olfactory learning in individually assayed Drosophila larvae. Learn Mem 2003; 10:217-25. [PMID: 12773586 PMCID: PMC202312 DOI: 10.1101/lm.57903] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Insect and mammalian olfactory systems are strikingly similar. Therefore, Drosophila can be used as a simple model for olfaction and olfactory learning. The brain of adult Drosophila, however, is still complex. We therefore chose to work on the larva with its yet simpler but adult-like olfactory system and provide evidence for olfactory learning in individually assayed Drosophila larvae. We developed a differential conditioning paradigm in which odorants are paired with positive ("+" fructose) or negative ("-" quinine or sodium chloride) gustatory reinforcers. Test performance of individuals from two treatment conditions is compared-one received odorant A with the positive reinforcer and odorant B with a negative reinforcer (A+/B-); animals from the other treatment condition were trained reciprocally (A-/B+). During test, differences in choice between A and B of individuals having undergone either A+/B- or A-/B+ training therefore indicate associative learning. We provide such evidence for both combinations of reinforcers; this was replicable across repetitions, laboratories, and experimenters. We further show that breaks improve performance, in accord with basic principles of associative learning. The present individual assay will facilitate electrophysiological studies, which necessarily use individuals. As such approaches are established for the larval neuromuscular synapse, but not in adults, an individual larval learning paradigm will serve to link behavioral levels of analysis to synaptic physiology.
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Affiliation(s)
- Sabine Scherer
- University of Fribourg, Department of Biology & Program in Neuroscience, CH 1700 Fribourg, Switzerland
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