Li B H, Rowland N E
Department of Psychology, University of Florida, Gainesville 32611-2250, USA.
Brain Res Bull. 1995;37(6):589-93. doi: 10.1016/0361-9230(95)00045-g.
This study compared the effects of bilateral subdiaphragmatic vagotomy on the Fos-like immunoreactivity (FLI), a marker of neuronal activation, in rat brain induced by two anorectic agents, cholecystokinin (CCK) and the serotonin agonist, dexfenfluramine (DFEN). In the nonvagotomized rats, both CCK (5 micrograms/kg, IP) and DFEN (2 mg/kg, IP) induced FLI in the nucleus of the solitary tract (NST), the external subdivision of the lateral parabrachial nuclei (LPBE), the lateral subdivision of the central amygdaloid nucleus (CeL), and the bed nucleus of the stria terminalis (BST). However, subregional distribution of the FLI induced by the two agents was different in most of these regions. Additionally, the area postrema and the medial subdivision of the hypothalamic paraventricular nucleus were preferentially activated by CCK but not DFEN, while the caudate-putamen was activated by DFEN but not CCK. Bilateral subdiaphragmatic vagotomy completely abolished CCK-induced FLI in all the brain regions but did not attenuate DFEN-induced FLI in any of these regions, including the NST. The results of the present study suggest that DFEN-activation of the NST-LPBE-CeL/BST neuraxis is not mediated by the vagus nerve. On the other hand, and consistent with a variety of other data, activation of various parts of the brain by peripherally administered CCK depends on a vagal pathway. These data are discussed in relation to a previously proposed interaction between CCK and serotonin in mediating satiety.
本研究比较了双侧膈下迷走神经切断术对两种食欲抑制剂——胆囊收缩素（CCK）和5-羟色胺激动剂右芬氟拉明（DFEN）诱导的大鼠脑内Fos样免疫反应性（FLI，一种神经元激活标记物）的影响。在未进行迷走神经切断术的大鼠中，CCK（5微克/千克，腹腔注射）和DFEN（2毫克/千克，腹腔注射）均可在孤束核（NST）、外侧臂旁核外侧亚区（LPBE）、中央杏仁核外侧亚区（CeL）和终纹床核（BST）诱导产生FLI。然而，在这些区域中的大多数，两种药物诱导的FLI的亚区域分布有所不同。此外，最后区和下丘脑室旁核内侧亚区优先被CCK激活，而不被DFEN激活，而尾状核-壳核被DFEN激活，而不被CCK激活。双侧膈下迷走神经切断术完全消除了所有脑区中CCK诱导的FLI，但并未减弱这些区域（包括NST）中任何一个区域DFEN诱导的FLI。本研究结果表明，DFEN对NST-LPBE-CeL/BST神经轴的激活不是由迷走神经介导的。另一方面，与其他各种数据一致，外周给予CCK对脑各部分的激活依赖于迷走神经通路。这些数据结合先前提出的CCK与5-羟色胺在介导饱腹感方面的相互作用进行了讨论。
