title: Cell types and coincident synapses in the ellipsoid body of Drosophila.
abstract: Cellular ultrastructures for signal integration are unknown in any nervous system. The ellipsoid body (EB) of the Drosophila brain is thought to control locomotion upon integration of various modalities of sensory signals with the animal internal status. However, the expected excitatory and inhibitory input convergence that virtually all brain centres exhibit is not yet described in the EB. Based on the EB expression domains of genetic constructs from the choline acetyl transferase (Cha), glutamic acid decarboxylase (GAD) and tyrosine hydroxylase (TH) genes, we identified a new set of neurons with the characteristic ring-shaped morphology (R neurons) which are presumably cholinergic, in addition to the existing GABA-expressing neurons. The R1 morphological subtype is represented in the Cha- and TH-expressing classes. In addition, using transmission electron microscopy, we identified a novel type of synapse in the EB, which exhibits the precise array of two independent active zones over the same postsynaptic dendritic domain, that we named 'agora'. This array is compatible with a coincidence detector role, and represents ~8% of all EB synapses in Drosophila. Presumably excitatory R neurons contribute to coincident synapses. Functional silencing of EB neurons by driving genetically tetanus toxin expression either reduces walking speed or alters movement orientation depending on the targeted R neuron subset, thus revealing functional specialisations in the EB for locomotion control.
authors.affiliation: Department of Cellular, Molecular and Developmental Neurobiology, Cajal Institute, C.S.I.C., Ave. Dr. Arce 37, E-28002, Madrid, Spain; Department of Neurology, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Martín-Peña
authors.forename: Angel
authors.initials: A
authors.lastname: Acebes
authors.forename: José-Rodrigo
authors.initials: JR
authors.lastname: Rodríguez
authors.forename: Valerie
authors.initials: V
authors.lastname: Chevalier
authors.forename: Sergio
authors.initials: S
authors.lastname: Casas-Tinto
authors.forename: Tilman
authors.initials: T
authors.lastname: Triphan
authors.forename: Roland
authors.initials: R
authors.lastname: Strauss
authors.forename: Alberto
authors.initials: A
authors.lastname: Ferrús
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001516:Bees; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004330:Drosophila / Q000166:cytology* / Q000254:growth & development / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D046529:Microscopy, Electron, Transmission; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D051761:Paired Box Transcription Factors / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D013744:Tetanus Toxin / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014796:Visual Perception / Q000502:physiology; D016138:Walking / Q000502:physiology; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C557617:GAL4 protein, Drosophila; D009419:Nerve Tissue Proteins; D051761:Paired Box Transcription Factors; C073863:Poxn protein, Drosophila; D013744:Tetanus Toxin; D014157:Transcription Factors; D049452:Green Fluorescent Proteins; D005680:gamma-Aminobutyric Acid; D002795:Choline O-Acetyltransferase
keywords: central complex; coincidence detectors; development; locomotion control