Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
Center for Neural Science, New York University, New York, NY, USA.
Nature. 2018 Sep;561(7723):391-395. doi: 10.1038/s41586-018-0520-5. Epub 2018 Sep 12.
Sounds can arise from the environment and also predictably from many of our own movements, such as vocalizing, walking, or playing music. The capacity to anticipate these movement-related (reafferent) sounds and distinguish them from environmental sounds is essential for normal hearing, but the neural circuits that learn to anticipate the often arbitrary and changeable sounds that result from our movements remain largely unknown. Here we developed an acoustic virtual reality (aVR) system in which a mouse learned to associate a novel sound with its locomotor movements, allowing us to identify the neural circuit mechanisms that learn to suppress reafferent sounds and to probe the behavioural consequences of this predictable sensorimotor experience. We found that aVR experience gradually and selectively suppressed auditory cortical responses to the reafferent frequency, in part by strengthening motor cortical activation of auditory cortical inhibitory neurons that respond to the reafferent tone. This plasticity is behaviourally adaptive, as aVR-experienced mice showed an enhanced ability to detect non-reafferent tones during movement. Together, these findings describe a dynamic sensory filter that involves motor cortical inputs to the auditory cortex that can be shaped by experience to selectively suppress the predictable acoustic consequences of movement.
声音既可以来自环境,也可以由我们自己的许多动作产生,如发声、行走或演奏音乐。能够预测这些与运动相关的(传入的)声音,并将它们与环境声音区分开来,对于正常听力是至关重要的,但对于学习预测我们运动产生的那些通常是任意和多变的声音的神经回路,我们仍然知之甚少。在这里,我们开发了一种声学虚拟现实 (aVR) 系统,在该系统中,老鼠学会将一种新声音与其运动联系起来,使我们能够识别学习抑制传入声音的神经回路机制,并探究这种可预测的感觉运动体验的行为后果。我们发现,aVR 体验逐渐且选择性地抑制了听觉皮层对传入频率的反应,部分原因是增强了听觉皮层抑制神经元对传入音调的运动皮层激活。这种可塑性具有行为适应性,因为 aVR 体验的老鼠在运动过程中表现出增强的检测非传入音调的能力。总之,这些发现描述了一种动态的感觉滤波器,它涉及到运动皮层对听觉皮层的输入,可以通过经验进行塑造,从而选择性地抑制运动的可预测声音后果。