Helen Wills Neuroscience Institute, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA; Redwood Center for Theoretical Neuroscience, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA.
Helen Wills Neuroscience Institute, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA; Department of Physics, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA; Redwood Center for Theoretical Neuroscience, University of California, Berkeley, 132 Barker Hall, Berkeley, CA 94720, USA.
Neuron. 2014 Jun 4;82(5):1157-70. doi: 10.1016/j.neuron.2014.04.031.
Animals can selectively respond to a target sound despite simultaneous distractors, just as humans can respond to one voice at a crowded cocktail party. To investigate the underlying neural mechanisms, we recorded single-unit activity in primary auditory cortex (A1) and medial prefrontal cortex (mPFC) of rats selectively responding to a target sound from a mixture. We found that prestimulus activity in mPFC encoded the selection rule-which sound from the mixture the rat should select. Moreover, electrically disrupting mPFC significantly impaired performance. Surprisingly, prestimulus activity in A1 also encoded selection rule, a cognitive variable typically considered the domain of prefrontal regions. Prestimulus changes correlated with stimulus-evoked changes, but stimulus tuning was not strongly affected. We suggest a model in which anticipatory activation of a specific network of neurons underlies the selection of a sound from a mixture, giving rise to robust and widespread rule encoding in both brain regions.
动物可以选择性地对目标声音做出反应，尽管同时存在干扰，就像人类可以在嘈杂的鸡尾酒会上只回应一个声音一样。为了研究潜在的神经机制，我们记录了在混合声音中选择性地对目标声音做出反应的大鼠初级听觉皮层 (A1) 和内侧前额叶皮层 (mPFC) 的单个神经元的活动。我们发现，mPFC 的预刺激活动编码了选择规则——大鼠应该从混合声音中选择哪个声音。此外，电干扰 mPFC 会显著损害表现。令人惊讶的是，A1 中的预刺激活动也编码了选择规则，这是一个通常被认为是前额区域领域的认知变量。预刺激变化与刺激诱发的变化相关，但刺激调谐没有受到强烈影响。我们提出了一个模型，其中特定神经元网络的预期激活是从混合声音中选择声音的基础，导致两个脑区中强大而广泛的规则编码。
