Two forms of single-vesicle astrocyte exocytosis imaged with total internal reflection fluorescence microscopy.

ABSTRACT: Transmitters such as glutamate and ATP are released from brain astrocytes. Several pathways for their release have been proposed, including exocytosis. In the present study we sought to measure exocytosis from astrocytes with single vesicle imaging methods using synaptopHlourin (SpH) as an optical reporter. We imaged single SpH-laden vesicles with total internal reflection fluorescence (TIRF) microscopy. We observed spontaneous, as well as evoked, single-vesicle exocytosis events. Analysis of the kinetics and spatial spread associated with these events indicated two discernible forms of single vesicle exocytosis. One form, constituting approximately 40% of the spontaneous events, was akin to kiss-and-run vesicle fusion and captured a mobile proton buffer from the extracellular medium. The

SUBMITTER: Bowser DN 

PROVIDER: S-EPMC1820734 | biostudies-literature | 2007 Mar

REPOSITORIES: biostudies-literature