Sex differences in aggression and its neural substrate in a cichlid fish

Area of Science:

• Neuroscience
• Ethology
• Comparative Psychology

Background:

• Aggression is crucial for social dominance in many species.
• Astatotilapia burtoni cichlids offer a robust model for studying aggression due to their social hierarchies.
• Understanding sex differences in aggression and its neural basis is fundamental.

Purpose of the Study:

• To characterize sex differences in aggressive behaviors of Astatotilapia burtoni using a mirror assay.
• To investigate sex-specific neural activation patterns in the social behavior network (SBN) associated with aggression.
• To explore the functional connectivity between brain regions involved in aggression.

Main Methods:

• A mirror assay was used to elicit and observe aggressive behaviors in male and female cichlids.
• Immunohistochemistry was employed to detect phospho-S6 ribosomal protein (pS6), a marker for neural activation.
• Neural activation patterns were quantified in key brain regions of the SBN.

Main Results:

• Both sexes displayed identical and sex-specific aggressive behaviors.
• Females showed higher pS6 immunoreactivity in the Vv (ventral part of the ventral telencephalon) compared to males.
• Males exhibited higher pS6 immunoreactivity in the ATn (anterior tuberal nucleus) post-aggression assay; ATn-POA connectivity was observed in males.

Conclusions:

• Male and female Astatotilapia burtoni exhibit distinct behavioral and neural activation patterns during aggression.
• The study identifies sex-specific neural circuitry underlying aggression in this cichlid species.
• Findings provide a foundation for future research into the molecular and neural mechanisms of sex differences in aggression.