Statistical Mechanics of soft low dimensional structures and dynamical phases of neuronal networks

软低维结构的统计力学和神经元网络的动态阶段

• 批准号: 1709785
• 负责人: Alexander Levine
• 金额: $ 34.5万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1709785&HistoricalAwards=false
• 关键词: Statistical; Mechanics; soft; low; dimensional

NONTECHNICAL SUMMARYThis award supports research and education into the behavior of a variety of complex biological systems including the mechanics of bundles of biopolymer filaments, cell membranes, and small networks of interacting neurons. The PI will explore the interplay of random fluctuations and shape on soft, elastic structures in the cell, e.g. on the mechanics of bundles of biopolymer filaments. These bundles are integral to the mechanics of our cells. In addition, the PI and his research team will explore the interaction of cell membrane undulations with the cell's underlying geometry. The complex geometry of the cellular membranes redirects and focuses these undulations, leading to cells having a spatially complex pattern of fluctuations. This award will support research into the underlying physical principles that govern these patterns and on how they affect membrane interactions. Finally, the researchers will explore how the complex connectivity of small networks of interacting neurons controls their collective electrical response and signal generation. The award also supports the education of undergraduate, graduate students, and postdoctoral scholars at UCLA. It will also contribute to the UCLA/California State University Dominguez Hills (CSUDH) scientific exchange program, which provides an opportunity for physics students at CSUDH to gain research experience at UCLA. The broader impacts of this research into the interplay of geometry, connectivity, and fluctuations in biological systems should include a deeper understanding of the principles of cellular mechanics and force generation. The work on membranes may also inform our understanding of undulations in graphene sheets and ribbons, which might play an important role in developing nanotechnologies. Finally, the work on neuronal networks should have direct impact on studies of respiratory rhythm generation in mammals. TECHNICAL SUMMARYThe award supports research and education on the interaction of fluctuations on soft, low-dimensional structures with an emphasis on biologically derived systems. These include: 1) filament bundles with transient cross linking, and 2) membranes with complex geometry. Another aspect of the project involves studying the collective dynamics of neurons interacting on quenched random networks. All three aims of the research are related by the study of biologically relevant fluctuations interacting with quenched random variables. More specifically, the focus of this project can be broken down into three parts:1) The study of bundles of semiflexible biopolymer filaments (e.g., F-actin) linked by transient cross linkers. These linkers exhibit long-ranged Casimir interactions resulting in their behaving within the bundle as a strongly-interacting linker fluid. In this project, the researchers will explore how that linker fluid affects the bundling/unbundling transition, and how it affects the dynamics of the bundle under the application of various forms of deformation. They will also study the driven dynamics of such systems in response to endogenous molecular motors.2) The research team will study the mechanics of undulations on curved filaments to address how bending modifies the Casimir interaction. They will expand these studies to explore the scattering of undulatory waves on elastic membranes from local changes in curvature. Using these results, they will explore the localization of undulatory waves on shells with quenched random geometry.3) The team will address the effect of quenched random connectivity in interacting neuronal networks by continuing their studies of the effect of certain topological structure called k-cores on the collective dynamics of central pattern generators.The award also supports the education of undergraduates, graduate students, and postdoctoral scholars at UCLA. It will also contribute to the UCLA/California State University Dominguez Hills (CSUDH) scientific exchange program. The broader impacts of this research into the interplay of geometry, connectivity, and fluctuations in biological systems should include a deeper understanding of the principles of cellular mechanics and force generation. The work on membranes may also have a broader impact on understanding undulations in graphene sheets and ribbons. Finally, the work on neuronal networks should have direct impact on studies of respiratory rhythm generation in mammals and possibly provide new insight into the basic principles controlling the stability of this essential central pattern generator.

非技术总结该奖项支持对各种复杂生物系统的行为的研究和教育，包括生物聚合物细丝、细胞膜和相互作用的神经元的小网络的力学。PI将探索随机波动和形状对细胞中柔软、弹性结构的相互作用，例如对生物聚合物细丝束的力学影响。这些束对我们细胞的机制是不可或缺的。此外，PI和他的研究团队将探索细胞膜波动与细胞基本几何结构的相互作用。细胞膜的复杂几何形状重定向并聚焦这些波动，导致细胞具有复杂的空间波动模式。该奖项将支持对支配这些模式的潜在物理原理以及它们如何影响膜相互作用的研究。最后，研究人员将探索由相互作用的神经元组成的小型网络的复杂连接如何控制它们的集体电反应和信号生成。该奖项还支持加州大学洛杉矶分校的本科生、研究生和博士后学者的教育。它还将为加州大学洛杉矶分校/加州州立大学多明格斯山庄(CSUDH)科学交流项目做出贡献，该项目为CSUDH的物理系学生提供了在加州大学洛杉矶分校获得研究经验的机会。这项研究对生物系统中几何学、连通性和涨落的相互作用的更广泛的影响应该包括对细胞力学和力产生原理的更深层次的理解。薄膜方面的工作也可能有助于我们理解石墨烯薄片和石墨烯带中的起伏，这可能在发展纳米技术方面发挥重要作用。最后，关于神经元网络的工作应该会对哺乳动物呼吸节律产生的研究产生直接影响。技术总结该奖项支持关于软性低维结构上波动相互作用的研究和教育，重点是生物衍生系统。这些包括：1)具有瞬时交联性的纤维束，以及2)具有复杂几何形状的膜。该项目的另一个方面涉及研究在猝灭的随机网络上相互作用的神经元的集体动力学。这项研究的三个目的都是通过研究生物相关的波动与猝灭的随机变量相互作用而联系在一起的。更具体地说，该项目的重点可以分为三个部分：1)通过瞬时交联剂连接的半柔性生物聚合物细丝(例如，F-肌动蛋白)束的研究。这些连接体表现出长距离的Casimir相互作用，导致它们在束内表现为强相互作用的连接体流体。在这个项目中，研究人员将探索连接流体如何影响捆绑/解绑转变，以及在各种形式的变形应用下，它如何影响捆绑的动力学。他们还将研究这类系统响应内源分子马达的驱动动力学2)研究小组将研究弯曲细丝上波动的机制，以解决弯曲如何修改Casimir相互作用。他们将扩展这些研究，以探索局部曲率变化引起的波动波在弹性膜上的散射。利用这些结果，他们将探索具有淬灭随机几何形状的壳上波动波的局部化。3)该团队将通过继续他们对被称为k核的特定拓扑结构对中央模式生成器集体动力学的影响的研究，来解决淬灭随机连通性在相互作用的神经元网络中的影响。该奖项还支持加州大学洛杉矶分校的本科生、研究生和博士后学者的教育。它还将为加州大学洛杉矶分校/加州州立大学多明格斯山庄(CSUDH)科学交流计划做出贡献。这项研究对生物系统中几何学、连通性和涨落的相互作用的更广泛的影响应该包括对细胞力学和力产生原理的更深层次的理解。膜方面的工作也可能对理解石墨烯薄片和带中的波动产生更广泛的影响。最后，关于神经元网络的工作应该会对哺乳动物呼吸节律产生的研究产生直接影响，并可能为控制这一重要的中枢模式发生器的稳定性的基本原理提供新的见解。

项目成果

Equilibrium fluctuations of a semiflexible filament cross linked into a network

交联成网络的半柔性细丝的平衡波动

• 发表时间: 2020
• 期刊: Physical review and Physical review letters index
• 作者: Kernes, Jonathan;Levine, Alex J.
• 通讯作者: Levine, Alex J.

Dynamics of undulatory fluctuations of semiflexible filaments in a network

• DOI: 10.1103/physreve.102.062406
• 发表时间: 2020-12-03
• 期刊: PHYSICAL REVIEW E
• 影响因子: 2.4
• 作者: Kernes, Jonathan;Levine, Alex J.
• 通讯作者: Levine, Alex J.

The conformation of a semiflexible filament in a random potential

半柔性细丝在随机电位下的构象

• 发表时间: 2019
• 期刊: Physical review and Physical review letters index
• 作者: Slepukhin, Valentin M.;Grill, Maximilian J.;Muller, Kei W.;Wall, Wolfgang A.;Levine, Alex J.
• 通讯作者: Levine, Alex J.

Actively Driven Fluctuations in a Fibrin Network

纤维蛋白网络中主动驱动的波动

• DOI: 10.3389/fphy.2020.568736
• 发表时间: 2021
• 期刊: Frontiers in Physics
• 影响因子: 3.1
• 作者: Hu, Qingda;Morris, Tessa Altair;Grosberg, Anna;Levine, Alex J.;Botvinick, Elliot L.
• 通讯作者: Botvinick, Elliot L.

Effects of curvature on the propagation of undulatory waves in lower dimensional elastic materials

• DOI: 10.1103/physreve.103.013002
• 发表时间: 2021-01-11
• 期刊: PHYSICAL REVIEW E
• 影响因子: 2.4
• 作者: Kernes, Jonathan;Levine, Alex J.
• 通讯作者: Levine, Alex J.