Collaborative Research: CRCNS Research Proposal: Presynaptic structure-function relationships that control AP waveforms, calcium ion, entry, and transmitter release at NMJs

神经细胞之间通过一种叫做动作电位的电脉冲进行交流。这些脉冲到达神经细胞的末端（在专门用于与邻近神经细胞进行化学通信的结构，称为突触或终端），在那里它们可以触发邻近神经细胞中的电脉冲。尽管这些通信事件对神经系统所做的一切都至关重要，并且可能受到神经疾病的影响，但我们对突触上这些电脉冲的有效性以及疾病如何改变这一过程知之甚少。该项目使用导致肌肉收缩的神经作为模型，并将神经末梢的生理学和药理学测量与显微镜相结合，以确定功能重要蛋白质的密度和分布。这些细节用于开发一种新的计算机建模方法，该方法使用结构和功能信息来产生电脉冲生成的详细模型。该项目产生的新数据和模型将推进关于突触功能的基础科学知识，并增强我们对神经疾病机制的理解。拟议中的工作也将产生广泛的影响K-12教育，本科教学和培训，本科生和研究生培训，社区推广，并在代表性不足的少数民族institutions.The突触前事件，控制在突触递质释放不完全理解，特别是相对于定位与递质释放网站（活动区）的各种离子通道的作用。我们假设活性区离子通道之间的结构-功能关系调节健康突触内的突触前动作电位波形，并且这种关系在疾病状态下被破坏。我们将使用来自四所大学的研究人员合作团队来处理这些问题，使用分为四个目标的方法：（1）电压成像以表征突触前动作电位的形状，包括在疾病模型突触中的影响，（2）动作电位波形对离子电流的影响的膜片钳测量，（3）使用超分辨率成像表征运动神经末梢中突触前离子通道的密度和分布，以及（4）使用来自先前研究的数据与本文收集的数据的组合，我们将开发一种新的建模方法，该方法将在真实的神经末梢环境中建模离子通道激活和离子通量与预测这些离子通量对突触前动作电位形状的影响的电压模拟器相结合。拟议的研究将推进与突触前功能相关的基础科学问题，并增强对神经肌肉疾病机制的理解。我们提出的工作也将对K-12教育，本科教学和培训，研究生和研究生培训，社区推广，在代表性不足的少数民族机构的培训，以及有关突触功能的基础知识产生广泛的影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nerve cells communicate with each other using travelling electrical pulses called action potentials. These pulses arrive at the end of nerve cells (at structures specialized for chemical communication with neighboring nerve cells called synapses or terminals), where they can trigger electrical pulses in neighboring nerve cells. Despite the fact that these communication events are crucial to everything that the nervous system does, and can be compromised by neural diseases, we know surprisingly little about what shapes the effectiveness of these electrical pulses at synapses, and how diseases change this process. This project uses nerves that cause muscles to contract as a model, and combines physiology and pharmacology measurements in nerve terminals with microscopy to determine the density and distribution of functionally-important proteins. These details are used to development a new computer modeling approach that uses structural and functional information to produce detailed models of electrical pulse generation. The new data and models that project produces will advance basic scientific knowledge about synapse function, and enhance our understanding of the mechanisms that underlie neural disease. The proposed work will also have a broad impact on K-12 education, undergraduate teaching and training, graduate and post-graduate training, community outreach, and science training at under-represented minority institutions.The presynaptic events that control transmitter release at synapses are incompletely understood, particularly with respect to the role of various ion channels positioned with transmitter release sites (active zones). We hypothesize that the structure-function relationships between active zone ion channels regulates the presynaptic action potential waveform within healthy synapses, and that this relationship is disrupted in disease states. We will approach these issues using a collaborative team of investigators from four universities using an approach broken into four aims: (1) voltage imaging to characterize the shape of the presynaptic action potential, including the effects in disease model synapses, (2) patch clamp measurements of the effects of action potential waveforms on ionic currents, (3) characterization of the density and distribution of presynaptic ion channels in motor nerve terminals using super-resolution imaging, and (4) using a combination of data from prior studies with those collected here, we will develop a novel modeling approach that combines modeling ion channel activation and ion flux in a realistic nerve terminal environment with a voltage simulator that predicts the effects of these ion fluxes on the shape of presynaptic action potentials. The proposed studies will advance basic science issues related to presynaptic function and also enhance understanding of the mechanisms that underlie neuromuscular diseases. Our proposed work will also have a broad impact on K-12 education, undergraduate teaching and training, graduate and postgraduate training, community outreach, training at under-represented minority institutions, and fundamental knowledge about synaptic function.This grant was cofunded by the Cellular Dynamics and Function Cluster in the Division of Molecular and Cellular Biosciences, and the Division of Emerging Frontiers in the Directorate for Biological Science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.