Sorbonne Université, Inserm U968, Vision Institute, Paris, France.
Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1266, 75014, Paris, France.
Nat Commun. 2024 Sep 2;15(1):7635. doi: 10.1038/s41467-024-49698-9.
Neurovascular coupling (NVC), which mediates rapid increases in cerebral blood flow in response to neuronal activation, is commonly used to map brain activation or dysfunction. Here we tested the reemerging hypothesis that CO generated by neuronal metabolism contributes to NVC. We combined functional ultrasound and two-photon imaging in the mouse barrel cortex to specifically examine the onsets of local changes in vessel diameter, blood flow dynamics, vascular/perivascular/intracellular pH, and intracellular calcium signals along the vascular arbor in response to a short and strong CO challenge (10 s, 20%) and whisker stimulation. We report that the brief hypercapnia reversibly acidifies all cells of the arteriole wall and the periarteriolar space 3-4 s prior to the arteriole dilation. During this prolonged lag period, NVC triggered by whisker stimulation is not affected by the acidification of the entire neurovascular unit. As it also persists under condition of continuous inflow of CO, we conclude that CO is not involved in NVC.
神经血管耦合（NVC）介导神经元激活时脑血流的快速增加，常用于绘制脑激活或功能障碍图。在这里，我们检验了一个重新出现的假说，即神经元代谢产生的 CO 有助于 NVC。我们在小鼠皮层桶状结构中结合功能超声和双光子成像，专门研究了在短时间强 CO 刺激（10 秒，20%）和胡须刺激下，血管直径、血流动力学、血管/血管周围/细胞内 pH 值和细胞内钙信号沿着血管树突的局部变化的起始时间。我们报告说，短暂的高碳酸血症可逆地酸化了动脉壁和血管周围空间的所有细胞，在动脉扩张前 3-4 秒。在这个延长的滞后期间，由胡须刺激触发的 NVC 不受整个神经血管单元酸化的影响。由于它在持续 CO 流入的情况下仍然存在，我们得出结论，CO 不参与 NVC。
