The somata of primary sensory neurons, including dorsal root ganglion (DRG) neurons and mesencephalic trigeminal nucleus (MeV) neurons, release neurotransmitters and neuropeptides. In addition to the conventional Ca2+-dependent secretion (CDS), Ca2+-independent but voltage-dependent secretion (ciVDS) also occurs in the somata of isolated DRG neurons (Zhang et al., 2002; Liu et al., 2011) and brain slice MeV neurons (Zhang et al., 2011). Electrical stimulation induces both CDS and ciVDS, which differ in size and are coupled with different types of endocytosis contributed by ciVDS and CDS, respectively. However, it is unclear whether they use a common vesicle pool, so we investigated the relationship between the vesicle pools of CDS and ciVDS. DRG neurons were isolated from Wistar rats (male, ~ 60 g) treated with 0.6 ml/100 g 25% urethane. Membrane capacitance recording and photolysis of a caged-Ca2+ compound showed that, in low external Ca2+ solutions, the depolarization-induced exocytosis contained two (fast and slow) phases, which were contributed by ciVDS and CDS respectively. Depletion of the CDS readily-releasable pool using photolysis did not affect the ciVDS. When the ciVDS and CDS vesicle pools were depleted by electrical stimulation, the pools had different sizes. Their kinetics of exocytosis-coupled endocytosis were also different. Thus, ciVDS and CDS used different vesicle pools in somata of primary sensory neurons.
37th Congress of IUPS (Birmingham, UK) (2013) Proc 37th IUPS, PCD165
Poster Communications: Mechanisms of calcium independent but voltage dependent secretion (ciVDS) and calcium dependent secrtion (CDS) in somata of primary sensory neurons
C. Wang1,2, X. Zhang1,2, X. Wu1,2, Z. Chai1,2, P. Hou3, H. Liu3, Y. Liu3, T. Liu1,2, Y. Wang1,2, B. Liu1,2, C. Zhang1,2, W. Guo1,2, S. Wang1,2, X. Zhang1,2, J. Ding3, Z. Zhou1,2
1. Peking University, State Key Laboratory of Biomembrane and Membrane Biotechnology and the Center For Life Sciences, Beijing, China. 2. Peking University, Institute of Molecular Medicine, Beijing, China. 3. Huazhong University of Science and Technology, School of Life Sciences, Wuhan, China.
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Where applicable, experiments conform with Society ethical requirements.