Department of Physiology of Cognitive Processes, Max-Planck Institute for Biological Cybernetics, 72076 Tübingen, Germany.
NIH/NINDS, Bethesda, MD 20824, USA.
Cell Rep. 2023 Nov 28;42(11):113341. doi: 10.1016/j.celrep.2023.113341. Epub 2023 Oct 31.
Blood-oxygenation-level-dependent functional magnetic resonance imaging (BOLD fMRI) of cortical layers relies on the hemodynamic response and is biased toward large veins on the cortical surface. Functional changes in the cerebral metabolic rate of oxygen (ΔCMRO) may reflect neural cortical function better than BOLD fMRI, but it is unknown whether the calibrated BOLD model for functional CMRO measurement remains valid at high resolution. Here, we measure laminar ΔCMRO elicited by visual stimulation in macaque primary visual cortex (V1) and find that ΔCMRO peaks in the middle of the cortex, in agreement with autoradiographic measures of metabolism. ΔCMRO values in gray matter are similar as found previously. Reductions in CMRO are associated with veins at the cortical surface, suggesting that techniques for vein removal may improve the accuracy of the model at very high resolution. However, our results show feasibility of laminar ΔCMRO measurement, providing a physiologically meaningful metric of laminar functional metabolism.
皮层血氧量依赖功能磁共振成像（BOLD fMRI）依赖于血液动力学反应，并且偏向于脑表面的大静脉。大脑氧代谢率（ΔCMRO）的功能变化可能比 BOLD fMRI 更能反映神经皮层功能，但尚不清楚用于功能 CMRO 测量的校准 BOLD 模型在高分辨率下是否仍然有效。在这里，我们测量了猴初级视觉皮层（V1）视觉刺激引起的皮层分层 ΔCMRO，发现 ΔCMRO 在皮层中部达到峰值，与代谢的放射自显影测量结果一致。与之前的研究结果相比，灰质中的 ΔCMRO 值相似。CMRO 的减少与皮层表面的静脉有关，这表明去除静脉的技术可能会提高非常高分辨率下模型的准确性。然而，我们的结果表明了皮层分层 ΔCMRO 测量的可行性，为皮层功能代谢的分层提供了一个具有生理意义的度量标准。
