Figure 2

Changes in the free amino acid concentrations in the chick brain corresponding to feeding behavior. Levels of l-arginine (a), l-tryptophan (b), l-tyrosine (c), l-phenylalanine (d), l-leucine (e), l-serine (f), l-isoleucine (g), l-valine (h), l-histidine (i), l-glutamine (j) were determined in different brain regions. Data are expressed as mean ± SEM of 7–8 chicks per group. Teln telencephalon, Dien diencephalon, Mesn mesencephalon, Cerl cerebellum, Bst brain stem, FB feeding behavior, BR brain region, NS not significant. *p < 0.05.