PDF(Pubmed)
Abstract：
Linking sensory input and its consequences is a fundamental brain operation. During behavior, the neural activity of neocortical and limbic systems often reflects dynamic combinations of sensory and task-dependent variables, and these \"mixed representations\" are suggested to be important for perception, learning, and plasticity. However, the extent to which such integrative computations might occur outside of the forebrain is less clear. Here, we conduct cellular-resolution two-photon Ca2+ imaging in the superficial \"shell\" layers of the inferior colliculus (IC), as head-fixed mice of either sex perform a reward-based psychometric auditory task. We find that the activity of individual shell IC neurons jointly reflects auditory cues, mice\'s actions, and behavioral trial outcomes, such that trajectories of neural population activity diverge depending on mice\'s behavioral choice. Consequently, simple classifier models trained on shell IC neuron activity can predict trial-by-trial outcomes, even when training data are restricted to neural activity occurring prior to mice\'s instrumental actions. Thus, in behaving mice, auditory midbrain neurons transmit a population code that reflects a joint representation of sound, actions, and task-dependent variables.
摘要：
将感官输入及其后果联系起来是一种基本的大脑操作。在行为期间，新皮层和边缘系统的神经活动通常反映感觉和任务相关变量的动态组合，这些“混合表示”被认为对感知很重要，学习,和可塑性。然而,这种综合计算可能发生在前脑之外的程度尚不清楚。这里,我们在下丘（IC）的浅表“壳”层中进行细胞分辨率双光子Ca2成像，作为任何性别的头部固定小鼠执行基于奖励的心理测量听觉任务。我们发现单个壳IC神经元的活动共同反映了听觉线索，老鼠的行动，和行为试验结果，这样，神经群体活动的轨迹根据小鼠的行为选择而不同。因此,在shellIC神经元活动上训练的简单分类器模型可以预测逐个试验的结果，即使训练数据仅限于在小鼠的器械作用之前发生的神经活动。因此，表现老鼠，听觉中脑神经元传递一种反映声音联合表示的群体代码，行动,和任务相关变量。意义陈述在IC的表面“壳”层中的神经元优先投射到由声音及其后果强烈激活的高阶丘脑核，从而结合感官和任务相关信息。这种感觉-行为整合被认为对各种行为相关功能至关重要，例如建立学习的合理价。然而,这种“混合表示”是否反映了丘脑皮层网络的独特性质，或者更确切地说存在于其他地区，不清楚。我们证明了在表现老鼠时，许多外壳IC神经元是由声音和老鼠的动作调制的。因此,shellIC群体活动足以在奖励行动之前预测试验结果。因此，我们的数据将壳IC核确定为与行为相关的混合表征的新颖场所。
