TY - JOUR
T1 - Mechanism of the excitatory Cl- response in mouse olfactory receptor neurons
AU - Reisert, Johannes
AU - Lai, Jun
AU - Yau, King Wai
AU - Bradley, Jonathan
N1 - Funding Information:
We thank Philippe Ascher, Vikas Bhandawhat, Chih-Ying Su, Michael Do, and Samar Hattar for comments; Eric Delpire for his kind gift of Nkcc1 +/− mice and the NKCC1 antibody; Haiqing Zhao and Randy Reed for the kind gift of the UbI7 mice; and Frank Müller and U.B. Kaupp for the kind gift of the CNGA2 monoclonal antibody. This work was supported by the Howard Hughes Medical Institute and NIH (DC 06904).
PY - 2005/2/17
Y1 - 2005/2/17
N2 - In vertebrate olfactory receptor neurons (ORNs), the odorant-triggered receptor current flows through two distinct ion channels on the sensory cilia: Ca2+ influx through a cyclic nucleotide-gated (CNG) channel followed by Cl- efflux through a Ca2+-activated anion channel. The excitatory Cl- current amplifies the small CNG current and crucially depends on a high intracellular Cl- concentration. We show here that a Na+-K+-2Cl- cotransporter, NKCC1, is required for this Cl- current, in that ORNs deficient in Nkcc1 or incubated with an NKCC blocker (bumetanide) lack the Cl- current. Surprisingly, immunocytochemistry indicates that NKCC1 is located on the somata and dendrites of ORNs rather than the cilia, where transduction occurs. This topography is remarkably similar to the situation in secretory epithelial cells, where basolateral Cl- uptake and apical Cl- efflux facilitate transepithelial fluid movement. Thus, a single functional architecture serves two entirely different purposes, probably underscoring the epithelial origin of the ORNs.
AB - In vertebrate olfactory receptor neurons (ORNs), the odorant-triggered receptor current flows through two distinct ion channels on the sensory cilia: Ca2+ influx through a cyclic nucleotide-gated (CNG) channel followed by Cl- efflux through a Ca2+-activated anion channel. The excitatory Cl- current amplifies the small CNG current and crucially depends on a high intracellular Cl- concentration. We show here that a Na+-K+-2Cl- cotransporter, NKCC1, is required for this Cl- current, in that ORNs deficient in Nkcc1 or incubated with an NKCC blocker (bumetanide) lack the Cl- current. Surprisingly, immunocytochemistry indicates that NKCC1 is located on the somata and dendrites of ORNs rather than the cilia, where transduction occurs. This topography is remarkably similar to the situation in secretory epithelial cells, where basolateral Cl- uptake and apical Cl- efflux facilitate transepithelial fluid movement. Thus, a single functional architecture serves two entirely different purposes, probably underscoring the epithelial origin of the ORNs.
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U2 - 10.1016/j.neuron.2005.01.012
DO - 10.1016/j.neuron.2005.01.012
M3 - Article
C2 - 15721241
AN - SCOPUS:13844294446
SN - 0896-6273
VL - 45
SP - 553
EP - 561
JO - Neuron
JF - Neuron
IS - 4
ER -