Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
Department of Radiology, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
Neuroimage. 2014 Jun;93 Pt 2:165-75. doi: 10.1016/j.neuroimage.2013.03.060. Epub 2013 Apr 6.
"In vivo Brodmann mapping" or non-invasive cortical parcellation using MRI, especially by measuring cortical myelination, has recently become a popular research topic, though myeloarchitectonic cortical parcellation in humans previously languished in favor of cytoarchitecture. We review recent in vivo myelin mapping studies and discuss some of the different methods for estimating myelin content. We discuss some ways in which myelin maps may improve surface registration and be useful for cross-modal and cross-species comparisons, including some preliminary cross-species results. Next, we consider neurobiological aspects of why some parts of cortex are more myelinated than others. Myelin content is inversely correlated with intracortical circuit complexity - in general, more myelin content means simpler and perhaps less dynamic intracortical circuits. Using existing PET data and functional network parcellations, we examine metabolic differences in the differently myelinated cortical functional networks. Lightly myelinated cognitive association networks tend to have higher aerobic glycolysis than heavily myelinated early sensory-motor ones, perhaps reflecting greater ongoing dynamic anabolic cortical processes. This finding is consistent with the hypothesis that intracortical myelination may stabilize intracortical circuits and inhibit synaptic plasticity. Finally, we discuss the future of the in vivo myeloarchitectural field and cortical parcellation--"in vivo Brodmann mapping"--in general.
“在体布罗德曼图谱”或使用 MRI 进行的非侵入性皮质分割，特别是通过测量皮质髓鞘化，最近已成为一个热门的研究课题，尽管人类以前的皮质形态学皮质分割倾向于细胞结构。我们回顾了最近的在体髓鞘图谱研究，并讨论了一些估计髓鞘含量的不同方法。我们讨论了髓鞘图谱可能改善表面配准并有助于跨模态和跨物种比较的一些方法，包括一些初步的跨物种结果。接下来，我们考虑了为什么皮质的某些部分比其他部分有更多髓鞘的神经生物学方面。髓鞘含量与皮质内回路复杂性呈负相关 - 一般来说，更多的髓鞘含量意味着更简单，也许更不活跃的皮质内回路。使用现有的 PET 数据和功能网络分割，我们检查了不同髓鞘化皮质功能网络的代谢差异。轻度髓鞘化的认知联想网络比重度髓鞘化的早期感觉运动网络具有更高的有氧糖酵解，这可能反映了更大的持续动态合成代谢皮质过程。这一发现与皮质内髓鞘化可能稳定皮质内回路并抑制突触可塑性的假设一致。最后，我们讨论了在体髓鞘结构领域和皮质分割的未来 - “在体布罗德曼图谱” - 一般来说。
