Raghuram Vineeth, Datye Aditya D, Fried Shelley I, Timko Brian P
Dept. of Biomedical Engineering, Tufts University, Medford, MA 02155, USA.
Boston Veterans Affairs Healthcare System, Boston, MA 02130, USA.
Device. 2024 Apr 19;2(4). doi: 10.1016/j.device.2024.100290. Epub 2024 Mar 5.
Micromagnetic stimulation (μMS) using small, implantable microcoils is a promising method for achieving neuronal activation with high spatial resolution and low toxicity. Herein, we report a microcoil array for localized activation of cortical neurons and retinal ganglion cells. We developed a computational model to relate the electric field gradient (activating function) to the geometry and arrangement of microcoils, and selected a design that produced an anisotropic region of activation <50 μm wide. The device was comprised of an SU-8/Cu/SU-8 tri-layer structure, which was flexible, transparent and conformal and featured four individually-addressable microcoils. Interfaced with cortex or retina explants from GCaMP6-expressing mice, we observed that individual neurons localized within 40 μm of a microcoil tip could be activated repeatedly and in a dose- (power-) dependent fashion. These results demonstrate the potential of μMS devices for brain-machine interfaces and could enable routes toward bioelectronic therapies including prosthetic vision devices.
使用小型可植入微线圈的微磁刺激（μMS）是一种有前景的方法，可实现具有高空间分辨率和低毒性的神经元激活。在此，我们报告一种用于局部激活皮层神经元和视网膜神经节细胞的微线圈阵列。我们开发了一种计算模型，将电场梯度（激活函数）与微线圈的几何形状和排列相关联，并选择了一种设计，该设计产生了宽度小于50μm的各向异性激活区域。该装置由SU-8/铜/SU-8三层结构组成，具有柔性、透明和贴合性，并且具有四个可单独寻址的微线圈。与来自表达GCaMP6的小鼠的皮层或视网膜外植体连接后，我们观察到位于微线圈尖端40μm范围内的单个神经元能够以剂量（功率）依赖性方式被重复激活。这些结果证明了μMS装置在脑机接口方面的潜力，并可能为包括假体视觉装置在内的生物电子疗法开辟道路。
