The ins and outs of intracellular chloride in olfactory receptor neurons

Stimulation of olfactory receptor neurons with odors culminates in opening of a ciliary Ca²⁺-activated Cl^- channel. Because intracellular Cl^- ([Cl^-]_i) is above electrochemical equilibrium in these cells, the result is cell depolarization that triggers action potentials that carry information to the olfactory bulb. In this issue of Neuron, Reisert and coworkers use combined pharmacological and mouse genetic approaches to show that the transporter responsible for maintaining Cl^- above electrochemical equilibrium is NKCC1, a Na ⁺2Cl^-K⁺ cotransporter found in other tissues, including neurons.