Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.

Naked mole-rats are eusocial rodents that live in subterranean colonies with a strict reproductive and social hierarchy. Breeders are socially dominant and other colony members are non-reproductive subordinates. The effects of manipulating the serotonergic system on aggression are well studied in many species, but not in eusocial rodents like the naked mole-rat. For the current study, the effects of fluoxetine hydrochloride (FLX) on status-specific behaviours of subordinates (Experiment 1) and queens (Experiment 2) were evaluated both in-colony and in a social-pairing paradigm to investigate how the serotonergic system influences aggression in this species. In accordance with our main hypothesis, chronic treatment of FLX attenuated the frequency and duration of aggression in queens, but not subordinates, when paired with an unfamiliar conspecific. Further exploration of pharmacological manipulation on status-specific behaviours of this eusocial species may elucidate the neurobiological mechanisms underlying their unique and rigid social hierarchy.