Cline Mark A, Nandar Wint, Rogers J Orion
Department of Biology, Radford University, P.O. Box 6931, Radford, VA 24142, USA.
Neuropeptides. 2007 Dec;41(6):433-9. doi: 10.1016/j.npep.2007.08.003. Epub 2007 Oct 22.
Information on the physiological functions of neuropeptide FF; NPFF, a morphine modulating octapeptide in avians is lacking. Thus, we designed a study to investigate the effects of central NPFF with particular emphasis on appetite-related processes. Cobb-500 chicks were intracerebroventricularly (ICV) injected with 0, 4.16, 8.32 or 16.6nmol NPFF, and feed and water intake were quantified. Feed intake was linearly decreased as NPFF dose increased, and this effect decayed over time and was not significant by 120min post-injection. Water intake was not affected by ICV NPFF. In a second exp, we observed that naloxone completely reversed the NPFF-induced decrease in feed intake. The amount of time a visible marker took to travel through the total length of the alimentary canal linearly increased as NPFF dose increased. We measured neuronal activation in the lateral hypothalamus (LH), paraventricular nucleus (PVN) dorsomedial nucleus (DMN) and ventromedial hypothalamus (VMN) of the hypothalamus, and nucleus dorsomedialis posterior thalami (DMP) of the thalamus. The DMN, DMP, PVN and VMH were all activated by ICV NPFF while the LH was not affected. Finally, we determined that the anorexigenic effect of ICV NPFF is primarily behavior specific, since behaviors unrelated to ingestion were not increased the same duration of time as was consumatory pecking. We conclude that NPFF causes anorexigenic effects in chicks that are primarily behavior specific.
关于神经肽FF(NPFF)生理功能的信息尚缺,NPFF是一种禽类体内调节吗啡的八肽。因此,我们设计了一项研究来调查中枢NPFF的作用,特别关注与食欲相关的过程。给Cobb - 500雏鸡脑室内(ICV)注射0、4.16、8.32或16.6 nmol的NPFF,并对采食量和饮水量进行量化。采食量随NPFF剂量增加呈线性下降,且这种作用随时间衰减,注射后120分钟时不显著。饮水量不受ICV注射NPFF的影响。在第二项实验中,我们观察到纳洛酮完全逆转了NPFF诱导的采食量下降。随着NPFF剂量增加,可见标记物穿过消化道全长所需的时间呈线性增加。我们测量了下丘脑的外侧下丘脑(LH)、室旁核(PVN)、背内侧核(DMN)和腹内侧下丘脑(VMN)以及丘脑的丘脑后内侧背核(DMP)中的神经元激活情况。ICV注射NPFF激活了DMN、DMP、PVN和VMH,而LH未受影响。最后,我们确定ICV注射NPFF的厌食作用主要是行为特异性的,因为与摄食无关的行为在相同时间内没有像摄食啄食那样增加。我们得出结论,NPFF在雏鸡中引起厌食作用,主要是行为特异性的。