Biophysical mechanisms of transient optical stimulation of peripheral nerve
Biophysical mechanisms of transient optical stimulation of peripheral nerve
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DOI：
10.1529/biophysj.107.104786
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发表时间：
2007-10-01
影响因子：
3.4
通讯作者：
Jansen, E. Duco
中科院分区：
文献类型：
--
作者：
Wells, Jonathon;Kao, Chris;Jansen, E. Duco
一种使用低强度，脉冲红外光进行体内神经激活的新方法，通过提供无接触式，空间选择性，无伪影刺激，在标准电气手段上具有优势。在这里，我们通过仔细检查吸收驱动的光组织相互作用后仔细检查可能的光生物学效应来研究这种现象的生物物理机制。用HONMIUM在体内刺激大鼠坐骨神经制剂：Yttrium铝石榴石激光器（2.12 MU M），游离电子激光器（2.1 MU M），Alexandrite Laser（750 nm）和原型固态固态固态激光抑制剂刺激器（750 nm）。我们从合理的相互作用类型列表中系统地确定了相对贡献，导致光刺激，包括热，压力，电场和光化学效应。总体而言，结果支持我们的假设，即用脉冲激光直接神经激活是由热瞬变诱导的。然后，我们提供了表征和量化此必需温度升高的空间和时间性质的数据，包括刺激周围神经所需的测量表面温度变化（6度C -10摄氏度C）。这种相互作用是来自中等瞬态组织加热的光热效应，在轴突水平上的时间和空间介导的温度梯度（3.8摄氏度-6.4度C），导致跨膜离子离子通道的直接或间接激活导致动作电位产生。
A new method for in vivo neural activation using low-intensity, pulsed infrared light exhibits advantages over standard electrical means by providing contact-free, spatially selective, artifact-free stimulation. Here we investigate the biophysical mechanism underlying this phenomenon by careful examination of possible photobiological effects after absorption-driven light-tissue interaction. The rat sciatic nerve preparation was stimulated in vivo with a Holmium: yttrium aluminum garnet laser (2.12 mu m), free electron laser (2.1 mu m), alexandrite laser (750 nm), and prototype solid-state laser nerve stimulator (1.87 mu m). We systematically determined relative contributions from a list of plausible interaction types resulting in optical stimulation, including thermal, pressure, electric field, and photochemical effects. Collectively, the results support our hypothesis that direct neural activation with pulsed laser light is induced by a thermal transient. We then present data that characterize and quantify the spatial and temporal nature of this required temperature rise, including a measured surface temperature change required for stimulation of the peripheral nerve (6 degrees C -10 degrees C). This interaction is a photothermal effect from moderate, transient tissue heating, a temporally and spatially mediated temperature gradient at the axon level (3.8 degrees C -6.4 degrees C), resulting in direct or indirect activation of transmembrane ion channels causing action potential generation.