Simultaneous functional MRI and Micro-Magnetic Nervous System Stimulation

点击翻译按钮获取中文摘要

ABSTRACT Micromagnetic stimulation (µMS) has several advantages over electrical stimulation. First, µMS does not require charge-balanced stimulation waveforms as in electrical stimulation. In µMS, neither sinks nor sources are present when the time-varying magnetic field induces a current. Thus µMS does not suffer from charge buildup as can occur with electrical stimulation. Second, magnetic stimulation via µMS is capable of activating neurons with specific axonal orientations. Third, it is contactless, so biocompatible materials such as parylene will allow implantation with minimal or no reaction. Moreover, as the probes can be insulated entirely from the brain tissue, we show to significantly reduce the problem of excessive power deposition into the tissue during magnetic resonance imaging (MRI). In this application, we propose to design, fabricate, and test microcoil structures for next-generation Nervous System Stimulation: the micro coils arrays will be designed for cortical stimulation like ECoGs and deep brain stimulation. The array will be novel in the sense that it will allocate optical fibers to perform onsite optogenetic calcium channels recording in awake and behaving animals, thus allowing for direct study of the underlying mechanisms of magnetic stimulation. All the micromagnetic stimulators will also be MRI compatible, allowing for large scale neural recordings with fMRI. This technology will serve Neuroscience research— investigating the function of neurons and neural networks in the peripheral and central nervous system (PNS and CNS)—enhancing or creating new applications for neuromodulation. All of these applications will allow us to employ neuromodulation and study how micromagnetic field pulses can be used for stimulating or blocking the flow of Action Potentials (APs) through the nervous system, as similarly transcranial magnetic stimulation (TMS) produces excitation and inhibition. The proposed µMS tools will also provide the community with a way to reach a more in-depth understanding of the mechanisms of actions of TMS.