鼠胚中脑多巴胺神经元的体外发育及靶细胞对其影响

１４天大鼠胚中脑腹侧神经元在体外进行分散培养，用抗酪氨酸羟化酶血清（ＴＨ）检测多巴胺（ＤＡ）神经元。培养２４小时即可见ＴＨ阳性神经元，３天后数量开始增加，高峰出现在１４天左右，此后逐渐减少。ＴＨ阳性神经元胞体随培养时间的延长渐增大，核浆比例减少，表明神经元趋向成熟。收集培养液用高效液相色谱一电化学仪（ＨＰＬＣ－ＥＣ）测定其中ＤＡ递质的含量，在培养最初的７２小时内其浓度极低，至１５天时为初７２小时的５０余倍，此后开始下降，与ＤＡ神经元的形态发育同步。将中脑腹侧多巴胺神经元与其靶细胞纹状体神经元共培养时．ＴＨ阳性神经元数明显增加．培养液中的ＤＡ浓度均为同期中脑腹侧神经元单纯培养时的一倍，ＴＨ活性也较单纯培养时为高，表明靶细胞能明显提高ＤＡ神经元的存活能力。

THE DEVELOPMENT OF MESENCEPHALIC DOPAMINERGIC NEURONS OF RAT EMBRYO IN VITRO AND THE EFFECT OF COCULTURE WITH THEIR TARGET CELLS

Dissociated ventral mesencephalic neurons of the 14th day erpbryoes were cultured invitro. Tyrosine hydroxylase (TH) positive neurons could be detected for 24 hour culturesand the number was increased after 3 DIV, .the peak of TH positive neurons appeared in 14DIV and then reduced. The Soma of TH positive neurons increased with the extension of cul.ture time, whereas the nuclei perikarya ratio decreased gradually. This suggested that theneurons ware gradually maturing. Culture media were collected and measured by usingHPLC-EC. In the first 72 hrs, DA concentration was low. It was 50 times greater than thatof the first 72 hrs in 15 DIV and then began to reduce.. In the cocultures of the mesencephalicand striatal neurons, TH positive neurons increased significantly, twice as many as those inthe pure mesencephalic neuron cultures. The DA concentration of the coculture media ateach stage was twice greater than that in the pure culture media and TH activities also increased in coculture dopaminergic neurons. From the above, we believe that the target cellsmay enhance the survival ability of the DA neurons.