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Mobility and turnover of vesicles at the synaptic ribbon
被引:39
|作者:
LoGiudice, Lisamarie
[1
,2
]
Sterling, Peter
[3
]
Matthews, Gary
[1
]
机构:
[1] SUNY Stony Brook, Dept Neurobiol & Behav, Stony Brook, NY 11794 USA
[2] SUNY Stony Brook, Grad Program Neurosci, Stony Brook, NY 11794 USA
[3] Univ Penn, Dept Neurosci, Philadelphia, PA 19104 USA
来源:
JOURNAL OF NEUROSCIENCE
|
2008年
/
28卷
/
12期
关键词:
retina;
ribbon synapse;
retinal bipolar cell;
synaptic transmission;
exocytosis;
neurotransmitter release;
D O I:
10.1523/JNEUROSCI.5753-07.2008
中图分类号:
Q189 [神经科学];
学科分类号:
071006 ;
摘要:
Ribbon synapses release neurotransmitter continuously at high rates, and the ribbons tether a large pool of synaptic vesicles. To determine whether the tethered vesicles are actually released, we tracked vesicles labeled with styryl dye in mouse retinal bipolar cell terminals whose ribbons had been labeled with a fluorescent peptide. We photobleached vesicles in regions with ribbons and without them and then followed recovery of fluorescence as bleached regions were repopulated by labeled vesicles. In the resting terminal, fluorescence recovered by similar to 50% in non-ribbon regions but by only similar to 20% at ribbons. Thus, at rest, vesicles associated with ribbons cannot exchange freely with cytoplasmic vesicles. Depolarization stimulated vesicle turnover at ribbons as bleached, immobile vesicles were released by exocytosis and were then replaced by fluorescent vesicles from the cytoplasm, producing an additional increase in fluorescence specifically at the ribbon location. We conclude that vesicles immobilized at synaptic ribbons participate in the readily releasable pool that is tapped rapidly during depolarization.
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页码:3150 / 3158
页数:9
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