title: Video-rate far-field optical nanoscopy dissects synaptic vesicle movement.
abstract: We present video-rate (28 frames per second) far-field optical imaging with a focal spot size of 62 nanometers in living cells. Fluorescently labeled synaptic vesicles inside the axons of cultured neurons were recorded with stimulated emission depletion (STED) microscopy in a 2.5-micrometer by 1.8-micrometer field of view. By reducing the cross-sectional area of the focal spot by about a factor of 18 below the diffraction limit (260 nanometers), STED allowed us to map and describe the vesicle mobility within the highly confined space of synaptic boutons. Although restricted within boutons, the vesicle movement was substantially faster in nonbouton areas, consistent with the observation that a sizable vesicle pool continuously transits through the axons. Our study demonstrates the emerging ability of optical microscopy to investigate intracellular physiological processes on the nanoscale in real time.
authors.affiliation: Department of NanoBiophotonics, Max-Planck-Institute for Biophysical Chemistry, Göttingen 37077, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Westphal
authors.forename: Silvio O
authors.initials: SO
authors.lastname: Rizzoli
authors.forename: Marcel A
authors.initials: MA
authors.lastname: Lauterbach
authors.forename: Dirk
authors.initials: D
authors.lastname: Kamin
authors.forename: Reinhard
authors.initials: R
authors.lastname: Jahn
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Hell
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000502:physiology / Q000648:ultrastructure*; D002478:Cells, Cultured; D005456:Fluorescent Dyes; D006624:Hippocampus / Q000502:physiology / Q000648:ultrastructure; D007700:Kinetics; D008856:Microscopy, Fluorescence / Q000379:methods*; D009068:Movement; D036103:Nanotechnology; D055095:Optics and Photonics; D051381:Rats; D013572:Synaptic Vesicles / Q000502:physiology* / Q000648:ultrastructure*; D014741:Video Recording
chemical_list: D005456:Fluorescent Dyes