Northwestern University, Feinberg School of Medicine, Department of Otolaryngology, Chicago, Illinois 60611, USA.
J Biomed Opt. 2011 Nov;16(11):118002. doi: 10.1117/1.3655590.
Artificial neural stimulation is widely used in clinic, rehabilitation, and research. One of the limitations of electrical stimulation is the current spread in tissue. Recently, pulsed mid-infrared laser stimulation of nerves has been investigated as an alternative stimulation method. The likely benefits of infrared neural stimulation (INS) include spatial selectivity of stimulation, noncontact mode of operation, and the lack of stimulation artifact in simultaneous electrical recordings. The hypothesis for this study is that INS of the cochlear spiral ganglion at low pulse energy is as spatially selective as low-level tonal stimulation of the cochlea. Spatial selectivity was measured using a masking method. An optical pulse with fixed optical parameters was delivered through a 200-μm diameter optical fiber. An acoustic tone, variable in frequency and level, was presented simultaneously with the optical pulse. Tone-on-light masking in gerbils revealed tuning curves with best frequencies between 5.3 and 11.4 kHz. The width of the tone-on-light tuning curves was similar to the width of tone-on-tone tuning curves. The results indicate that the spatial area of INS in the gerbil cochlea is similar to the cochlear area excited by a low level acoustic tone, showing promising results for future use of INS in implantable cochlear prostheses.
人工神经刺激在临床、康复和研究中得到了广泛应用。电刺激的一个局限性是电流在组织中的扩散。最近，已经研究了脉冲中红外激光刺激神经作为替代刺激方法。红外神经刺激（INS）的可能益处包括刺激的空间选择性、非接触操作模式以及在同时进行的电记录中缺乏刺激伪影。本研究的假设是，低脉冲能量下 INS 对耳蜗螺旋神经节的刺激与耳蜗的低水平音调刺激一样具有空间选择性。使用掩蔽方法测量空间选择性。通过 200-μm 直径的光纤传输具有固定光学参数的光脉冲。同时呈现可变频率和水平的声音。在沙鼠中进行的光音掩蔽实验揭示了最佳频率在 5.3 到 11.4 kHz 之间的调谐曲线。光音调谐曲线的宽度与音音调谐曲线的宽度相似。结果表明，在沙鼠耳蜗中 INS 的空间区域与由低水平声刺激激发的耳蜗区域相似，这为未来在植入式耳蜗假体中使用 INS 提供了有希望的结果。
