Mice recognize recent urine scent marks by the molecular composition.

Area of Science:

• Animal Behavior
• Chemical Ecology
• Olfactory Communication

Background:

• Male mice utilize urine scent marks for territory ownership, with frequent renewal indicating territorial maintenance.
• The perception of scent mark freshness influences male mouse behavior, including sniffing and countermarking.

Purpose of the Study:

• To investigate the relationship between specific volatile compounds in male mouse urine and behavioral responses.
• To identify scent features that signal the recency of urine marks to male mice.

Main Methods:

• Male mice responses were measured towards urine spots of varying ages (0-24 hours).
• Volatile compounds in urine spots were identified and quantified using gas chromatography and mass spectrometry.
• Behavioral variables (sniffing, marking, fecal pellets) were correlated with identified urine compounds.

Main Results:

• A strong canonical correlation (R = 0.96) was found between molecular profiles and behavioral responses.
• Compounds 2,4-dehydro-exo-brevicomin, linalool, and 2-sec-butyl-4,5-dihydrothiazole were associated with increased sniffing.
• These specific compounds negatively correlated with countermarking behavior, suggesting they indicate fresh urine.

Conclusions:

• Specific volatile organic compounds in male mouse urine act as semantic signals for freshness.
• The identified compounds play a crucial role in mediating territorial communication and behavior in male mice.