Title: | Calcium activates a chloride conductance likely involved in olfactory receptor neuron repolarization in the moth Spodoptera littoralis |
Author(s): | Pezier A; Grauso M; Acquistapace A; Monsempes C; Rospars JP; Lucas P; |
Address: | "Unite Mixte de Recherche 1272 Physiologie de l'Insecte, Signalisation et Communication, Institut National de la Recherche Agronomique, F-78000 Versailles, France" |
DOI: | 10.1523/JNEUROSCI.0261-10.2010 |
ISSN/ISBN: | 1529-2401 (Electronic) 0270-6474 (Print) 0270-6474 (Linking) |
Abstract: | "The response of insect olfactory receptor neurons (ORNs) to odorants involves the opening of Ca(2+)-permeable channels, generating an increase in intracellular Ca(2+) concentration. Here, we studied the downstream effect of this Ca(2+) rise in cultured ORNs of the moth Spodoptera littoralis. Intracellular dialysis of Ca(2+) from the patch pipette in whole-cell patch-clamp configuration activated a conductance with a K(1/2) of 2.8 microm. Intracellular and extracellular anionic and cationic substitutions demonstrated that Cl(-) carries this current. The anion permeability sequence I(-) > NO(3)(-) > Br(-) > Cl(-) > CH(3)SO(3)(-) >> gluconate(-) of the Ca(2+)-activated Cl(-) channel suggests a weak electrical field pore of the channel. The Ca(2+)-activated current partly inactivated over time and did not depend on protein kinase C (PKC) and CaMKII activity or on calmodulin. Application of Cl(-) channel blockers, flufenamic acid, 5-nitro-2-(3-phenylpropylamino) benzoic acid, or niflumic acid reversibly blocked the Ca(2+)-activated current. In addition, lowering Cl(-) concentration in the sensillar lymph bathing the ORN outer dendrites caused a significant delay in pheromone response termination in vivo. The present work identifies a new Cl(-) conductance activated by Ca(2+) in insect ORNs presumably required for ORN repolarization" |
Keywords: | Animals Anions/metabolism Calcium/pharmacology/*physiology Calcium Signaling/drug effects Calcium-Calmodulin-Dependent Protein Kinase Type 2/antagonists & inhibitors Calmodulin/pharmacology Cell Culture Techniques/methods Chloride Channels/antagonists & i; |
Notes: | "MedlinePezier, Adeline Grauso, Marta Acquistapace, Adrien Monsempes, Christelle Rospars, Jean-Pierre Lucas, Philippe eng Research Support, Non-U.S. Gov't 2010/05/07 J Neurosci. 2010 May 5; 30(18):6323-33. doi: 10.1523/JNEUROSCI.0261-10.2010" |