In vivo calcium imaging from dentate granule cells with wide-field fluorescence microscopy

• Published in: PloS one Vol. 12; no. 7; p. e0180452
• Main Authors: Hayashi, Yuichiro, Yawata, Satoshi, Funabiki, Kazuo, Hikida, Takatoshi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.07.2017; Public Library of Science (PLoS)
• Subjects: Animals; Biology and Life Sciences; Brain research; Calcium; Calcium imaging; Calcium Signaling; Coding; Data processing; Dentate gyrus; Dentate Gyrus - cytology; Dentate Gyrus - metabolism; Dentate Gyrus - physiology; Engineering and Technology; Fluorescence; Fluorescence microscopy; Granule cells; Image processing; Image segmentation; Independent component analysis; Indicators; Laboratories; Lenses; Medicine and Health Sciences; Methods; Mice; Mice, Inbred C57BL; Micro-optics; Micrometers; Microscopy; Neuroimaging - instrumentation; Neuroimaging - methods; Neurons; Neurons - metabolism; Neurons - physiology; Neurophysiology; Numerical aperture; Optical Imaging - instrumentation; Optical Imaging - methods; Optical sectioning; Optics; Research and Analysis Methods; Rodents; University graduates; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0180452

A combination of genetically-encoded calcium indicators and micro-optics has enabled monitoring of large-scale dynamics of neuronal activity from behaving animals. In these studies, wide-field microscopy is often used to visualize neural activity. However, this method lacks optical sectioning capability, and therefore its axial resolution is generally poor. At present, it is unclear whether wide-field microscopy can visualize activity of densely packed small neurons at cellular resolution. To examine the applicability of wide-field microscopy for small-sized neurons, we recorded calcium activity of dentate granule cells having a small soma diameter of approximately 10 micrometers. Using a combination of high numerical aperture (0.8) objective lens and independent component analysis-based image segmentation technique, activity of putative single granule cell activity was separated from wide-field calcium imaging data. The result encourages wider application of wide-field microscopy in in vivo neurophysiology.