Autonomic modulation by low-intensity focused ultrasound stimulation of the vagus nerve
Autonomic modulation by low-intensity focused ultrasound stimulation of the vagus nerve
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DOI：
10.1088/1741-2552/aca8cd
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发表时间：
2022-12
影响因子：
4
通讯作者：
Ning Ji;Yuanheng Li;J. Wei;Fei Chen;Lisheng Xu;Guanglin Li;Wan-Hua Lin
中科院分区：
文献类型：
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作者：
Ning Ji;Yuanheng Li;J. Wei;Fei Chen;Lisheng Xu;Guanglin Li;Wan-Hua Lin
Objective.我们前期的研究表明，低强度聚焦超声刺激（FUS）迷走神经可以调节血压（BP），但其机制尚不清楚。我们假设迷走神经的低强度FUS将调节自主神经功能，从而调节血压。Approach. 17只麻醉的自发性高血压大鼠，每次用低强度FUS刺激左侧迷走神经15 min。同时记录连续BP、心率、呼吸率（RR）和核心体温，以评估对BP和其他生理参数的影响。计算心率变异性（HRV）、收缩压变异性和压力反射敏感性以评价自主调节功能。还检查了无刺激的对照-假手术组和另一个具有非靶刺激的对照-FUS组，以排除潜在混杂因素对自主调节的影响。主要结果。低强度FUS后，血压、脉压、RR、HRV低频功率、HRV低频/高频功率比均较基线和对照组显著降低，表明交感神经系统活动受到抑制。HRV标准化高频功率的持续显著增加提示副交感神经活动的激活。意义左侧迷走神经低强度FUS通过激活副交感传出神经和抑制交感传出神经，有效地改善了自主神经功能，有助于降低血压。这些发现揭示了FUS的发病机制。
Objective. Our previous study has shown that low-intensity focused ultrasound stimulation (FUS) of the vagus nerve could modulate blood pressure (BP), but its underlying mechanisms remain unclear. We hypothesized that low-intensity FUS of the vagus nerve would regulate autonomic function and thus BP. Approach. 17 anesthetized spontaneously hypertensive rats were treated with low-intensity FUS of the left vagus nerve for 15 min each trial. Continuous BP, heart rate, respiration rate (RR), and core body temperature were simultaneously recorded to evaluate the effects on BP and other physiological parameters. Heart rate variability (HRV), systolic BP variability, and baroreflex sensitivity were computed to evaluate the autonomic modulation function. A Control-sham group without stimulation and another Control-FUS group with non-target stimulation were also examined to exclude the influence of potential confounding factors on autonomic modulation. Main results. A prolonged significant decrease in BP, pulse pressure, RR, the normalized low-frequency power of HRV, and the low-to-high frequency power ratio of HRV were found after the low-intensity FUS of the left vagus nerve in comparison with the baseline and those of the control groups, demonstrating that activities of the sympathetic nervous system were inhibited. The prolonged significant increase of the normalized high-frequency power of HRV suggested the activation of parasympathetic activity. Significance. Low-intensity FUS of the left vagus nerve effectively improved the autonomic function by activating parasympathetic efferent and inhibiting sympathetic efferent, which contributes to BP reduction. The findings shed light on the hypotensive mechanism underlying FUS.