Calcium dependence of exo- and endocytotic coupling at a glutamatergic synapse.
The mechanism coupling exocytosis and endocytosis remains to be elucidated at central synapses. Here, we show that the mechanism linking these two processes is dependent on microdomain-[Ca2+](i) similar to that which triggers exocytosis, as well as the exocytotic protein synaptobrevin/VAMP. Furthermore, block of endocytosis has a limited, retrograde action on exocytosis, delaying recruitment of release-ready vesicles and enhancing short-term depression. This effect sets in so rapidly that it cannot be explained by the nonavailability of recycled vesicles. Rather, we postulate that perturbation of a step linking exocytosis and endocytosis temporarily prevents new vesicles from docking at specialized sites for exocytosis.
Hosoi
Nobutake
N
Independent Junior Research Group of Biophysics of Synaptic Transmission, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Holt
Matthew
M
Sakaba
Takeshi
T
D000818:Animals; D001933:Brain Stem / Q000166:cytology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000502:physiology*; D034281:Dynamins / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D005089:Exocytosis / Q000502:physiology*; D018698:Glutamic Acid / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D009924:Organ Culture Techniques; D017729:Presynaptic Terminals / Q000378:metabolism; D050683:R-SNARE Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology
D050683:R-SNARE Proteins; D018698:Glutamic Acid; D034281:Dynamins; D002118:Calcium