Abstract

Conventional acoustic brain stimulators that transmit low frequency (< 1 MHz) bursts in a pulse repetition frequency with large-sized transducers are barely compatible with small animal models because of broad beam width, possible stimulation of auditory pathways, and blocking of field-of-view for in vivo imaging of brain hemodynamics and neuronal activities. A miniaturized ultrasound stimulator with higher stimulation frequencies will enhance spatial specificity and enable simultaneous eliciting and monitoring brain activities. Moreover, the use of non-periodic pulse sequences may reduce unintended stimulations on auditory cortex, which might be caused by transmitting periodic bursting patterns. A platform for ultrasound brain stimulations for small animal models, including a soft housing 10 MHz needle transducer with a beam size of 680 μm, random transmission sequences, and optical imaging systems, was developed. The platform can deliver focal stimulations to the visual and barrel cortex of mice and monitor subsequent brain activities. The stimulated sites in both the visual and primary somatosensory cortices (S1) showed approximately two to three times higher neuronal calcium signal levels than those in peripheral regions. Activities in the auditory cortex were elicited by periodic sequence stimulation, while it was reduced by 67 and 35% for barrel and visual cortex stimulation with the random sequence, respectively.

中文翻译：

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一种用于小动物大脑局部刺激的软外壳针头超声换能器。

摘要

传统的声学脑刺激器使用大型换能器以脉冲重复频率发射低频（<1 MHz）突发脉冲，因为光束宽度较宽，可能刺激听觉通路并阻碍了视野，因此与小型动物模型几乎不兼容。查看体内脑血流动力学和神经元活动的成像。具有更高刺激频率的小型超声刺激器将增强空间特异性，并能够同时引发和监测大脑活动。而且，非周期性脉冲序列的使用可以减少听觉皮层上的意外刺激，这可能是由于发射周期性爆发模式而引起的。一种用于超声脑刺激对小动物模型，包括软外壳10兆赫针换能器680的光束尺寸平台 μm，随机传输序列和光学成像系统，已开发。该平台可以向小鼠的视觉和桶状皮质提供局部刺激，并监视随后的大脑活动。视觉和初级体感皮质（S1）的受刺激部位显示的神经元钙信号水平比周围区域高约2至3倍。听觉皮层中的活动是通过周期性的序列刺激引起的，而随机序列的桶形和视觉皮层刺激则分别使听觉皮层的活性降低了67％和35％。