Cline Mark A, Smith Marissa L
Department of Biology (6931), Radford University, Radford, VA 24142, USA.
Physiol Behav. 2007 Aug 15;91(5):588-92. doi: 10.1016/j.physbeh.2007.03.021. Epub 2007 Mar 31.
This experiment was conducted to determine the effects of central alpha-melanocyte stimulating hormone (alpha-MSH) and its interaction with neuropeptide Y (NPY) on ingestive and non-ingestive behaviors in chicks. Chicks received intracerebroventricular injections of either 0, 0.12 nM alpha-MSH, 0.06 nM NPY, or 0.12 nM alpha-MSH+0.06 nM NPY. Immediately following injection, chicks were placed in an observation arena and the number of steps, jumps, feed pecks, drinks, exploratory pecks, escape attempts, the total distance traveled, and the amount of time spent standing, sitting, sleeping, and preening were monitored for 60 min. Chicks treated with NPY consumed 69% more feed than controls whereas alpha-MSH-treated chicks consumed 71% less. Feed intake of the NPY+alpha-MSH groups was similar to alpha-MSH-treated chicks at 66% less than aCSF-treated chicks. Differences in pecking were found and followed a similar pattern as feed intake. All treatments increased the amount of time chicks were in a sitting posture, and the alpha-MSH+NPY group spent more time sitting than alpha-MSH and NPY alone. The sitting response after alpha-MSH+NPY treatment was similar to the alpha-MSH group but not the NPY group. Other behaviors were not affected by treatment. Thus, we conclude that alpha-MSH, at a concentration that causes a similar magnitude decrease in feed intake as NPY increases feed intake, is a more potent appetite-related signal than NPY. alpha-MSH causes behavioral effects that may secondarily affect feed intake at a low magnitude and may modulate the behavioral effects of NPY in chicks, contributing to the overall effect on feed intake.
本实验旨在确定中枢α-黑素细胞刺激素（α-MSH）及其与神经肽Y（NPY）的相互作用对雏鸡摄食和非摄食行为的影响。雏鸡接受脑室内注射，分别为0、0.12 nM α-MSH、0.06 nM NPY或0.12 nM α-MSH + 0.06 nM NPY。注射后立即将雏鸡放入观察场，监测60分钟内的步数、跳跃次数、啄食次数、饮水次数、探索性啄食次数、逃跑尝试次数、总行进距离以及站立、坐着、睡觉和梳理羽毛所花费的时间。用NPY处理的雏鸡比对照组多消耗69%的饲料，而用α-MSH处理的雏鸡消耗减少71%。NPY + α-MSH组的采食量与用α-MSH处理的雏鸡相似，比用人工脑脊液（aCSF）处理的雏鸡少66%。发现啄食差异，且与采食量遵循相似模式。所有处理均增加了雏鸡坐着的时间，α-MSH + NPY组坐着的时间比单独使用α-MSH和NPY组更多。α-MSH + NPY处理后的坐着反应与α-MSH组相似，但与NPY组不同。其他行为不受处理影响。因此，我们得出结论，在导致采食量下降幅度与NPY增加采食量幅度相似的浓度下，α-MSH是比NPY更强的与食欲相关的信号。α-MSH会产生行为效应，可能在低程度上继发影响采食量，并可能调节雏鸡中NPY的行为效应，从而对采食量产生总体影响。
