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技术领域。考虑到我们最珍视的高级心理功能，如语言和记忆，依赖于大脑回路的精细调节和复杂处理，科学界和公众对脑成像技术进步的兴趣越来越大，这是完全合理的。这些大脑回路以分布式网络的形式存在，随着信息的处理动态激活。近年来，我们在非侵入性地观察大脑内部和观察这些网络处理信息的各个方面的能力方面取得了重大的技术进步——将我们的大脑工作视为“激活”。但是，这种激活是什么意思呢？***我之前的工作重点是更好地理解分布式大脑网络中的“激活”概念——这是了解更多高级心理功能的基本步骤。在这个过程中，发现了一个缺失的环节。大脑分为两种大致相等的组织（灰质和白质）；当考虑分布式网络时，灰质可以被认为是点，白质是连接点的线。缺失的一环：“激活”的大脑成像只看到点，这实际上只代表了图像的50%。如果不能隔离连接这些点的活动线，即使不是不可能，也很难识别这些重要的分布式网络。本提案的主要目标是识别白质中的活动连接（线），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，我们的小组在使用功能磁共振成像检测大脑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）中的激活。下一步将是发现和描述白质激活的最佳测量方法，并探索其潜在的生物学基础。最终的目标是帮助更好地识别在工作和休息时支持重要的高级心理功能的大脑网络。这项基础研究有望在脑功能障碍（例如多发性硬化症和阿尔茨海默病）的神经学评估中带来实际应用。***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步奠定基础，以帮助三分之一的加拿大人在他们的生活中受到大脑相关疾病的影响。＊＊＊＊＊＊＊＊

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. ********