Title: | Calcium-activated chloride current amplifies the response to urine in mouse vomeronasal sensory neurons |
Address: | "Department of Biology, University of Vermont, Burlington, VT 05405, USA" |
ISSN/ISBN: | 1540-7748 (Electronic) 0022-1295 (Print) 0022-1295 (Linking) |
Abstract: | "The vomeronasal organ (VNO) is an odor detection system that mediates many pheromone-sensitive behaviors. Vomeronasal sensory neurons (VSNs), located in the VNO, are the initial site of interaction with odors/pheromones. However, how an individual VSN transduces chemical signals into electrical signals is still unresolved. Here, we show that a Ca2+-activated Cl- current contributes approximately 80% of the response to urine in mouse VSNs. Using perforated patch clamp recordings with gramicidin, which leaves intracellular chloride undisrupted, we found that the urine-induced inward current (V(hold) = -80 mV) was decreased in the presence of chloride channel blockers. This was confirmed using whole cell recordings and altering extracellular chloride to shift the reversal potential. Further, the urine-induced currents were eliminated when both extracellular Ca2+ and Na+ were removed. Using inside-out patches from dendritic tips, we recorded Ca2+-activated Cl- channel activity. Several candidates for this Ca2+-activated Cl- channel were detected in VNO by reverse transcription-polymerase chain reaction. In addition, a chloride cotransporter, Na+-K+-2Cl- isoform 1, was detected and found to mediate much of the chloride accumulation in VSNs. Collectively, our data demonstrate that chloride acts as a major amplifier for signal transduction in mouse VSNs. This amplification would increase the responsiveness to pheromones or odorants" |
Keywords: | "Animals Calcium/*metabolism Cells, Cultured Chloride Channels/drug effects/*physiology Ion Channel Gating/drug effects/*physiology Mice Mice, Inbred C57BL Olfactory Receptor Neurons/drug effects/*physiology *Urine Vomeronasal Organ/cytology/drug effects/*;" |
Notes: | "MedlineYang, Chun Delay, Rona J eng P20 RR016435/RR/NCRR NIH HHS/ R01 DC006939/DC/NIDCD NIH HHS/ P20RR16435/RR/NCRR NIH HHS/ DC006939/DC/NIDCD NIH HHS/ Research Support, N.I.H., Extramural 2009/12/30 J Gen Physiol. 2010 Jan; 135(1):3-13. doi: 10.1085/jgp.200910265" |