Department of Otolaryngology, Northwestern University, Chicago, IL 60611, USA.
J Neural Eng. 2011 Oct;8(5):056006. doi: 10.1088/1741-2560/8/5/056006. Epub 2011 Aug 10.
Infrared neural stimulation (INS) has received considerable attention over the last few years. It provides an alternative method to artificially stimulate neurons without electrical current or the introduction of exogenous chromophores. One of the primary benefits of INS could be the improved spatial selectivity when compared with electrical stimulation. In the present study, we have evaluated the spatial selectivity of INS in the acutely damaged cochlea of guinea pigs and compared it to stimulation with acoustic tone pips in normal-hearing animals. The radiation was delivered via a 200 µm diameter optical fiber, which was inserted through a cochleostomy into the scala tympani of the basal cochlear turn. The stimulated section along the cochlear spiral ganglion was estimated from the neural responses recorded from the central nucleus of the inferior colliculus (ICC). ICC responses were recorded in response to cochlear INS using a multichannel penetrating electrode array. Spatial tuning curves (STCs) were constructed from the responses. For INS, approximately 55% of the activation profiles showed a single maximum, ∼22% had two maxima and ∼13% had multiple maxima. The remaining 10% of the profiles occurred at the limits of the electrode array and could not be classified. The majority of ICC STCs indicated that the spread of activation evoked by optical stimuli is comparable to that produced by acoustic tone pips.
近红外神经刺激（INS）在过去几年中受到了相当多的关注。它提供了一种替代方法，可以在不使用电流或引入外源性生色团的情况下人为地刺激神经元。与电刺激相比，INS 的一个主要优点可能是改善了空间选择性。在本研究中，我们评估了 INS 在豚鼠急性损伤耳蜗中的空间选择性，并将其与正常听力动物的声刺激进行了比较。辐射通过 200µm 直径的光纤传输，光纤通过鼓室切开术插入基底耳蜗转的鼓阶。根据从中耳下丘中央核记录的神经反应来估计耳蜗 INS 刺激的刺激段。使用多通道穿透电极阵列记录 ICC 反应。从反应中构建空间调谐曲线（STC）。对于 INS，大约 55%的激活曲线显示单个最大值，约 22%有两个最大值，约 13%有多个最大值。其余 10%的曲线发生在电极阵列的极限处，无法分类。大多数 ICC STC 表明，光学刺激引起的激活扩散与声刺激产生的扩散相当。
