Ultrasonic modulation of cellular electrical signaling

超声（US）神经调节（NM）利用来自声音的机械能通过机械敏感离子通道（MSIC）调节可兴奋细胞的生理学。其非侵入性的骨穿透性质与独特的聚焦能力相结合，提供了优于光遗传学和化学遗传学的优势。最近，FDA批准了经颅USNM。对于US如何调节细胞兴奋性缺乏分子理解。此外，并非所有细胞都表达对US作出反应的通道。为了解决这些问题，将实施新的实验系统和技术，以提取机械生物物理信息和工程师声遗传工具，用于强大的转基因表达。最近的生物物理效应的US对TRAAK K+通道的特点，因为它的潜力，作为一个sonogenetic沉默的神经元。当靶向白色物质中的天然有髓鞘轴突时，TRAAK在郎维叶结的内源性表达也使其成为抑制性NM的有吸引力的候选者。在指导阶段（目标1，K99），将继续在TRAAK和其他通道上表征US的基本生物物理效应。这包括计算张力和测量最佳US参数以最大化通道刺激的实验。初步数据表明CFTR Cl-通道对US敏感。其他MSIC也将被筛选，以确定那些敏感的US。下一个目标（目标2，K99/R 00）旨在将TRAAK和其他MSIC优化为声遗传工具。为了将TRAAK转化为US超敏动作电位发生器，将使用结构导向诱变来增加其对超声的敏感性和对Na+的渗透性。目标3（R 00阶段）旨在通过刺激内源性MSIC和转基因表达的声基因工具来实现NM。它们将在体外小鼠脑切片和培养的神经元中被激活，并在活小鼠体内被激活。总之，该提议着眼于用US筛选和优化内源性MSIC的激活，并且还设计新颖的声基因工具。在短时间内，这项工作将促进我们的理解，美国对MSIC和NM的影响。长期目标是将这些工具用于微创NM的临床应用。这项研究计划将产生一个互补技术和适用知识的平台，也可以被其他人应用于声音遗传学和USNM的进一步研究。Sorum博士的导师，教授。Brohawn和Adesnik拥有跨越神经科学许多领域的专业知识，包括机械生物学，MSIC结构/功能，光遗传学，NM，神经回路和行为。另外两年的培训将使他能够充分发展分子，细胞和系统神经科学方面的技能，并将其与USNM和声音遗传学相结合。

Ultrasound (US) neuromodulation (NM) utilizes mechanical energy from sound to modulate the physiology of excitable cells through mechanosensitive ion channels (MSIC). Its uninvasive bone-penetrating nature combined with a unique focusing capability provides advantages over optogenetics and chemogenetics. Recently, the FDA has approved transcranial USNM. There is a lack of a molecular understanding on how US modulates cellular excitability. Furthermore, not all cells express channels that respond to US. To address these issues, novel experimental systems and techniques will be implemented to extract mechanistic biophysical information and engineer sonogenetic tools for robust transgenic expression. The biophysical effects of US on TRAAK K+ channels were recently characterized because of its potential to serve as a sonogenetic silencer of neurons. The endogenous expression of TRAAK at the nodes of Ranvier also makes it an attractive candidate for inhibitory NM when targeting native myelinated axons in the white matter. During the mentored phase (Aim 1, K99), the fundamental biophysical effects of US will continue to be characterized on TRAAK and other channels. This includes experiments to calculate tension and surveying optimal US parameters to maximize channel stimulation. Preliminary data suggests that the CFTR Cl- channel is sensitive to US. Other MSIC will also be screened to identify those sensitive to US. The next aim (Aim 2, K99/R00) looks to optimize TRAAK and other MSIC into sonogenetic tools. To transform TRAAK into a US-hypersensitive action potential generator, structure guided mutagenesis will be used to increase its sensitivity to ultrasound and permeability to Na+. Aim 3 (R00 phase) looks to implement NM by stimulating endogenous MSIC and transgenically expressed sonogenetic tools. They will be activated in vitro in mouse brain slices and cultured neurons, and in vivo in live mice. In summary, this proposal looks to screen for and optimize the activation of endogenous MSIC with US, and also engineer novel sonogenetic tools. In a short period of time, this work will advance our understanding of the effects of US on MSIC and NM. The long-term goal is to implement these tools for clinical use in minimally invasive NM. This research program will generate a platform of complementary techniques and applicable knowledge that can also be applied by others for further studies in sonogenetics and USNM. Dr. Sorum's mentors, Profs. Brohawn and Adesnik, have expertise that spans many areas of neuroscience including mechanobiology, MSIC structure/function, optogenetics, NM, neural circuits, and behavior. Two additional years of training will allow him to fully develop skills in molecular, cellular and systems neuroscience and merge them with USNM and sonogenetics.