体外长期培养大鼠中脑多巴胺神经元的形态学观察

本文研究了中脑多巴胺神经元在体外长期培养过程中的形态发育。动物选用胚胎14天SD大鼠,取中脑腹侧部制成细胞密度为2×10~5/ml的悬液,接种于24孔培养板中,培养1天至6周,以酪胺酸羟化酶免疫组化方法、单纯荧光组化方法和外源性儿茶酚胺荧光组化方法,观察中脑多巴胺神经元的体外长期培养发育状况。培养3天后多巴胺神经元已有单极或双极的突起发出,培养1周突起进一步伸长,并在沿途开始发出分支,有些末端见有生长锥。除散在分布的多巴胶神经元外,还能见到多巴胺神经元细胞群。培养2至3周,突起的分支增多,并明显出现念珠状膨大。在培养4-6周的标本中,仍可见到部分发育成熟的多巴胺神经元。多巴胺神经元在体外培养中的形态可分为二类,即梭形细胞和多极细胞。棱形细胞一般有两个突起,分别从胞体两极发出;多极细胞胞体呈圆形、多角形或三角形,可发出3-6个突起。实验结果表明多巴胺神经元的体外发育过程与在体相似。

MORPHOLOGICAL OBSERVATION OF RAT MESENCEPHALIC DOPAMINERGIC NEURONS IN LONG-TERM CULTURE

The morphological development of mesencephalic dopaminergic (DA) neurons of rat in vitro was studied. The suspensions (Cell density=2×10~5) of ventral mesencephalic area obtained from E 14 rat were planted on 24 well culture plate. After 1 day to 6 weeks incubation, the cells were examined with the tyrosine hydroxylase(TH) immunocytochemistry ABC method and Faglu fluorescence histochemistry of catecholamines. On 3 DIV the DA neurons extended out one or two processes. After one week the processes extended further and ramified out some branches on the way. The active growth cones could be found at the terminals of processes. Besides scattering DA neurons, some aggregates of DA neurons could be seen. After two to three weeks in vitro the processes of DA neurons divided more branches and exhibited numerous varicosities. Some mature neurons could survive 4 to 6 weeks in vitro, The shape of DA neurons of the explant could be classified into two types: fusiform cells and multipolar cells. The fusiform cells stretched out two processes from their somas at two poles. The shape of multipolar cells were round and triangular or polygonal with 3 to 6 processes. The results indicated that the development of DA neurons in vitro is similar to that in vivo.