Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA; Jiangsu Key Laboratory of Molecule Imaging and Functional Imaging, Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing 210009, PR China.
Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY 11794, USA.
Neuroimage. 2018 Jan 15;165:251-264. doi: 10.1016/j.neuroimage.2017.09.055. Epub 2017 Sep 30.
Cerebral hemodynamics are modulated in response to changes in neuronal activity, a process termed neurovascular coupling (NVC), which can be disrupted by neuropsychiatric diseases (e.g., stroke, Alzheimer's disease). Thus, there is growing interest to image long-term NVC dynamics with high spatiotemporal resolutions. Here, by combining the use of a genetically-encoded calcium indicator with optical techniques, we develop a longitudinal multimodal optical imaging platform (MIP) that enabled time-lapse tracking of NVC over a relatively large field of view in the mouse somatosensory cortex at single cell and single vessel resolutions. Specifically, GCaMP6f was used as marker of neuronal activity, which along with MIP allowed us to simultaneously measure the changes in neuronal [Ca] fluorescence, cerebral blood flow velocity (CBFv) and hemodynamics longitudinally for more than eight weeks. We show that [Ca] fluorescence was detectable one week post viral injection and the damage to local microvasculature and perfusion recovered two weeks after injection. By three weeks post viral injection, maximal neuronal and CBFv responses to hindpaw stimulations were observed. Moreover, single neuronal activation in response to hindpaw stimulation was consistently recorded, followed by ∼2 s delayed dilation of contiguous microvessels. Additionally, resting-state spontaneous neuronal and hemodynamic oscillations were detectable throughout the eight weeks of study. Our results demonstrate the capability of MIP for longitudinal investigation of the organization and plasticity of the neurovascular network during resting state and during stimulation-evoked neuronal activation at high spatiotemporal resolutions.
大脑血流动力学会根据神经元活动的变化而调节，这一过程被称为神经血管耦合（NVC），它可能会被神经精神疾病（如中风、阿尔茨海默病）所破坏。因此，人们越来越有兴趣以高时空分辨率来成像长期的 NVC 动力学。在这里，我们通过结合使用基因编码的钙指示剂和光学技术，开发了一种纵向多模态光学成像平台（MIP），该平台能够以单细胞和单血管分辨率在小鼠体感皮层的相对较大视野中进行 NVC 的延时跟踪。具体来说，我们使用 GCaMP6f 作为神经元活动的标志物，它与 MIP 一起使我们能够同时测量神经元[Ca]荧光、脑血流速度（CBFv）和血流动力学的变化，持续超过八周。我们发现，[Ca]荧光在病毒注射后一周即可检测到，并且局部微血管和灌注的损伤在注射后两周内得到恢复。在病毒注射后三周，观察到了对后爪刺激的最大神经元和 CBFv 反应。此外，对后爪刺激的单个神经元激活也被持续记录下来，随后是大约 2 秒的相邻微血管的延迟扩张。此外，在整个八周的研究中，都可以检测到静息状态下自发的神经元和血流动力学的振荡。我们的结果表明，MIP 具有在静息状态和刺激诱导的神经元激活期间以高时空分辨率对神经血管网络的组织和可塑性进行纵向研究的能力。
