Fig. 5.

Canonical transduction pathway in the cilia of OSNs. An odor ligand binding to a specific receptor activates the G-protein ${\mathrm{G}}_{\mathrm{olf}}$, which then activates ACIII to convert intracellular ATP to cAMP. The CNG channel is opened by binding nearby cAMP and allows depolarizing cations, including ${\mathrm{Ca}}^{2+}$, to enter the cell. High ${\mathrm{Ca}}^{2+}$ concentration may also activate downstream ${\mathrm{Cl}}_{\mathrm{Ca}}$ channels, which further depolarizes the cell. Also illustrated are representations of the antibodies conjugated with Atto 594 and Atto 647N that label the CNG and ACIII proteins.