The Interplay between Central and Peripheral Systems in Feed Intake Regulation in European Seabass (Dicentrarchus labrax) Juveniles

SIMPLE SUMMARY: The effect of feeding and feed deprivation on the regulation of feed intake in European seabass was evaluated. European seabass possess feed intake regulation mechanisms similar to those found in mammals and fish. Fasting and feeding conditions induce different responses in feed intake regulation mechanisms in European seabass. The present results are important to identify and understand the mechanisms of appetite regulation of European seabass, and therefore contribute to feeding optimization processes, ensuring the growth and sustainability of the aquaculture industry. ABSTRACT: The present study aimed to evaluate the effects of feeding or feed deprivation on the orexigenic and anorexigenic responses at the central (whole brain) and peripheral (anterior and posterior intestine, stomach, and liver) system levels in European seabass. For this purpose, a group of fish (208 g) was fed a single meal daily for 8 days (fed group) and another group was feed-deprived for 8 days (unfed group). Compared to the fed group, in the whole brain, feed deprivation did not induce changes in npy, agrp1, and cart2 expression, but increased agrp2 and pomc1 expression. In the anterior intestine, feed deprivation increased cck expression, while in the posterior intestine, the npy expression increased and pyyb decreased. In the stomach, the ghr expression decreased regardless of the feeding status. The hepatic lep expression increased in the unfed fish. The present results suggest a feed intake regulation mechanism in European seabass similar to that observed in other teleosts.