PDF(Pubmed)
Abstract：
Neuronal regulation of cerebrovasculature underlies brain imaging techniques reliant on cerebral blood flow (CBF) changes. However, interpreting these signals requires understanding their neural correlates. Parvalbumin (PV) interneurons are crucial in network activity, but their impact on CBF is not fully understood. Optogenetic studies show that stimulating cortical PV interneurons induces diverse CBF responses, including rapid increases, decreases, and slower delayed increases. To clarify this relationship, we measured hemodynamic and neural responses to optogenetic stimulation of PV interneurons expressing Channelrhodopsin-2 during evoked and ongoing resting-state activity in the somatosensory cortex of awake mice. Two-photon microscopy (2P) Ca2+ imaging showed robust activation of PV-positive (PV+) cells and inhibition of PV-negative (PV-) cells. Prolonged PV+ cell stimulation led to a delayed, slow CBF increase, resembling a secondary peak in the CBF response to whisker stimulation. 2P vessel diameter measurements revealed that PV+ cell stimulation induced rapid arterial vasodilation in superficial layers and delayed vasodilation in deeper layers. Ongoing activity recordings indicated that both PV+ and PV- cell populations modulate arterial fluctuations at rest, with PV+ cells having a greater impact. These findings show that PV interneurons generate a complex depth-dependent vascular response, dominated by slow vascular changes in deeper layers.
摘要：
脑血管系统的神经元调节是依赖于脑血流量（CBF）变化的脑成像技术的基础。然而,解释这些信号需要理解它们的神经相关性。小白蛋白（PV）中间神经元在网络活动中至关重要，但是它们对CBF的影响还没有完全理解。光遗传学研究表明，刺激皮层PV中间神经元诱导不同的CBF反应，包括快速增长，减少,和较慢的延迟增长。为了澄清这种关系，我们测量了清醒小鼠体感皮层中在诱发和持续静息状态活动期间,对表达视紫红质-2的PV中间神经元的光遗传学刺激的血流动力学和神经反应。双光子显微镜（2P）Ca2成像显示PV阳性（PV）细胞的强烈激活和PV阴性（PV）细胞的抑制。长时间的PV+细胞刺激导致延迟，CBF缓慢增加，类似于CBF对胡须刺激的反应中的第二峰。2P血管直径测量显示,PV+细胞刺激诱导浅层中的快速动脉血管舒张,并在较深层中延迟血管舒张。正在进行的活动记录表明，PV和PV细胞群均可调节静止时的动脉波动，与PV+电池具有更大的影响。这些发现表明，PV中间神经元产生复杂的深度依赖性血管反应，以深层缓慢的血管变化为主。
