Odor-specific transmembrane receptors and GTP-binding protein (Gs[olf])

Each receptor in the cilia of the olfactory neurons
binds specifically to one odorant. Binding
of the receptor activates adenylate cyclase via a
specific GTP-binding protein (stimulatory G
protein of the olfactory system, Gs[olf]). This
opens a sodium ion channel and initiates a cascade
of intracellular signals that result in a
nerve signal, which is transmitted to the brain.