Development of Local Mechanical Stimulation Method for Clarifying Mechanism of Ultrasound Neuromodulation

Neuromodulation is the process of stimulating neuron cells in the brain to regulate and control their activity. By using ultrasound, it is possible to stimulate the cells locally and noninvasively. In experiments using anesthetized rats, it has been observed that ultrasonic stimulation induces limb movement. However, the mechanism behind this phenomenon remains unclear. In this study, we aimed to investigate the response of neuron cells to mechanical stimulation through ultrasound. We conducted experiments using cultured neuron cells with and without microbubbles. As the wavelength of ultrasound is significantly larger than the cell size, microbubbles are utilized to localize the mechanical stimulation. The results revealed a significant enhancement in release of Calcium ions in neuron cells in the presence of microbubbles. Further investigation will explore the relationship between ultrasound wavelength scale and the localized microbubble-enhanced stimulation.