Alarm pheromone induces stress analgesia via an opioid system in the honeybee.
Changes of the stinging response threshold of Apis mellifera scutellata were measured on foragers fixed on a holder and stimulated with an electric shock as a noxious stimulus. The threshold of responsiveness to the noxious stimulus increased when bees were previously stimulated with isopentyl acetate, which is a main component of the alarm pheromone of the sting chamber. This effect is antagonised by previous injection of naloxone-hydrochloride (Endo Laboratories Inc.). Results suggest that in the honeybee an endogenous opioid system activated by isopentyl acetate is responsible for modulation of perception for nociceptive stimuli. The resulting stress-induced analgesia in the defender bee would reduce its probability of withdrawal thus increasing its efficiency against enemies.
Núñez
J
J
Department of Biological Sciences, FCEyN, Universidad de Buenos Aires, Argentina. postmast@insect.uba.ar
Almeida
L
L
Balderrama
N
N
Giurfa
M
M
D000698:Analgesia; D000818:Animals; D001516:Bees / Q000502:physiology*; D004558:Electric Stimulation; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects / Q000502:physiology; D010675:Pheromones / Q000494:pharmacology*; D011957:Receptors, Opioid / Q000187:drug effects*; D013315:Stress, Psychological / Q000523:psychology*
D009292:Narcotic Antagonists; D010675:Pheromones; D011957:Receptors, Opioid; D009270:Naloxone