The ability of the tissue to sense available nutrients alters tissue nutrient metabolism and tissue growth and possibly influences food intake. The AMP protein kinase (AMPK) is an evolutionarily conserved nutrient sensor critical for proper growth and development. In our previous study in channel catfish, expression of AMPK mRNA was influenced in a subunit-specific fashion by food intake in the liver but not in the brain or muscle tissues. Whether changes in the expression observed in channel catfish will be similar in other fish species is unclear. In the current study, we hypothesized that changes in food intake affect the AMPK mRNA expression in Atlantic salmon. The objective of this study was to examine muscle and liver expression of AMPK mRNA in response to changes in food intake. 72 Juvenile Atlantic salmon (6 fish per tank) were cultured in 12 flow-through tanks during a 14-day feeding study (). On day 0 of the study, we randomly assigned tanks to one of three feeding groups (n=4 tanks per group). One group received feed twice daily (fed, control), whereas the fasted group did not receive food for 14 days. The third group did not receive food for the first seven days of the study and was fed twice daily for the subsequent seven days (Refed). Muscle and liver were collected on day 14, and the expression of AMPK alpha 1 and beta 1 subunit mRNA was measured using qRT -PCR. The AMPK alpha 1 and beta 1 mRNA expression in the liver and muscle was similar among the three feeding groups. Given the preliminary nature of the current study, we plan to investigate to clarify the role of AMPK regulates growth, food intake, and nutrient metabolism in Atlantic salmon.