联合培养中心肌细胞诱导结状神经节神经元的迁移及P物质的表达

目的：探测联合培养中心肌细胞对迷走神经结状神经节神经元的迁移和P物质表达的影响作用。方法：建立Wistar大鼠结状神经节与心肌细胞联合培养的模型，用倒置相差显微镜观察结状神经节与心肌细胞培养不同时间的活细胞生长状况。联合培养72、96h，用Holmes还原银染色法观察神经元的迁移，用免疫组织化学法观察P物质的表达。结果：联合培养72、96h，与单纯培养的结状神经节组织块相比，结状神经节与心肌细胞联合培养的标本中神经元迁出的数目明显增多（P＜0.05）。结状神经节与心肌细胞联合培养96h，探测到了P物质免疫反应阳性神经元和神经纤维。而在单纯结状神经节组织块培养72、96h以及结状神经节与心肌细胞联合培养72h的标本中，均没有探测到P物质的表达。结论：联合培养中心肌细胞可诱导神经元的迁移和神经递质P物质的表达。神经元在形态学上的发育成熟可能需要72h就可以完成，而在联合培养中神经递质合成的发育成熟则需要96h。神经元在形态学上的发育成熟并不能代表神经递质合成的发育就已经完成。这一结果对于进一步研究心肌细胞的选择性神经支配以及神经与心肌的相互作用开辟了一条新的研究途径。

Neuronal migration and substance P expression induced by cardiac myocytes in co-cultures of nodose ganglion and cardiac myocytes

Objective: To determine the effects of cardiac myocytes on nodose ganglial neuronal migration and substance P expression in co-cultures of nodose ganglion and cardiac myocytes of newborn Wistar rats. Methods: Neuromuscular co-cultures of nodose ganglion and cardiac myocytes were established. The living cells of the cultures were observed with an inverted contrast microscope at different culture ages. At 72 h and 96 h of culture, the cultures were examined by the Holmes-reduced silver stain technique to observe neuronal migration. An immunohistochemical staining method was used for investigating the expression of substance P (SP). Results: The number of migrated neurons increased in neuromuscular co-cultures compared with that in the cultures of nodose ganglial explants alone at 72 h and 96 h of culture (P＜0.05). SP-immunoreactive neurons and nerve fibers were observed in the co-cultures at 96 h of culture age. However, in the neuromuscular co-cultures at 72 h of culture, and in the cultures of nodose ganglial explants alone at 72 h and 96 h of culture, no SP-immunoreactive neurons and nerve fibers were observed. Conclusion: Cardiac myocytes may have inductive effects on nodose ganglial neuronal migration and SP expression in neuromuscular co-cultures. The neuronal morphorlogical maturation cannot represent the maturation of neurotransmitter synthesis. The synthesis of neurotransmitters had not maturated in the neuromuscular co-cultures until 96 h of culture. The results provide a new method to study the selective innervation of cardiac myocytes and the interactions between neurons and cardiac myocytes.