IEEE Trans Biomed Eng. 2023 Jul;70(7):1992-2001. doi: 10.1109/TBME.2022.3233345. Epub 2023 Jun 19.
Here we investigate the ability of low-intensity ultrasound (LIUS) applied to the spinal cord to modulate the transmission of motor signals.
Male adult Sprague-Dawley rats (n = 10, 250-300 g, 15 weeks old) were used in this study. Anesthesia was initially induced with 2% isoflurane carried by oxygen at 4 L/min via a nose cone. Cranial, upper extremity, and lower extremity electrodes were placed. A thoracic laminectomy was performed to expose the spinal cord at the T11 and T12 vertebral levels. A LIUS transducer was coupled to the exposed spinal cord, and motor evoked potentials (MEPs) were acquired each minute for either 5- or 10-minutes of sonication. Following the sonication period, the ultrasound was turned off and post-sonication MEPs were acquired for an additional 5 minutes.
Hindlimb MEP amplitude significantly decreased during sonication in both the 5- (p < 0.001) and 10-min (p = 0.004) cohorts with a corresponding gradual recovery to baseline. Forelimb MEP amplitude did not demonstrate any statistically significant changes during sonication in either the 5- (p = 0.46) or 10-min (p = 0.80) trials.
LIUS applied to the spinal cord suppresses MEP signals caudal to the site of sonication, with recovery of MEPs to baseline after sonication.
LIUS can suppress motor signals in the spinal cord and may be useful in treating movement disorders driven by excessive excitation of spinal neurons.
本研究旨在探讨应用于脊髓的低强度超声（LIUS）调节运动信号传递的能力。
本研究使用雄性成年 Sprague-Dawley 大鼠（n = 10，体重 250-300g，15 周龄）。首先通过鼻管以 4L/min 的氧气输送 2%异氟醚诱导麻醉。放置颅顶、上肢和下肢电极。行胸段椎板切除术以暴露 T11 和 T12 椎体水平的脊髓。将 LIUS 换能器耦合到暴露的脊髓上，分别进行 5 分钟或 10 分钟的超声处理，每分钟采集一次运动诱发电位（MEP）。超声处理期结束后，关闭超声并额外采集 5 分钟的超声后 MEP。
在 5 分钟（p < 0.001）和 10 分钟（p = 0.004）两组中，超声处理期间后肢 MEP 幅度均显著降低，且随着时间逐渐恢复至基线水平。在 5 分钟（p = 0.46）和 10 分钟（p = 0.80）两组中，超声处理期间前肢 MEP 幅度均未显示出任何统计学上的显著变化。
LIUS 施加于脊髓可抑制超声作用部位以下的 MEP 信号，且在超声处理后 MEPs 恢复至基线。
LIUS 可抑制脊髓中的运动信号，可能有助于治疗由脊髓神经元过度兴奋引起的运动障碍。
