Activity dependent plasticity and neuronal spiking homeostasis in vivo

体内活动依赖性可塑性和神经元尖峰稳态

• 批准号: 8455441
• 负责人: Keith B. Hengen
• 金额: $ 4.92万
• 依托单位: BRANDEIS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-16 至 2015-01-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8455441
• 关键词: AMPA Receptors; Address; Adolescent; Age; Aging; Alzheimer' s Disease; Animals; Arousal; Attenuated; Behavior; Behavioral; Behavioral Mechanisms; Biological Neural Networks; Brain; Cells; Chronic; Circadian Rhythms; Complex; Data; Depressed mood; Development; Disease; Dominant-Negative Mutation; Environment; Epilepsy; Etiology; Excitatory Synapse; Exhibits; Future; Homeostasis; Implant; In Vitro; Individual; Investigation; Knowledge; Modeling; Molecular; Neuronal Plasticity; Neurons; Pathogenesis; Pathology; Pattern; Physiological; Plastics; Play; Preparation; Process; Property; Rattus; Regulation; Rett Syndrome; Role; Sleep; Sleep Wake Cycle; Slice; Stimulus; Synapses; Synaptic plasticity; System; Techniques; Testing; Time; Visual Cortex; Work; age related; area striata; awake; computational neuroscience; deprivation; genetic manipulation; in vitro activity; in vivo; information processing; insight; monocular deprivation; mutant; neocortical; nervous system disorder; response; scale up; visual deprivation

DESCRIPTION (provided by applicant): In order to properly transmit and store information, neural networks must be able to compensate for short and long-term changes in internal environment (e.g. sleep/wake cycles, development, aging, and disease) as well rapid changes in external, stimulus-driven inputs. Homeostatic plasticity mechanisms that stabilize neuronal activity in the face of such perturbations have been described in vitro (1), but little is known about their role in stabilizing circuit function in the freely behaving animal. Dysregulation of homeostatic plasticity is widely hypothesized to contribute to debilitating pathologies including Alzheimer's disease (2), Rett syndrome (3), and epilepsy (4), thus an understanding of its role in vivo is critical. It is currently unknown whether neurons and neural networks exhibit homeostatic regulation of spike activity (firing rate homeostasis) and/or complex network properties in the awake and freely behaving animal, a prediction I aim to test in this study by following the activit of individual neocortical neurons over time in the freely behaving rat. First, neuronal activity an the response to activity deprivation will be assessed in the visual cortex of freely behaving and freely viewing juvenile rats. Through the use of genetic manipulations and activity deprivation, the mechanistic role of a well- studied form of homeostatic synaptic plasticity, synaptic scaling, in firing rate homeostasis in vivo will be investigated. Finally, I will exploit a unique feature o this experimental technique to examine the interaction between plasticity mechanisms and behavioral state. Chronic recordings in normally behaving animals enable me to ask whether the expression of homeostatic plasticity is governed by behavior, arousal state, network state (via local field potentials), and circadian factors (5). Characterization of firing rate homeostasi in the normally behaving animal is essential for understanding how neural networks operate. Investigating the contributions of homeostatic plasticity mechanisms such as synaptic scaling to normal brain function is critical for understanding their physiological role. Further, an examination of the role of activity and arousal-state in the expression of homeostatic plasticity will clarify the role of sleep in brain function and plasticity. This knowledge will advance our understanding of basic cellular, systems, and computational neuroscience, as well as provide insight for future investigations of diseases that disrupt neuronal homeostasis. PUBLIC HEALTH RELEVANCE: It is widely hypothesized that dysregulation of homeostatic plasticity is important in the pathogenesis of many neurological disorders, including Alzheimer's disease, epilepsy, and Rett syndrome. In order to begin addressing the role of homeostatic plasticity in disease, it is essential first to understand how homeostatic plasticity of neuronal activity operates in the intact, freely behaving animal. This work will provide the first characterization of homeostatic plasticity in the normally behaving animal, will explore molecular mechanisms of this plasticity, and will determine the expression patterns of homeostatic plasticity as they relate to behavior and activity state.

描述（由申请人提供）：为了正确传输和存储信息，神经网络必须能够补偿内部环境的短期和长期变化（例如睡眠/觉醒周期、发育、衰老和疾病）以及快速变化。外部刺激驱动的输入发生变化。在体外描述了在面临此类扰动时稳定神经元活动的稳态可塑性机制 (1)，但对其在稳定自由行为动物的回路功能中的作用知之甚少。人们普遍认为，稳态可塑性失调会导致包括阿尔茨海默病 (2)、雷特综合征 (3) 和癫痫 (4) 在内的衰弱性疾病，因此了解其在体内的作用至关重要。目前尚不清楚在清醒和自由行为的动物中，神经元和神经网络是否表现出尖峰活动的稳态调节（放电率稳态）和/或复杂的网络特性，我旨在通过跟踪个体新皮质的活动来在本研究中测试这一预测。自由行为大鼠的神经元随时间的变化。首先，将评估自由行为和自由观看的幼年大鼠的视觉皮层的神经元活动和对活动剥夺的反应。通过使用基因操作和活动剥夺，将研究经过充分研究的稳态突触可塑性、突触缩放形式在体内放电率稳态中的机械作用。最后，我将利用这种实验技术的独特功能来检查可塑性机制和行为状态之间的相互作用。正常行为动物的慢性记录使我能够询问稳态可塑性的表达是否受到行为、唤醒状态、网络状态（通过局部场电位）和昼夜节律因素的控制（5）。正常行为动物的放电率稳态特征对于理解神经网络如何运作至关重要。研究突触缩放等稳态可塑性机制对正常大脑功能的贡献对于理解其生理作用至关重要。此外，检查活动和唤醒状态在稳态可塑性表达中的作用将阐明睡眠在大脑功能和可塑性中的作用。这些知识将增进我们对基础细胞、系统和计算神经科学的理解，并为未来研究破坏神经元稳态的疾病提供见解。 公共健康相关性：人们普遍认为，稳态可塑性失调在许多神经系统疾病的发病机制中很重要，包括阿尔茨海默病、癫痫和雷特综合征。为了开始研究稳态可塑性在疾病中的作用，首先必须了解神经元活动的稳态可塑性如何在完整、自由行为的动物中发挥作用。这项工作将首次描述正常行为动物的稳态可塑性，探索这种可塑性的分子机制，并确定稳态可塑性与行为和活动状态相关的表达模式。