Synaptic dysregulation in a mouse model of Alzheimer's disease

直到最近才有证据表明，远端兴奋性突触与近端兴奋性突触在海马体中是不同的，这些差异赋予远端突触与近端突触对神经元输出的同样影响。同样，最近才表明，与阿尔茨海默病(AD)相关的生化处理以突触为目标，并影响与突触后膜结合的AMPA受体(AMPAR)的数量。这项拟议的研究将通过对AD小鼠模型(5XFAD转基因系)及其非转基因猫咪对照的突触进行多学科分析，研究距离相关的突触缩放机制及其对类似AD的生化处理的脆弱性。这项建议的中心目标是帮助首席研究人员建立他的独立性，并获得一个终身教职的教职，这样他就可以领导一个旨在了解突触、行为和疾病之间相互作用的重大研究计划。该计划的指导阶段将在植入免疫金电子显微镜和全细胞膜片钳生理学之后，分别从各自领域的两位专家：Yuri Geinisman博士和Nelson Spruston博士那里为申请者提供连续部分的培训。这样的多学科培训将通过使申请人能够在多个互补的分析水平上设计、执行和解释实验来促进他向独立的过渡。在指导阶段，申请者将确定CA1锥体神经元树突远端区域的突触是否比近端区域的突触更强，以及5XFAD小鼠中AD相关的基因突变是否扰乱了这种突触强度的距离依赖调节。在独立阶段，申请者将结合他在电子显微镜和全细胞膜片钳生理学方面的训练来确定对照小鼠CA1锥体神经元树突轴上突触的数量、大小和可塑性是否在单个树突内受到调节，以及这些参数是否因A？5XFAD小鼠的生产过剩。总之，拟议的实验将有助于确定突触亚型对海马神经元中位置无关突触交流的贡献，同时确定突触是否为AD的目标，以及某些突触亚型是否比其他亚型更危险。这项建议利用了西北大学的协作环境，包括在各种光学和电子显微镜研讨会上的培训、基于实验室的细胞生理学培训、期刊俱乐部、小鼠基因分型和计算机编程。此外，培训环境将通过国家研究报告、合作、指导学生和负责任的研究行为培训，为职业发展提供大量机会。

Only recently has it become evident that distal excitatory synapses are different from proximal excitatory synapses in the hippocampus, and that these differences confer to distal synapses the same influence on neuronal output as their more proximal counterparts. Similarly, it has been shown only recently that Diochemical processing related to Alzheimer's disease (AD) targets synapses and affects the number of AMPA receptors (AMPARs) bound to their postsynaptic membrane. The proposed research will examine the mechanisms of distance-dependent synaptic scaling and their vulnerability to AD-like biochemical processing using a multi-disciplinary analysis of synapses in a mouse model of AD (the 5XFAD transgenic line) and their nontransgenic littermate controls. The central goal of this proposal is assist the Principal Investigator establish his independence and secure a tenure-track faculty position such that he can lead a major research program aimed at understanding the interplay among synapses, behavior, and disease. The Mentored Phase of this proposal will provide the applicant with training in serial section postembedding immunogold electron microscopy and whole-cell patch-clamp physiology from two experts in their fields: Dr. Yuri Geinisman and Dr. Nelson Spruston, respectively. Such multidisciplinary training will facilitate the applicant's transition to independence by enabling him to design, perform, and interpret experiments at multiple, complementary levels of analysis. In the Mentored Phase, the applicant will determine whether synapses in distal regions of the CA1 pyramidal neuron dendrites are stronger than those in more proximal regions, and whether the AD-linked genetic mutations in 5XFAD mice disrupt this distance-dependent regulation of synaptic strength. During the Independent Phase, the applicant will combine his training in electron microscopy and whole-cell patch-clamp physiology to determine whether the number, size, and plasticity in synapses throughout the dendritic axis of CA1 pyramidal neurons are regulated within single dendrites in control mice, and whether these parameters are dysregulated as a consequence of A? overproduction in 5XFAD mice. Together, the proposed experiments will help identify the contributions of synaptic subtypes to location-independent synaptic communication in hippocampal neurons, while simultaneously determining whether synapses are targeted by AD, and whether some synaptic subtypes are more at risk than others. This proposal takes advantage of the collaborative environment at Northwestern University and includes training at various light and electron microscopy workshops, laboratory-based training in cellular physiology, journal clubs, mouse genotyping, and computer programming. In addition, the training environment will provide numerous opportunities for career development through national research presentations, collaborations, mentoring students, and training on the responsible conduct of research.