Portillo F, Carrasco M, Vallo J J
Departamento de Fisiologia, Facultad de Medicina, Universidad de Cádiz, Spain.
J Chem Neuroanat. 1998 Mar;14(2):95-102. doi: 10.1016/s0891-0618(97)10022-9.
The role of different hypothalamic nuclei, particularly the paraventricular nucleus (PVN), in the control of food intake and feeding behaviour is well known. It is also well established that lithium chloride (LiCl) causes various disorders in feeding behaviour. In this study, we analyzed the precise distribution of hypothalamic neurons activated by i.p. LiCl administration (LCA neurons) and compared it to that of hypothalamic neurons which project to autonomic preganglionic levels (HAP neurons). We also analysed the possibility that some neurons belong to both populations of nerve cells. To this end, a multiple-labelling technique, using two retrograde fluorescent tracers together with c-Fos-like immunohistochemistry, was performed. Fast Blue was injected in the dorsal motor nucleus of the vagus and Fluorogold (FG) in the thoracic intermedial-lateral cell column, to trace parasympathetic and sympathetic pathways, respectively. LiCl was used as stimulus for c-Fos-like immunohistochemistry. HAP neurons were located mainly in the dorsal, ventral and lateral regions of the parvocellular PVN, while LCA neurons were observed predominantly in the magnocellular region of the PVN rostrally to HAP neurons. A significant number of FG/Fos double-labelled neurons were located in the dorsal parvocellular subnucleus of the PVN (dp) in the LiCl-stimulated rats. We concluded that there is a clear segregation of LCA neurons from HAP neurons within the PVN. The presence of FG/Fos double-labelled neurons in the dp suggests that this nucleus could mediate a sympathetic response after LiCl administration.
不同下丘脑核团，特别是室旁核（PVN）在控制食物摄入和进食行为中的作用已广为人知。氯化锂（LiCl）会导致进食行为出现各种紊乱，这一点也已得到充分证实。在本研究中，我们分析了腹腔注射LiCl激活的下丘脑神经元（LCA神经元）的精确分布，并将其与投射到自主神经节前水平的下丘脑神经元（HAP神经元）的分布进行了比较。我们还分析了一些神经元是否同时属于这两种神经细胞群体的可能性。为此，我们采用了一种多重标记技术，将两种逆行荧光示踪剂与c-Fos样免疫组织化学相结合。分别向迷走神经背运动核注射快蓝，向胸段中间外侧细胞柱注射荧光金（FG），以分别追踪副交感神经和交感神经通路。LiCl用作c-Fos样免疫组织化学的刺激物。HAP神经元主要位于小细胞PVN的背侧、腹侧和外侧区域，而LCA神经元主要在PVN的大细胞区域中观察到，位于HAP神经元的前方。在LiCl刺激的大鼠中，大量FG/Fos双标记神经元位于PVN的背侧小细胞亚核（dp）中。我们得出结论，PVN内LCA神经元与HAP神经元存在明显的分离。dp中FG/Fos双标记神经元的存在表明，该核团可能在注射LiCl后介导交感反应。
