Functional analysis of broadly tuned odorant receptors expressed in the mouse septal organ through patch-clamp recordings in an intact preparation and luciferase assay in a heterologous expression system

The septal organ (SO) is a small island of olfactory epithelium located at the ventral base of the nasal septum. SO neurons express identified odorant receptors, but its function remains unknown. Using perforated patch clamp recordings, we investigated the response properties of SO neurons in the intact epithelium of mice to a panel of 45 odorants or mixtures. Out of 328 neurons tested, approximately 70% responded to odor stimulation. Among the responsive neurons, 72.5 % responded to multiple odorants. Responding neurons were tested with increasing concentrations of 3 odorants (octanoic acid, (+) camphor, amylacetate) and a mixture (fox urine). Dose-response curves show nanomolar threshold …