High-affinity olfactory receptor for the death-associated odor cadaverine

Area of Science:

• Neuroscience
• Olfaction Research
• Animal Behavior

Background:

• Carrion odor, primarily from diamines like putrescine and cadaverine, elicits strong reactions in many species.
• The specific olfactory receptors and neural pathways for detecting these diamines remain largely unknown across species.
• Zebrafish are a valuable model for studying vertebrate olfaction and innate behaviors.

Purpose of the Study:

• To investigate olfactory-mediated behavioral responses to diamines in zebrafish.
• To identify the olfactory receptors responsible for detecting cadaverine and putrescine in zebrafish.
• To establish a molecular basis for understanding the neural circuits involved in diamine detection and avoidance.

Main Methods:

• Behavioral assays to assess zebrafish avoidance of cadaverine and related diamines.
• In vivo calcium imaging to identify activated olfactory sensory neurons.
• Structure-activity relationship analysis of olfactory receptors using various diamines.
• Testing receptor activation with physiologically relevant sources like decaying fish extracts.

Main Results:

• Zebrafish exhibit robust olfactory-mediated avoidance behavior towards cadaverine and related diamines.
• A sparse population of olfactory sensory neurons is activated by these diamines.
• Trace amine-associated receptor 13c (TAAR13c) is highly expressed in neurons activated by low concentrations of cadaverine.
• TAAR13c functions as a general diamine sensor, selective for medium-chain odd-numbered diamines, and responds to decaying fish extracts.

Conclusions:

• A specific olfactory receptor, TAAR13c, has been identified in zebrafish for detecting cadaverine and putrescine.
• This discovery provides a molecular foundation for studying the neural basis of innate avoidance behaviors triggered by diamines.
• TAAR13c's role as a diamine sensor opens avenues for research into vertebrate olfaction and chemical communication.