Mechanisms of Synaptic Transmission in Healthy and Disease States

对突触前过程的直接检查历来受到分辨率限制的限制 传统光学显微镜。因此，我们对囊泡运动、融合和作用的大部分了解 回收依赖于间接电生理和/或生化测定或电子分析的推论 反映动态系统单个瞬间的显微照片。我的研究计划的长期目标是 了解中央突触突触传递的基本机制，包括细节 正常条件下的时空动态，以及哪些干扰会导致疾病状态。当前 实验室的项目解决了两个核心知识差距。首先，我们直接探测和跟踪动态突触前 通过应用我们自己的新颖的纳米级分辨率成像技术在活体组织中进行处理。使用这个 方法，我们将第一次在单个突触小泡的水平上可视化这些过程 识别出突触。我们已经使用这种方法做出了重大贡献，包括 发现突触小泡动力学是主动的，而不是被动的，并且由肌动蛋白细胞骨架控制 肌球蛋白马达。我们解决的第二个主要知识差距是突触前缺陷对 脆性 X 综合征 (FXS) 的病理生理学。 FXS 是遗传性智力障碍最常见的已知原因 残疾和自闭症。我们最近的发现引发了该领域的必要转变，转向考虑 除了突触后机制之外，突触前机制的贡献，从而创造了一个全新的 一系列诊断和治疗的可能性。该领域的持续工作将侧重于连接突触前 电路层面异常的缺陷以及这些异常对行为和行为的影响 认知。通过 R35 机制持续提供资金将支持采取多管齐下的方法来解决这些问题 重要的神经生物学问题将最大限度地发挥协同作用和转化影响的潜力。

Direct examination of presynaptic processes has historically been limited by the resolution constraints of conventional light microscopy. As a result, much of what we know about vesicle movement, fusion, and recycling relies on inferences from indirect electrophysiological and/or biochemical assays, or from electron micrographs that reflect a single instant of a dynamic system. The long-term goal of my research program is to understand the fundamental mechanisms of synaptic transmission at central synapses, including details of spatiotemporal dynamics under normal conditions, and what disruptions lead to disease states. Current projects in the lab address two central knowledge gaps. First, we directly probe and track dynamic presynaptic processes in living tissue by applying our own novel, nanoscale resolution imaging technology. Using this approach, we will, for the first time, visualize these processes at the level of single synaptic vesicles within identified synapses. We have already made significant contributions using this approach, including the discovery that synaptic vesicle dynamics are active, not passive, and are controlled by actin cytoskeleton and myosin motors. The second major knowledge gap we address is the contribution of presynaptic deficits to pathophysiology of Fragile X syndrome (FXS). FXS is the most common known cause of heritable intellectual disability and autism. Our recent findings have triggered a necessary shift in the field towards considering the contributions of presynaptic mechanisms in addition to postsynaptic mechanisms, thus creating an entirely new array of diagnostic and therapeutic possibilities. Continuing work in this area will focus on linking presynaptic defects with abnormalities at the circuit level and the implications of these abnormalities for behavior and cognition. Sustained funding through this R35 mechanism will support a multipronged approach to these important neurobiological questions that will maximize the potential for synergy and translational impact.