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摘要 : 将控制运动的大脑区域与涉及听觉控制的区域连接起来的神经元,被发现可以抑制小鼠移动时的听觉反应。但对于这种抑制作用的原因目前还不清楚。现在,杜克大学医学院神经科学系的研究人员揭示了这个谜题。相关文章发表于要2014年8月27日的《Nature》杂志上。


为了解自己的环境,大脑的感觉区域不仅必须处理外部刺激,而且必须处理内部产生的神经信号,如运动指令。Richard Mooney及同事对运动信号影响自由行动小鼠的听觉皮层活动的突触和回路机制进行了定性。

在运动、梳理和发声过程中,听觉皮层的激发性神经元会降低它们的活动,而与这种降低同时发生的是抑制性中间神经元活动的增加。通过对“次运动皮层”中的神经元(它们向听觉皮层产生长距离投射)进行光遗传学控制,便足以改变听觉皮层中由感觉激发的活动。这些发现为自主运动和外部感觉信号何以能够被整合在一起以便有可能来帮助提高听力提供了一个回路基础(circuit basis)。


A synaptic and circuit basis for corollary discharge in the auditory cortex

David M. Schneider, Anders Nelson & Richard Mooney

Sensory regions of the brain integrate environmental cues with copies of motor-related signals important for imminent and ongoing movements. In mammals, signals propagating from the motor cortex to the auditory cortex are thought to have a critical role in normal hearing and behaviour, yet the synaptic and circuit mechanisms by which these motor-related signals influence auditory cortical activity remain poorly understood. Using in vivo intracellular recordings in behaving mice, we find that excitatory neurons in the auditory cortex are suppressed before and during movement, owing in part to increased activity of local parvalbumin-positive interneurons. Electrophysiology and optogenetic gain- and loss-of-function experiments reveal that motor-related changes in auditory cortical dynamics are driven by a subset of neurons in the secondary motor cortex that innervate the auditory cortex and are active during movement. These findings provide a synaptic and circuit basis for the motor-related corollary discharge hypothesized to facilitate hearing and auditory-guided behaviours.

对应Nature杂志: 2014年9月11日Nature杂志精选

来源: Nature 浏览次数:78


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