Social Transitions Cause Rapid Behavioral and Neuroendocrine Changes

Area of Science:

• Neuroendocrinology
• Animal Behavior
• Social Hierarchy Dynamics

Background:

• Dominance hierarchies are common in species, with rank changes impacting individuals.
• Social rank transitions can rapidly alter an animal's behavior, physiology, and brain.
• The African cichlid fish (Astatotilapia burtoni) exhibits plastic and reversible social phenotypes.

Purpose of the Study:

• To explore how social rank transitions rapidly impact behavior, physiology, and brain.
• To investigate the neuroendocrine and behavioral changes associated with social ascent and descent in A. burtoni.
• To examine hormone-behavior correlations during rapid social ascent.

Main Methods:

• Manipulating the social environment to induce rank changes (ascent and descent).
• Measuring behavioral changes, circulating hormone levels (steroids, cortisol), and gene expression in the brain.
• Analyzing correlations between plasma steroid levels and behavior during social ascent.

Main Results:

• Social ascent rapidly induced bright coloration, increased dominance behaviors, and altered brain activity within minutes.
• Plasma levels of testosterone, 11-ketotestosterone, estradiol, progestins, and cortisol increased rapidly after social ascent.
• Behavioral changes during social ascent were dissociated from initial endocrine status changes.
• Social descent led to faded coloration, decreased dominance, increased subordinate behaviors, and elevated cortisol.

Conclusions:

• Rapid social transitions are translated into adaptive behavioral and neuroendocrine changes.
• The brain rapidly processes social cues to mediate appropriate physiological and behavioral responses.
• Understanding these mechanisms is crucial for comprehending social plasticity and fitness outcomes.