Mechanisms for feeding and sleeping behavior in the neonatal chick

促肾上腺皮质激素释放因子(CRF)、Urocortin和Urotensin I具有相同的氨基酸序列，它们抑制哺乳动物的摄食。比较了三种多肽对初生雏鸡摄食量的影响。结果表明，CRF对大鼠摄食量的抑制作用最强，其次是尾加压素I，其次是尿皮质激素。CRF和胰升糖素样肽-1(GLP-1)都会抑制雏鸡的摄食量，但它们也会产生其他行为。总而言之，CRF和GLP-1在鸡的大脑中相互作用，但反应取决于被测量的行为。研究了内源性胰升糖素样肽-1(GLP-1)对雏鸡饲喂的影响。内源性GLP-1可能在蛋鸡的饲喂调节中起重要作用，但在肉鸡中不起作用。神经肽Y(NPY)是已知的诱导动物摄食的最有效的神经肽之一，被认为是食物摄取的生理信号。除神经肽Y-(13-36)外，NPY受体激动剂是雏鸡摄食量的强效刺激剂。Ghrelin是生长激素(GH)促分泌(GHS)受体的内源性配体。研究了中心注射不同生长激素(包括鸡、牛蛙生长激素)和合成生长激素释放肽(GHRP)对初生雏鸡饲喂效果的影响。结果表明，鸡GHS受体受多种形式的GHS影响，GHS受体激动剂抑制新生雏鸡的摄食量。L-吡咯酸(L-PA)，L-赖氨酸(L-赖氨酸)在脑内的主要代谢中间体。结果提示，L-PA对新生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.