title: Even-Skipped(+) Interneurons Are Core Components of a Sensorimotor Circuit that Maintains Left-Right Symmetric Muscle Contraction Amplitude.
abstract: Bilaterally symmetric motor patterns--those in which left-right pairs of muscles contract synchronously and with equal amplitude (such as breathing, smiling, whisking, and locomotion)--are widespread throughout the animal kingdom. Yet, surprisingly little is known about the underlying neural circuits. We performed a thermogenetic screen to identify neurons required for bilaterally symmetric locomotion in Drosophila larvae and identified the evolutionarily conserved Even-skipped(+) interneurons (Eve/Evx). Activation or ablation of Eve(+) interneurons disrupted bilaterally symmetric muscle contraction amplitude, without affecting the timing of motor output. Eve(+) interneurons are not rhythmically active and thus function independently of the locomotor CPG. GCaMP6 calcium imaging of Eve(+) interneurons in freely moving larvae showed left-right asymmetric activation that correlated with larval behavior. TEM reconstruction of Eve(+) interneuron inputs and outputs showed that the Eve(+) interneurons are at the core of a sensorimotor circuit capable of detecting and modifying body wall muscle contraction.
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA. Electronic address: heckscher@uchicago.edu.
authors.forename: Ellie S
authors.initials: ES
authors.lastname: Heckscher
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA.
authors.forename: Aref Arzan
authors.initials: AA
authors.lastname: Zarin
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA.
authors.forename: Serge
authors.initials: S
authors.lastname: Faumont
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA.
authors.forename: Matthew Q
authors.initials: MQ
authors.lastname: Clark
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA.
authors.forename: Laurina
authors.initials: L
authors.lastname: Manning
authors.affiliation: Janelia Research Campus, HHMI, Ashburn, VA 20147, USA.
authors.forename: Akira
authors.initials: A
authors.lastname: Fushiki
authors.affiliation: Janelia Research Campus, HHMI, Ashburn, VA 20147, USA.
authors.forename: Casey M
authors.initials: CM
authors.lastname: Schneider-Mizell
authors.affiliation: Janelia Research Campus, HHMI, Ashburn, VA 20147, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Fetter
authors.affiliation: Janelia Research Campus, HHMI, Ashburn, VA 20147, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Truman
authors.affiliation: Janelia Research Campus, HHMI, Ashburn, VA 20147, USA; Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: Maarten F
authors.initials: MF
authors.lastname: Zwart
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: Matthias
authors.initials: M
authors.lastname: Landgraf
authors.affiliation: Janelia Research Campus, HHMI, Ashburn, VA 20147, USA.
authors.forename: Albert
authors.initials: A
authors.lastname: Cardona
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA.
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Lockery
authors.affiliation: Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA; Howard Hughes Medical Institute, University of Oregon, Eugene, OR 97403, USA. Electronic address: cdoe@uoregon.edu.
authors.forename: Chris Q
authors.initials: CQ
authors.lastname: Doe
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D029721:Drosophila Proteins / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D018398:Homeodomain Proteins / Q000502:physiology*; D007395:Interneurons / Q000737:chemistry / Q000502:physiology*; D009119:Muscle Contraction / Q000502:physiology*; D009415:Nerve Net / Q000737:chemistry / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D029721:Drosophila Proteins; C557617:GAL4 protein, Drosophila; D018398:Homeodomain Proteins; D014157:Transcription Factors; C052837:eve protein, Drosophila