Magnetic Resonance Research Center and Departments of Diagnostic Radiology, Biomedical Engineering, Neurology, and Neurobiology, Yale University, New Haven, CT 06520.
Proc Natl Acad Sci U S A. 2013 Sep 10;110(37):15115-20. doi: 10.1073/pnas.1307154110. Epub 2013 Aug 26.
Layer-specific neurophysiologic, hemodynamic, and metabolic measurements are needed to interpret high-resolution functional magnetic resonance imaging (fMRI) data in the cerebral cortex. We examined how neurovascular and neurometabolic couplings vary vertically in the rat's somatosensory cortex. During sensory stimulation we measured dynamic layer-specific responses of local field potential (LFP) and multiunit activity (MUA) as well as blood oxygenation level-dependent (BOLD) signal and cerebral blood volume (CBV) and blood flow (CBF), which in turn were used to calculate changes in oxidative metabolism (CMR(O2)) with calibrated fMRI. Both BOLD signal and CBV decreased from superficial to deep laminae, but these responses were not well correlated with either layer-specific LFP or MUA. However, CBF changes were quite stable across laminae, similar to LFP. However, changes in CMR(O2) and MUA varied across cortex in a correlated manner and both were reduced in superficial lamina. These results lay the framework for quantitative neuroimaging across cortical laminae with calibrated fMRI methods.
需要对皮质层进行特定的神经生理、血液动力学和代谢测量，以解释高分辨率功能磁共振成像 (fMRI) 数据。我们研究了神经血管和神经代谢偶联如何在大鼠感觉皮层中垂直变化。在感觉刺激过程中，我们测量了局部场电位 (LFP) 和多单位活动 (MUA) 的动态、特定层的反应，以及血氧水平依赖 (BOLD) 信号和脑血容量 (CBV) 和脑血流 (CBF)，这些反过来又用于计算经校准 fMRI 测量的氧化代谢变化 (CMR(O2))。BOLD 信号和 CBV 从浅层到深层逐渐减少，但这些反应与特定层的 LFP 或 MUA 相关性不强。然而，CBF 的变化在整个皮层中非常稳定，类似于 LFP。然而，CMR(O2) 和 MUA 的变化在皮层中以相关的方式变化，并且浅层的变化都减少了。这些结果为使用校准 fMRI 方法进行皮质层的定量神经影像学奠定了基础。
