Modeling the Interactions of Stimuli and Ongoing Activity in Cortical Networks

模拟皮质网络中刺激和持续活动的相互作用

• 批准号: 1712922
• 负责人: Bard Ermentrout
• 金额: $ 40万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1712922&HistoricalAwards=false
• 关键词: Modeling; Interactions; Stimuli; Ongoing; Activity

How we perceive the world is governed both by the sensory inputs with which we are constantly bombarded, by ongoing activity in the brain, and by our previous experience. This activity as well as the natural wiring of the nervous system shapes the spontaneous behavior of our brains and this spontaneous activity strongly modulates the sensory inputs. In this project, computational and mathematical models of neurons (the cells that make up the brain) are used to understand what kinds of spontaneous behavior are possible, how this depends on the wiring and how this activity interacts with sensory inputs. The ongoing and evoked behavior is carefully controlled by a balance of positive (excitatory) and negative (inhibitory) influences. The loss of this balance can disrupt normal behavior and lead to diseases such as epilepsy and schizophrenia. Mathematical models of the nervous system provide a way to test hypotheses put forth by experimenalists and to also suggest new experiments based on the predictions of these models. Ongoing activity in the nervous system and how it impacts sensory and other inputs is the subject of much recent experimental activity. In particular, it is clear that the intrinsic interactions between neuronal circuits in absence of inputs can have a strong impact on how the system responds to incoming stimuli even at the large scale cognitive level. Thus, nonlinear dynamics methods will be applied to problems in theoretical neuroscience dealing with this question. Various forms of spatiotemporal activity are observed in experiments which include spatially localized activity, oscillations, and propagating waves. Perturbation and numerical methods will be used to analyze the dynamics of these patterns when subjected to various stimuli such as flickering light, localized or moving stimuli, and spatially periodic patterns. Uniform flickering stimuli lead to the perception of moving geometric patterns and these can be explained by the analysis of mean field models of visual cortex. In collaboration with an experimental group we will use the modeling to make predictions about how this percept is altered as parameters of the flicker vary. Related to this is the appearance of flicker when presented with high contrast spatially periodic patterns. Stability of the steady periodic state will be studied in order to see if the appearance of oscillations is the result of a Hopf bifurcation. This effect may also offer an explanation for why some images (such as op art) can induce visual discomfort. The existence an properties of traveling waves in nonlocally connected networks will also be studied in this project.

我们对世界的感知方式既受我们不断受到的感官输入的影响，也受大脑中正在进行的活动和我们以前的经验的影响。这种活动以及神经系统的自然布线塑造了我们大脑的自发行为，这种自发活动强烈地调节了感官输入。 在这个项目中，神经元（构成大脑的细胞）的计算和数学模型被用来理解什么样的自发行为是可能的，这如何取决于布线以及这种活动如何与感官输入相互作用。正在进行的和诱发的行为是由积极（兴奋）和消极（抑制）影响的平衡精心控制的。这种平衡的丧失会扰乱正常行为，导致癫痫和精神分裂症等疾病。神经系统的数学模型提供了一种方法来检验实验学家提出的假设，并根据这些模型的预测提出新的实验。 神经系统中正在进行的活动以及它如何影响感觉和其他输入是最近许多实验活动的主题。特别是，很明显，在没有输入的情况下，神经元回路之间的内在相互作用可以对系统如何响应传入的刺激产生强烈的影响，即使在大规模的认知水平。因此，非线性动力学方法将被应用于处理这个问题的理论神经科学的问题。在实验中观察到各种形式的时空活动，包括空间局部活动，振荡和传播波。扰动和数值方法将被用来分析这些模式的动态时，受到各种刺激，如闪烁的光，局部或移动的刺激，和空间周期性图案。均匀的闪烁刺激导致运动的几何图案的感知，这些可以解释的平均场模型的视觉皮层的分析。在与一个实验小组的合作中，我们将使用建模来预测这种感知如何随着闪烁参数的变化而改变。与此相关的是当呈现高对比度空间周期性图案时闪烁的出现。稳定的周期性状态将被研究，以查看振荡的外观是一个霍普夫分岔的结果。这种效应也可以解释为什么某些图像（如光学艺术）会引起视觉不适。 本计画也将研究非局部连接网路中行波的存在性与性质。

项目成果

Traveling Pulses in a Nonlocal Equation Arising Near a Saddle-Node Infinite Cycle Bifurcation

鞍结点无限循环分岔附近产生的非局部方程中的行进脉冲

• DOI: 10.1137/16m1093367
• 发表时间: 2017
• 期刊: SIAM Journal on Applied Mathematics
• 影响因子: 1.9
• 作者: Chen, Xinfu;Ermentrout, Bard
• 通讯作者: Ermentrout, Bard

A multiple timescales approach to bridging spiking- and population-level dynamics

桥接尖峰和群体水平动态的多时间尺度方法

• DOI: 10.1063/1.5029841
• 发表时间: 2018
• 期刊: Chaos: An Interdisciplinary Journal of Nonlinear Science
• 作者: Park, Youngmin;Ermentrout, G. Bard
• 通讯作者: Ermentrout, G. Bard

Interactions of solitary pulses of E. coli in a one-dimensional nutrient gradient

一维营养梯度中大肠杆菌孤立脉冲的相互作用

• DOI: 10.1016/j.physd.2019.02.007
• 发表时间: 2019
• 期刊: Physica D: Nonlinear Phenomena
• 作者: Young, Glenn;Demir, Mahmut;Salman, Hanna;Ermentrout, G. Bard;Rubin, Jonathan E.
• 通讯作者: Rubin, Jonathan E.

Actomyosin meshwork mechanosensing enables tissue shape to orient cell force.

• DOI: 10.1038/ncomms15014
• 发表时间: 2017-05-15
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Chanet S;Miller CJ;Vaishnav ED;Ermentrout B;Davidson LA;Martin AC
• 通讯作者: Martin AC

Synchronization of oscillators via active media

通过有源介质同步振荡器

• DOI: 10.1103/physreve.99.052218
• 发表时间: 2019
• 期刊: Physical Review E
• 影响因子: 2.4
• 作者: Orr, Derek;Ermentrout, Bard
• 通讯作者: Ermentrout, Bard