TSC and sensory processing

这项建议的目标是确定单基因遗传病中大脑发育异常的原因 涉及PI3K-mTOR通路的疾病(例如结节性硬化症复合体[TSC])会导致 电路和信息处理方面的变化。TSC是mTOR的一种经典障碍 TSC1或TSC2二次打击体细胞突变导致mTOR的信号通路 与癫痫和神经系统相关的多动症和发育畸形 赤字。50%-60%的TSC儿童有严重的认知缺陷和自闭症，并伴有 异常的感觉处理。我们实验室发表的研究发现了一种分子组合 以及mTOR过度活跃的小鼠神经元的细胞变化。这些改动包括 神经元错位和畸形发生是跨皮质区域和 在老鼠和人类之间。然而，这些缺陷对电路形成和 信息处理，以及对mTOR和电路中下游通路的依赖 水平仍不清楚。在这里，我们建议使用小鼠的桶状皮质作为一个成熟的 模型系统开始解决神经元异常和脑内病变之间的联系 电路和感官处理。根据我们之前的发现，我们假设 大鼠TSC内L 4层桶状皮质神经元的畸形发生与mTOR依赖 在电路、功能连接和感觉反应方面的异常。我们有以下几个方面 两个目的：(1)检验L4神经元mTOR多动改变桶状回路的假说 和功能连接。(2)检验假设，在短时间内减少mTOR活动 关键窗口和归一化两条下游通路可防止电路和 在TSC条件下的感觉反应。为了达到这些目的，我们将使用宫内电穿孔 利用CRISPR/Cas9在L4神经元中表达RhebCA并产生人源化TSC1突变 桶状皮质的。

The goal of this proposal is to identify how abnormalities of brain development in monogenic disorders involving the PI3K-mTOR pathway (e.g., tuberous sclerosis complex [TSC]) lead to alterations in circuit and in information processing. TSC is a classical disorder of the mTOR signaling pathway due to second-hit somatic mutations in TSC1 or TSC2 leading to mTOR hyperactivity and developmental malformations associated with seizures and neurological deficits. 50-60% of children with TSC have severe cognitive deficits and autism accompanied with abnormal sensory processing. Published work from our lab identified a combination of molecular and cellular alterations in murine neurons with hyperactive mTOR. These alterations include neuron misplacement and dysmorphogenesis that are conserved across cortical regions and between mice and humans. However, the impact of these defects on circuit formation and information processing, and the dependence on mTOR and downstream pathways at the circuit level remain unclear. Here, we propose to use the mouse barrel cortex as a well-established model system to start addressing the link between neuronal abnormalities and alterations in circuitry and sensory processing. Building from our previous findings, we hypothesize that dysmorphogenesis of layer (L) 4 barrel cortex neurons in TSC contributes to mTOR-dependent abnormalities in circuitry, functional connectivity, and sensory responses. We have the following two aims: (1) To test the hypothesis that mTOR hyperactivity in L4 neurons alters barrel circuitry and functional connectivity. (2) To test the hypothesis that reducing mTOR activity during a brief critical window and normalizing two downstream pathways prevent abnormalities in circuit and sensory responses in TSC condition. To address these aims, we will use in utero electroporation to express RhebCA and generate humanized Tsc1 mutations using CRISPR/Cas9 in L4 neurons of the barrel cortex.