Limbic Circuit Dysfunction in Offspring following Maternal Immune Activation

项目摘要/摘要 在一般人群中，只有不到1%的儿童出现癫痫发作，而患有自闭症的儿童超过30%。 谱系障碍(ASD)在青春期就会这样。孕期母体感染是两种疾病的危险因素 ASD和癫痫，然而，我们对早期免疫侮辱如何改变神经的了解有限 这两种疾病都与电路有关。内侧前额叶皮质(MPFC)是大脑的一个重要区域， 调节自闭症患者改变的各种认知和情绪行为。我们已经获得了试验数据支持 孕期暴露于病毒模拟物多肌苷：多胞苷后mPFC通路功能的改变 (Poly(I：C))。在急性mPFC脑片中使用高通量多点场电位记录方法，我们的 初步结果表明，母体免疫激活(MIA)会导致mPFC的持续变化 突触前和突触后的活动，增加了癫痫的易感性 体外活性。拟议中的实验将阐明精确的细胞类型和板层特异性变化。 网络兴奋性的潜在变化。本提案的目标1将确定皮质内功能区的变化 MPFC内的连接性。怀孕的水坝将用生理盐水或聚(i：c)进行治疗，以安装急性抗病毒药物。 炎症反应。含有mPFC的急性脑片将从成年后代中制备，从3岁到30岁 四个月大。基于图案化谷氨酸去除的激光扫描光刺激将被用于 MAP在mPFC内光兴奋突触前神经元和 单个突触后锥体神经元和中间神经元。将层流特定输入更改为兴奋性和 MIA后抑制性细胞类型将通过细胞内突触电压钳记录进行评估 活动。免疫组织化学方法将确定细胞类型、位置和形态，并将用于 识别层压中的结构缺陷。目标2将评估在招募远端输入到 来自两个区域的mPFC与边缘癫痫的启动和扩散密切相关，即基底外侧区 杏仁核(BLA)和腹侧海马区(VHC)。AAv-CaMKII-ChR2/EYFP用于靶向表达 视紫红质-EYFP或EYFP通道单独作用于这些额叶外结构中的兴奋性神经元。 将测量L2/3和L5神经元mPFC中的突触后电流，以响应光遗传激活 分别检测BLA和VHC终末的变化，并评估兴奋性和抑制性成分的变化。 这些目标一起解决了电路内部和外部的变化，这些变化可能有助于共享 ASD与癫痫的发病机制。从询问mPFC电路中获得的信息 已建立的MIA模型将确定可能作为治疗目标的神经病理改变。

PROJECT SUMMARY/ABSTRACT In the general population, less than 1% of children develop seizures, whereas over 30% of children with autism spectrum disorder (ASD) do so by adolescence. Maternal infection during pregnancy is a risk factor for both ASD and epilepsy, however we have limited understanding of how early-life immune insults alter neural circuitry implicated in both disorders. The medial prefrontal cortex (mPFC) is a brain region important for regulating diverse cognitive and emotional behaviors altered in ASD. We have obtained pilot data supporting altered mPFC circuit function after gestational exposure to a viral mimetic polyinosinic:polycytidylic acid (poly(I:C)). Using a high-throughput multisite field potential recording approach in acute mPFC brain slices, our preliminary results indicate that maternal immune activation (MIA) leads to persistent alterations in mPFC activity, at both presynaptic and postsynaptic loci, and an increased susceptibility to generation of epileptic activities in vitro. The proposed experiments will elucidate the precise cell type- and lamina-specific alterations underlying changes in network excitability. Aim 1 of this proposal will identify changes to functional intracortical connectivity within the mPFC. Pregnant dams will be treated with saline or poly(I:C) to mount an acute antiviral inflammatory response. Acute brain slices containing mPFC will be prepared from adult offspring at three to four months of age. Laser scanning photostimulation based on patterned glutamate uncaging will be used to map excitatory synaptic connectivity within the mPFC between photo-excited presynaptic neurons and individual postsynaptic pyramidal and interneurons. Changes to laminar-specific inputs to excitatory and inhibitory cells types following MIA will be assessed by intracellular voltage-clamp recordings of synaptic activity. Immunohistochemical methods will confirm cell type, location and morphology and will be used to identify structural defects in lamination. Aim 2 will evaluate alterations in the recruitment of distal inputs to the mPFC from two regions highly implicated in the initiation and spread of limbic seizures, the basolateral amygdala (BLA) and ventral hippocampus (vHC). AAV-CamKII-ChR2/eYFP will be used to target expression of channelrhodopsin-eYFP or eYFP alone to excitatory neurons in these extra-prefrontal structures. Postsynaptic currents in mPFC in L2/3 and L5 neurons will be measured in response to optogenetic activation of BLA and vHC terminals, respectively, and changes in excitatory and inhibitory components assessed. Together these aims address circuit intrinsic and extrinsic changes that may contribute to the shared pathogenesis of ASD and epilepsy. Information gained from the interrogation of mPFC circuitry in an established MIA model will identify neuropathological alterations that might be targeted for therapies.