114.5 Saturday, Jan. 7 The link between stress and behavior in zebrafish: is embryonic perturbation a factor? WIEDEBACK, B D*; OSWALD, M E; ROBISON, B D; University of Idaho; University of Notre Dame; University of Idaho firstname.lastname@example.org
It is well known that embryonic exposure to stress hormones can affect adult behavior in mammals. However, the effect of embryonic stress exposure in determining the adult behavior of fish is not as well understood. In this presentation we describe results from two experiments that test for linkages between stress and anxiety related behaviors in the zebrafish. First, we show that in lines of zebrafish selected for shy and bold behavior, production of cortisol is higher in male zebrafish relative to females. In addition, while cortisol does not appear to vary between shy and bold lines, the expression of key stress related genes in the brain is significantly different between them. Most notable is the increase in expression of two splice variants of the glucorticoid receptor in shy fish. In the second and ongoing experiment, we sought to determine if the differences we observed among the sexes and among selected lines could be explained by changes in the early embryonic environment experienced by the fish. We therefore administered five different cortisol treatments (a control, an ethanol carrier treatment, and three cortisol treatments of 1mg/L, 10mg/L and 100mg/L) to 150 fish from the Scientific Hatcheries strain. Dosing occurred for the first 48 hours of development. This experiment will help us determine whether exposure to cortisol, a glucocorticoid related to the long term stress response, during early development has a dose dependent effect on the behavior, gene expression, and stress responsiveness of adult (3 month old) zebrafish.