Improving the characterization of activity in white matter systems: links within distributed neural networks

了解大脑是如何工作的是一个快速发展的科学和技术领域。科学和公众对大脑成像进展的兴趣与日俱增，这是完全有道理的，因为我们最珍视的高级心理功能，如语言和记忆，依赖于对大脑回路的精细、复杂的处理。这些大脑回路以分布式网络的形式存在，随着信息的处理而动态激活。近年来，在我们非侵入性地窥视大脑内部并观看这些网络处理信息的各个方面的能力方面，有了重大的技术进步--将我们的大脑在工作时可视化为“激活”。但是，这种激活意味着什么？*我之前的工作集中在寻求更好地理解分布式大脑网络中的“激活”概念--这是学习更多高级精神功能的基本步骤。在这一过程中，发现了一个缺失的环节。大脑被分为两种大致相等的组织类型(灰质和白质)；在考虑分布式网络时，灰质可以被认为是点，而白质则是连接这些点的线。缺失的环节：“激活”的大脑成像只看到点，这实际上只代表了图片的50%。如果不能隔离连接这些点的活动线路，识别这些重要的分布式网络即使不是不可能，也是困难的。*该提案的关键目标是识别白质中的活动连接(线路)，以便更好地理解这些动态网络。我的研究将利用脑成像的进步，使用功能磁共振成像(FMRI)和相关的基于MRI的技术。到目前为止，我们的团队已经在使用功能磁共振成像来检测大脑中的白质激活方面处于领先地位。通过一系列的实验，我们已经证明了白质在特定的大脑连接(主要是胼胝体)中被激活。下一步将是发现和表征白质激活的最佳测量方法，并探索其潜在的生物学基础。归根结底，目标是帮助更好地识别大脑网络，无论是在工作中还是在休息时，这些网络支持至关重要的更高级别的精神功能。这项基础性研究有望在脑功能障碍(如多发性硬化症和阿尔茨海默病)的神经学评估中带来现实世界的应用。*这项工作的预期结果是提高我们对高水平功能和功能障碍期间大脑激活的理解。通过提高我们可视化分布式大脑网络的能力，这项研究将为未来的一系列进展奠定基础，帮助三分之一的加拿大人在一生中受到与大脑相关的疾病的影响。********

Understanding how the brain works is a rapidly advancing area of science and technology. The growing scientific and public interest in brain imaging advances makes perfect sense when considering that our most prized higher-level mental functions, like language and memory, rely on finely tuned, complex processing of brain circuits. These brain circuits exist as distributed networks that are dynamically activated as information is processed. In recent years, there have been major technological advances in our ability to non-invasively peer inside the brain and watch aspects of these networks process information - to visualize our brain at work as "activation." But, what does this activation mean?***My prior work was focused on seeking a better understanding of the concept of "activation" in distributed brain networks - a fundamental step towards learning more about higher mental functions. In the process, a missing link was identified. The brain is divided into two, approximately equal, types of tissues (gray matter and white matter); when considering distributed networks, gray matter can be thought of as the dots, with white matter as the lines connecting the dots. The missing link: brain imaging of "activation" sees only the dots, which effectively represents only 50% of the picture. Without being able to isolate the active lines that connect the dots, it is difficult, if not impossible, to identify these vital distributed networks.***The key objective of this proposal is to identify active connections (the lines) in white matter in order to better understand these dynamic networks. My research will capitalize on advancements in brain imaging, using functional magnetic resonance imaging (fMRI) and related MRI-based techniques. To date, our group has led in the use of fMRI to detect white matter activation in the brain. Through a series of experiments, we have demonstrated white matter activation in specific brain connections (primarily the corpus callosum). The next step will be to discover and characterize the optimal measurement of, and explore the underlying biological basis for, white matter activation. Ultimately, the goal is to help better identify brain networks, at work and at rest, that support vital higher-level mental functions. This fundamental research is then hoped to bring real-world applications in the neurological evaluation of brain dysfunction (e.g., multiple sclerosis and Alzheimer's Disease).***The anticipated outcome of this work is to improve our understanding of brain activation during high-level function and dysfunction. By improving our ability to visualize distributed brain networks, this research will lay the foundation for a host of future advances to help the one-third of all Canadians who are affected by brain-related conditions during their lives. ********