The Role of Dopaminergic and Oxytocinergic Systems in Social Affiliation and Bonding Behaviors of Convict Cichlids

What is the driving force responsible for bonding and affiliative behaviors in animals? This study investigates the effects of specific drug injections on female convict cichlids, aiming to explore the neuroendocrine mechanisms underlying the formation and maintenance of these behaviors. The study focuses on a monogamous vertebrate species, the convict cichlid, which shares similarities with the human endocrine system. Female cichlids are administered one of three treatments: a phosphate buffer solution (control), an oxytocin antagonist, or a dopamine 2 (D2) antagonist. Following the injection, each female is reunited with her male partner, and their behaviors are observed for 10 minutes. After this observation period, the male is subjected to a DAS stress test, and the level of affiliative behaviors displayed between the pair is recorded post-stress. Comparative analysis reveals a decline in affiliative behaviors post-stress in female cichlids treated with the D2 antagonist. Conversely, females treated with either the oxytocin antagonist or the phosphate buffer solution exhibit an increase in affiliative behaviors following stress. This outcome suggests a correlation between reduced affiliative behaviors and the administration of a D2 antagonist, while treatments with the oxytocin antagonist produce results similar to the control (phosphate buffer solution). Although these findings do not definitively establish that blocking the D2 pathway directly causes a decrease in affiliative behaviors, they raise important questions for future research. The results imply that the neuroendocrine system is more complex than previously understood, highlighting the need for continued exploration of the mechanisms that govern social bonding.