Prenatal Alcohol and Adult Hippocampal Neurogenesis

描述（由申请人提供）：本提案的总体目标是阐明产前暴露于中等剂量酒精导致富集介导的成年海马神经发生长期受损的机制，并将这种缺陷与我们的胎儿酒精谱系障碍（FASD）小鼠模型中的海马依赖性学习受损联系起来。FASD小鼠在依赖于学习任务的学习中表现出认知能力受损，并表现出抑郁症的迹象。FASD小鼠还显示出成年海马神经发生的持续缺陷，当小鼠暴露于丰富的环境中受到行为挑战时，这变得明显。在这个建议中，实验的目的是确定是否FASD表型的机制，包括受损的神经元分化和成熟的神经干细胞在成年海马，并减少成人产生的齿状颗粒细胞纳入空间记忆网络。为了测试这一点，我们将利用一种新的条件性和诱导性巢蛋白-CreERT 2：YFP转基因小鼠，其允许非侵入性标记大量成体神经干细胞及其后代。FASD和Sacc（对照）小鼠将在nestin-CreERT 2：YFP品系中产生，并用于解决以下特定目的。 具体目的1确定产前乙醇暴露是否损害成年海马神经干细胞的神经元分化和成熟。nestin-CreERT 2：YFP菌株将用于体内（SA1.1）和体外分离成年NSC后（SA1.2）FASD和Sacc（对照）小鼠成年海马中神经干细胞的命运图和神经元分化特征。 具体目标二：目的：探讨产前酒精暴露是否会损害成年大鼠齿状核颗粒细胞（DGC）的突触成熟和可塑性。他莫昔芬将用于出生日期和YFP标记新生DGC，用于FASD和Sacc nestin-CreERT 2：YFP小鼠成年海马切片制备物的电生理记录。使用这种方法，我们将测试的假设，产前酒精暴露破坏成熟的GABA和谷氨酸介导的电流（SA2.1）和衰减LTP可塑性在成年出生的DGC（SA2.2）。 具体目标3：确定产前乙醇暴露是否损害新产生的DGC优先纳入空间记忆网络的能力。我们将确定是否优先激活的新生神经元衰减在成年海马FASD小鼠回忆的空间记忆任务，评估立即早期基因（c-fos）表达nestin-CreERT 2：YFP小鼠。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to elucidate the mechanisms by which prenatal exposure to moderate doses of alcohol results in long-lasting impairment of enrichment-mediated adult hippocampal neurogenesis, and to link this deficit with impairment of hippocampal-dependent learning in our mouse model of fetal alcohol spectrum disorder (FASD). FASD mice display impaired cognitive ability in hippocampal-dependent learning tasks and show signs of depressive disorder. FASD mice also display persistent deficits in adult hippocampal neurogenesis, which become apparent when the mice are behaviorally challenged by exposure to enriched environment. In this proposal, experiments are designed to determine whether the mechanisms underlying the FASD phenotype include impaired neuronal differentiation and maturation of neural stem cells in adult hippocampus, and diminished incorporation of adult-generated dentate granule cells into spatial memory networks. To test this, we will utilize a novel conditional and inducible nestin- CreERT2:YFP transgenic mouse which allows non-invasive labeling of large numbers of adult neural stem cells and their progeny. FASD and Sacc (control) mice will be generated in the nestin-CreERT2:YFP strain and utilized to address the following Specific Aims. Specific Aim 1 To determine whether prenatal ethanol exposure impairs neuronal differentiation and maturation of adult hippocampal neural stem cells. The nestin-CreERT2:YFP strain will be used to fate map and characterize neuronal differentiation of neural stem cells in adult hippocampus of FASD and Sacc (control) mice in vivo (SA1.1) and following isolation of adult NSCs in vitro (SA1.2). Specific Aim 2: To determine whether prenatal exposure to alcohol impairs synaptic maturation and plasticity of adult-born dentate granule cells (DGCs). Tamoxifen will be used to birthdate and YFP label newborn DGCs for electrophysiological recordings in adult hippocampal slice preparations from FASD and Sacc nestin-CreERT2:YFP mice. Using this approach, we will test the hypotheses that prenatal alcohol exposure disrupts the maturation of GABA- and glutamate-mediated currents (SA2.1) and attenuates LTP plasticity in adult born DGCs (SA2.2). Specific Aim 3: To determine whether prenatal ethanol exposure impairs the ability of newly- generated DGCs to preferentially incorporate into spatial memory networks. We will determine whether preferential activation of newborn neurons is attenuated in adult hippocampus of FASD mice during recall of a spatial memory task, as assessed by immediate early gene (c-fos) expression nestin-CreERT2:YFP mice.