title: A simulation study on the Ca2+-independent but voltage-dependent exocytosis and endocytosis in dorsal root ganglion neurons.
abstract: In patch-clamped somata of dorsal root ganglion (DRG) neurons, two types of secretion have been proposed: Ca(2+)-dependent secretion and Ca(2+)-independent but voltage-dependent secretion (CIVDS). The Ca(2+)-induced and the depolarization-induced membrane capacitance (C(m)) increases contribute 80 and 20% to the total C(m) increase, respectively (Zhang and Zhou in Nat Neurosci 5:425, 2002). In order to explore the mechanism of the voltage-dependent C(m) change (DeltaC(m)), we constructed a model with sequential states. The simulation with this model closely approximates all the experimental data. The model predicts that the majority of fusion events (approximately 80%) are so-called "kiss-and-run" events, which account for the fast recovery or the rapid retrieval feature of the signals. The remaining 20% are attributed to full fusion events, which account for a slow retrieval feature. On the basis of the model, one mechanism of the activity-dependent endocytosis has revealed a differential distribution of vesicles between the kiss-and-run and full fusion states at different stimulation frequencies. The quantitative model presented in this study may help us to understand the mechanism of the CIVDS and the tightly coupled endocytosis found in mammalian DRG neurons.
authors.affiliation: Institute of Biophysics and Biochemistry, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Zheng
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Zhuan
authors.initials: Z
authors.lastname: Zhou
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.forename: Jiu Ping
authors.initials: JP
authors.lastname: Ding
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000502:physiology; D002478:Cells, Cultured; D003198:Computer Simulation; D004705:Endocytosis / Q000502:physiology*; D005089:Exocytosis / Q000502:physiology*; D005727:Ganglia, Spinal / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology*; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000502:physiology
chemical_list: D018377:Neurotransmitter Agents; D002118:Calcium