As a noninvasive technique, ultrasound stimulation is known to modulate neuronal activity both in vitro and in vivo. The latest explanation of this phenomenon is that the acoustic wave can activate the ion channels and further impact the electrophysiological properties of targeted neurons. However, the underlying mechanism of low-intensity pulsed ultrasound (LIPUS)-induced neuro-modulation effects is still unclear. Here, we characterize the excitatory effects of LIPUS on spontaneous activity and the intracellular Ca²⁺ homeostasis in cultured hippocampal neurons. By whole-cell patch clamp recording, we found that 15 min of 1-MHz LIPUS boosts the frequency of both spontaneous action potentials and spontaneous excitatory synaptic currents (sEPSCs) and also increases the amplitude of sEPSCs in hippocampal neurons. This phenomenon lasts for > 10 min after LIPUS exposure. Together with Ca²⁺ imaging, we clarified that LIPUS increases the [Ca²⁺]_cyto level by facilitating L-type Ca²⁺ channels (LTCCs). In addition, due to the [Ca²⁺]_cyto elevation by LIPUS exposure, the Ca²⁺-dependent CaMKII-CREB pathway can be activated within 30 min to further regulate the gene transcription and protein expression. Our work suggests that LIPUS regulates neuronal activity in a Ca²⁺-dependent manner via LTCCs. This may also explain the multi-activation effects of LIPUS beyond neurons. LIPUS stimulation potentiates spontaneous neuronal activity by increasing Ca²⁺ influx.

作为一种非侵入性技术，超声刺激已知可以调节体外和体内的神经元活动。对这种现象的最新解释是声波可以激活离子通道并进一步影响目标神经元的电生理特性。然而，低强度脉冲超声（LIPUS）引起的神经调节作用的潜在机制仍不清楚。在这里，我们描述了 LIPUS 对培养的海马神经元自发活动和细胞内 Ca ²⁺稳态的兴奋作用。通过全细胞膜片钳记录，我们发现 1 MHz LIPUS 15 分钟会提高自发动作电位和自发兴奋性突触电流 (sEPSC) 的频率，并且还会增加海马神经元中 sEPSC 的振幅。LIPUS 暴露后，这种现象持续 > 10 分钟。与Ca ²⁺成像一起，我们阐明了LIPUS通过促进L 型Ca ^{2+通道（LTCC）来增加[Ca 2+} ]_细胞水平。此外，由于LIPUS暴露导致[Ca ²⁺ ]_{细胞升高，Ca} ²⁺依赖的CaMKII-CREB途径可以在30分钟内被激活，进一步调节基因转录和蛋白表达。我们的工作表明，LIPUS通过LTCC 以 Ca ²⁺依赖性方式调节神经元活动。这也可以解释 LIPUS 对神经元以外的多重激活作用。^{LIPUS 刺激通过增加 Ca 2+}流入来增强自发神经元活动。