MODERATE ETHANOL PRENATALLY ON NMDA PHOSPHORYLATION

我们实验室和其他实验室的研究表明，产前和产后早期乙醇暴露导致NMDA受体功能和数量显着减少。 NMDA受体与大脑发育、学习和记忆的重要方面有关。 因此，乙醇相关的NMDA功能缺陷可能不仅在胎儿酒精综合征（FAS）的严重认知和行为缺陷中至关重要，而且在通常表现为与胎儿酒精效应（FAE）相关的行为症状的酒精相关神经发育障碍（ARND）中也至关重要。 我们最近发现，在大鼠产前乙醇暴露导致NMDA受体功能的下降伴随着减少，但不是所有的，亚基组成的NMDA受体复合物。NMDAR 2A和NMDAR 2B亚基显著减少，而NMDAR 1亚基不受影响。 迄今为止进行的研究已经检查了产前和产后高剂量乙醇对NMDA受体功能和亚基水平的影响。具体目标1至4中提出的研究旨在确定产前乙醇处理对1）使用Fura-2负载的解离神经元和H-MK 801结合的NMDA受体激活的功能测量，2）NMDAR 1和NMDAR 2亚单位蛋白的剂量-反应关系（Western印迹分析）和信使RNA水平（RNA酶保护测定），和3）如通过免疫沉淀研究测量的NMDA受体亚基组成的变化。 具体目标4将检查NMDA受体亚基变化与亚基磷酸化变化的关系。 这个建议的总体假设是，产前乙醇暴露，即使在适度的浓度，将导致在NMDA受体的功能明显的缺陷。 我们预计缺陷的程度与剂量相关。 进一步假设乙醇在这方面的作用可能与NMDA受体磷酸化的异常有关。

Studies in our laboratory and by others indicate that prenatal and early postnatal ethanol exposure results in a significant reduction of NMDA receptor function and number. NMDA receptors are linked with important aspects of brain development and learning and memory. Ethanol-related deficits in NMDA function, therefore, may be of key importance not only in the severe cognitive and behavioral deficiencies of fetal alcohol syndrome (FAS) but also in alcohol-related neurodevelopmental disorders (ARND) typically expressed as behavioral symptoms associated with fetal alcohol effects (FAE). We have recently found that decreases in NMDA receptor function resulting from prenatal ethanol exposure in rats are accompanied by reductions in some, but not all, of the subunits comprising the NMDA receptor complex. NMDAR2A and NMDAR2B subunits are significantly reduced, while the NMDAR1 subunit is unaffected. Studies conducted thus far have examined the effects of high doses of ethanol prenatally and postnatally on NMDA receptor function and subunit levels. Studies proposed in specific aims 1 through 4 are designed to determine the dose-response relationships of prenatal ethanol treatment on 1) functional measures of NMDA receptor activation using fura-2 loaded dissociated neurons and H-MK801 binding, 2) NMDAR1 and NMDAR2 subunit protein (Western blot analysis) and messenger RNA levels (RNase protection assay), and 3) changes in NMDA receptor subunit composition as measured by immunoprecipitation studies. Specific aim 4 will examine the relationship(s) of NMDA receptor subunit changes with changes in subunit phosphorylation. The overall hypothesis of this proposal is that prenatal ethanol exposure, even at modest concentrations, will result in demonstrable deficits in the function of NMDA receptors. We expect the magnitude of the deficits to be dose-related. It is hypothesized further that ethanol's actions in this regard may be linked with abnormalities of NMDA receptor phosphorylation.