We describe preliminary results from the application of time-varying caloric vestibular stimulation (tvCVS) to volunteers during a continuous blood oxygen level dependent (BOLD) functional MRI (fMRI) acquisition, recording baseline, during-tvCVS and post-tvCVS epochs. The modifications necessary to enable the use of this novel device in a 3-Tesla magnetic field are discussed. Independent component analysis (ICA) was used as a model-free method to highlight spatially and temporally coherent brain networks. The ICA results are consistent with tvCVS induction being mediated principally by thermoconvection in the vestibular labyrinth and not by direct thermal effects. The activation of hub networks identified by ICA is consistent with the concept of sensory neuromodulation, which posits that a modulatory signal introduced to a sensory organ is able to traverse the regions innervated (directly and indirectly) by that organ, while being transformed so as to be "matched" to regional neuronal dynamics. The data suggest that regional neurovascular coupling and a systemic cerebral blood flow component account for the BOLD contrast observed. The ability to modulate cerebral hemodynamics is of significant interest. The implications of these initial findings for the use of tvCVS therapeutically are discussed.

中文翻译：

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用 fMRI 评估的时变热量前庭刺激的急性影响。

我们描述了在连续血氧水平依赖 (BOLD) 功能 MRI (fMRI) 采集、记录基线、tvCVS 期间和 tvCVS 后时期对志愿者应用时变热量前庭刺激 (tvCVS) 的初步结果。讨论了在 3 特斯拉磁场中使用这种新型设备所需的修改。独立分量分析 (ICA) 被用作一种无模型方法来突出空间和时间连贯的大脑网络。ICA 结果与主要由前庭迷路中的热对流而非直接热效应介导的 tvCVS 诱导一致。ICA识别的枢纽网络的激活与感觉神经调节的概念一致，它假定引入感觉器官的调节信号能够穿过由该器官（直接和间接）支配的区域，同时被转换以与区域神经元动力学“匹配”。数据表明区域神经血管耦合和全身脑血流分量是观察到的 BOLD 对比度的原因。调节脑血流动力学的能力具有重要意义。讨论了这些初步发现对 tvCVS 治疗使用的影响。调节脑血流动力学的能力具有重要意义。讨论了这些初步发现对 tvCVS 治疗使用的影响。调节脑血流动力学的能力具有重要意义。讨论了这些初步发现对 tvCVS 治疗使用的影响。