大鼠的 GCaMP6 光纤光度测定法和 fMRI 的同步检测。
Simultaneous GCaMP6-based fiber photometry and fMRI in rats.
机构信息
Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States; The Huck Institutes of Life Sciences, The Pennsylvania State University, University Park, PA, 16802, United States; Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, 200031 China.
Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, United States.
出版信息
J Neurosci Methods. 2017 Sep 1;289:31-38. doi: 10.1016/j.jneumeth.2017.07.002. Epub 2017 Jul 4.
BACKGROUND
Understanding the relationship between neural and vascular signals is essential for interpretation of functional MRI (fMRI) results with respect to underlying neuronal activity. Simultaneously measuring neural activity using electrophysiology with fMRI has been highly valuable in elucidating the neural basis of the blood oxygenation-level dependent (BOLD) signal. However, this approach is also technically challenging due to the electromagnetic interference that is observed in electrophysiological recordings during MRI scanning.
NEW METHOD
Recording optical correlates of neural activity, such as calcium signals, avoids this issue, and has opened a new avenue to simultaneously acquire neural and BOLD signals.
RESULTS
The present study is the first to demonstrate the feasibility of simultaneously and repeatedly acquiring calcium and BOLD signals in animals using a genetically encoded calcium indicator, GCaMP6. This approach was validated with a visual stimulation experiment, during which robust increases of both calcium and BOLD signals in the superior colliculus were observed. In addition, repeated measurement in the same animal demonstrated reproducible calcium and BOLD responses to the same stimuli.
COMPARISON WITH EXISTING METHOD(S): Taken together, simultaneous GCaMP6-based fiber photometry and fMRI recording presents a novel, artifact-free approach to simultaneously measuring neural and fMRI signals. Furthermore, given the cell-type specificity of GCaMP6, this approach has the potential to mechanistically dissect the contributions of individual neuron populations to BOLD signal, and ultimately reveal its underlying neural mechanisms.
CONCLUSIONS
The current study established the method for simultaneous GCaMP6-based fiber photometry and fMRI in rats.
背景
理解神经和血管信号之间的关系对于解释功能磁共振成像（fMRI）结果与潜在神经元活动之间的关系至关重要。通过同时使用电生理学和 fMRI 测量神经活动，对于阐明血氧水平依赖（BOLD）信号的神经基础非常有价值。然而，由于在 MRI 扫描期间观察到的电磁干扰，这种方法在技术上也具有挑战性。
新方法
记录神经活动的光学相关物，如钙信号，可避免此问题，并为同时获取神经和 BOLD 信号开辟了新途径。
结果
本研究首次证明了使用基因编码钙指示剂 GCaMP6 在动物中同时和重复获取钙和 BOLD 信号的可行性。该方法通过视觉刺激实验得到验证，在此实验中，观察到上丘中钙和 BOLD 信号的强烈增加。此外，在同一动物中进行重复测量表明，对相同刺激的钙和 BOLD 反应具有可重复性。
与现有方法的比较
总的来说，基于 GCaMP6 的光纤光度法和 fMRI 记录的同步测量提供了一种新颖的、无伪影的方法来同时测量神经和 fMRI 信号。此外，鉴于 GCaMP6 的细胞类型特异性，该方法有可能从机制上剖析单个神经元群体对 BOLD 信号的贡献，并最终揭示其潜在的神经机制。
结论
本研究在大鼠中建立了基于 GCaMP6 的光纤光度法和 fMRI 的同步测量方法。
Zotero 插件