Sensory gating, where responses to stimuli during sensor motion are reduced in amplitude, is a hallmark of active sensing systems. In the rodent whisker system, sensory gating has been described only at the thalamic and cortical stages of sensory processing. However, does sensory gating originate at an even earlier synaptic level? Most importantly, is sensory gating under top-down or bottom-up control? To address these questions, we used an active touch task in behaving rodents while recording from the trigeminal sensory nuclei. First, we show that sensory gating occurs in the brainstem at the first synaptic level. Second, we demonstrate that sensory gating is pathway-specific, present in the lemniscal but not in the extralemniscal stream. Third, using cortical lesions resulting in the complete abolition of sensory gating, we demonstrate its cortical dependence. Fourth, we show accompanying decreases in whisking-related activity, which could be the putative gating signal.

中文翻译：

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大鼠晶须系统中主动触摸过程中感觉流的皮质调节。

传感门控是传感器在运动过程中对刺激的响应幅度减小的一种方法，它是主动传感系统的标志。在啮齿动物的晶须系统中，仅在丘脑和皮质的感觉处理阶段对感觉门控进行了描述。但是，感觉门控是否起源于更早的突触水平？最重要的是，感觉门控是在自上而下还是自下而上的控制之下？为了解决这些问题，我们在记录三叉神经感觉核的过程中使用了主动接触行为来表现啮齿动物的行为。首先，我们表明感觉门控发生在第一个突触水平的脑干中。其次，我们证明感觉门控是通路特异性的，存在于双侧脑膜而非双侧脑膜流中。第三，利用皮层病变完全消除感觉门控，我们证明了它对皮层的依赖性。第四，我们显示了与打蛋相关的活动的伴随减少，这可能是推测的门控信号。