Oyama Kotaro, Zeeb Vadim, Kawamura Yuki, Arai Tomomi, Gotoh Mizuho, Itoh Hideki, Itabashi Takeshi, Suzuki Madoka, Ishiwata Shin'ichi
Department of Physics, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Department of Cell Physiology, The Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan.
Sci Rep. 2015 Nov 16;5:16611. doi: 10.1038/srep16611.
Optical microheating is a powerful non-invasive method for manipulating biological functions such as gene expression, muscle contraction, and cell excitation. Here, we demonstrate its potential usage for regulating neurite outgrowth. We found that optical microheating with a water-absorbable 1,455-nm laser beam triggers directional and explosive neurite outgrowth and branching in rat hippocampal neurons. The focused laser beam under a microscope rapidly increases the local temperature from 36 °C to 41 °C (stabilized within 2 s), resulting in the elongation of neurites by more than 10 μm within 1 min. This high-speed, persistent elongation of neurites was suppressed by inhibitors of both microtubule and actin polymerization, indicating that the thermosensitive dynamics of these cytoskeletons play crucial roles in this heat-induced neurite outgrowth. Furthermore, we showed that microheating induced the regrowth of injured neurites and the interconnection of neurites. These results demonstrate the efficacy of optical microheating methods for the construction of arbitrary neural networks.
光学微加热是一种用于操纵生物功能（如基因表达、肌肉收缩和细胞兴奋）的强大非侵入性方法。在此，我们展示了其在调节神经突生长方面的潜在用途。我们发现，用可吸收水的1455纳米激光束进行光学微加热会触发大鼠海马神经元中定向且爆发性的神经突生长和分支。显微镜下聚焦的激光束会使局部温度迅速从36°C升高到41°C（在2秒内稳定），导致神经突在1分钟内伸长超过10μm。这种高速、持续的神经突伸长受到微管和肌动蛋白聚合抑制剂的抑制，表明这些细胞骨架的热敏动力学在这种热诱导的神经突生长中起关键作用。此外，我们表明微加热诱导了受损神经突的再生以及神经突的相互连接。这些结果证明了光学微加热方法在构建任意神经网络方面的有效性。
