Mechanisms for feeding and sleeping behavior in the neonatal chick

促肾上腺皮质激素释放因子（CRF）、尿皮质素和尿紧张素I具有相同的氨基酸序列，它们抑制哺乳动物的食物摄入。比较了这三种多肽对雏鸡摄食量的影响。结果表明，CRF对摄食的抑制作用最强，其次是尿紧张素I，其次是尿皮质素。CRF和胰高血糖素样肽-1 （glucagon-like peptide-1, GLP-1）都能抑制雏鸡的摄食，但也会产生其他行为。综上所述，CRF和GLP-1在小鸡大脑中相互作用，但反应取决于被测量的行为。研究了内源性胰高血糖素样肽-1 （GLP-1）在雏鸡摄食中的作用。内源性GLP-1可能在蛋鸡摄食调节中起重要作用，但在肉鸡中不起作用。神经肽Y （NPY）是已知诱导动物摄食的最有效的神经肽之一，已被认为是食物摄入的生理信号。研究表明，除了神经肽Y-(13-36)外，NPY受体激动剂是新生雏鸡食物摄入的有效刺激物。胃饥饿素是生长激素（GH）促分泌素（GHS）受体的内源性配体。研究了中心注射不同胃饥饿素（鸡和牛蛙的胃饥饿素）和合成gh释放肽（GHRP）对初生雏鸡摄食的影响。结果表明，鸡GHS受体受到多种形式GHS的影响，并且GHS受体激动剂可以抑制雏鸡的摄食量。L-pipecolic acid (L-PA)，大脑中l -赖氨酸（L-Lys）的主要代谢中间体。结果表明，L-PA对雏鸡的摄食和睡眠行为具有重要的调节作用。

Corticotropin-releasing factor (CRF), urocortin and urotensin I share amino acid sequences, and they inhibit food intake in mammals. The effect of these three peptides on food intake in the neonatal chick was compared. The results indicated that the suppressive effect on food intake was strongest for CRF followed by urotensin I, then urocortin. Both CRF and glucagon-like peptide-1 (GLP-1) inhibit food intake of chicks, but they also produce other behaviors. In conclusion, CRF and GLP-1 interact in the chick brain, but the response depends on the behavior being measured. The involvement of endogenous glucagon-like peptide-1 (GLP-1) on feeding in chicks was examined. Endogenous GLP-1 may be important in the regulation of feeding in layer-type chicks but not in broiler chicks. Neuropeptide Y (NPY) is one of the most potent neuropeptides known to induce feeding in animals, and has been suggested to be a physiological signal for food intake. It was elucidated that NPY receptor agonists, except for neuropeptide Y-(13-36), are potent stimulators of food intake in the neonatal chick. Ghrelin is an endogenous ligand for the growth hormone (GH) secretagogue (GHS) receptor. The effect of central injection of different ghrelins including chicken and bullfrog ghrelin, and synthetic GH-releasing peptide (GHRP) on feeding of neonatal chicks was investigated. The results indicate that the chicken GHS receptor is affected by several forms of GHS, and that food intake of neonatal chicks is inhibited by GHS receptor agonists. L-pipecolic acid (L-PA), a major metabolic intermediate of L-lysine (L-Lys) in the brain. The results suggest that L-PA has an important role for the regulation of feeding and sleeping behaviors in the neonatal chick.