Parsons R L, Neel D S, McKeon T W, Carraway R E
J Neurosci. 1987 Mar;7(3):837-46. doi: 10.1523/JNEUROSCI.07-03-00837.1987.
A correlated biochemical and histochemical study was undertaken to identify and quantify the presence of different biogenic amines and a substance P-like peptide within the parasympathetic cardiac ganglion of the mudpuppy (Necturus maculosus). Tissue extracts of the cardiac septum containing the parasympathetic cardiac ganglia from control animals were found, by high-pressure liquid chromatography, to contain significant amounts of norepinephrine (NE), epinephrine (E), dopamine (DA), and 5-HT. To allow neural elements of extraganglionic origin to degenerate, ganglia were explanted and maintained in organ culture for 8 d. Extracts from these explanted preparations had no detectable level of E, and NE was reduced, whereas DA and 5-HT levels were similar to those of control preparations. The results indicated that some of the neurons intrinsic to the cardiac septum contain DA and 5-HT and that most (greater than 70%) of the E and NE found in this tissue is of extrinsic origin. Histochemistry of control and explanted preparations showed 5-HT-immunoreactive and catecholamine-containing intrinsic neurons. A substance P-like peptide was identified by radioimmune assay in septal extracts. The peptide content diminished by one-third to one-fifth in preparations maintained in organ culture for 8-14 d, suggesting that a significant amount of the substance P-like peptide is derived from extraganglionic sources. Immunocytochemical studies demonstrated the presence of numerous long substance P-immunoreactive fibers coursing across the septum, branching over cardiac muscle fibers, and forming pericellular networks around individual parasympathetic ganglion cells and clusters of ganglion cells. In addition, numerous small intrinsic neurons exhibited immunoreactivity for substance P. Comparison of the substance P-staining patterns in control and explanted ganglia suggests that the majority of the long substance P-immunoreactive fibers innervating the mudpuppy cardiac ganglion cells are not parasympathetic preganglionic fibers. Rather, it is hypothesized that these fibers are processes of primary sensory fibers. The present observations indicate that the mudpuppy cardiac ganglion exhibits a complex organization similar to that of mammalian sympathetic and enteric ganglia.
进行了一项相关的生化和组织化学研究，以鉴定和定量泥螈（Necturus maculosus）副交感神经心脏神经节内不同生物胺和P物质样肽的存在。通过高压液相色谱法发现，来自对照动物的含有副交感神经心脏神经节的心脏中隔组织提取物含有大量去甲肾上腺素（NE）、肾上腺素（E）、多巴胺（DA）和5-羟色胺（5-HT）。为使神经节外起源的神经元成分退化，将神经节移出并在器官培养中维持8天。这些移出标本的提取物中未检测到E水平，NE减少，而DA和5-HT水平与对照标本相似。结果表明，心脏中隔固有的一些神经元含有DA和5-HT，并且该组织中发现的大部分（超过70%）E和NE来源于外部。对照和移出标本的组织化学显示5-HT免疫反应性和含儿茶酚胺的固有神经元。通过放射免疫测定法在中隔提取物中鉴定出一种P物质样肽。在器官培养中维持8 - 14天的标本中，该肽含量减少了三分之一至五分之一，这表明大量的P物质样肽来源于神经节外。免疫细胞化学研究表明，有许多长的P物质免疫反应性纤维穿过中隔，在心肌纤维上分支，并在单个副交感神经节细胞和神经节细胞簇周围形成细胞周网络。此外，许多小的固有神经元对P物质表现出免疫反应性。对照和移出神经节中P物质染色模式的比较表明，支配泥螈心脏神经节细胞的大多数长P物质免疫反应性纤维不是副交感神经节前纤维。相反，据推测这些纤维是初级感觉纤维的突起。目前的观察结果表明，泥螈心脏神经节呈现出与哺乳动物交感神经节和肠神经节相似的复杂组织结构。
