Central gastrin inhibits feeding behavior and food passage in neonatal chicks

The gastrin/cholecystokinin (CCK) family is recognized as the principal fam ily of hormones involved in regulation of the gastrointestinal tract. CCK i s recognized as a satiety hormone in mammalian species, but it has been sug gested that gastrin rather CCK may have an important role in controlling fe eding behavior in the neonatal chick through a poorly developed blood brain barrier. So far, however, there is no direct evidence that central gastrin inhibits food intake in neonatal chicks. The aim of this study was to eluc idate whether central administration of gastrin 1) inhibits feeding behavio r and 2) alters food passage from the crop. The effects of central administ ration of gastrin on food intake were investigated in experiment 1. Birds ( 2-day-old) were food-deprived for 3 h and then gastrin or saline was inject ed intracerebroventricularly. Gastrin strongly inhibited food intake in a d ose-dependent fashion for 2 h. Thereafter, the effects of central gastrin o n feeding behavior and serum corticosterone concentration were examined in experiment 2. Following central administration of gastrin, food intake was depressed and pecking behavior was inhibited. Serum corticosterone concentr ation was not altered by central administration of gastrin. The influence o f central gastrin on food passage from the crop was investigated in experim ent 3. Central administration of gastrin clearly delayed food passage. In c onclusion, central gastrin appears to have a strong effect for the satiety and gastrointestinal motility in the neonatal chick.