Brain Amide Proton Transfer Imaging of Rat With Alzheimer's Disease Using Saturation With Frequency Alternating RF Irradiation Method.

Runrun Wang,Zhuozhi Dai,Peidong Chen,Yanyan Tang,Renhua Wu,Lihua Lai,Gang Xiao,Xiaodan Zong,Bingna Zhang,Yan Li,Guisen Lin,Zhiwei Shen,Yuanfeng Chen

doi:10.3389/fnagi.2019.00217

Abstract

Amyloid-β (Aβ) deposits and some proteins play essential roles in the pathogenesis of Alzheimer’s disease (AD). Amide proton transfer (APT) imaging, as an imaging modality to detect tissue protein, has shown promising features for the diagnosis of AD disease. In this study, we chose 10 AD model rats as the experimental group and 10 sham-operated rats as the control group. All the rats underwent a Y-maze test before APT image acquisition, using saturation with frequency alternating RF irradiation (APTSAFARI) method on a 7.0 T animal MRI scanner. Compared with the control group, APT (3.5 ppm) values of brain were significantly reduced in AD models (p < 0.002). The APTSAFARI imaging is more significant than APT imaging (p < 0.0001). AD model mice showed spatial learning and memory loss in the Y-maze experiment. In addition, there was significant neuronal loss in the hippocampal CA1 region and cortex compared with sham-operated rats. In conclusion, we demonstrated that APT imaging could potentially provide molecular biomarkers for the non-invasive diagnosis of AD. APTSAFARI MRI could be used as an effective tool to improve the accuracy of diagnosis of AD compared with conventional APT imaging.

Highlights

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease in the world, which is characterized with progressive memory decline (Chen et al, 2018)
In the Y-maze test, significant decrease of the spontaneous alternation was found in AD model group compared with the sham operated control group (p < 0.05, Figure 1A)
This report demonstrated the value of APTSAFARI as a noninvasive Magnetic resonance imaging (MRI) technique for assessment of AD rat model

Summary

Introduction

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease in the world, which is characterized with progressive memory decline (Chen et al, 2018). The reliable AD model rat can be made by intracerebroventricular (icv) injection of well-characterized toxic soluble Aβ species into rat brain (Kasza et al, 2017). The injection of Aβ species in rat induced loss of learning and memory behavior, which could be detected using the Y-maze (Hwang et al, 2017). The rat model of AD was used to observe the effect of drug therapy (Fahanik-Babaei et al, 2018) and was often used to establish and validate biomarkers as a surrogate for patients (Prestia et al, 2018) as well

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Discussion

Conclusion