TY - JOUR
T1 - Submillisecond kinetics of glutamate release from a sensory synapse
AU - Von Gersdorff, Henrique
AU - Sakaba, Takeshi
AU - Berglund, Ken
AU - Tachibana, Masao
N1 - Funding Information:
We thank Erwin Neher for comments on the manuscript and continuous support, Gary Matthews, Aaron Fox and Heinz Wässle for discussions, and Haruo Kasai and Erwin Neher for the loan of equipment. This work was supported by the Ministry of Education, Science, Sports and Culture of Japan (M. T.) and the Human Frontier Science Program (H. v. G.).
PY - 1998/11
Y1 - 1998/11
N2 - Exocytosis-mediated glutamate release from ribbon-type synaptic terminals of retinal bipolar cells was studied using AMPA receptors and simultaneous membrane capacitance measurements. Release onset (delay <0.8 ms) and offset were closely tied to Ca2+ channel opening and closing. Asynchronous release was not copious and we estimate that there are ~5 Ca2+ channels per docked synaptic vesicle. Depending on Ca2+ current amplitude, release occurred in a single fast bout or in two successive bouts with fast and slow onset kinetics. The second, slower bout may reflect a mobilization rate of reserve vesicles toward fusion sites that is accelerated by increasing Ca2+ influx. Bipolar cell synaptic ribbons thus are remarkably versatile signal transducers, capable of transmitting rapidly changing sensory input, as well as sustained stimuli, due to their large pool of releasable vesicles.
AB - Exocytosis-mediated glutamate release from ribbon-type synaptic terminals of retinal bipolar cells was studied using AMPA receptors and simultaneous membrane capacitance measurements. Release onset (delay <0.8 ms) and offset were closely tied to Ca2+ channel opening and closing. Asynchronous release was not copious and we estimate that there are ~5 Ca2+ channels per docked synaptic vesicle. Depending on Ca2+ current amplitude, release occurred in a single fast bout or in two successive bouts with fast and slow onset kinetics. The second, slower bout may reflect a mobilization rate of reserve vesicles toward fusion sites that is accelerated by increasing Ca2+ influx. Bipolar cell synaptic ribbons thus are remarkably versatile signal transducers, capable of transmitting rapidly changing sensory input, as well as sustained stimuli, due to their large pool of releasable vesicles.
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U2 - 10.1016/S0896-6273(00)80634-0
DO - 10.1016/S0896-6273(00)80634-0
M3 - Article
C2 - 9856472
AN - SCOPUS:0009681349
SN - 0896-6273
VL - 21
SP - 1177
EP - 1188
JO - Neuron
JF - Neuron
IS - 5
ER -