Meeting Abstract
P2.113 Friday, Jan. 4 Stressed out? Novel methods and experimental assessment of the interaction between social stress and aggression in convict cichlid fish (Cryptoheros nigrofasciatus) WONG, Stephanie C.*; MA, Jacqueline; EARLEY, Ryan L.; California State University, Fresno stephc.wong@gmail.com
Stressors initiate a physiological response that entails activation of the neuroendocrine stress axis, elevations in cortisol concentrations, and changes in behavior. Acute cortisol release has been correlated with the expression of aggressive behavior, and studies that manipulate cortisol exogenously have shown that acute increases in cortisol correlate with increased aggressive behavior. We validated sesame oil injections of exogenous cortisol and metyrapone (cortisol biosynthesis inhibitor) and observed that a low dose of cortisol (1ug/1g fish) facilitated negative feedback, characterized by low circulating cortisol levels. We observed that a high dose of cortisol (100ug/1g fish) perhaps overrode negative feedback leading to high cortisol levels. Both doses of metyrapone successfully depressed circulating cortisol levels. We also evaluated stress responsiveness in convict cichlid fish, Cryptoheros nigrofasciatus, both before and after exposure to a social stressor by assessing water-borne cortisol concentrations. The social stressor entailed confining pairs of size-matched individuals in 10 gallon tanks separated by an opaque partition. After two days of confinement, the partition was lifted and the two individuals were allowed to interact across a clear partition for 15 minutes. Social interaction was recorded and behavior was later quantified. Water-borne cortisol was collected on each of the 4d preceding social interaction and immediately following the interaction. We present preliminary data on the interactive effects of social stress (exposure to an opponent across a glass partition), cortisol levels, and aggressive behavior, and we discuss these results in light of the role of the stress response in regulating aggressive behavior.
