Astrocyte-Neuron Network Activity During In Vivo Brain Stimulation

项目摘要 皮质内微刺激（ICMS）是基础神经科学研究的主要组成部分， 在神经修复中的感觉恢复或感觉反馈方面具有巨大的潜力。尽管电的广泛使用 神经修复术中的刺激和干预，如脊髓刺激和脑深部刺激 (DBS)，定义治疗功效的基本生理和机械特性仍然很差 明白例如，目前还不清楚哪些细胞类型被激活，它们在治疗中发挥什么作用， 结果，以及如何调整刺激参数以选择性地引发这些细胞类型中的相关活动， 感觉恢复特别感兴趣的是非神经元细胞如星形胶质细胞的贡献。星形细胞 在感觉处理过程中，它们在调节神经元活动中成为重要细胞， 响应神经递质与钙升高导致神经活性物质的释放，以调节 突触功能（即，胶质传递）。重要的是，星形胶质细胞调节神经元和 突触活动与ICMS诱导的神经活动一致。正是因为这些最近受到赞赏的角色， 关于星形胶质细胞-神经元通讯，星形胶质细胞被认为是大脑的重要组成部分， 刺激.然而，目前尚不清楚星形胶质细胞如何响应临床相关的刺激参数， 网络水平以及这种激活如何随后调节清醒动物的神经元活动。解决 这个知识的差距，这项建议将首先量化皮质星形胶质细胞和跨一个更大的钙活性， ICMS诱导的网络具有不同的频率和时间模式，已知具有不同的治疗效果 使用双光子显微镜和中尺度成像两者的功效。接下来，该提案将量化ICMS- 当星形胶质细胞钙活性选择性增加时，诱导的神经元活性被调节（光遗传学），或 减少（质膜钙泵的病毒转导），以确定星形胶质细胞如何调节 ICMS期间的神经元网络活动。因为星形胶质细胞的钙离子活性调节着这些重要的细胞 调节神经元的活动，这项建议的累积结果将提供有价值的见解的基本 神经科学研究和刺激范式的设计，以引起与感觉神经元相关的星形胶质细胞活动。 修复

PROJECT SUMMARY Intracortical microstimulation (ICMS) is a primary component of fundamental neuroscience research and holds great potential for sensory restoration or sensory feedback in neuroprosthetics. Despite the wide use of electrical stimulation in neuroprosthetics and interventions such as spinal cord stimulation and deep brain stimulation (DBS), the fundamental physiological and mechanistic properties defining therapeutic efficacy remain poorly understood. For example, it is still unclear which cell types are activated, what role they play in therapeutic outcomes, and how to tune stimulation parameters to selectively elicit relevant activity in those cell types for sensory restoration. Of particular interest is the contribution of non-neuronal cells such as astrocytes. Astrocytes are emerging as important cells in the modulation of neuronal activity during sensory processing in which they respond to neurotransmitters with calcium elevations leading to the release of neuroactive substances to regulate synaptic function (i.e., gliotransmission). Importantly, the time scale in which astrocytes modulate neuronal and synaptic activity is consistent with ICMS-induced neural activity. It is because of these recently appreciated roles regarding astrocyte-neuron communication that astrocytes have been suggested as a vital component to brain stimulation. However, it is unclear how astrocytes respond to clinically relevant stimulation parameters on a network level and how that activation subsequently modulates neuronal activity in an awake animal. To address this gap in knowledge, this proposal will first quantify the calcium activity in cortical astrocytes and across a larger network induced by ICMS with different frequencies and temporal patterns known to have differential therapeutic efficacy using both two-photon microscopy and mesoscale imaging. Next, this proposal will quantify how ICMS- induced neuronal activity is modulated when astrocyte calcium activity is selectively increased (optogenetics) or decreased (viral transduction of a plasma membrane calcium pump) to determine how astrocytes regulate neuronal network activity during ICMS. Because astrocyte calcium activity regulates how these important cells modulate neuronal activity, the cumulative results of this proposal will provide valuable insight for fundamental neuroscience research and the design of stimulation paradigms to elicit astrocyte activity relevant to sensory restoration.