Voigt Mathias Benjamin, Hubka Peter, Kral Andrej
Institute of AudioNeuroTechnology (VIANNA), Dept. of Experimental Otology, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany; Cluster of Excellence "Hearing4all", Germany.
Institute of AudioNeuroTechnology (VIANNA), Dept. of Experimental Otology, Hannover Medical School, Stadtfelddamm 34, 30625 Hannover, Germany.
Brain Stimul. 2017 May-Jun;10(3):684-694. doi: 10.1016/j.brs.2017.02.009. Epub 2017 Feb 27.
Intracortical microstimulation is one of the most common techniques to causally interfere with neuronal processing, but neuronal recordings spanning the whole cortical depth during stimulation are exceptionally rare.
OBJECTIVE/HYPOTHESIS: Here we combined layer-specific intracortical microstimulation with extracellular recordings on the same shank of a linear multi-electrode array to study the effects of electrical stimulation in different cortical depths on intracortical processing in the auditory cortex in vivo.
Population responses (local field potentials and multi-unit activity) were recorded from the auditory cortex of 8 guinea pigs under ketamine/xylazine anesthesia while single current pulses (charge-balanced, biphasic, square-wave, 0.1-45 μA, 200 μs/phase) were delivered in different cortical depths.
The cortical responses differed with a change in the stimulation parameters, with significant factors being the stimulating current (p < 0.0001), stimulation depth (p = 0.03) and the recording depth (p = 0.002) considering the local field potential amplitude. A cross-correlation analysis between responses evoked by intracortical microstimulation and physiological auditory stimuli revealed the closest match when stimulating the middle granular layer (p < 0.05).
Intracortical response profiles to low-current intracortical microstimulation were layer specific. The most natural cortical response was achieved by stimulation in the thalamo-recipient layer. These findings contribute to a basis for designing cortical neuroprosthetics.
皮层内微刺激是因果性干扰神经元处理过程的最常用技术之一，但在刺激过程中跨越整个皮层深度的神经元记录极为罕见。
目的/假设：在此，我们将层特异性皮层内微刺激与线性多电极阵列同一支杆上的细胞外记录相结合，以研究体内不同皮层深度的电刺激对听觉皮层内处理过程的影响。
在氯胺酮/赛拉嗪麻醉下，从8只豚鼠的听觉皮层记录群体反应（局部场电位和多单位活动），同时在不同皮层深度施加单个电流脉冲（电荷平衡、双相、方波，0.1 - 45 μA，每相200 μs）。
考虑局部场电位幅度时，皮层反应随刺激参数的变化而不同，显著因素包括刺激电流（p < 0.0001）、刺激深度（p = 0.03）和记录深度（p = 0.002）。皮层内微刺激诱发的反应与生理性听觉刺激诱发的反应之间的互相关分析显示，刺激中间颗粒层时匹配度最高（p < 0.05）。
对低电流皮层内微刺激的皮层反应模式具有层特异性。通过在丘脑接受层进行刺激可实现最自然的皮层反应。这些发现为设计皮层神经假体奠定了基础。
