Chronic Stress Affects Feeding Behavior in Zebrafish

Stress responses are conserved reactions exhibited by most animal taxa. Enduring stress can lead to changes in behaviors such as sleep and feeding. We have developed the larval zebrafish as a model for investigating neuronal mechanisms underlying stress. A mild electric shock in larval zebrafish induces changes in behavior, particularly affecting feeding. We found that when larvae are exposed to random period of shock over a 5-day period during early life (2-6 days post fertilization), they display increased feeding later in life as juveniles. We have quantified the total brine shrimp consumption of juveniles and found that those subjected to chronic stress have a 2-fold increase in total intake. To probe the neuronal circuits underlying these changes, we have focused on the hypothalamus. We are currently testing the hypothesis that increased feeding may be caused by altered activity of neurons producing agouti-related protein (agrp).