Action potential modulates Ca2+-dependent and Ca 2+-independent secretion in a sensory neuron

Hui Zheng, Juan Fan, Wei Xiong, Chen Zhang, Xiao Bing Wang, Tao Liu, Hong Ju Liu, Lei Sun, Ye Shi Wang, Liang Hong Zheng, Bai Ren Wang, Claire Xi Zhang, Zhuan Zhou

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17 Citations (Scopus)


Neurotransmitter release normally requires calcium triggering. However, the somata of dorsal root ganglion (DRG) neurons possess a calcium-independent but voltage-dependent secretion (CIVDS) in addition to the classic calcium-dependent secretion (CDS). Here, we investigated the physiological role of CIVDS and the contributions of CIVDS and CDS induced by action potentials (APs) in DRG soma. Using membrane capacitance measurements, caged calcium photolysis, and membrane capacitance kinetics analysis, we demonstrated that AP-induced secretion had both CIVDS and CDS components. Following physiological stimuli, the dominant component of AP-induced secretion was either CIVDS for spontaneous firing or CDS for high-intensity stimuli. AP frequency modulates CDS-coupled exocytosis and CIVDS-coupled endocytosis but not CIVDScoupled exocytosis and CDS-coupled endocytosis. Finally, CIVDS did not contribute to excitatory postsynaptic currents induced by APs in DRG presynaptic terminals in the spinal cord. Thus, CIVDS is probably an essential physiological component of AP-induced secretion in the soma. These findings bring novel insights into primary sensory processes in DRG neurons.

Original languageEnglish
Pages (from-to)2449-2456
Number of pages8
JournalBiophysical Journal
Issue number6
Publication statusPublished - 2009
Externally publishedYes

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