Social decision making network involved in intrasexual aggression in zebrafish.

MARIA FLORENCIA SCAIA; IBUKUN AKINRINADE ; RUI OLIVEIRA

Daegu

Congreso; 10th IBRO World Congress; 2019

International Brain Research Organization (IBRO)

The neural substrate of social behavior has been described as a?social behavior network? (SBN), and each brain area is involvedin multiple forms of social behavior which are reciprocally connected,including aggression. Moreover, the mesolimbic rewardsystem and the SBN are better understood as an integrated socialdecision-making (SDM) network regulating responses to salientstimuli. Aggression and the neural mechanisms involved in fightingbehaviors are usually studied in males but not in females,despite the fact that in different species both sexes show aggressivebehavior. The aim of this study is to compare male and femaleintrasexual aggression in agonistic encounters, and to comparepatterns of brain activation in the SDM network in winners andlosers from both sexes. We exposed adult zebrafish to social interactionwith an opponent of the same sex (n = 20 contests per sex).We recorded the encounter and, after distinguishing a winner anda loser, samples were collected to determine brain activation byimmunohistochemistry of the phosphorylated ribosomal proteinpS6. The latency did not vary between sexes, while the time ofresolution is shorter in females. Our results suggest that in bothsexes, animals exposed to social interaction had higher overallbrain activation than non-interacting controls. Moreover, femalesshow more overall brain activation than males. In order to studyhow brain activation is interconnected among different areas ineach social group, we performed network analysis. Our analysissuggests that female winners have a brain network with majority ofpositive correlations, while brain network in female losers is moresimilar to males, with mainly negative correlations. These resultssuggest that, even though intrasexual aggression follows similarstructure and behavioural displays in both sexes, females solveconflict faster than males and this could be related to differentialpattern of brain activation.