Enhancing the photostimulation kinetics of channelrhodopsin-2 encoded neurons

增强通道视紫红质 2 编码神经元的光刺激动力学

• 批准号: BB/F021127/1
• 负责人: Patrick Degenaar
• 金额: $ 42.91万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FF021127%2F1
• 关键词: Enhancing; photostimulation; kinetics; channelrhodopsin; encoded

This proposal aims to investigate a technique to induce electrical activity in neurons with optical means, which has many advantages over present electrical approaches. This work aims to better characterize and improve the kinetics of the light sensitization agent. Electrophysiology itself dates back to the early work by Luigi Galvani who began investigating the effect of electrical stimuli on frog's legs in 1766. Since then, the field has improved with the advent of patch clamp techniques, in-vivo multi-site stimulation electrodes and commercial in-vitro microelectrode arrays. Also, the application has broadened from basic neuroscience to prosthetic applications. Cochlear implants and heart pacemakers have been available for many years. There are however drawbacks to electronic stimulation in-vivo. The electrodes in many cases can degrade, and the electrodes can get fouled or covered with layers of dead tissue decreasing their efficiency. At a basic neuroscience level, large electrical pulses will mask any signally during their moment of stimulus, making certain types of experiments more difficult. Thus if we can optically stimulate neurons, there could be many advantages. There have been attempts at optical neural stimulation for some time, but the field has been significantly advanced with the discoveries of novel opsin membrane proteins; Melanopsin in 1998 and Channelrhodopsin in 2003. Channelrhodopsin (Chr2) has shown particular promise. It is a simple light gated ion channel that opens when illuminated with blue (470nm peak) light. Previous work has shown it engineered both in-vitro and in-vivo. However, there has been a uniform barrier in these publications to stimulate the neurons beyond a rate of 50 spikes per second compared to around 1000Hz, to which they are capable. This proposal aims to fully experimentally characterize the kinetics of the ChR2 via spectroscopy and photostimulated electrical recordings. We have access to novel LED array technology through our collaborators which we will use to investigate the contribution of multiple subcellular components to the electrical signal. We then want to use the experimental findings to build a model of what ultimately ChR2 is and is not capable of.

该提案旨在研究一种利用光学手段诱导神经元电活动的技术，该技术比现有的电方法具有许多优点。这项工作旨在更好地表征和改善光敏化剂的动力学。电生理学本身可以追溯到 Luigi Galvani 的早期工作，他于 1766 年开始研究电刺激对青蛙腿的影响。从那时起，随着膜片钳技术、体内多部位刺激电极和商业体外微电极阵列的出现，该领域得到了进步。此外，该应用已从基础神经科学扩展到假肢应用。人工耳蜗和心脏起搏器已经面世多年。然而体内电子刺激也有缺点。在许多情况下，电极可能会降解，并且电极可能会被污染或被死组织层覆盖，从而降低其效率。在基本的神经科学水平上，大的电脉冲会掩盖刺激时刻的任何信号，使某些类型的实验变得更加困难。因此，如果我们能够以光学方式刺激神经元，将会有很多优势。人们对光学神经刺激的尝试已经有一段时间了，但随着新型视蛋白膜蛋白的发现，该领域已经取得了显着的进步。 1998 年的黑视蛋白和 2003 年的视紫红质通道蛋白。视紫红质通道蛋白 (Chr2) 表现出了特别的前景。它是一个简单的光门控离子通道，在蓝色（470nm 峰值）光照射下打开。之前的研究表明它可以在体外和体内进行设计。然而，这些出版物中存在一个统一的障碍，即刺激神经元的速率超过每秒 50 个尖峰，而它们能够达到的频率约为 1000Hz。该提案旨在通过光谱学和光刺激电记录充分实验表征 ChR2 的动力学。我们可以通过合作者获得新颖的 LED 阵列技术，我们将利用该技术来研究多个亚细胞成分对电信号的贡献。然后，我们希望利用实验结果建立一个模型，了解 ChR2 最终能做什么和不能做什么。