Evaluation of the Electroacupuncture Effect on Cerebral Blood Flow in APP/PS1 Mice by Using the Laser Speckle Technique

Summary

Here, we present a protocol centered on laser speckle contrast imaging to quantify cerebral blood flow, combined with the Morris Water Maze, for evaluating electroacupuncture's effects in APP/PS1 (AD model) mice, valuable for AD cerebrovascular research.

Abstract

Alzheimer's disease (AD) is characterized by progressive cognitive decline and cerebrovascular dysfunction, including reduced cerebral blood flow (CBF) and neurovascular unit impairment. Electroacupuncture (EA) has shown potential in improving neurological functions, its mechanism may be related to regulating CBF. Laser speckle imaging is a wide-field method for real-time assessment of CBF and can precisely evaluate changes in cerebral blood perfusion. In this experiment, we observed the effects of electroacupuncture on CBF and cognitive ability in AD model mice (APP/PS1 transgenic mice). The blood perfusion of the middle cerebral artery and its branch vessels in mice was observed by laser speckle imaging. The spatial cognitive function of mice was evaluated using the Morris water maze. The results showed that EA could improve the cognitive function of APP/PS1 mice, and the escape latency was significantly decreased in the Morris water maze test (P<0.05). Furthermore, Laser speckle contrast imaging (LSCI) confirmed significant cerebral hypoperfusion in AD model mice compared to wild-type controls (P < 0.05), and importantly, EA treatment induced a statistically significant increase in CBF (P < 0.05), reversing the cerebral hypoperfusion in AD mice. Laser speckle imaging is a visualization technique for evaluating EA-induced cerebrovascular improvements. These findings support EA as a potential adjunct therapy for AD by targeting cerebrovascular dysfunction.

Introduction

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the progressive cognitive impairment and memory decline. It processes the pathological features of the deposition of extracellular beta-amyloid (Aβ) plaques, intracellular neurofibrillary tangle (NFTs), and neuronal loss¹. While these classic features have been the primary focus of therapeutic research, growing evidence underscores the critical role of decreased cerebral blood flow (CBF) in the pathogenesis and progression of AD². CBF reduction occurs in the early stage of AD onset and is associated with the severity of cogniti....

Protocol

This protocol was approved by the Animal Ethics Committee of Beijing University of Chinese Medicine (BUCM20250708-005), and it was in accordance with all guidelines for the Care and Use of Laboratory Animals of China.

1. Preparation

1. Twelve 6-month-old male APP/PS1 mice and six 6-month-old male C57bl/6 mice were used in this experiment.
2. All mice were housed in the Animal Experiment Center of Beijing University of Chinese Medicine, with three mice per cage. They had free access to sterile drinking water and standard pellet diet.
3. The housing environment was maintained on a 12 h light/dark cycle, with the ambient....

Results

Effects of EA on spatial learning and memory in AD model mice

The results of the Morris water maze test are shown in Figure 2. Figure 2A shows the escape latency during the hidden platform test over five days. The escape latency of AD group showed a fluctuating trend, while the WT and EA groups decreased steadily. The escape latency of the AD group was significantly longer than that of the WT group from Day 4 to Day 5.......

Discussion

The present study demonstrates that long-term EA intervention at Baihui (GV20) and Yintang (GV29) acupoints significantly ameliorates spatial learning deficits in APP/PS1 transgenic mice, as reflected by the shortened escape latency in the Morris Water Maze hidden platform test. This finding is consistent with previous reports that EA improves cognitive function in various AD models via mechanisms such as reduced Aβ deposition and attenuated neuroinflammation¹³. Notably, acupoint selection wa.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
acupuncture needle	(Beijing Zhongyan Taihe Medicine Company, Ltd., China	0.25 mm × 13 mm	acupuncture needle
Laser speckle contrast imaging system	Gene&I Scientific. Ltd.	MoorFLPI-2
mouse restrainer	Hengtai Laboratory Equipment Center	HT-A2
Tribromoethanol	Nanjing Aibei Biotechnology Co.,Ltd.	M2910	anesthesia