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在双光子电压成像上的光学约束
F Phil Brooks1, Hunter C Davis1, J David Wong-Campos1
1Harvard University, Department of Chemistry and Chemical Biology, Cambridge, Massachusetts, United States.
Neurophotonics
|August 14, 2024
概括
在体内,双光子 (2P) 电压成像需要比单光子 (1P) 成像更多的照明功率,同时记录只限于少数神经元. 对大脑深处许多神经元的高SNR 2P成像,需要在遗传编码电压指示器 (GEVI) 或新型成像技术方面取得进展.
科学领域:
- 神经科学是一个神经科学.
- 生物物理学的生物物理.
- 光学成像技术的成像
背景情况:
- 在体内神经电路研究中,基因编码的电压指示器 (GEVIs) 是至关重要的.
- 一光子 (1P) 和两光子 (2P) 电压成像的比较性能仍然不太清楚.
研究的目的:
- 描述1P和2P电压成像的光学和生物物理限制.
- 为了比较常见的GEVI在1P和2P激发下的成像特性.
主要方法:
- 在1P和2P照明下测量了GEVI的亮度和电压灵敏度.
- 评估光衰变与深度在小鼠大脑组织.
- 开发了一个模型来预测可测量的细胞,基于记者属性,成像参数和SNR.
主要成果:
- 对于相似的光子速率,2P激发要求每单元显著更高的照明功率,而不是1P.
- 使用当前的技术,在小鼠皮质中的2P电压成像 (1kHz带宽,200mW激光,500μm深度,SNR 10) 可以成像最多100个神经元.
结论:
- 现有的GEVI表现出适度的电压敏感性,在2P电压成像中创建了射击噪声和光损伤之间的权衡.
- 实现深度数百个神经元的高SNR2P成像,需要在GEVIs或创新的成像方法中进行实质性改进.
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