The Key Laboratory of Biomedical Information Engineering of the Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
UMR 1253, iBrain, Université de Tours, Inserm, France.
Ultrason Sonochem. 2020 May;63:104935. doi: 10.1016/j.ultsonch.2019.104935. Epub 2019 Dec 19.
Previous studies have indicated that the presence of microbubbles (MBs) during sonication has an impact on neuronal activity, while the underlying mechanisms remain to be revealed. In this study, a model for the scattered pressures produced by the pulsating lipid-encapsulated MBs in mouse brain was developed to numerically investigate the effect of MBs on neuronal activity during transcranial focused ultrasound stimulation. The additional summed scattered pressure (P) from the oscillating MBs was calculated from the model. The level of neuronal activity was experimentally verified using an immunofluorescence assay with antibodies against c-fos. The pressure difference (ΔP) between acoustic pressures at which the same level of neuronal activity is excited by ultrasound stimulation with and without MBs was obtained from the experiments. The results showed that P accounts for about half of the ΔP when the MBs experience a "compression-only" response. The P suddenly increased at a critical acoustic pressure, around which a rapid enhancement of ΔP obtained from experiment also occurred. This work suggested that the additional scattered pressures from pulsating MBs are probably a mechanism that affects neuronal activity under transcranial focused ultrasound stimulation.
先前的研究表明，超声处理过程中微泡（MBs）的存在会对神经元活动产生影响，但其潜在机制仍有待揭示。在这项研究中，我们建立了一个模型来模拟脂质包裹的 MBs 在小鼠大脑中产生的散射压力，以数值研究 MBs 在经颅聚焦超声刺激期间对神经元活动的影响。通过该模型计算了来自振荡 MBs 的附加总和散射压力（P）。通过针对 c-fos 的免疫荧光测定实验来验证神经元活动的水平。从实验中获得了在有和没有 MBs 的情况下超声刺激激发相同水平神经元活动的声压差（ΔP）。结果表明，当 MBs 经历“仅压缩”响应时，P 约占 ΔP 的一半。当声压达到一个临界值时，P 突然增加，同时实验也得到了 ΔP 的快速增强。这项工作表明，来自脉动 MBs 的附加散射压力可能是影响经颅聚焦超声刺激下神经元活动的一种机制。
