ROBUST DETECTION OF OCULAR DOMINANCE IN HUMANS BOLD 7 T

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 哺乳动物大脑中的细胞往往根据它们的传入和传出连接以及它们的生理特性被组合在一起。新皮质的柱状结构是这种模块化组织的突出例子，并在大鼠、猫和猴子的解剖学和生理学实验中得到了广泛的研究。对这类结构进行非侵入性研究的重要性，特别是在人类受试者身上，无论怎么强调都不为过。因此，人们使用功能磁共振成像(FMRI)进行了许多尝试，以绘制皮质柱图，这并不令人惊讶。然而，迄今为止使用的功能磁共振成像方法的健壮性、可重复性和通用性一直是激烈辩论的主题。在高磁场磁体(7T)上使用差分映射，我们在这里展示了Hahn Spin-Echo(HSE)BOLD能够在几天内高精度地重现人类视觉皮质的眼优势柱(ODC)，相对于预期的尸检数据空间模式。另一方面，由于非特异性信号的存在，传统的梯度回声(GE)血氧水平依赖(BOLD)信号在某些情况下无法在所选灰质区域均匀地分辨ODC。HSE信号统一解析ODC模式，提供了一种更通用的映射方法(即不需要基于功能组织和血管结构的先验知识或假设来调整实验方法，以避免混淆大血管效应)来映射人类大脑中未知的柱状系统，可能为研究人类感觉皮质的功能架构和特定认知过程的大脑模块铺平道路。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cells in the mammalian brain tend to be grouped together according to their afferent and efferent connectivity, as well as their physiological properties. The columnar structures of neocortex are prominent examples of such modular organization, and have been studied extensively in anatomical and physiological experiments in rats, cats and monkeys. The importance of noninvasive study of such structures, in particular in human subjects, cannot be overemphasized. Not surprisingly, therefore, many attempts were made to map cortical columns using functional magnetic resonance imaging (fMRI). Yet, the robustness, repeatability, and generality of the hitherto used fMRI methodologies have been a subject of intensive debate. Using differential mapping in a high magnetic field magnet (7 T), we demonstrate here the ability of Hahn Spin-Echo (HSE) BOLD to map the ocular dominance columns (ODCs) of the human visual cortex reproducibly over several days with a high degree of accuracy, relative to expected spatial patterns from post-mortem data. On the other hand, the conventional Gradient-Echo (GE) blood oxygen level dependent (BOLD) signal in some cases failed to resolve ODCs uniformly across the selected gray matter region, due to the presence of non-specific signals. HSE signals uniformly resolved the ODC patterns, providing a more generalized mapping methodology (i.e. one that does not require adjusting experimental approaches based on prior knowledge or assumptions about functional organization and vascular structure in order to avoid confounding large vessel effects) to map unknown columnar systems in the human brain, potentially paving the way both for the study of the functional architecture of human sensory cortices, and of brain modules underlying specific cognitive processes.