Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, 21224, USA.
School of Electrical Engineering and Computer Science, University of North Dakota, Grand Forks, ND, 58202, USA.
Sci Rep. 2022 Oct 6;12(1):16686. doi: 10.1038/s41598-022-21022-9.
Miniature fluorescence microscopes are becoming an increasingly established tool to investigate neural circuits in freely moving animals. In this work we present a lightweight one-photon microscope capable of imaging at different focal depths. The focal plane can be changed dynamically by modulating the pulse width of the control signal to a variable focus liquid lens, which is synchronized to the image sensor to enable changing focal plane between frames. The system was tested by imaging GCaMP7f expressing neurons in the mouse medial prefrontal cortex (mPFC) in vivo during open field test. Results showed that with the proposed design it is possible to image neurons across an axial scan of ~ 60 μm, resulting in a ~ 40% increase of total neurons imaged compared to single plane imaging.
微型荧光显微镜正逐渐成为一种研究自由活动动物神经回路的常用工具。在这项工作中，我们提出了一种能够在不同焦点深度进行成像的轻量级单光子显微镜。通过调制控制信号的脉冲宽度来改变可变焦液体透镜的焦点平面，该透镜与图像传感器同步，从而实现了在帧之间改变焦点平面。该系统通过在开放式场测试中对表达 GCaMP7f 的小鼠内侧前额叶皮层 (mPFC) 中的神经元进行成像进行了测试。结果表明，通过所提出的设计，可以对大约 60μm 的轴向扫描进行成像，与单平面成像相比，可增加大约 40%的总成像神经元数量。
