Novel method to assess axonal excitability using channelrhodopsin-based photoactivation.
Novel method to assess axonal excitability using channelrhodopsin-based photoactivation.
复制标题
使用基于视紫红质的光激活评估轴突兴奋性的新方法。
DOI：
10.1152/jn.00982.2014
复制
发表时间：
2015
影响因子：
2.5
通讯作者：
Prescott,StevenA
中科院分区：
文献类型：
--
作者：
Zhu,Yi;Feng,Bin;Schwartz,EricaS;Gebhart,GF;Prescott,StevenA
测量单个轴突的兴奋性由于难以获得细胞内记录而变得复杂。在这里，我们提出了一种创新的方法，使当地的兴奋性进行测量的任何地方在channelrhodopsin（ChR 2）表达神经元。该方法取决于在空间和时间上精确地激活ChR 2，同时从远程站点记录所产生的尖峰序列。我们在初级传入神经元（PAN）中验证了这种方法。躯体感觉刺激的初始编码依赖于将物理刺激转导成受体电位和将受体电位转化成尖峰序列;转化过程取决于最远端PAN末端的兴奋性，但是如上所述，使用传统方法原位研究非常困难。使用ChR 2的光活化，我们显示1）PAN轴突的远端和更近端部分之间的兴奋性不同，2）PAN之间的转化过程不同，和3）转化过程直接受炎症影响。除了提出一种研究轴突兴奋性的创新方法外，这项研究还验证了它在帮助破译体感编码的最早阶段方面的实用性。
Measuring the excitability of individual axons is complicated by the prohibitive difficulty in obtaining intracellular recordings. Here, we present an innovative methodology that enables local excitability to be measured anywhere in a channelrhodopsin (ChR2)-expressing neuron. The approach hinges on activating ChR2 in a spatially and temporally precise manner while recording the resulting spike train from a remote site. We validated this approach in primary afferent neurons (PANs). Initial encoding of somatosensory stimuli relies on transduction of the physical stimulus into a receptor potential and transformation of the receptor potential into a spike train; the transformation process depends on the excitability of the most distal PAN endings but, as explained above, is extraordinarily difficult to study in situ using traditional methods. Using ChR2-based photoactivation, we show1) that excitability differs between the distal endings and more proximal portions of PAN axons,2) that the transformation process differs between PANs, and3) that the transformation process is directly affected by inflammation. Beyond presenting an innovative method by which to study axonal excitability, this study has validated its utility in helping to decipher the earliest stages of somatosensory encoding.