Quinn Joseph G, O'Hare Eugene, Levine Allen S, Kim Eun-Mee
School of Psychology, University of Ulster at Jordanstown, Shore Road, Newtownabbey, Co Antrim BT37 0QB, Northern Ireland, UK.
Brain Res. 2003 Nov 21;991(1-2):206-11. doi: 10.1016/j.brainres.2003.08.020.
The paraventricular nucleus (PVN) and the ventral tegmental area (VTA) have been shown to be involved in opioid mediated feeding behavior. The present study examined whether mu-opioid signalling between the PVN and VTA affected feeding behavior. Male Sprague-Dawley rats were cannulated with one cannula placed in the PVN and two cannulae placed in the VTA, which allowed for co-administration of the mu-opioid receptor agonist [D-Ala(2), NMe-Phe(4), Gly-ol(5)]-enkephalin (DAMGO) in one site and the opioid antagonist naltrexone (NTX) in the other site. Bilateral administration of DAMGO (1.2, 2.4 and 4.9 nmol) into the VTA stimulated feeding dose dependently at 2.4 and 4.9 nmol (P<0.05). The DAMGO (2.4 nmol)-induced increase of food intake following injection into the PVN was blocked by bilateral injection of NTX (6.6, 13.2 and 26.5 nmol) into the VTA at 2 and 4 h (P<0.05). In the reverse situation, the DAMGO (2.4 nmol)-induced increase of food intake following injection into the VTA was blocked by injection of NTX (13.2 and 26.5 nmol) into the PVN at 2 and 4 h (P<0.05). The present study suggests that a bidirectional mu-opioid-opioid signalling pathway exists between the PVN and the VTA which influences feeding.
室旁核（PVN）和腹侧被盖区（VTA）已被证明与阿片类药物介导的进食行为有关。本研究探讨了PVN和VTA之间的μ-阿片信号传导是否会影响进食行为。将雄性Sprague-Dawley大鼠进行插管，一根插管置于PVN，两根插管置于VTA，这使得可以在一个部位共同给予μ-阿片受体激动剂[D-Ala(2), NMe-Phe(4), Gly-ol(5)]-脑啡肽（DAMGO），在另一个部位给予阿片拮抗剂纳曲酮（NTX）。向VTA双侧注射DAMGO（1.2、2.4和4.9 nmol），在剂量为2.4和4.9 nmol时，依赖性地刺激进食（P<0.05）。在注射后2小时和4小时，向VTA双侧注射NTX（6.6、13.2和26.5 nmol）可阻断向PVN注射DAMGO（2.4 nmol）后引起的食物摄入量增加（P<0.05）。在相反的情况下，在注射后2小时和4小时，向PVN注射NTX（13.2和26.5 nmol）可阻断向VTA注射DAMGO（2.4 nmol）后引起的食物摄入量增加（P<0.05）。本研究表明，PVN和VTA之间存在双向的μ-阿片-阿片信号通路，该通路影响进食。
