TY - JOUR
T1 - An isolated pool of vesicles recycles at rest and drives spontaneous neurotransmission
AU - Sara, Yildirim
AU - Virmani, Tuhin
AU - Deák, Ferenc
AU - Liu, Xinran
AU - Kavalali, Ege T.
N1 - Funding Information:
We would like to thank K. Huber, H. Krämer, L. Monteggia, and T.C. Südhof for helpful discussions and for critically reading the manuscript. This work was supported by grants from the National Institute of Mental Health (MH068437 and MH066198) and Rett Syndrome Research Foundation to E.T.K.
PY - 2005/2/17
Y1 - 2005/2/17
N2 - Spontaneous synaptic vesicle fusion is a common property of all synapses. To trace the origin of spontaneously fused vesicles in hippocampal synapses, we tagged vesicles with fluorescent styryl dyes, antibodies against synaptotagmin-1, or horseradish peroxidase. We could show that synaptic vesicles recycle at rest, and after spontaneous exo-endocytosis, they populate a reluctantly releasable pool of limited size. Interestingly, vesicles in this spontaneously labeled pool were more likely to re-fuse spontaneously compared to vesicles labeled with activity. We found that blocking vesicle refilling at rest selectively depleted neurotransmitter from spontaneously fusing vesicles without significantly altering evoked transmission. Furthermore, in the absence of the vesicle SNARE protein synaptobrevin (VAMP), activity-dependent and spontaneously recycling vesicles could mix, suggesting a role for synaptobrevin in the separation of the two pools. Taken together these results suggest that spontaneously recycling vesicles and activity-dependent recycling vesicles originate from distinct pools with limited cross-talk with each other.
AB - Spontaneous synaptic vesicle fusion is a common property of all synapses. To trace the origin of spontaneously fused vesicles in hippocampal synapses, we tagged vesicles with fluorescent styryl dyes, antibodies against synaptotagmin-1, or horseradish peroxidase. We could show that synaptic vesicles recycle at rest, and after spontaneous exo-endocytosis, they populate a reluctantly releasable pool of limited size. Interestingly, vesicles in this spontaneously labeled pool were more likely to re-fuse spontaneously compared to vesicles labeled with activity. We found that blocking vesicle refilling at rest selectively depleted neurotransmitter from spontaneously fusing vesicles without significantly altering evoked transmission. Furthermore, in the absence of the vesicle SNARE protein synaptobrevin (VAMP), activity-dependent and spontaneously recycling vesicles could mix, suggesting a role for synaptobrevin in the separation of the two pools. Taken together these results suggest that spontaneously recycling vesicles and activity-dependent recycling vesicles originate from distinct pools with limited cross-talk with each other.
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U2 - 10.1016/j.neuron.2004.12.056
DO - 10.1016/j.neuron.2004.12.056
M3 - Article
C2 - 15721242
AN - SCOPUS:13844266201
SN - 0896-6273
VL - 45
SP - 563
EP - 573
JO - Neuron
JF - Neuron
IS - 4
ER -