Self-Tuned Critical Networks

脊椎动物的神经系统由神经元组成，这些神经元通过被称为突触的连接相互作用。由于神经元的活动模式，突触连接强度的变化被认为是大脑可塑性的基础。此外，人们普遍认为突触连接强度的微妙平衡对神经系统功能至关重要。不受阻碍的连接会导致大脑停止运转，产生一种类似癫痫病的反馈振荡的不和谐声音；如果抑制占主导地位，刺激将无法引起冷漠、平淡的大脑的反应。在这两种无用的行为模式之间的微妙界面上，存在着一种机制，在这种机制中，神经元群处于振荡的边缘，可能会根据外部影响迅速启动或停止反应。该项目将发展一种自我定位理论，在该理论中，平衡突触反应的局部活动依赖规则导致许多神经元组处于这种动态不稳定的边缘。该理论将发展自定与微观结构之间的相互作用，其中局部神经元微电路被连接在一起形成全局状态，以及与宏观结构之间的相互作用，其中不同的自定区域进行通信和相互作用。这个项目产生的新理论将有助于理解大脑的整体活动模式，如脑电图（EEG）或皮质电图（ECoG）。拟议的研究将直接为高中学生、本科生和研究生以及博士后研究人员的教育和推广项目做出贡献。这些活动将通过洛克菲勒大学正在进行的项目进行协调。促进少数民族本科生和研究生参与研究环境将是本计划的优先事项。该项目的成果将被纳入生物学学生的网络理论和高级建模的新研究生课程中。

The vertebrate nervous system consists of neurons that interact with each other through connections, called synapses. Changes in the strengths of the synaptic connections, due to the activity patterns of the neurons, are thought to underlie the plasticity of the brain. Furthermore, it is widely recognized that a delicate balancing of synaptic connection strength is essential to nervous system function. Unhindered connections would cause the brain to cease to operate, in a cacophony of epileptic-like feedback oscillations; if suppression dominated, stimuli would be unable to elicit a response from an apathetic, flatline brain. At the delicate interface between these two useless modes of behavior lies a regime in which groups of neurons are on the verge of oscillation, and may rapidly start or stop responding according to external influences.This project will develop a theory of self-poising, in which local activity-dependent rules for balancing synaptic response result in many groups of neurons poised at the edge of this dynamical instability. The theory will develop the interaction between self-poising and microstructure, in which local neuronal microcircuits are threaded together into global states, and the interaction with macrostructure, in which different self-poised areas communicate and interact. New theory resulting from this project will aid understanding of global activity patterns in the brain, such as Electroencephalography (EEG) or Electrocorticography (ECoG). The proposed research will contribute directly to education and outreach programs for high school students, undergraduate and graduate students, and postdoctoral researchers. These activities will be coordinated through ongoing programs at Rockefeller University. Promoting the involvement of minority undergraduate and graduate students in research environments will be a priority of this program. Results from the project will be incorporated into novel graduate courses on network theory and advanced modeling for biology students.