In mammals, action potentials fired by rapidly adapting mechanosensitive afferents are known to reliably time lock to the cycles of a vibration. How and where along the ascending neuraxis is the peripheral afferent temporal code transformed into a rate code are currently not clear. Here, we probed the encoding of vibrotactile stimuli with electrophysiological recordings along major stages of the ascending somatosensory pathway in mice. We discovered the main transformation step was identified at the level of the thalamus, and parvalbumin-positive interneurons in thalamic reticular nucleus participate in sharpening frequency selectivity and in disrupting the precise spike timing. When frequency-specific microstimulation was applied within the brainstem, it generated frequency selectivity reminiscent of real vibration responses in the somatosensory cortex and could provide informative and robust signals for learning in behaving mice. Taken together, these findings could guide biomimetic stimulus strategies to activate specific nuclei along the ascending somatosensory pathway for neural prostheses.

中文翻译：

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沿上行体感通路的振动触觉刺激神经编码的转化


在哺乳动物中，已知由快速适应的机械敏感传入神经触发的动作电位可以可靠地将时间锁定到振动的周期。目前尚不清楚外周传入时间代码如何以及在何处转化为速率代码。在这里，我们沿着小鼠上升体感通路的主要阶段用电生理记录探测了振动触觉刺激的编码。我们发现主要的转化步骤是在丘脑水平确定的，丘脑网状核中的小白蛋白阳性中间神经元参与锐化频率选择性和破坏精确的尖峰时间。当在脑干内应用特定频率的微刺激时，它会产生让人想起体感皮层中真实振动反应的频率选择性，并且可以为行为良好的小鼠的学习提供信息和强大的信号。综上所述，这些发现可以指导仿生刺激策略，以激活神经假体沿升行体感通路的特定细胞核。