Matsushita Yumi, Yoshida Kaede, Yoshiya Miyuki, Shimizu Takahiro, Tsukamoto Satoshi, Kudo Nobuki, Takeuchi Yuichi, Higuchi Makoto, Shimojo Masafumi
Advanced Neuroimaging Center, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan.
Department of Biopharmaceutical Sciences and Pharmacy, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Proc Natl Acad Sci U S A. 2024 Dec 10;121(50):e2404877121. doi: 10.1073/pnas.2404877121. Epub 2024 Dec 3.
Ultrasound neuromodulation has become an innovative technology that enables noninvasive intervention in mammalian brain circuits with high spatiotemporal precision. Despite the expanding utility of ultrasound neuromodulation in the neuroscience research field and clinical applications, the molecular and cellular mechanisms by which ultrasound impacts neural activity in the brain are still largely unknown. Here, we report that transient receptor potential canonical 6 (TRPC6), a mechanosensitive nonselective cation channel, is essential for ultrasound neuromodulation of mammalian neurons in vitro and in vivo. We first demonstrated that ultrasound irradiation elicited rapid and robust Ca transients mediated via extracellular Ca influx in cultured mouse cortical and hippocampal neurons. Ultrasound-induced neuronal responses were massively diminished by blocking either the generation of action potential or synaptic transmission. Importantly, both pharmacological inhibition and genetic deficiency of TRPC6 almost completely abolished neuronal responses to ultrasound. Furthermore, we found that intracerebroventricular administration of a TRPC6 blocker significantly attenuated the number of neuronal firings in the cerebral cortex evoked by transcranial ultrasound irradiation in mice. Our findings indicate that TRPC6 is an indispensable molecule of ultrasound neuromodulation in intact mammalian brains, providing fundamental understanding of biophysical molecular mechanisms of ultrasound neuromodulation as well as insight into its future feasibility in neuroscience and translational research in humans.
超声神经调节已成为一项创新技术,能够以高时空精度对哺乳动物脑回路进行非侵入性干预。尽管超声神经调节在神经科学研究领域和临床应用中的效用不断扩大,但其影响大脑神经活动的分子和细胞机制仍大多未知。在此,我们报告瞬时受体电位香草酸亚型6(TRPC6),一种机械敏感的非选择性阳离子通道,在体外和体内对哺乳动物神经元的超声神经调节中至关重要。我们首先证明,超声照射在培养的小鼠皮质和海马神经元中引发了通过细胞外钙内流介导的快速而强烈的钙瞬变。通过阻断动作电位的产生或突触传递,超声诱导的神经元反应大幅减弱。重要的是,TRPC6的药理学抑制和基因缺陷几乎完全消除了神经元对超声的反应。此外,我们发现,向小鼠脑室内注射TRPC6阻滞剂可显著减少经颅超声照射诱发的小鼠大脑皮质神经元放电数量。我们的研究结果表明,TRPC6是完整哺乳动物大脑中超声神经调节不可或缺的分子,为超声神经调节的生物物理分子机制提供了基本认识,并为其在神经科学和人类转化研究中的未来可行性提供了见解。