dos Santos Rúbia Lima Dias, Mansur Samira Schultz, Steffens Sérgio Murilo, Faria Moacir Serralvo, Marino-Neto José, Paschoalini Marta Aparecida
Department of Physiological Sciences-CCB, Centre of Biological Sciences, Federal University of Santa Catarina (UFSC), 88040-970 Florianópolis, SC, Brazil.
Behav Brain Res. 2009 Feb 11;197(2):411-6. doi: 10.1016/j.bbr.2008.10.008. Epub 2008 Oct 15.
The present study examined the effects of local injections of adrenaline (AD) or noradrenaline (NA) in equimolar doses (6, 20, and 60 nmol) into the median raphe nucleus (MRN) on ingestive and non-ingestive behaviors of free-feeding rats. The results showed that the treatment with AD at doses of 20 and 60 nmol increased food intake. While the hyperphagic response evoked by 60 nmol dose of AD was accompanied by a reduction of the latency to start feeding and an increase in the frequency of feeding, the 20 nmol dose of AD was unable to change these behavioral aspects of feeding response. The meal size and non-ingestive behaviors were not affected by AD treatment in the MRN. While water intake remained unchanged after the treatment with 20 nmol of AD in the MRN, this dose decreased the latency to start drinking. Feeding and drinking behaviors were not affected by treatment with NA in the MRN. These data suggest that adrenergic receptors of MRN participate in mechanisms that control food intake initiation or appetite. In addition, our results also indicate that the availability of energetic substrate could affect the adrenergic influence on MRN neurons since previous data indicated that the injection of AD into the MRN of food restricted rats decreased food intake.
本研究检测了向自由进食大鼠的中缝正中核（MRN）局部注射等摩尔剂量（6、20和60纳摩尔）的肾上腺素（AD）或去甲肾上腺素（NA）对其摄食和非摄食行为的影响。结果显示，20纳摩尔和60纳摩尔剂量的AD处理可增加食物摄入量。虽然60纳摩尔剂量的AD引起的摄食亢进反应伴随着开始进食潜伏期的缩短和进食频率的增加，但20纳摩尔剂量的AD无法改变进食反应的这些行为方面。MRN中AD处理对餐量和非摄食行为没有影响。虽然MRN中20纳摩尔的AD处理后饮水量保持不变，但该剂量缩短了开始饮水的潜伏期。MRN中NA处理对进食和饮水行为没有影响。这些数据表明，MRN的肾上腺素能受体参与了控制食物摄入起始或食欲的机制。此外，我们的结果还表明，能量底物的可用性可能会影响肾上腺素能对MRN神经元的影响，因为先前的数据表明，向食物受限大鼠的MRN注射AD会减少食物摄入量。
