Encoding the Odor of Cigarette Smoke

Area of Science:

• Neuroscience
• Olfactory receptor research
• Chemosensation

Background:

• Odor perception relies on combinatorial codes from odorant receptors (ORs) and trace-amine associated receptors (TAARs).
• Understanding how complex odors, like cigarette smoke, activate these receptors in vivo is crucial for deciphering olfactory coding.

Purpose of the Study:

• To investigate the in vivo receptor response patterns to cigarette smoke and its components.
• To determine the roles of ORs and TAARs in encoding complex odors.

Main Methods:

• Measured in vivo responses of ORs and TAARs in mice exposed to cigarette smoke and 1-pentanethiol.
• Analyzed receptor response patterns to identify key odorants and their contribution to the overall code.

Main Results:

• Cigarette smoke activated 144 ORs and 3 TAARs in mice, representing the first simultaneous in vivo measurement for both receptor types.
• A simplified mimic of cigarette smoke odor, containing 1-pentanethiol, elicited similar OR response patterns.
• 1-pentanethiol was identified by humans as critical for the mimic's perception and activated a subset of ORs also responsive to cigarette smoke.

Conclusions:

• Complex odor encoding involves broad patterns across ORs and TAARs, demonstrating an enriched signal through both receptor families.
• 1-pentanethiol is a significant component of cigarette smoke odor, contributing to its specific receptor activation pattern.