Effect of striatal cells on in vitro maturation of mesencephalic dopaminergic neurones grown in serum-free conditions
Effect of striatal cells on in vitro maturation of mesencephalic dopaminergic neurones grown in serum-free conditions
复制标题
纹状体细胞对无血清条件下生长的中脑多巴胺能神经元体外成熟的影响
作者：
U. Porzio;M. Daguet;J. Glowinski;A. Prochiantz
有充分证据表明，靶细胞可以调节外周传入神经元的形态和生化发育1,2，但人们对中枢神经系统中是否存在这种调节机制知之甚少。因此，我们之前研究了纹状体靶细胞对黑质纹状体多巴胺能神经元体外成熟的影响，黑质纹状体多巴胺能神经元在培养物中存活超过5周，形成密集的树枝状结构，并通过高亲和力的特异性过程摄取3H-多巴胺（DA）并从3H-酪氨酸合成3H-DA。此外，钾或藜芦定的去极化通过钙依赖性机制刺激 DA 的释放，而河鲀毒素则阻止藜芦定引起的递质释放4。当神经元与来自纹状体的靶细胞一起培养时，3H-DA 摄取位点的数量和 3H-DA 合成的能力至少增加了一倍。为了确定在血清补充培养基中增殖的神经胶质细胞是否部分负责多巴胺能神经元的成熟和/或纹状体细胞的作用，我们现在使用无血清培养基重复了该实验，其中可以获得几乎纯的神经元群5-7。神经胶质细胞数量的减少既不影响多巴胺能细胞的成熟，也不影响纹状体细胞的作用。对多巴胺能细胞数量的放射自显影分析强烈表明，刺激作用与每个多巴胺能神经元 3H-DA 摄取和合成能力的增加有关。
It is well documented that target cells can regulate the morphological and biochemical development of peripheral afferent neurones1,2, but little is known about the existence of such regulatory mechanisms in the central nervous system. We therefore investigated previously the influence of striatal target cells on the maturation in vitro of nigrostriatal dopaminergic neurones, which survive in culture for more than 5 weeks, develop dense arborizations and both take up 3H-dopamine(DA) by a high-affinity specific process and synthesize 3H-DA from 3H-tyrosine3. Furthermore, depolarization by potassium or veratridine stimulates the release of DA through a calcium-dependent mechanism and tetrodotoxin prevents the veratridine-evoked release of the transmitter4. Both the number of 3H-DA uptake sites and the capacity for 3H-DA synthesis were at least doubled when the neurones were cultured with target cells from the striatum3. To determine whether glial cells which proliferate in serum-complemented medium are partly responsible for the maturation of dopaminergic neurones and/or for the effect of striatal cells, we have now repeated the experiment using serum-free medium in which virtually pure neuronal populations can be obtained5–7. The reduction in the number of glia did not affect either the maturation of dopaminergic cells alone, or the effect of striatal cells. Autoradiographic analysis of the number of dopaminergic cells strongly suggests that the stimulatory effect is related to increased capacities of 3H-DA uptake and synthesis per dopaminergic neurone.