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Flash Photolysis of Caged Compounds in the Cilia of Olfactory Sensory Neurons
Published on: October 29, 2011
Action potential modulates Ca2+-dependent and Ca2+-independent secretion in a sensory neuron
Biophysical Journal
|March 18, 2009
Summary
Dorsal root ganglion neurons exhibit calcium-independent secretion (CIVDS) alongside calcium-dependent secretion (CDS). CIVDS plays a key role in spontaneous firing, while CDS dominates high-intensity stimuli, revealing new insights into sensory neuron function.
Area of Science:
- Neuroscience
- Cell Biology
- Physiology
Background:
- Neurotransmitter release typically relies on calcium influx.
- Dorsal root ganglion (DRG) neurons exhibit a unique calcium-independent but voltage-dependent secretion (CIVDS) mechanism.
- This mechanism coexists with the established calcium-dependent secretion (CDS).
Purpose of the Study:
- To investigate the physiological role of CIVDS in DRG neurons.
- To determine the contributions of CIVDS and CDS to action potential (AP)-induced secretion in the DRG soma.
- To understand how AP frequency influences these secretion pathways.
Main Methods:
- Membrane capacitance measurements.
- Caged calcium photolysis.
- Kinetic analysis of membrane capacitance changes.
Main Results:
- AP-induced secretion in DRG soma comprises both CIVDS and CDS components.
- CIVDS is dominant during spontaneous firing, whereas CDS dominates during high-intensity stimuli.
- AP frequency differentially modulates CIVDS-coupled endocytosis and CDS-coupled exocytosis.
Conclusions:
- CIVDS is a significant physiological component of AP-induced secretion in the DRG soma.
- This finding offers novel insights into the mechanisms underlying primary sensory processes.
- CIVDS does not appear to contribute to neurotransmission at DRG presynaptic terminals in the spinal cord.
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Overview
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