Synthesis of voltage-sensitive optical signals: Application to panoramic optical mapping
Synthesis of voltage-sensitive optical signals: Application to panoramic optical mapping
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DOI：
10.1529/biophysj.105.076505
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发表时间：
2006-04-01
影响因子：
3.4
通讯作者：
Gavaghan, DJ
中科院分区：
文献类型：
--
作者：
Bishop, MJ;Rodriguez, B;Gavaghan, DJ
已知荧光光子散射会扭曲心脏跨膜电位的光学记录；然而，这一过程没有很好地量化，阻碍了对实验数据的解释。本研究提出了一种新颖的模型，可以准确地合成兔子心室不规则几何形状的荧光记录。利用该模型，本研究的目的是为制备和周围介质的不同光学特性提供荧光信号畸变的量化。电活动的双域表示与模拟激发和发射过程的光子扩散方程的有限元解相结合，以及在心外膜处的物理现实边界条件，允许模拟不同的实验设置。我们证明，由于荧光光子散射导致的光信号失真是一种真正的三维现象，并且主要取决于制备的几何形状、组织的散射特性、波前传播的方向和实验装置的具体情况。重要的是，我们表明，在解剖精确的心室几何和纤维方向模型中，光信号的形态不能提供关于波前传播的内部方向的可靠信息。这些发现强调了新模型在解释实验数据方面的潜力。
Fluorescent photon scattering is known to distort optical recordings of cardiac transmembrane potentials; however, this process is not well quantified, hampering interpretation of experimental data. This study presents a novel model, which accurately synthesizes fluorescent recordings over the irregular geometry of the rabbit ventricles. Using the model, the study aims to provide quantification of fluorescent signal distortion for different optical characteristics of the preparation and of the surrounding medium. A bi-domain representation of electrical activity is combined with finite element solutions to the photon diffusion equation simulating both the excitation and emission processes, along with physically realistic boundary conditions at the epicardium, which allow simulation of different experimental setups. We demonstrate that distortion in the optical signal as a result of fluorescent photon scattering is truly a three-dimensional phenomenon and depends critically upon the geometry of the preparation, the scattering properties of the tissue, the direction of wavefront propagation, and the specifics of the experimental setup. Importantly, we show that in an anatomically accurate model of ventricular geometry and fiber orientation, the morphology of the optical signal does not provide reliable information regarding the intramural direction of wavefront propagation. These findings underscore the potential of the new model in interpreting experimental data.