Liu Xiuli, Gong Hui, Li Xiangning, Zhou Wei
Britton Chance Center for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan 430074, PR China.
J Biosci Bioeng. 2008 Feb;105(2):106-9. doi: 10.1263/jbb.105.106.
The calcium ion, a second messenger in the brain, plays key roles in neuronal signaling pathways. Ca(2+) signals in neurons are often highly localized and difficult to measure accurately. The quantification of calcium concentration is thus critical for understanding neuronal signaling. In this study, a yellow cameleon (YC3.60) excited using a 458 nm laser was used to monitor the calcium signals in neurons, and the dynamic range (R(max)/R(min)) of YC3.60 was found to reach 250%. The spatial distribution of calcium and the physiological changes in hippocampal neurons and even in spines were determined by the fluorescence resonance energy transfer (FRET) method. It was proved that cameleon could be used for the quantitative measurement of calcium concentration in neurons. Fluorescence readout of the calcium concentration in neurons by FRET is nondestructive, quantifiable with high spatiotemporal resolution, and even applicable to dendritic spines.
钙离子作为大脑中的第二信使，在神经元信号通路中发挥着关键作用。神经元中的Ca(2+)信号通常高度局部化，难以准确测量。因此，钙浓度的量化对于理解神经元信号至关重要。在本研究中，使用458 nm激光激发的黄色钙指示剂（YC3.60）来监测神经元中的钙信号，发现YC3.60的动态范围（R(max)/R(min)）达到250%。通过荧光共振能量转移（FRET）方法确定了钙的空间分布以及海马神经元甚至树突棘中的生理变化。结果证明，钙指示剂可用于定量测量神经元中的钙浓度。通过FRET对神经元中钙浓度进行荧光读出具有无损性，可在高时空分辨率下进行量化，甚至适用于树突棘。
