Wave of single-impulse-stimulated fast initial dip in single vessels of mouse brains imaged by high-speed functional photoacoustic microscopy
Wave of single-impulse-stimulated fast initial dip in single vessels of mouse brains imaged by high-speed functional photoacoustic microscopy
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DOI：
10.1117/1.jbo.25.6.066501
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发表时间：
2020-06-01
影响因子：
3.5
通讯作者：
Wang, Lihong, V
中科院分区：
文献类型：
--
作者：
He, Yun;Shi, Junhui;Wang, Lihong, V
意义：血红蛋白氧合反应对刺激的初始下降是一种空间受限的内源性指标，比血流反应更快，使其成为绘制神经活动所需的无标记对比。一个基本问题是，比响应延迟短得多的单脉冲刺激是否可以在不重复刺激的情况下产生可观察到的初始下降。目的：为了回答这个问题，我们报告了高速功能光声 (PA) 显微镜来研究小鼠大脑中的初始下降。方法：我们开发了一种基于拉曼激光的双波长功能 PA 显微镜，可以以 1 MHz 一维成像速率对毛细血管水平的血液氧合进行成像。该技术用于监测小鼠前爪施加脉冲刺激后脑血管系统的血流动力学。结果：我们观察到早在刺激开始后 0.13 秒，脑微血管就出现了短暂的初始下降。初始下降和随后的过冲表现出在不同微血管区室中传播的波模式。结论：我们以单血管分辨率在空间和时间上量化了小鼠大脑中单脉冲刺激的微血管血流动力学。单脉冲响应的快速无标记成像为实时脑机接口带来了希望。 (C) 作者。由 SPIE 根据 Creative Commons Attribution 4.0 Unported 许可证发布。
Significance: The initial dip in hemoglobin-oxygenation response to stimulations is a spatially confined endogenous indicator that is faster than the blood flow response, making it a desired label-free contrast to map the neural activity. A fundamental question is whether a single-impulse stimulus, much shorter than the response delay, could produce an observable initial dip without repeated stimulation.Aim: To answer this question, we report high-speed functional photoacoustic (PA) microscopy to investigate the initial dip in mouse brains.Approach: We developed a Raman-laser-based dual-wavelength functional PA microscope that can image capillary-level blood oxygenation at a 1-MHz one-dimensional imaging rate. This technology was applied to monitor the hemodynamics of mouse cerebral vasculature after applying an impulse stimulus to the forepaw.Results: We observed a transient initial dip in cerebral microvessels starting as early as 0.13 s after the onset of the stimulus. The initial dip and the subsequent overshoot manifested a wave pattern propagating across different microvascular compartments.Conclusions: We quantified both spatially and temporally the single-impulse-stimulated microvascular hemodynamics in mouse brains at single-vessel resolution. Fast label-free imaging of single-impulse response holds promise for real-time brain-computer interfaces. (C) The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License.