title: In search of evidence for the experience of pain in honeybees: A self-administration study.
abstract: Despite their common use as model organisms in scientific experiments, pain and suffering in insects remains controversial and poorly understood. Here we explore potential pain experience in honeybees (Apis mellifera) by testing the self-administration of an analgesic drug. Foragers were subjected to two different types of injuries: (i) a clip that applied continuous pressure to one leg and (ii) amputation of one tarsus. The bees were given a choice between two feeders, one offering pure sucrose solution, the other sucrose solution plus morphine. We found that sustained pinching had no effect on the amount of morphine consumed, and hence is unlikely to be experienced as painful. The amputated bees did not shift their relative preference towards the analgesic either, but consumed more morphine and more solution in total compared to intact controls. While our data do not provide evidence for the self-administration of morphine in response to pain, they suggest that injured bees increase their overall food intake, presumably to meet the increased energy requirements for an immune response caused by wounding. We conclude that further experiments are required to gain insights into potential pain-like states in honeybees and other insects.
authors.affiliation: The Queensland Brain Institute, University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Julia
authors.initials: J
authors.lastname: Groening
authors.affiliation: The Queensland Brain Institute, University of Queensland, Brisbane QLD 4072, Australia.|School of Psychology, University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Dustin
authors.initials: D
authors.lastname: Venini
authors.affiliation: The Queensland Brain Institute, University of Queensland, Brisbane QLD 4072, Australia.|School of Information Technology and Electrical Engineering (ITEE), University of Queensland, Brisbane QLD 4072, Australia.|ARC Centre of Excellence in Vision Science, University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Mandyam V
authors.initials: MV
authors.lastname: Srinivasan
mesh_terms: D000818:Animals; D001516:Bees / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology; D004435:Eating / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology; D009020:Morphine / Q000494:pharmacology*; D010146:Pain / Q000188:drug therapy* / Q000503:physiopathology; D012646:Self Administration; D013395:Sucrose / Q000494:pharmacology
chemical_list: D013395:Sucrose; D009020:Morphine