TY - JOUR
T1 - Evidence that vesicles on the synaptic ribbon of retinal bipolar neurons can be rapidly released
AU - Von Gersdorff, Henrique
AU - Vardi, Eilat
AU - Matthews, Gary
AU - Sterling, Peter
N1 - Funding Information:
We thank Sally Shrom for preparing and photographing the serial sections, Dan Jurow and Sharron Fina for preparing the illustrations, Noga Vardi for helpful discussions, and Keith Studholme and Stephen Yazulla (State University of New York, Stony Brook) for assistance with tissue fixation. Supported by National Institutes of Health grant EY00828 (P. S.) and National Research Service Award fellowships EY06506 (H. v. G.) and EY03821 (G. M.).
PY - 1996/6
Y1 - 1996/6
N2 - We relate the ultrastructure of the giant bipolar synapse in goldfish retina to the jump in capacitance that accompanies depolarization-evoked exocytosis. Mean vesicle diameter is 29 ± 4 nm, giving 26.4 aF/vesicle, so the maximum evoked capacitance (150 fF within 200 ms) represents fusion of about 5700 vesicles. Two terminals contained, respectively, 45 and 65 ribbon- type synaptic outputs, and a fully loaded ribbon tethers about 110 vesicles. Thus, the tethered pool, about 6000 vesicles, corresponds to the rapidly released pool. Further, the difference between small and large terminals in number of tethered vesicles matches their difference in capacitance jump. This suggests, within a 'fire and reload' model of exocytosis, that the ribbon translocates synaptic vesicles very rapidly to membrane docking sites, supporting a maximum release rate of 500 vesicles/active zone/s, until the population of tethered vesicles is exhausted.
AB - We relate the ultrastructure of the giant bipolar synapse in goldfish retina to the jump in capacitance that accompanies depolarization-evoked exocytosis. Mean vesicle diameter is 29 ± 4 nm, giving 26.4 aF/vesicle, so the maximum evoked capacitance (150 fF within 200 ms) represents fusion of about 5700 vesicles. Two terminals contained, respectively, 45 and 65 ribbon- type synaptic outputs, and a fully loaded ribbon tethers about 110 vesicles. Thus, the tethered pool, about 6000 vesicles, corresponds to the rapidly released pool. Further, the difference between small and large terminals in number of tethered vesicles matches their difference in capacitance jump. This suggests, within a 'fire and reload' model of exocytosis, that the ribbon translocates synaptic vesicles very rapidly to membrane docking sites, supporting a maximum release rate of 500 vesicles/active zone/s, until the population of tethered vesicles is exhausted.
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U2 - 10.1016/S0896-6273(00)80148-8
DO - 10.1016/S0896-6273(00)80148-8
M3 - Article
C2 - 8663998
AN - SCOPUS:0030175780
SN - 0896-6273
VL - 16
SP - 1221
EP - 1227
JO - Neuron
JF - Neuron
IS - 6
ER -