In vitro and In vivo models for ethanol withdrawal and antepartum hypoxia

描述（由申请人提供）：胎儿酒精谱系障碍描述了产前酒精暴露可能导致的广泛行为和缺陷。这些影响可以从相对轻微的学习缺陷到严重的智力迟钝。人们对酒精影响的敏感性差异提出了各种解释。一种理论认为，“刺激因素”可以在增加严重性和/或提供乙醇的破坏性影响增加的背景中发挥作用。我们建议，产前酒精暴露可能会增加短期缺氧的不良后果，在产前期间，短期缺氧经常发生。通常情况下，胎儿/新生儿在分娩和分娩期间对轻度缺氧具有相当的适应力，然而，额外的挑战（如宫内酒精暴露史或酒精戒断史）可能会使这些婴儿的不良结局风险增加。在本申请中，我们建议开发两种模型。第一种是取自1日龄大鼠的体外器官型海马切片培养模型。这些培养物将暴露于慢性酒精，随后戒断并用氧葡萄糖剥夺进行挑战（作为缺氧模型）。假设酒精和缺氧会比单独暴露于任何一种挑战产生更大的损害。亚阈值剂量也将纳入本具体目标中，以评估海马体对这些挑战的敏感性。我们将开发的第二个模型涉及妊娠三个月的体内酒精给药，首先给予妊娠母鼠，然后给予出生后第1-7天的Sprague道利大鼠幼仔。在酒精戒断后，幼崽也将暴露于轻度缺氧挑战，随后测试各种行为终点，包括活动和学习记忆的测量。我们的工作假设是，酒精暴露和/或戒断和缺氧挑战具有相似的机制（包括NMDAR过度活性，GLU活性增加和多胺释放），可能导致兴奋性毒性损伤增加。提出的研究将使我们能够确定这些模型的潜在有效性。此外，一旦我们建立了这些模型，我们就可以开始研究潜在的机制和潜在的药物干预措施，以尝试减少与酒精戒断和缺氧相关的损伤/缺陷。这些数据可能具有重要的临床潜力，因为我们的前提（和模型）侧重于一个相对狭窄的发育窗口，在概念上与女性通常寻求医疗援助（即分娩和分娩）和更有可能进行干预的时间重叠。 公共卫生相关性：轻度缺氧（或氧气供应减少）通常发生在正常分娩和分娩过程中，如果发作不严重，新生儿通常不会受到这些影响。我们认为，产前酒精暴露的影响之一是增加这些小发作的风险，导致行为和中枢神经系统损伤。本申请中的研究将开发细胞培养和啮齿动物模型，以开始解决这一临床相关问题。

DESCRIPTION (provided by applicant): Fetal Alcohol Spectrum Disorder describes a wide range of behaviors and deficits that can occur as a consequence of prenatal alcohol exposure. These effects can range from relatively subtle learning deficits to significant mental retardation. Various explanations for differences in sensitivity to alcohol's effects have been proposed. One theory suggests that "provocative factors" can play a role in increasing the severity and/or providing a context in which the damaging effects of ethanol are increased. We propose that prenatal alcohol exposure may increase the adverse consequences of brief periods of hypoxia during the antepartum period when brief periods of hypoxia routinely occur. Normally, the fetus/newborn is fairly resilient against mild hypoxia during labor and delivery, however, additional challenges (such as a history of in utero alcohol exposure or alcohol withdrawal) may put these infants at increased risk for adverse outcome. In this application, we propose to develop two models. The first is an in vitro organotypic hippocampal slice culture model taken from 1-day-old rats. These cultures will be exposed to chronic alcohol, followed by withdrawal and challenged with oxygen glucose deprivation (as a model of hypoxia). The hypothesis is that alcohol and hypoxia will produce greater damage than exposure to either challenge alone. Sub-threshold doses will also be included in this Specific Aim to assess the sensitivity of the hippocampus to these challenges. The 2nd model we will develop involves three trimester in vivo administration of alcohol first to pregnant dams and then to Sprague Dawley rat pups on postnatal day 1-7. Following alcohol withdrawal, the pups will also be exposed to a mild hypoxic challenge and subsequently tested for a variety of behavioral endpoints including activity and measures of learning and memory. Our working hypothesis is that alcohol exposure and/or withdrawal and hypoxic challenges share similar mechanisms (including overactivity of NMDAR, increased GLU activity and polyamine release) that could result in increased excitotoxic damage. The studies proposed will allow us to determine the potential validity of these models. In addition, once we have established these models, we can begin to study the underlying mechanisms and potential pharmacotherapeutic interventions to try and reduce the damage/deficits associated with alcohol withdrawal and hypoxia. These data could have significant clinical potential since our premise (and model) focuses on a relatively narrow developmental window which conceptually overlaps a time when women would typically be seeking medical assistance (i.e. labor and delivery) and intervention would be more likely. PUBLIC HEALTH RELEVANCE: Mild bouts of hypoxia (or reduced oxygen availability) commonly occur during normal labor and delivery and the newborn is usually not affected by these if the bouts are not severe. We propose that one of the effects of prenatal alcohol exposure is to increase the risk of these minor bouts resulting in behavioral and CNS damage. The studies in this application will develop cell culture and rodent models to begin to address this clinically-relevant question.