title: Synaptic vesicles in motor synapses change size and distribution during the day.
abstract: The morphology of Drosophila motor terminals changes along the day with a circadian rhythm controlled by the biological clock. Here, we used electron microscopy to investigate the size, number, and distribution of synaptic vesicles, at intervals of 6 h during 2 consecutive days, under light-dark (LD) or the first 2 days in constant darkness (DD). We found changes in the size and distribution of vesicles located either at the active zone or in the reserve pool, indicating a circadian rhythm of synapse reorganization. Vesicles at the active zone were generally smaller than those in the reserve pool in LD and DD conditions. The size of active zones vesicles decreased twice in LD, corresponding with times of more intense locomotion activity, but only once in DD conditions.
authors.affiliation: Departamento de Biología del Neurodesarrollo, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay.
authors.forename: Santiago
authors.initials: S
authors.lastname: Ruiz
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Ferreiro
authors.forename: Gabriela
authors.initials: G
authors.lastname: Casanova
authors.forename: Alvaro
authors.initials: A
authors.lastname: Olivera
authors.forename: Rafael
authors.initials: R
authors.lastname: Cantera
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D004331:Drosophila melanogaster / Q000502:physiology* / Q000648:ultrastructure*; D046529:Microscopy, Electron, Transmission; D018482:Muscle, Skeletal / Q000502:physiology / Q000648:ultrastructure; D009469:Neuromuscular Junction / Q000502:physiology / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000502:physiology* / Q000648:ultrastructure*