A new platform for long-term tracking and recording of neural activity and simultaneous optogenetic control in freely behaving Caenorhabditis elegans

作者:Gengyo Ando Keiko; Kagawa Nagamura Yuko; Ohkura Masamichi; Fei Xianfeng; Chen Min; Hashimoto Koichi; Nakai Junichi
来源:Journal of Neuroscience Methods, 2017, 286: 56-68.
DOI:10.1016/j.jneumeth.2017.05.017

摘要

Background: Real-time recording and manipulation of neural activity in freely behaving animals can greatly advance our understanding of how neural circuits regulate behavior. Ca2+ imaging and optogenetic manipulation with optical probes are key technologies for this purpose. However, integrating the two optical approaches with behavioral analysis has been technically challenging. New method: Here, we developed a new imaging system, ICaST (Integrated platform for Ca2+ imaging, Stimulation, and Tracking), which combines an automatic worm tracking system and a fast-scanning laser confocal microscope, to image neurons of interest in freely behaving C. elegans. We optimized different excitation wavelengths for the concurrent use of channelrhodopsin-2 and G-CaMP, a green fluorescent protein (GFP)-based, genetically encoded Ca2+ indicator. Results: Using ICaST in conjunction with an improved G-CaMP7, we successfully achieved long-term tracking and Ca2+ imaging of the AVA backward command interneurons while tracking the head of a moving animal. We also performed all-optical manipulation and simultaneous recording of Ca2+ dynamics from GABAergic motor neurons in conjunction with behavior monitoring. Comparison with existing method(s): Our system differs from conventional systems in that it does not require fluorescent markers for tracking and can track any part of the worm's body via bright-field imaging at high magnification. Consequently, this approach enables the long-term imaging of activity from neurons or nerve processes of interest with high spatiotemporal resolution. Conclusion: Our imaging system is a powerful tool for studying the neural circuit mechanisms of C. elegans behavior and has potential for use in other small animals.

  • 出版日期2017-7-15