Ultrasound can modulate activity in the central nervous system, including the induction of motor responses in rodents. Recent studies investigating ultrasound-induced motor movements have described mostly bilateral limb responses, but quantitative evaluations have failed to reveal lateralization or differences in response characteristics between separate limbs or how specific brain targets dictate distinct limb responses. This study uses high-resolution focused ultrasound (FUS) to elicit motor responses in anesthetized mice in vivo and four-limb electromyography (EMG) to evaluate the latency, duration and power of paired motor responses (n = 1768). The results indicate that FUS generates target-specific differences in electromyographic characteristics and that brain targets separated by as little as 1 mm can modulate the responses in individual limbs differentially. Exploiting these differences may provide a tool for quantifying the susceptibility of underlying neural volumes to FUS, understanding the functioning of the targeted neuroanatomy and aiding in mechanistic studies of this non-invasive neuromodulation technique.

超声波可以调节中枢神经系统的活动，包括诱导啮齿动物的运动反应。最近调查超声引起的运动运动的研究主要描述了双侧肢体反应，但定量评估未能揭示不同肢体之间的侧向化或反应特征的差异，或者特定的大脑目标如何决定不同的肢体反应。本研究使用高分辨率聚焦超声 (FUS)在体内诱导麻醉小鼠的运动反应和四肢肌电图 (EMG)，以评估配对运动反应的潜伏期、持续时间和功率 (n = 1768)。结果表明，FUS 会在肌电图特征上产生特定于目标的差异，并且相隔仅 1 mm 的大脑目标可以不同地调节个体肢体的反应。利用这些差异可以提供一种工具，用于量化潜在神经体积对 FUS 的敏感性，了解目标神经解剖学的功能，并有助于这种非侵入性神经调节技术的机制研究。