MORPHOLOGICAL-DIFFERENTIATION OF EMBRYONIC RAT SYMPATHETIC NEURONS IN TISSUE-CULTURE .1. CONDITIONS UNDER WHICH NEURONS FORM AXONS BUT NOT DENDRITES
MORPHOLOGICAL-DIFFERENTIATION OF EMBRYONIC RAT SYMPATHETIC NEURONS IN TISSUE-CULTURE .1. CONDITIONS UNDER WHICH NEURONS FORM AXONS BUT NOT DENDRITES
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DOI：
10.1016/0012-1606(88)90295-3
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发表时间：
1988-08-01
影响因子：
2.7
通讯作者：
HIGGINS, D
中科院分区：
文献类型：
--
作者：
BRUCKENSTEIN, DA;HIGGINS, D
我们研究了胎鼠交感神经元的形态生长在无血清培养基中的非神经元细胞的情况下。由于细胞密度可影响体外表型表达，因此将形态学分析细分为分离的神经元（其胞体距其最近邻至少150 μ m的神经元）和更高度聚集的神经元的研究。当分离的神经元注射细胞内标记物，发现大多数（79%）有一个单一的过程，从他们的胞体，这种单极状态持续至少8周在体外。单极交感神经元的突起具有轴突的外观，因为它们细而长，具有恒定的直径，并且相对不分支。细胞化学方法揭示了这些过程具有其他轴突特征：（1）它们与针对M和H神经丝亚基的磷酸化形式的单克隆抗体的反应性比与针对这些蛋白质的非磷酸化形式的抗体的反应性更强;（2）它们还与针对τ的抗体反应。微管相关蛋白和磷酸化形式的H神经丝亚单位;和（3）它们只含有少量的RNA作为确定的[3 H]尿苷放射自显影。这些数据表明，在体内正常形成树突的神经元不需要在体外表达这种能力，轴突和树突的生长可以在某些条件下分离的文化。虽然大多数孤立的神经元是单极的，神经元细胞密度高的区域的神经元通常是多极的。除了轴突之外，多极神经元还具有一些预期具有原始树突特征的突起：它们局部终止（通常在100 μ m内），通常高度分支，并与M和H神经丝亚基的非磷酸化形式的抗体反应。密度的影响是最突出的，当神经元内的聚集体中的胞体是在密切的并列。当神经元胞体分开更大的距离（30-100 μ m）时，观察到形态的密度依赖性变化的频率较低。这些数据表明，交感神经元的形态受到环境的调节，神经元-神经元的相互作用可以促进在体外的原始树突的延伸。
We have examined the morphology of fetal rat sympathetic neurons grown in serum-free medium in the absence of nonneuronal cells. Because cell density can affect phenotypic expression in vitro, the morphological analysis was subdivided into the study of isolated neurons (neurons whose somata were at least 150 .mu.m from their nearest neighbor) and of more highly aggregated neurons. When isolated neurons were injected with intracellular markers, it was found that most (79%) had a single process emanating from their somata and that this unipolar state persisted for at least 8 weeks in vitro. The processes of unipolar sympathetic neurons had the appearance of axons in that they were thin and long, had a constant diameter, and were relatively unbranched. Cytochemical methods revealed that such processes had other axonal characteristics: (1) they were more reactive with a monoclonal antibody against phosphorylated forms of the M and H neurofilament subunits than with an antibody to nonphosphorylated forms of these proteins; (2) they also reacted with antibodies to the .tau. microtubule-associated protein and to the phosphorylated forms of the H neurofilament subunit; and (3) they contained only small amounts of RNA as determiend by [3H]uridine autoradiography. These data indicate that neurons which normally form dendrites in vivo need not express this capacity in vitro and that axonal and dendritic growth can be dissociated under some conditions in culture. While most isolated neurons were unipolar, neurons in regions of high neuronal cell density were usually multipolar. In addition to axons, multipolar neurons had processes with some of the characteristics expected of rudimentry dendrites: they ended locally (usually within 100 .mu.m), were often highly branched, and reacted with an antibody to nonphosphorylated forms of the M and H neurofilament subunits. The effects of density were most prominent when neurons were within aggregates in which the somata were in close apposition. Density-dependent changes in morphology were less frequently observed when neuronal somata were separated by greater distances (30-100 .mu.m). These data indicate that the morphology of sympathetic neurons is subject to environmental regulation and that neuron-neuron interactions can promote the extension of rudimentary dendrites in vitro.