Non-invasive assessment and modulation of brain-gut interoception in humans

项目总结/摘要 内感受是指对生物体内部状态的表征，包括以下过程： 它感知、解释、整合和调节来自自身的信号。内感受越来越 被视为大脑和身体之间的双向过程，其中多重反馈和前馈 循环导致身体的内部表示。迷走神经与自主神经系统密切相关， 上消化道（GI）的控制，具有到延髓脑干核的传入投射。反过来， 内感受性通路也可以直接靶向用于临床有益的神经调节， 与脑干迷走神经回路相互作用的神经调节技术，包括经皮耳 迷走神经刺激（taVNS）已经被报道通过内脏迷走神经传导通路调节传出内脏迷走神经通路。 孤束核（NTS）的参与。然而，更广泛地理解taVNS对胃的影响， 功能和大脑对胃内感受性信号的反应是需要的，并且需要工具来直接探测胃内感受性信号。 人类的肠脑轴在我们的研究中，我们将结合联合收割机一个完全非侵入性的实验框架，包括 连续胃和脑磁共振成像（MRI）与校准的膳食摄入和MRI- 兼容的taVNS，以评估内脏内感受沿着脑肠轴的调节。目标1将 评价标准餐后胃功能和大脑对胃内感受信号的反应 摄入在目标2中，我们将研究taVNS对胃功能的调节和对胃电刺激的脑反应。 内感受信号这项研究将为双向肠-脑机制提供新的见解。 胃内感受的相互作用及其通过非侵入性神经调节技术的调节 特异性靶向内感受途径（即taVNS）。

PROJECT SUMMARY/ABSTRACT Interoception refers to the representation of the internal states of an organism, and includes the processes by which it senses, interprets, integrates, and regulates signals from within itself. Interoception is increasingly viewed as a bidirectional process between the brain and body, in which multiple feedback and feedforward loops lead to an internal representation of the body. The vagus nerve is intimately involved in autonomic control of the upper gastrointestinal (GI) tract, with afferent projections to medullary brainstem nuclei. In turn, interoceptive pathways can also be directly targeted for clinically beneficial neuromodulation and non-invasive neuromodulatory techniques that interact with brainstem vagal circuitry, including transcutaneous auricular vagal nerve stimulation (taVNS), have been reported to modulate efferent visceral vagal pathways via the engagement of nucleus tractus solitarii (NTS). However, broader understanding of taVNS effects on gastric function and brain response to gastric interoceptive signaling is needed, and requires tools to directly probe the gut-brain axis in humans. In our study, we will combine a fully non-invasive experimental framework including sequential gastric and brain Magnetic Resonance Imaging (MRI) with calibrated meal ingestion and MRI- compatible taVNS to evaluate the modulation of visceral interoception along the brain-gut axis. Aim 1 will evaluate gastric function and brain response to gastric interoceptive signaling following calibrated meal ingestion. In Aim 2, we will then investigate taVNS modulation of gastric function and brain response to gastric interoceptive signaling. The proposed study will contribute new insights into the bidirectional gut-brain interaction underlying gastric interoception, and its modulation via non-invasive neuromodulatory techniques that specifically target interoceptive pathways (i.e. taVNS).