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Flash Photolysis of Caged Compounds in the Cilia of Olfactory Sensory Neurons
Published on: October 29, 2011
Calmodulin contributes to gating control in olfactory calcium-activated chloride channels
Hiroshi Kaneko1, Frank Möhrlen, Stephan Frings
1Department of Molecular Physiology, University of Heidelberg, 69120 Heidelberg, Germany.
The Journal of General Physiology
|June 1, 2006
Summary
Calmodulin plays a key role in amplifying olfactory signals in sensory neurons. This protein mediates calcium-activated chloride currents, crucial for neuron excitation and signal processing.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Physiology
Background:
- Sensory neurons amplify receptor potentials via depolarizing chloride currents.
- Olfactory sensory neurons (OSNs) use cAMP-gated Ca channels and Ca-activated Cl channels for signal amplification.
- This anion-based amplification significantly boosts the initial receptor current, leading to neuron excitation.
Purpose of the Study:
- To investigate the activation mechanism of Ca-dependent Cl channels in olfactory sensory neurons.
- To determine the role of calmodulin in the gating process of these channels.
- To understand the contribution of calmodulin to signal amplification in olfactory cilia.
Main Methods:
- Utilized the Odora cell line, derived from rat olfactory epithelium precursor cells, which expresses Ca-activated Cl channels.
- Characterized Odora channels by examining single-channel conductance, ion selectivity, voltage dependence, niflumic acid sensitivity, and Ca sensitivity.
- Employed CaM mutants to assess the impact on Ca sensitivity of the Cl channels.
Main Results:
- Odora channels exhibit properties consistent with those found in OSN channels.
- Transfection with CaM mutants significantly reduced the Ca sensitivity of the Cl channels in Odora cells.
- Calmodulin is implicated in the gating of Ca-activated Cl channels.
Conclusions:
- Calmodulin is instrumental in the generation of the excitatory Cl current in OSNs.
- Calmodulin plays a pivotal role in peripheral signal processing of olfactory information.
- Calmodulin-mediated, anion-based signal amplification may be a widespread mechanism converting Ca signals into membrane depolarization in various cell types.
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