Investigating Neural Processing of Cerebrovascular Dynamics via Calcium Imaging of Vascular Cells and Neurons, and by Optogenetic Vascular Pertubation, In Vivo

项目摘要 了解神经血管通讯对临床和基础研究至关重要。血管周围神经元 (PVN)活动可以驱动脑血管动力学。然而，血管事件对神经系统的影响 对这一活动的调查很少。我们的实验室已经发现， 躯体感觉皮层（SI）在体内编码脑血管活动。然而，这种编码的性质及其 解剖学组织，是未经检验的。血管-PVN信号传导可支持血管稳态和丰富的 跨系统通信。这些信号与使用血流来绘制神经活动的研究有关 (e.g., fMRI）。研究这种信号的扰动可能阐明脑血管疾病的机制。 功能障碍（例如，如局部缺血、帕金森病和MS）。 为了分析PVN对血管活动的编码，我将使用在体神经和血管的双光子成像， 细胞和光遗传学来扰动血管并分析PVN反应。在目标一中，我将检验假设 血管编码PVN在SI中普遍存在，它们的活动由皮质层和血管组织组成。 通过在神经元中表达钙指示剂（jRGECO 1a）和在血管内皮细胞中表达钙指示剂（GCaMP 6 f）， 同时拍摄他们的活动我的初步数据确定了在空间上不同的钙事件， 预测随后PVN活动的血管信号。在该范例中，血管响应PVN的频率 将根据它们的固定活动和解剖位置进行分类。我们实验室的初步数据还表明， 显示选择性光遗传血管驱动可以调节PVN活性。在目标II中，我将检验这个假设 由光遗传学诱发的血管直径变化驱动的PVN也将通过以下方式在解剖学上组织： 它们的活性、它们对内源性血管事件的反应将与它们对光遗传学的反应平行。 血管驱动我将通过驱动内皮通道视紫红质， 他们与平滑肌盐视紫红质，并唤起自然触觉驱动的功能性充血，以分析 表达GCaMP 6的PVN的反应。在目标III中，我将检验PVN对以下假设的反应： 光遗传学驱动的血管活性可被TRPV 4和腺苷A1受体干扰 拮抗剂，但它们可能不受阻断谷氨酸能信号传导的影响。我将测试这个预测， 如在Aim II中那样引起PVN对光遗传血管活性的响应，并且通过将SI皮质暴露于受体 对手。 培训环境：该项目将在布朗大学进行三年 克里斯托弗摩尔博士指导下的神经科学研究生课程。研究培训计划 包括教学专业，技术和科学写作培训，以及动手技术研讨会。

PROJECT SUMMARY Understanding neural-vascular communication is vital to clinical and basic research. Perivascular neuron (PVN) activity can drive cerebral blood vessel dynamics. However, the impact of vascular events on neural activity has been only sparsely investigated. Our lab has found that a population of PVNs in primary somatosensory cortex (SI) encode cerebrovascular activity in vivo. However, the nature of this encoding, and its anatomical organization, is untested. Vessel-to-PVN signaling may support vascular homeostasis and rich communication across systems. These signals are relevant for research using blood flow to map neural activity (e.g., fMRI). Investigating perturbations of this signaling may elucidate mechanisms of cerebrovascular disfunction (e.g., as in ischemia, Parkinson’s Disease, and M.S.). To analyze PVN encoding of vascular activity, I will use in vivo two-photon imaging of neural and vascular cells, and optogenetics to perturb vessels and analyze the PVN response. In Aim I, I will test the hypothesis that vascular-encoding PVNs occur commonly in SI, and their activity is organized by cortical layer and vascular compartment, by expressing calcium indicators (jRGECO1a) in neurons and (GCaMP6f) in vascular endothelia to image their activity simultaneously. My preliminary data identified spatially distinct calcium events in the vascular signal that predict subsequent PVN activity. In this paradigm, the frequency of vessel responsive PVNs will be categorized by their stereotyped activity and anatomical location. Preliminary data in our lab has also shown that selective optogenetic vascular drive can modulate PVN activity. In Aim II, I will test the hypothesis that PVNs driven by optogenetically evoked vascular diameter changes will also be organized anatomically by their activity, that and their response to endogenous vascular events will parallel their response to optogenetic vascular drive. I will optogenetically constrict SI blood vessels by driving endothelial channelrhodopsin, dilate them with smooth muscle halorhodopsin, and evoke natural tactile driven functional hyperemia, to analyze the responses of PVNs expressing GCaMP6s. In Aim III, I will test the hypothesis that PVN responses to optogenetically driven vascular activity can be pharmacologically perturbed by TRPV4 and adenosine A1 receptor antagonists, but that they are likely unaffected by blocking glutamatergic signaling. I will test this prediction by evoking PVN responses to optogenetic vascular activity as in Aim II, and by exposing SI cortex to receptor antagonists. Training Environment: This project will take place over three years in the Brown University Neuroscience Graduate Program under the mentorship of Dr. Christopher Moore. The Research Training Plan includes didactic professional, technical, and science writing training, as well as hands-on technical seminars.