RESEARCH PROJECT: "Mechanisms of B(a)P Induced Neurotoxicity"

这些研究的长期目标是确定妊娠期B（a）P暴露是否 干扰C57 BL小鼠的正常行为和神经功能，如通过以下方面的显著缺陷所证明的： “脂突触可塑性和行为。有待检验的中心假设是， 暴露于B（a）P气溶胶（PM2.5 μ），在某些环境中的人类中观察到的水平， 学习和记忆缺陷，这些缺陷是介导的，至少部分是通过调节， 发育中NMDA/AMPA谷氨酸受体亚单位的表达和功能， 兴奋性突触在C57 BL小鼠的海马体中形成。目标#1将决定 妊娠第14、16、18天和出生后第1天F1胎脑（C57 BL小鼠）中B（a）P的分布 (PND)0、50、100和200 μ g/m3 A剂量吸入暴露后GD 14 -17海马中的0 同时测定对子宫内谷氨酸受体亚单位表达的影响， 使用离体原代神经元培养物进行。AIM #2将测试妊娠期暴露于 相同吸入剂量的B（a）P导致学习缺陷，使用先前显示依赖于 海马体功能目的#3将妊娠期暴露于B（a）P与海马神经元的测量结果相关联。 F1代小鼠在PND 60和120时评价的长时程增强（LTP）。的参与 将通过以下方法评估该LTP中的NMDA和/或AMPA受体及其由于B（a）P暴露引起的变化： 在对照和B（a）P的LTP分析之前应用NMDA或AMPA选择性受体拮抗剂 F1代小鼠。目的#4将测试妊娠期暴露于B（a）P剂量是否 导致行为学习和生理缺陷也调节各种NMDA和 AMPA受体亚单位，使用真实的时间分析GD 18和PND 0、5、10、20和60的表达水平 PCR（用于mRNA评估）和Western印迹分析（用于亚基蛋白评估）， B（a）P暴露F1代C57 BL小鼠。这些研究将作为使用查询的第一步， 妊娠期暴露于B（a）P后谷氨酸受体亚单位表达改变的因果关系 成年动物学习行为的衰减，这将在未来的研究中通过利用小鼠来扩展 遗传改变以修饰相关AMPA或NMDA受体亚基的表达，或其 下游效应分子。这些研究与B（a）P对人类的影响直接相关 暴露，我们预计，我们的研究将导致一个重要的动物严格的特征 模型既了解环境毒素引起的神经功能障碍的病因， 关于有效治疗或其他干预措施的假设。

The long-term objective of the proposed studies is to determine whether gestational B(a)P exposure nterferes with normal behavior and neural function in C57BL mice as demonstrated by significant deficits in "lippocampal synaptic plasticity and behavior. The central hypothesis to be tested is that gestational exposure to B(a)P aerosol (PM2.5mu) at levels seen in humans in certain environments result in lifelong learning and memory deficits, and that these deficits that are mediated, at least in part, through modulation of developmental NMDA/AMPA glutamate receptor subunit expression and function at a time when excitatory synapses are being formed in the hippocampus of C57BL mice. AIM #1 will determine the disposition of B(a)P in F1 fetal brain (in C57BL mice) on gestational day (GD) 14, 16, 18, and postnatal day (PND) 0 in the hippocampus after GD14-17 inhalation exposure at doses of 0, 50, 100 and 200 mu g/m3A simultaneous determination of the effect on glutamate receptor subunit expression in utero will be conducted, using ex vivo primary neuronal cultures. AIM #2 will test whether gestational exposure to the same inhalational doses of B(a)P results in deficits in learning, using behaviors previously shown to depend on hippocampal function. AIM #3 will correlate gestational exposure to B(a)P with measures of hippocampal long-term potentiation (LTP), evaluated at PND 60 and 120 in F1 generation mice. The involvement of NMDA and/or, AMPA receptors in this LTP, and its changes due to B(a)P exposure, will be assessed by application of NMDA or AMPA-selective receptor antagonists prior to LTP analysis of control and B(a)P exposed F1 generation mice. AIM #4 will test whether gestational exposure to the doses of B(a)P which lead to behavioral learning and physiological deficits also modulate the expression of various NMDA and AMPA receptor subnits, profiled for expression levels on GD18 and PND 0, 5, 10, 20, and 60 using real time PCR (for mRNA assessment) and Western blot analyses( for subunit protein assessment) in control and B(a)P exposed F1 generation C57BL mice. These studies will serve as the first step in querying the with the causality of altered glutamate receptor subunit expression subsequent to gestational exposure to B(a)P in attenuation of learning behaviors in adult animals, which will be extended in future studies by exploiting mice genetically altered to modify the expression of relevant AMPA or NMDA receptor subunits, or their downstream effector molecules. These studies are directly relevant to human consequences of B(a)P exposure, and we anticipate that our studies will lead to the rigorous characterization of an important animal model both to understand the etiology of environmental toxin-induced neurological dysfunction and to test hypotheses regarding effective therapeutic or other interventions .