Zhu Jing-Ning, Guo Chun-Li, Li Hong-Zhao, Wang Jian-Jun
Department of Biological Science and Technology and State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China.
J Neurosci Res. 2007 Nov 1;85(14):3193-204. doi: 10.1002/jnr.21420.
Several studies have implicated the dorsomedial hypothalamic nucleus (DMN) in regulation of feeding behavior and body weight, but clear mechanisms by which it controls food intake are not well understood. We report the results of the present study, which showed that the DMN receives important peripheral short- and long-term feeding-related afferent signals, including gastric vagal, glycemia, and cholecystokinin (CCK) inputs, as well as from leptin, an adipostatic signal that forcefully inhibits food intake and increases metabolic rate. Among the 279 DMN neurons recorded, 173 (62.0%) responded to stimulation of gastric vagal nerves. Also, of the 123 DMN neurons responsive to gastric vagal stimulation that were tested with the administration of intravenous glucose, 75 (61.0%) were identified as being glycemia sensitive. Moreover, it is noteworthy that of the 23 DMN neurons that responded to both gastric vagal and intravenous glucose stimulation, most (19 of 23, 82.6%) were sensitive to circulating leptin, and some neurons (n = 7) were also responsive to systemic CCK, suggesting that gastric vagal, glycemic, CCK, and leptin inputs converge on single DMN neurons. Furthermore, synergistic interactions between leptin and glucose on single DMN neurons were observed (n = 6). These results demonstrate that those important peripheral feeding-related gastric vagal, glycemic, CCK and leptin signals not only reach the DMN but also interact on single DMN neurons, suggesting that the DMN may not just function as a relay station, but independently integrate the short-term and long-term feeding-associated information and actively participate in the direct regulation of feeding behavior.
多项研究表明,下丘脑背内侧核(DMN)参与进食行为和体重的调节,但其控制食物摄入的明确机制尚不清楚。我们报告了本研究的结果,该结果表明,DMN接收重要的外周短期和长期进食相关传入信号,包括胃迷走神经、血糖和胆囊收缩素(CCK)输入,以及来自瘦素的信号,瘦素是一种脂肪稳态信号,可强力抑制食物摄入并提高代谢率。在记录的279个DMN神经元中,173个(62.0%)对胃迷走神经刺激有反应。此外,在123个对胃迷走神经刺激有反应的DMN神经元中,经静脉注射葡萄糖测试,75个(61.0%)被确定为对血糖敏感。此外,值得注意的是,在23个对胃迷走神经和静脉注射葡萄糖刺激均有反应的DMN神经元中,大多数(23个中的19个,82.6%)对循环中的瘦素敏感,一些神经元(n = 7)也对全身CCK有反应,这表明胃迷走神经、血糖、CCK和瘦素输入汇聚于单个DMN神经元。此外,还观察到瘦素和葡萄糖在单个DMN神经元上的协同相互作用(n = 6)。这些结果表明,那些重要的外周进食相关胃迷走神经、血糖、CCK和瘦素信号不仅到达DMN,而且在单个DMN神经元上相互作用,这表明DMN可能不仅仅起到中继站的作用,而是独立整合短期和长期进食相关信息,并积极参与进食行为的直接调节。