Significance: Cerebral blood flow (CBF) regulation at neurovascular coupling (NVC) plays an important role in normal brain functioning to support oxygen delivery to activating neurons. Therefore, studying the mechanisms of CBF adjustment is crucial for the improved understanding of brain activity. Aim: We investigated the temporal profile of hemodynamic signal change in mouse cortex caused by neural activation and its variation over cortical depth. Approach: Following the cranial window surgery, intrinsic optical signal imaging (IOSI) was used to spatially locate the activated region in mouse cortex during whisker stimulation. Optical microangiography (OMAG), the functional extension of optical coherence tomography, was applied to image the activated and control regions identified by IOSI. Temporal profiles of hemodynamic response signals obtained by IOSI and OMAG were compared, and OMAG signal was analyzed over cortical layers. Results: Our results showed that the hemodynamic response to neural activity revealed by blood flow change signal signal through IOSI is slower than that observed by OMAG signal. OMAG also indicated the laminar variation of the response over cortical depth, showing the largest response in cortical layer IV. Conclusions: Overall, we demonstrated the development and application of dual-modality imaging system composed of IOSI and OMAG, which may have potential to enable the future investigations of depth-resolved CBF and to provide the insights of hemodynamic events associated with the NVC.

中文翻译：

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光学微血管造影显示在晶须刺激期间小鼠桶状皮层的时间和深度分辨的血流动力学变化。

意义：神经血管耦合 (NVC) 的脑血流 (CBF) 调节在正常大脑功能中起着重要作用，以支持向激活神经元输送氧气。因此，研究 CBF 调节的机制对于提高对大脑活动的理解至关重要。目的：我们研究了由神经激活引起的小鼠皮层血流动力学信号变化的时间分布及其随皮层深度的变化。方法：在颅窗手术后，使用内在光学信号成像 (IOSI) 在晶须刺激期间在空间上定位小鼠皮层中的激活区域。光学微血管造影 (OMAG) 是光学相干断层扫描的功能扩展，用于对 IOSI 识别的激活和控制区域进行成像。比较了由 IOSI 和 OMAG 获得的血流动力学响应信号的时间分布，并在皮质层上分析了 OMAG 信号。结果：我们的结果表明，通过 IOSI 的血流变化信号信号显示的对神经活动的血流动力学反应比 OMAG 信号观察到的慢。OMAG 还表明响应随皮质深度的层流变化，显示皮质层 IV 中的响应最大。结论：总的来说，我们展示了由 IOSI 和 OMAG 组成的双模态成像系统的开发和应用，这可能有助于未来深度分辨 CBF 的研究，并提供与 NVC 相关的血流动力学事件的见解。我们的结果表明，通过 IOSI 的血流变化信号信号显示的对神经活动的血流动力学反应比 OMAG 信号观察到的慢。OMAG 还表明响应随皮质深度的层流变化，显示皮质层 IV 中的响应最大。结论：总的来说，我们展示了由 IOSI 和 OMAG 组成的双模态成像系统的开发和应用，这可能有助于未来深度分辨 CBF 的研究，并提供与 NVC 相关的血流动力学事件的见解。我们的结果表明，通过 IOSI 的血流变化信号信号显示的对神经活动的血流动力学反应比 OMAG 信号观察到的慢。OMAG 还表明响应随皮质深度的层流变化，显示皮质层 IV 中的响应最大。结论：总体而言，我们展示了由 IOSI 和 OMAG 组成的双模态成像系统的开发和应用，这可能有助于未来深度分辨 CBF 的研究，并提供与 NVC 相关的血流动力学事件的见解。