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Capture of extracellular zinc ions by astrocytes
Author(s) -
Varea Emilio,
AlonsoLlosà Gregori,
Molowny Asunción,
LopezGarcia Carlos,
Ponsoda Xavier
Publication year - 2006
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.20382
Subject(s) - extracellular , endocytic cycle , zinc , neurotransmission , hippocampal formation , biology , microbiology and biotechnology , postsynaptic potential , biophysics , neuroscience , lysosome , synaptic cleft , biochemistry , chemistry , endocytosis , receptor , organic chemistry , enzyme
Abstract Synaptic zinc ions released during synaptic transmission interact with pre‐ and postsynaptic neuroreceptors, thus modulating neurotransmission. It is likely that they have to be efficiently cleared from the extracellular milieu to assure subsequent synaptic events. Both neurons and glia are assumed to participate in this clearance by mechanisms that are not fully understood. In this study, electron microscopic zinc cytochemistry has shown zinc‐electrondense particles associated with hippocampal astrocytic membranes frequently found accumulated in stacked lamellae. In cultured astrocytes, the use of zinc fluorochromes and endocytic markers allowed the simultaneous imaging of the capture of extracellular zinc simultaneously to plasma membrane markers; this endocytic process was inhibited by high sucrose concentrations. Finally, electron microscopy of zinc‐loaded and fluorochrome photoconverted cells demonstrated some early events of extracellular zinc capture as well as its late accumulation in lysosome‐like organelles. © 2006 Wiley‐Liss, Inc.