Title
Photoacoustic microscopy of obesity-induced cerebrovascular alterations.
Abstract
Cerebral small vessel disease has been linked to cognitive, psychiatric and physical disabilities, especially in the elderly. However, the underlying pathophysiology remains incompletely understood, largely due to the limited accessibility of these small vessels in the live brain. Here, we report an intravital imaging and analysis platform for high-resolution, quantitative and comprehensive characterization of pathological alterations in the mouse cerebral microvasculature. By exploiting multi-parametric photoacoustic microscopy (PAM), microvascular structure, blood perfusion, oxygenation and flow were imaged in the awake brain. With the aid of vessel segmentation, these structural and functional parameters were extracted at the single-microvessel level, from which vascular density, tortuosity, wall shear stress, resistance and associated cerebral oxygen extraction fraction and metabolism were also quantified. With the use of vasodilatory stimulus, multifaceted cerebrovascular reactivity (CVR) was characterized in vivo. By extending the classic Evans blue assay to in vivo, permeability of the blood-brain barrier (BBB) was dynamically evaluated. The utility of this enabling technique was examined by studying cerebrovascular alterations in an established mouse model of high-fat diet-induced obesity. Our results revealed increased vascular density, reduced arterial flow, enhanced oxygen extraction, impaired BBB integrity, and increased multifaceted CVR in the obese brain. Interestingly, the ‘counterintuitive’ increase of CVR was supported by the elevated active endothelial nitric oxide synthase in the obese mouse. Providing comprehensive and quantitative insights into cerebral microvessels and their responses under pathological conditions, this technique opens a new door to mechanistic studies of the cerebral small vessel disease and its implications in neurodegeneration and stroke.
Year
DOI
Venue
2019
10.1016/j.neuroimage.2018.12.027
NeuroImage
Keywords
Field
DocType
Photoacoustic microscopy,Single-vessel analysis,Cerebrovascular reactivity,Blood-brain barrier,Obesity
Evans Blue,Stroke,Cognitive psychology,Psychology,Neurodegeneration,Oxygenation,In vivo,Nitric oxide synthase,Vasodilation,Pathology,Perfusion
Journal
Volume
ISSN
Citations 
188
1053-8119
0
PageRank 
References 
Authors
0.34
4
5
Name
Order
Citations
PageRank
Rui Cao130.82
Jun Li220434.80
Chenchu Zhang300.34
Zhiyi Zuo430.82
Song Hu551.68