NO activates the olfactory cyclic nucleotide-gated conductance independent from cGMP in isolated rat olfactory receptor neurons.

Nitric oxide (NO) is a putative neuronal messenger in the olfactory epithelium. We analysed the electrical responses of rat olfactory receptor neurones to NO stimulation in the whole-cell patch clamp mode and found that NO activates the cyclic nucleotide-gated conductance, independent from cyclic GMP. As NO may also open calcium-dependent potassium channels and raise cyclic GMP levels, it appears to act as a complex modulator of olfactory receptor neuron physiology in vivo.