Rosas-Arellano M P, Solano-Flores L P, Ciriello J
Department of Physiology, University of Western Ontario, London, Canada.
Brain Res. 1996 Jan 15;706(2):323-7. doi: 10.1016/0006-8993(95)01339-3.
Two series of experiments were done in the rat to investigate whether neurons in arcuate nucleus of the hypothalamus (Arc) containing neurotensin (NT)-like immunoreactivity projected to subfornical organ (SFO). In the first series, the anterograde tract-tracer Phaseolus vulgaris leucoagglutinin (PHA-L) was microiontrophoresed into the region of Arc that contains NT neurons. After a 9-12 day survival period the animals were sacrificed and forebrain sections that contained SFO were processed for combined PHA-L and NT immunoreactivity. In the second series of experiments, unilateral or bilateral electrolytic lesions of Arc were made and after a 10-17 day survival period SFO was examined to determine the relative contribution of NT Arc neurons to NT immunoreactivity within SFO. PHA-L labelled fibers with terminal-like boutons were found in SFO primarily on the side ipsilateral to the site of injection. A small number of the PHA-L labelled fibers in the lateral aspect of SFO was also immunoreactive to NT. Unilateral lesions reduced, whereas bilateral lesions of Arc eliminated most of the NT-like immunoreactivity within SFO. These data demonstrate the existence of a direct pathway from Arc to SFO that contains the putative neurotransmitter NT. These results suggest that this pathway may function in the modulation of neural and/or humoral events related to cardiovascular regulation and body fluid homeostasis by influencing the activity of SFO neurons.
在大鼠身上进行了两个系列的实验，以研究下丘脑弓状核（Arc）中含有神经降压素（NT）样免疫反应性的神经元是否投射到穹窿下器（SFO）。在第一个系列中，将顺行性示踪剂菜豆凝集素（PHA-L）微量离子电泳到含有NT神经元的Arc区域。在9 - 12天的存活期后，处死动物，对含有SFO的前脑切片进行PHA-L和NT免疫反应性的联合检测。在第二个系列实验中，对Arc进行单侧或双侧电解损伤，在10 - 17天的存活期后检查SFO，以确定NT Arc神经元对SFO内NT免疫反应性的相对贡献。在SFO中发现PHA-L标记的纤维以及终末样小体，主要位于注射部位同侧。SFO外侧的少数PHA-L标记纤维也对NT有免疫反应性。单侧损伤减少了，而双侧损伤则消除了SFO内大部分的NT样免疫反应性。这些数据证明了从Arc到SFO存在一条直接通路，其中含有假定的神经递质NT。这些结果表明，该通路可能通过影响SFO神经元的活动，在调节与心血管调节和体液稳态相关的神经和/或体液事件中发挥作用。
