中红外光表现出组织特异性透过率并调节沿轴突的神经信号传导，这一成果由复旦大学舒友生小组经过不懈努力而取得。2025年11月10日出版的《神经科学通报》杂志发表了这项成果。

利用同步辐射红外（SR-FTIR）微光谱技术，研究组系统地绘制了新鲜分离的成年小鼠颅骨组织层和脑组织（灰质和白质）的透射光谱。在光谱采集过程中，通过微流体和充氧人工脑脊液（ACSF）的灌注维持脑组织的活力。该课题组确定了两个相对较高的通过颅骨组织的红外窗口：近红外（NIR）窗口（波长：1.5-3.0 μm）和中红外（MIR）窗口（3.5-6.0 μm）。值得注意的是，与周围的浴液相比，在5.2 ~ 5.7 μm范围内的MIR子带通过神经组织，特别是轴突束的透射率相对较高。

进一步的电生理实验表明，波长为5.6 μm的MIR显著降低了体细胞和轴突动作电位的振幅和持续时间，同时促进了它们沿有髓鞘和无髓鞘轴突的传导速度。总之，这些结果确定了可以穿透颅骨组织层的特定红外波段，并揭示了神经信号的波长特异性调制，为红外神经调节提供了一种有前途的非侵入性策略。

研究人员表示，非侵入性红外（IR）调制需要红外光子穿透多层颅骨屏障，包括皮肤、颅骨和硬脑膜。然而，波长依赖的透射率分布和红外光对神经信号的调制作用仍然知之甚少。

附：英文原文

Title: Mid-Infrared Light Exhibits Tissue-Specific Transmittance and Modulates Neural Signal Conduction Along Axons

Author: Liu, Xi, Wang, Zhuoyi, Qiao, Zhi, Xiao, Yujie, Guo, Hui, Shu, Yousheng

Issue&Volume: 2025-11-10

Abstract: Non-invasive infrared (IR) modulation requires IR photons to penetrate multi-layered cranial barriers, including skin, skull bone, and dura mater. However, the wavelength-dependent transmittance profiles and the modulatory effect of IR light on neural signals remain poorly understood. Using synchrotron radiation Fourier-transform infrared (SR-FTIR) microspectroscopy, we systematically mapped transmittance spectra of freshly isolated cranial tissue layers and brain tissues (gray matter and white matter) obtained from adult mice. The viability of brain tissue was maintained through microfluidic and oxygenated artificial cerebrospinal fluid (ACSF) perfusion during spectral acquisition. We identified two IR windows with relatively high transmittance through cranial tissues: a near-infrared (NIR) window (wavelength: 1.5–3.0 μm) and a mid-infrared (MIR) window (3.5–6.0 μm). Notably, the MIR sub-band ranging from 5.2 to 5.7 μm exhibited a relatively higher transmittance through neural tissue, particularly in axon bundles, compared to the surrounding bath solution. Further electrophysiological experiments revealed that MIR with a wavelength of 5.6 μm substantially decreased the amplitude and duration of both somatic and axonal action potentials, while simultaneously facilitating their conduction velocity along both myelinated and unmyelinated axons. Together, these results identify specific IR bands that can penetrate the cranial tissue layers and reveal a wavelength-specific modulation of neural signals, providing a promising non-invasive strategy for IR neuromodulation.

DOI: 10.1007/s12264-025-01542-w

Source: https://link.springer.com/article/10.1007/s12264-025-01542-w