Yanni Penelope A, Rising Lisa J, Ingraham Christine A, Lindsley Tara A
Center for Neuropharmacology and Neuroscience, Albany Medical College, Albany, New York.
Glia. 2002 Jun;38(4):292-302. doi: 10.1002/glia.10071.
Numerous studies in vivo and in vitro have demonstrated that ethanol disrupts neuromorphogenesis. However, it has not been determined what role, if any, is played by non-neuronal cells in mediating this effect. We recently reported that ethanol inhibits dendritic development in low-density cultures of fetal rat hippocampal pyramidal neurons (Yanni and Lindsley, 2000: Dev Brain Res 120:233-243). In this culture system, cortical astrocytes precondition neuronal culture media for 2 days before the addition of neurons, which then develop on a separate substrate in coculture with the astrocytes. To determine whether astrocyte response to ethanol mediates the effects of ethanol on neurons, the present study compared dendritic development of neurons after 6 days in medium containing 400 mg/dl ethanol in coculture with live astrocytes and in conditioned medium from astrocytes that were never exposed to ethanol. The same experiment was also performed with and without ethanol present during astrocyte preconditioning of the medium. The effects of ethanol differed depending on when it was added to the cultures relative to addition of newly dissociated neurons. However, the effects of ethanol were not related to whether neurons were cocultured with live astrocytes. When astrocytes preconditioned the medium normally, ethanol added at plating inhibited dendritic development of neurons regardless of whether they were maintained in coculture with live astrocytes or in conditioned medium. In surprising contrast, the presence of ethanol during astrocyte preconditioning of the media had a growth promoting effect on subsequent dendrite development despite the continued presence of ethanol in the medium. Thus, astrocytes release soluble factors in response to ethanol that can protect neurons from the inhibitory effects of ethanol on dendritic growth, but the timing of neuronal exposure to these factors, or their concentration, may influence their activity.
众多体内和体外研究表明，乙醇会破坏神经形态发生。然而，尚未确定非神经元细胞在介导这种效应中是否发挥作用以及发挥何种作用。我们最近报道，乙醇会抑制胎鼠海马锥体神经元低密度培养物中的树突发育（Yanni和Lindsley，2000年：《发育脑研究》120：233 - 243）。在这个培养系统中，皮质星形胶质细胞在添加神经元之前先对神经元培养基进行2天预处理，然后神经元在与星形胶质细胞共培养的单独基质上发育。为了确定星形胶质细胞对乙醇的反应是否介导了乙醇对神经元的影响，本研究比较了在含有400 mg/dl乙醇的培养基中与活星形胶质细胞共培养6天后以及在从未接触过乙醇的星形胶质细胞的条件培养基中培养6天后神经元的树突发育情况。在星形胶质细胞对培养基进行预处理期间，还分别进行了有无乙醇存在的相同实验。乙醇的作用因相对于新解离神经元添加时间的不同而有所差异。然而，乙醇的作用与神经元是否与活星形胶质细胞共培养无关。当星形胶质细胞正常预处理培养基时，接种时添加乙醇会抑制神经元的树突发育，无论它们是与活星形胶质细胞共培养还是在条件培养基中培养。令人惊讶的是，与之形成对比的是，在星形胶质细胞对培养基进行预处理期间存在乙醇，尽管培养基中持续存在乙醇，但对随后的树突发育却有促进生长的作用。因此，星形胶质细胞会响应乙醇释放可溶性因子，这些因子可以保护神经元免受乙醇对树突生长的抑制作用，但神经元接触这些因子的时间或其浓度可能会影响它们的活性。
