Mechanisms of synaptic and behavioral dysfunction after postnatal anesthesia

在美国，每年有超过400万婴幼儿接受全身麻醉(GA)。实验 有证据表明，几种哺乳动物可能会经历神经退化，然后是长期的 认知障碍，当暴露在普通的静脉和吸入麻醉剂时，在危重阶段 大脑发育。最近的研究也证明了挥发性遗传后睡眠-觉醒行为的中断 麻醉剂。到目前为止，GA后观察到的行为功能障碍的潜在机制仍然 早期麻醉暴露对突触功能的影响尚不完全清楚 进行了详细的探索。因此，这项提案的长期目标是确定对GA的敞口如何改变 发育中海马区的突触可塑性、突触网络和行为输出及其破译 赤霉素A诱导突触调节失调的机制。我们解决了特定的假设，即一个关键字 神经递质释放机制的组成部分突触素I在糖尿病的病理生理学中起决定性作用。 GA诱导的突触和认知功能障碍。该项目包括三个具体目标。具体而言 目的1、检测赤霉素A对突触前神经递质表达的影响 机械部件。这是通过蛋白质印迹和定量聚合酶链式反应定量几个关键成分来实现的。 用于囊泡释放的机器。在特定目标2中，我们测试了GA诱导的细胞损伤的细胞效应 关于突触传递和可塑性的释放机制。这是通过系统地实现的 基础突触传递、可塑性、兴奋性和网络的电生理学实验。在……里面 具体目标3，我们测试麻醉剂对学习、记忆和睡眠-觉醒行为的影响，使用 Barnes迷宫、恐惧条件反射测试和睡眠-觉醒模式的定量脑电分析。 总之，这些拟议的研究将为我们提供新的分子和细胞机制的理解。 GA诱导的突触调节障碍和行为障碍，以及新治疗策略的理论基础 预防或改善GA后的认知、睡眠觉醒和其他行为发育障碍 曝光。由于我的培训和研究经验，我拥有成功所需的专业知识 开展这项工作。我召集了一支高级调查员队伍，他们热情地参与了我的 导师和我的主席承诺为我提供受保护的时间，所有设施和设备 需要发展成为一名成功的翻译研究科学家。我的短期目标是利用这一点 获得新技能奖，以追求我自己的研究利基，专注于睡眠在麻醉中的作用- 青年和老年脑内诱发的认知功能障碍及突触融合机制的作用 在神经紊乱和神经传递不平衡方面。我的长期职业目标是成为一名 独立、全额医疗外资助的临床医生研究科学家，最终成功竞争R01 来自美国国立卫生研究院的支持。

Over 4 million infants and young children undergo general anesthesia (GA) every year in the US. Experimental evidence suggests that several mammalian species may suffer neurodegeneration, followed by long-lasting cognitive impairment, when exposed to common intravenous and inhaled anesthetics during critical stages of brain development. Recent studies also document disruption of sleep-wake behavior following GA with volatile anesthetics. To date, the mechanisms underlying the behavioral dysfunctions observed after GA remain incompletely understood and the effects of an early anesthetic exposure on synaptic function have not been explored in detail. Thus, the long term objectives of this proposal are to establish how exposure to GA alters synaptic plasticity, synaptic networking and behavioral output in the developing hippocampus and to decipher the mechanisms of GA-induced synaptic dysregulation. We address the specific hypothesis that a key component of the neurotransmitter release machinery, synapsin I, features decisively in the pathophysiology of GA-induced synaptic and cognitive dysfunction. This project encompasses three specific aims. In Specific Aim 1, we test the molecular effects of GA on the expression of pre-synaptic neurotransmitter release machinery components. This is achieved by western blot and qPCR quantification of several key components of the machine for vesicle release. In Specific Aim 2, we test the cellular effects of GA-induced impairment of the release machinery on synaptic transmission and plasticity. This is achieved by systematic electrophysiology experiments of basal synaptic transmission, plasticity, excitability and networking. In Specific Aim 3, we test the effects of anesthetics on learning, memory and sleep-wake behavior, using the Barnes maze, fear conditioning test and quantitative electroencephalographic analysis of sleep-wake patterns. Collectively, the proposed studies will provide new understanding of the molecular and cellular mechanisms of GA-induced synaptic dysregulation and behavioral dysfunction, and the rationale for new therapeutic strategies to prevent or improve cognitive, sleep-wake and other behavioral developmental dysfunctions after GA exposure. As a result of my training and research experience, I have the expertise necessary to successfully carry out this work. I assembled a cadre of senior investigators who are participating enthusiastically in my mentoring and my Chair has committed to me the protected time, all of the facilities and equipment that are needed to develop into a successful translational research scientist. My short term objective is to use this Award to acquire new skills to pursue my own niche of research, focusing on the role of sleep in anesthesia- induced cognitive dysfunction in the young and aging brain, and on the role of the synaptic fusion mechanism in neurological disorders and imbalances of neurotransmission. My long-term career objective is to become an independent fully extramurally funded clinician research scientist by ultimately successfully competing for R01 support from the NIH.