Network encoding of short-term memory in primary auditory cortex

项目总结/摘要 短时记忆是听觉的一个基本组成部分，对言语的形成至关重要 理解和听觉交流。越来越多的证据表明，小学的活动 当我们执行听觉任务时，听觉皮层（A1）会发生变化。在这个项目中，我们的长期目标是 了解A1在听觉短时记忆维持过程中如何改变其神经活动和连接。 我们将研究听觉短时记忆如何在A1层2/3（L2/3）的神经网络结构中编码。 我们选择研究L2/3是因为听觉短时记忆涉及到皮层内回路，而L2/3在皮层内是密集的。 皮质内连通性据我们所知，STM在神经网络结构中的表示 在A1中没有研究过。为了探索这个话题，我们将让动物比较两个连续的声音， 被无声的延迟隔开。动物们必须记住第一个声音来与第二个声音进行比较 在任务期间发出正确的行为反应。我们将记录A1 L2/3中的神经元反应 而动物们则在执行这个任务。我们假设在第一次发声时产生的神经网络 将在延迟期间持续，直到第二个声音。我们将使用简单和复杂的声音， 了解声学复杂性如何影响神经元网络结构。此外，我们将确定，如果 存在声学周期性的刺激不变表示，即，神经网络中的“音高”。我们 初步结果表明，听觉皮层的神经活动取决于动物是否成功地 区分高频与低频纯音。因此，我们的研究结果揭示了大脑是如何 听觉反应取决于我们如何倾听和对声音作出反应。 听力对健康人和听力受损的人来说都是一个挑战。我们的研究将有助于 阐明大脑如何让我们倾听的基本理解。因此，我们的工作将有助于 未来的治疗旨在使更好的听力在日常设置。

Project Summary/Abstract Short-term memory (STM) is a fundamental component of hearing that is critical to speech comprehension and auditory communication. Mounting evidence has indicated that the activity in primary auditory cortex (A1) changes when we perform auditory tasks. In this project, our long-term objective is to understand how A1 changes its neural activity and connectivity during the maintenance of auditory STM. We will study how auditory STM is encoded in the structure of neural networks in A1 layer 2/3 (L2/3). We choose to study L2/3 because auditory STM involves an intracortical circuit, and L2/3 is dense in intracortical connectivity. To the best of our knowledge, the representation of STM in neural network structure has not been studied in A1. To explore this topic, we will have animals compare two sequential sounds that are separated by a silent delay. The animals must memorize the first sound to compare with the second sound to give a correct behavioral response during the task. We will record neuronal responses in A1 L2/3 while the animals perform this task. We hypothesize that the neural networks that arise during the first sound will be sustained during the delay until the second sound. We will use both simple and complex sounds to understand how acoustic complexity affects neuronal network structure. Furthermore, we will determine if there exists a stimulus-invariant representation of acoustic periodicity, i.e., `pitch', in neuronal networks. Our preliminary results suggest that neural activity in auditory cortex depends on if the animal successfully discriminates between high vs. low frequency pure-tones. Thus, our results shed light on how the brain's auditory responsiveness depends on how we listen and react to sound. Listening can be challenging for both healthy and hearing-impaired people. Our studies will help clarify the basic understanding of how the brain allows us to listen. As a result, our work will contribute to future therapies designed to enable better hearing in every-day settings.