Mapping the Human Brain Circuitry and Function through Transcranial Magnetic Stimulation Combined with Electroencephalography

点击翻译按钮获取中文摘要

The recent global initiatives in mapping the human brain structure and function have created enthusiasm in the scientific community to design innovative technologies to safely and reliably identify metrics of the brain structural and functional health. In the past six years, we have contributed to advancing a scientific approach that involves simultaneous combination of a non-invasive brain stimulation technique called transcranial magnetic stimulation (TMS) with a non-invasive neural recording method called electroencephalography (EEG). This technique has enabled transferring the investigation of the human brain circuitries from brain slices or animal models to investigation of the brain circuitry from the intact scalp of humans. This combination permits examining the brain circuitries in an input-output (TMS-EEG) manner. When a TMS pulse is delivered to a brain region, it can activate neurons. The parameters of TMS can be chosen to activate a specific circuitry, for example inhibition, the brain braking mechanism. Then, EEG captures the response of this activated circuitry. EEG recordings are analyzed to extract metrics related to integrity of this specific circuitry. By comparing these metrics across different brain regions, individuals or over time, TMS-EEG can allow us to examine and monitor specific brain processes. However, the wide spread application of TMS-EEG as a tool for decoding and monitoring the brain health further relies on validation and standardization of this technique. It has been shown that the brain circuitries change across age and behavioral states such as resting compared to performing a task. Furthermore, EEG signals are multidimensional and several algorithms can be employed to characterize them. Our research program is designed to address these challenges and opportunities. In the next five years, we will contribute to identifying reliable metrics of two key brain processes of inhibition and connectivity across several brain regions and behavioral states in young, middle age and old healthy subjects. In parallel, we advance TMS-EEG tool by developing and refining EEG signal processing algorithms and comparing TMS-EEG with other neuroimaging methods. Our research program will provide important insight into the validity and added value of TMS-EEG as a brain mapping technology. Our program will provide important insight into characteristics of neural inhibition and connectivity across different brain states, taking us a step closer to ultimately obtaining an atlas of the human brain electrical properties and metrics of health. Finally, our program will provide critical evidence in support of the translational value and application of TMS-EEG in various disciplines of basic and cognitive neuroscience, neurorehabilitation, and in guiding the design of inexpensive solutions for monitoring the brain health across the life span in any individual.