近日，加拿大蒙特利尔大学Ravi L. Rungta及其课题组发现，远端活动模式塑造神经血管耦合的空间特异性。2024年9月4日，《自然—神经科学》杂志在线发表了这项成果。

通过多尺度成像技术，研究人员揭示了不同柱状结构和小鼠大脑皮层层中的血管活动与单根触须引发的神经元活动在空间上的关联。研究人员展示了介观尺度的血流动力学信号可以定量反映跨空间的神经元活动，但其由单个血管段的高度异质性反应模式组成，且难以通过局部神经元活动来预测。

这种异质性取决于血管的方向性，特别是在丘脑皮层输入的第4层，毛细血管更倾向于响应其下游灌注域内的神经元活动模式。因此，毛细血管基于远端活动微调血流，并对特定层的活动模式进行编码。这些发现表明，血管解剖结构为功能成像信号设定了分辨率的限制，单个血管不能准确报告其周围的神经元活动，而是整合沿血管树的活动模式。

研究人员表示，神经血管耦合将大脑活动与局部血流变化联系起来，构成了非侵入性脑成像的基础。

附：英文原文

Title: Distal activity patterns shape the spatial specificity of neurovascular coupling

Author: Martineau, ric, Malescot, Antoine, Elmkinssi, Nouha, Rungta, Ravi L.

Issue&Volume: 2024-09-04

Abstract: Neurovascular coupling links brain activity to local changes in blood flow, forming the basis for non-invasive brain mapping. Using multiscale imaging, we investigated how vascular activity spatially relates to neuronal activity elicited by single whiskers across different columns and layers of mouse cortex. Here we show that mesoscopic hemodynamic signals quantitatively reflect neuronal activity across space but are composed of a highly heterogeneous pattern of responses across individual vessel segments that is poorly predicted by local neuronal activity. Rather, this heterogeneity is dependent on vessel directionality, specifically in thalamocortical input layer 4, where capillaries respond preferentially to neuronal activity patterns along their downstream perfusion domain. Thus, capillaries fine-tune blood flow based on distant activity and encode laminar-specific activity patterns. These findings imply that vascular anatomy sets a resolution limit on functional imaging signals, where individual blood vessels inaccurately report neuronal activity in their immediate vicinity but, instead, integrate activity patterns along the vascular arbor. The spatial relationship between neuronal and vascular activity remains highly debated. In this study, the authors used multiscale optical imaging to show how vascular architecture limits the spatial specificity of neurovascular coupling.

DOI: 10.1038/s41593-024-01756-7

Source: https://www.nature.com/articles/s41593-024-01756-7