Interrogating the propagation of electrical stimulation across scales in vivo

项目摘要 脑电刺激(EBS)仍然是临床和临床研究的中心方法。 几种动物模型系统。然而，人们实际上对神经元激活的集合知之甚少。 典型的和临床的颅内EBS方案。这些刺激方案通常需要反复试验 学习阶段(在侵入性神经外科手术中和之后)以确定刺激参数是什么 有效的，如果有的话，是有效的。为什么一些刺激模式在临床上起作用仍然是个谜。 而其他人则没有，以及各种刺激模式激活了哪些潜在的合奏。 已知，局灶性电刺激激活附近的可兴奋膜，包括神经 胞体、树突和轴突。同样已知的是，招募的神经元集合可能是局部非 临床效果可能更多地依赖于传代轴突而不是躯体刺激。努力实现 模型EBS不能克服我们目前在关于局部传播的同质性和 全脑范围的激活程度。这种模糊性要求对当地电场有更详细的了解。 繁殖，特别是在活体哺乳动物的大脑中。利用最近的技术进步，我们建议 用高密度的电生理监测和时间上的精确来填补这些空白 荧光标记方法，以高空间分辨率量化临床相关的激活模式 和细胞类型特异性。 在这里，我们提出了一项在小鼠身上进行的实验研究，基于小鼠大脑的生物物理模型。 大脑皮层，通过局灶性EBS激活的时空传播。这项研究将检验这一假设 局部电刺激是非各向同性的，是细胞类型特异性的。我们建议测量EBS的刺激 有1000多个电极三维排列在刺激部位周围，结合 通过光学标记进行遗传细胞类型识别(目标1)。以不可知的方式隔离激活的全脑集合 通过EBS，我们将荧光报告与电刺激相结合，用于体外全脑组织清除和 光片成像(目标2)。

Project Summary Intracranial electrical brain stimulation (EBS) remains a central method in the clinic as well as for research in several animal model systems. However, little is actually known about the ensembles of neurons activated by typical and clinical intracranial EBS protocols. These stimulation protocols often require a trial-and-error learning period (during and after invasive neurosurgery) to determine what stimulation parameters are effective, if any at all are effective. It remains mysterious why some stimulation patterns work in the clinic while others do not, and what underlying ensembles are activated by various stimulation patterns. It is known that focal electrical microstimulation activates nearby excitable membranes, including neural somas, dendrites, and axons. It is also known that the recruited ensemble of neurons may be locally non- homogenous and that clinical effects may rely more on axons of passage than somatic stimulation. Efforts to model EBS cannot overcome our current gaps in knowledge about the homogeneity of local propagation and brain-wide extent of activation. This ambiguity demands a more detailed understanding of local electric field propagation, particularly in the in vivo mammalian brain. Utilizing recent technological advances, we propose to fill these gaps empirically with high density electrophysiological monitoring and temporally precise fluorescent labeling methods, to quantify clinically relevant activation patterns with high spatial resolution and cell-type specificity. Here we propose an experimental study in mice, based on a biophysically realistic model of mouse cerebral cortex, of the spatial and temporal propagation of activation via focal EBS. The study will test the hypothesis that local electrical stimulation is non-isotropic and cell-type specific. We propose to measure EBS stimulation with more than 1000 electrodes arranges in three dimensions around a site of stimulation, in combination with genetic cell type identity through optotagging (Aim 1). To agnostically isolate brain-wide ensembled activated by EBS, we couple a fluorescent reporter to electrical stimulation for ex vivo whole-brain tissue clearing and light sheet imaging (Aim 2).