Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
Heart Rhythm. 2011 May;8(5):731-8. doi: 10.1016/j.hrthm.2011.01.013. Epub 2011 Jan 11.
The intrinsic neural plexus of the mouse heart has not been adequately investigated despite the extensive use of this species in experimental cardiology.
The purpose of this study was to determine the distribution of cholinergic, adrenergic, and sensory neural components in whole-mount mouse heart preparations using double immunohistochemical labeling.
METHODS/RESULTS: Intrinsic neurons were concentrated within 19 ± 3 ganglia (n = 20 mice) of varying size, scattered on the medial side of the inferior caval (caudal) vein on the right atrium and close to the pulmonary veins on the left atrium. Of a total of 1,082 ± 160 neurons, most somata (83%) were choline acetyltransferase (ChAT) immunoreactive, whereas 4% were tyrosine hydroxylase (TH) immunoreactive; 14% of ganglionic cells were biphenotypic for ChAT and TH. The most intense ChAT staining was observed in axonal varicosities. ChAT was evident in nerve fibers interconnecting intrinsic ganglia. Both ChAT and TH immunoreactivity were abundant within the nerves accessing the heart. However, epicardial TH-immunoreactive nerve fibers were predominant on the dorsal and ventral left atrium, whereas most ChAT-positive axons proceeded on the heart base toward the large intrinsic ganglia and on the epicardium of the root of the right cranial vein. Substance P-positive and calcitonin gene-related peptide-immunoreactive nerve fibers were abundant on the epicardium and within ganglia adjacent to the heart hilum. Small intensely fluorescent cells were grouped into clusters of 3 to 8 and were dispersed within large ganglia or separately on the atrial and ventricular walls.
Although some nerves and neuronal bundles of the mouse epicardial plexus are mixed, most express either adrenergic or cholinergic markers. Therefore, selective stimulation and/or ablation of the functionally distinct intrinsic neural pathways should allow the study of specific effects on cardiac function.
尽管小鼠在实验心脏病学中被广泛应用，但对其心脏固有神经丛的研究还不够充分。
本研究旨在通过双重免疫组织化学标记，确定全心脏铺片小鼠心脏标本中胆碱能、肾上腺素能和感觉神经成分的分布。
方法/结果：固有神经元集中在 19 ± 3 个大小不一的神经节（n = 20 只小鼠）内，分布在右心房下腔静脉（尾侧）内侧和左心房肺静脉附近。在总共 1082 ± 160 个神经元中，大多数神经元（83%）为胆碱乙酰转移酶（ChAT）免疫反应阳性，而 4%为酪氨酸羟化酶（TH）免疫反应阳性；14%的神经节细胞同时表达 ChAT 和 TH。ChAT 染色最强的是轴突末梢的轴突。ChAT 在连接固有神经节的神经纤维中可见。神经纤维中 ChAT 和 TH 免疫反应均丰富，神经纤维与心脏相连。然而，心外膜 TH 免疫反应阳性的神经纤维在左心房背侧和腹侧占优势，而大多数 ChAT 阳性的轴突则沿着心脏基底向大的固有神经节以及右颅静脉根部的心外膜行进。P 物质阳性和降钙素基因相关肽免疫反应阳性的神经纤维在心外膜和心脏门附近的神经节中丰富。小而强烈荧光的细胞聚集在 3 到 8 个细胞的簇中，分布在大神经节内或心房和心室壁上。
尽管小鼠心外膜神经丛的一些神经和神经束是混合的，但大多数表达肾上腺素能或胆碱能标志物。因此，选择性刺激和/或消融功能不同的固有神经通路应该可以研究对心脏功能的特定影响。
