Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, USA.
Brain Stimul. 2021 Mar-Apr;14(2):261-272. doi: 10.1016/j.brs.2021.01.006. Epub 2021 Jan 15.
Transcranial focused ultrasound (FUS) stimulation under MRI guidance, coupled with functional MRI (fMRI) monitoring of effects, offers a precise, noninvasive technology to dissect functional brain circuits and to modulate altered brain functional networks in neurological and psychiatric disorders. Here we show that ultrasound at moderate intensities modulated neural activity bi-directionally. Concurrent sonication of somatosensory areas 3a/3b with 250 kHz FUS suppressed the fMRI signals produced there by peripheral tactile stimulation, while at the same time eliciting fMRI activation at inter-connected, off-target brain regions. Direct FUS stimulation of the cortex resulted in different degrees of BOLD signal changes across all five off-target regions, indicating that its modulatory effects on active and resting neurons differed. This is the first demonstration of the dual suppressive and excitative modulations of FUS on a specific functional circuit and of ability of concurrent FUS and MRI to evaluate causal interactions between functional circuits with neuron-class selectivity.
经磁共振成像 (MRI) 引导的经颅聚焦超声 (FUS) 刺激，结合功能磁共振成像 (fMRI) 对效果的监测，为剖析功能脑回路和调节神经和精神疾病中改变的大脑功能网络提供了一种精确、非侵入性的技术。在这里，我们展示了中等强度的超声可以双向调节神经活动。用 250 kHz 的 FUS 同时对体感区 3a/3b 进行超声处理，抑制了外周触觉刺激在该处产生的 fMRI 信号，同时在相互连接的、非靶向的大脑区域引起 fMRI 激活。直接对皮质进行 FUS 刺激，导致所有五个非靶向区域的 BOLD 信号变化程度不同，表明其对活跃和静止神经元的调制作用不同。这是首次证明 FUS 对特定功能回路的双重抑制和兴奋调节，以及同时进行的 FUS 和 MRI 评估具有神经元类选择性的功能回路之间因果相互作用的能力。
