Koegler F H, Ritter S
Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Washington State University, Pullman 99164-6520, USA.
Physiol Behav. 1998 Feb 15;63(4):521-7. doi: 10.1016/s0031-9384(97)00480-0.
Feeding can be stimulated by injection of galanin into the area postrema/nucleus of the solitary tract (AP/NTS) or fourth ventricle (4V). However, the threshold for galanin-induced feeding is lower when galanin is injected into the paraventricular nucleus of the hypothalamus (PVN) than when injected into the NTS. The greater apparent sensitivity of the PVN to galanin and the proximity of this nucleus to the third ventricle raise the possibility that galanin injected into the AP/NTS or 4V may stimulate feeding by accessing receptors in the PVN rather than by a local action in the hindbrain. To assess this possibility, feeding in response to NTS galanin was evaluated in rats with bilateral electrolytic lesions of the PVN. We found that PVN lesions did not abolish feeding induced by injections of galanin into the NTS. Rather, galanin-induced feeding, but not mercaptoacetate- or 2-deoxy-D-glucose-induced feeding, was significantly enhanced in PVN-lesioned rats compared to sham-operated controls. These results suggest that galanin receptors in the NTS region mediate feeding in response to galanin and that the galaninergic nerve terminals innervating these receptors may originate in part from cell bodies in the PVN.
向最后区/孤束核（AP/NTS）或第四脑室（4V）注射甘丙肽可刺激进食。然而，与注射到NTS相比，当向下丘脑室旁核（PVN）注射甘丙肽时，甘丙肽诱导进食的阈值更低。PVN对甘丙肽的明显敏感性更高，且该核与第三脑室相邻，这增加了一种可能性，即注射到AP/NTS或4V的甘丙肽可能通过作用于PVN中的受体而非通过在后脑的局部作用来刺激进食。为评估这种可能性，我们在PVN双侧电解损伤的大鼠中评估了对NTS甘丙肽的进食反应。我们发现，PVN损伤并未消除向NTS注射甘丙肽诱导的进食。相反，与假手术对照组相比，PVN损伤大鼠中甘丙肽诱导的进食显著增强，但巯基乙酸或2-脱氧-D-葡萄糖诱导的进食并未增强。这些结果表明，NTS区域的甘丙肽受体介导了对甘丙肽的进食反应，且支配这些受体的甘丙肽能神经末梢可能部分起源于PVN中的细胞体。
