Meeting Abstract
Neighboring territorial males of many species exhibit less aggression toward each other than toward strangers, a phenomenon known as the “dear enemy” effect. While this effect occurs across taxa, the neuromolecular mechanisms remain unknown. The oxytocin (OT) pathway serves a critical role in mediating male-female pair bonding in several species and thus is an interesting candidate mediator of male-male bonding. Using the African cichlid fish Astatotilapia burtoni, we use male-male bonding in the context of the “dear enemy” effect to investigate the role of isotocin (IT), the teleost homolog of OT. We examine IT receptor expression in the putative homologues of the hippocampus (Dlv), basolateral amygdala (Dm), and in the preoptic area (POA). We find ITR expression is upregulated in “dear enemy” males in the hippocampus and amygdala, while it is downregulated in the preoptic area. To further examine the role of the IT pathway, we use double-labeling immunohistochemistry to identify the role of IT neurons activated in the “dear enemy” context. Lastly, we pharmacologically perturb the IT pathway to prevent the formation of male bonds. Our results demonstrate a critical role of the IT pathway, as well as involvement of several brain regions in the Social Decision-Making Network in regulating male-male bonding in the context of the ethologically relevant “dear enemy” effect.
