A glass-coated tungsten microelectrode enclosing optical fibers for optogenetic exploration in primate deep brain structures
A glass-coated tungsten microelectrode enclosing optical fibers for optogenetic exploration in primate deep brain structures
复制标题
DOI：
10.1016/j.jneumeth.2012.08.004
复制
发表时间：
2012-10-15
影响因子：
3
通讯作者：
Miyashita, Yasushi
中科院分区：
文献类型：
--
作者：
Tamura, Keita;Ohashi, Yohei;Miyashita, Yasushi
灵长类动物脑回路的光遗传学方法具有无与伦比的潜力，可以揭示高级脑功能的遗传和时间分辨的神经元机制。为了对光遗传学研究大型复杂的灵长类动物大脑，必须将光/电探针或“光极”深深插入，这要求光极不仅长且硬，而且锋利且光滑，以减少可能的组织损伤。本研究提出了一种基于钨微电极的光极，其绝缘玻璃内封装光纤。光纤和钨丝紧紧地绑在一起，并涂上一层光滑的薄玻璃。该设计满足了用于脑深部结构的结构要求。然后在注射了携带通道视紫红质-2-增强黄色荧光蛋白（ChR 2-EYFP）转基因的慢病毒载体的大鼠和猕猴的丘脑中检查光极的性能。通过光纤的荧光测量，ChR 2-EYFP表达在体内被清楚地检测到，这通过大鼠的组织学分析得到证实。通过光刺激和细胞外记录，在猴子中分离出光响应的单单位活动。这些单位的深度分布和EYFP荧光谱的峰彼此一致地重叠。因此，通过开发新的探针，光遗传学方法成功地应用于灵长类动物皮层下结构。这种光滑的玻璃涂层光极是一种很有前途的工具，用于各种研究目标的长期体内实验，包括行为猴子的深部脑结构。(C)2012爱思唯尔有限公司版权所有。
The optogenetic approach to primate brain circuitry has unparalleled potential for uncovering genetically and temporally resolved neuronal mechanisms of higher brain functions. In order to optogenetically investigate the large and complex primate brain, an optical-/electrical probe, or "optrode", must be inserted deeply, which requires the optrode to be not only long and stiff, but also sharp and smooth to reduce possible tissue damage. This study presents a tungsten microelectrode-based optrode that encloses optical fibers within its insulation glass. Optical fibers and a tungsten wire were tightly bound to each other and integrally coated with a smooth, thin layer of glass. This design satisfied the structural requirements for use in deep brain structures. The performance of the optrode was then examined in the thalamus of the rat and macaque monkeys which were injected with lentiviral vectors carrying the channelrhodopsin-2-enhanced yellow fluorescent protein (ChR2-EYFP) transgene. With fluorescence measurements via the optical fiber, ChR2-EYFP expression was detected clearly in vivo, which was confirmed by histological analysis in the rat. With photostimulation and extracellular recording, photo-responsive single-unit activities were isolated in the monkeys. The depth distribution of these units and the peak of the EYFP fluorescence profile overlapped consistently with each other. Thus, by developing a new probe, optogenetic methodology was successfully applied to a primate subcortical structure. This smooth glass-coated optrode is a promising tool for chronic in vivo experiments with various research targets including deep brain structures in behaving monkeys. (C) 2012 Elsevier B.V. All rights reserved.