Cortical feedback to the vestibular brainstem

 描述(申请人提供)：此R21应用程序的目标是了解从皮质到早期感觉区的反馈的性质。具体地说，我们的目标是对前庭皮质到前庭脑干的反馈如何影响翻译感知(标题)的理论开发和计算模型进行测试。我们打算了解顶岛前庭皮质(PIVC)的失活是如何改变前庭核神经元的反应特性的，PIVC增加了感知方向阈值。感觉神经反应和知觉选择之间最著名的相关联系被称为“选择概率”。与选择概率的来源相关的是神经元之间的“共享噪声”的量，它被测量为神经元间的尖峰率相关性(“噪声相关性”)。首先，使用机械模型，我们将把以前确定的神经调节、噪声相关性和选择概率之间的关系推广到包含循环连通性的网络架构。其次，我们将比较各种标准模型，这些模型为我们的任务指定了神经反馈的功能和形式，并从它们中推导出对相同实验量的预测。然后我们将在记录的数据(神经敏感度、选择概率和噪声相关性)上测试这些理论的预测 PIVC失活前后前庭核神经元的变化。这些研究的结果对于理解感觉信号如何影响知觉至关重要。表明知觉、选择驱动的信号被反馈到早期感觉区域，这些区域本身为丘脑-皮质网络提供了主要贡献，这将为“主动感觉”以及如何从多个相互连接的环路和网络的协调活动中产生知觉提供有价值的新见解。

 DESCRIPTION (provided by applicant): The goal of this R21 application is to understand the nature of feedback from cortex to early sensory areas. Specifically, our goal is the theoretical development and testing of computational models of how feedback from the vestibular cortex to the vestibular brainstem affects the perception of translation (heading). We propose to understand how inactivation of the parieto-insular vestibular cortex (PIVC), which increases perceptual heading thresholds, alters the response properties of neurons in the vestibular nuclei. The best known correlational link between sensory neural responses and perceptual choice is known as the `choice probability'. Relevant to the origin of choice probabilities is the amount of `shared noise' among neurons, which is measured as interneuronal correlation of spike rates (`noise correlations'). First, using mechanistic models, we will generalize previously identified relationships between neural tuning, noise correlations, and choice probabilities to network architectures that incorporate recurrent connectivity. Second, we will compare various normative models that specify the function and form of neural feedback for our tasks, and derive from them predictions for the same experimental quantities. We will then test the predictions of these theories on data (neural sensitivities, choice probabilities and noise correlations) recorded from vestibular nuclei neurons before and after PIVC inactivation. Results from these studies are critical for understanding how sensory signals contribute to perception. Showing that perceptual, choice-driven signals are fed back onto the early sensory areas that themselves provide the main contributions to the thalamo-cortical network will provide valuable new insights about `active sensing' and how perception arises from the coordinated activity of multiple interconnected loops and networks.