Correlation between olfactory receptor basal activity and odor response: An observational study

Olfactory receptors (ORs) are the largest group of G-protein-coupled human receptors responsible for detecting and distinguishing odors. However, the fundamental mechanisms underlying OR responses remain poorly understood. This study aims to evaluate the basal activity of mouse and human ORs in the Hana3A cell line and examine the correlation between their basal activity and response characteristics to odor stimuli. Using a luciferase assay on the Hana3A cell line, the results showed that the 10 mouse ORs with the highest basal activity levels were positively correlated with their total response to odor stimuli. However, there was no significant correlation between the basal activity of human-derived ORs and their total response to odor stimuli. These findings indicate that basal activity levels significantly influence OR responses to odors, as evidenced by the positive correlation in the 10 mouse ORs with the highest basal activity levels and their odor response. This supports the notion that the receptor binding cavity is crucial in determining OR responses to odors.