Transcranial magneto-acoustic electrical stimulation (TMAES) is a novel method of brain nerve regulation and research, which uses induction current generated by the coupling of ultrasound and magnetic field to regulate neural electrical activity in different brain regions. As the second special envoy of nerve signal, calcium plays a key role in nerve signal transmission. In order to investigate the effect of TMAES on prefrontal cortex electrical activity, 15 mice were divided into control group, ultrasound stimulation (TUS) group and TMAES group. The TMAES group received 2.6 W/cm 2 and 0.3 T of magnetic induction intensity, the TUS group received only ultrasound stimulation, and the control group received no ultrasound and magnetic field for one week. The calcium ion concentration in the prefrontal cortex of mice was recorded in real time by optical fiber photometric detection technology. The new object recognition experiment was conducted to compare the behavioral differences and the time-frequency distribution of calcium signal in each group. The results showed that the mean value of calcium transient signal in the TMAES group was (4.84 ± 0.11)% within 10 s after the stimulation, which was higher than that in the TUS group (4.40 ± 0.10)% and the control group (4.22 ± 0.08)%, and the waveform of calcium transient signal was slower, suggesting that calcium metabolism was faster. The main energy band of the TMAES group was 0-20 Hz, that of the TUS group was 0-12 Hz and that of the control group was 0-8 Hz. The cognitive index was 0.71 in the TMAES group, 0.63 in the TUS group, and 0.58 in the control group, indicating that both ultrasonic and magneto-acoustic stimulation could improve the cognitive ability of mice, but the effect of the TMAES group was better than that of the TUS group. These results suggest that TMAES can change the calcium homeostasis of prefrontal cortex nerve clusters, regulate the discharge activity of prefrontal nerve clusters, and promote cognitive function. The results of this study provide data support and reference for further exploration of the deep neural mechanism of TMAES.
经颅磁声电刺激（TMAES）作为一种新型的脑神经调控和研究手段，利用超声和磁场耦合产生的感应电流调节不同脑区的神经电活动。钙离子作为神经信号第二特使，在神经信号传递中起着关键作用。为了探究经颅磁声电刺激对前额叶皮层放电活动的影响，将15只小鼠分为对照组、超声组和磁声组，磁声组接受超声强度为2.6 W/cm 2和磁感应强度为0.3 T的刺激，超声组仅接受相同强度的超声刺激，对照组无超声和磁场，持续刺激一周。通过光纤光度检测技术实时记录小鼠刺激过程中前额叶皮层钙离子浓度，并进行新物体识别实验，对比各组行为学差异和钙信号的时频分布。实验结果显示，经颅磁声组在刺激后10 s内钙瞬变信号均值（4.84 ± 0.11）%大于超声组（4.40 ± 0.10）%和对照组（4.22 ± 0.08）%，且钙瞬变信号波形变缓，提示钙离子代谢变快；磁声组主要能量频带分布在0～20 Hz，超声组为0～12 Hz，对照组为0～8 Hz；磁声组认知指数为0.71，超声组为0.63，对照组为0.58，表明超声刺激和磁声电刺激均能提高小鼠的认知能力，但磁声组效果优于超声组。以上结果显示，经颅磁声电刺激能够改变前额叶皮层神经集群的钙稳态，实现对前额叶神经集群放电活动的调控，对认知功能具有促进效果。研究结果为进一步探索经颅磁声电刺激的深层神经作用机制提供了数据支撑和参考。.
Keywords: Calcium concentration; Neuromodulation; Optical fiber photometric detection technology; Transcranial magneto-acoustic-electrical stimulation; Ultrasonic stimulation.