Brain regulation of feeding behavior and food intake in fish

In mammals, the orexigenic and anorexigenic neuronal systems are morphologi cally and functionally connected, forming an interconnected network in the hypothalamus to govern food intake and body weight. However, there are rela tively few studies on the brain control of feeding behavior in fish. Recent studies using mammalian neuropeptides or fish homologs of mammalian neurop eptides indicate that brain orexigenic signal molecules include neuropeptid e Y, orexins, galanin and beta-endorphin, whereas brain anorexigenic signal molecules include cholecystokinin, bombesin, corticotropin-releasing facto r, cocaine- and amphetamine-regulated transcript, and serotonin. Tachykinin s may also have an anorectic action in fish. The brain hypothalamic area, i s associated with regulation of food intake, while sites outside the hypoth alamus are also involved in this function. There is correlation between sho rt-term changes in serum growth hormone levels and feeding behavior, althou gh possible mechanisms integrating these functions remain to be defined. (C ) 2000 Elsevier Science Inc. All rights reserved.