Pheromones modulate responsiveness to a noxious stimulus in honey bees

Area of Science:

• Animal behavior
• Chemical ecology
• Neuroethology

Background:

• Pheromones are species-specific chemical signals influencing social behaviors.
• A novel hypothesis suggests pheromones also modulate behavioral plasticity by altering stimulus evaluation.

Purpose of the Study:

• To investigate if pheromones affect the subjective evaluation of aversive stimuli.
• To determine if pheromone valence (positive/negative) influences responses to negative events.

Main Methods:

• Bees were exposed to three pheromonal components: isopentyl acetate (negative), 2-heptanone (negative), and geraniol (positive).
• Responsiveness to increasing electric shock voltages was measured before and after pheromone exposure in two experiments with different time intervals.
• Shock responsiveness was quantified to assess changes in aversive stimulus evaluation.

Main Results:

• Isopentyl acetate enhanced shock responsiveness, counteracting fatigue effects in experiment 1 and showing a significant effect in experiment 2.
• Geraniol decreased aversive responsiveness in experiment 2.
• 2-heptanone did not significantly affect shock responsiveness in either experiment.

Conclusions:

• Pheromones modulate the salience of aversive stimuli based on their associated valence.
• This modulation influences motivation for aversive responses, acting as key modulators of behavioral plasticity in bees.