Visualization of Microcirculation at Acupoints in vivo of Alzheimer's Disease Animal Model with Photoacoustic Microscope: A Pilot Study

Abstract

Background: Alzheimer's disease may be effectively treated with acupoint-based acupuncture, which is acknowledged globally. However, more research is needed to understand the alterations in acupoints that occur throughout the illness and acupuncture treatment.

Objective: This research investigated the differences in acupoint microcirculation between normal mice and AD animals in vivo. This research also examined how acupuncture affected AD animal models and acupoint microcirculation.

Methods: 6-month-old SAMP8 mice were divided into two groups: the AD group and the acupuncture group. Additionally, SAMR1 mice of the same month were included as the normal group. The study involved subjecting a group of mice to 28 consecutive days of acupuncture at the ST36 (Zusanli) and CV12 (Zhongwan) acupoints. Following this treatment, the Morris water maze test was conducted to assess the mice's learning and memory abilities; the acoustic-resolution photoacoustic microscope (AR-PAM) imaging system was utilized to observe the microcirculation in CV12 acupoint region and head-specific region of each group of mice.

Results: In comparison to the control group, the mice in the AD group exhibited a considerable decline in their learning and memory capabilities (p < 0.01). In comparison to the control group, the vascular in the CV12 region and head-specific region in mice from the AD group exhibited a considerable reduction in length, distance, and diameter r (p < 0.01). The implementation of acupuncture treatment had the potential to enhance the aforementioned condition to a certain degree.

Conclusions: These findings offered tangible visual evidence that supports the ongoing investigation into the underlying mechanisms of acupuncture's therapeutic effects.

Keywords: Acupuncture; Alzheimer’s disease; microcirculation; photoacoustic microscope; senescence-accelerated mouse prone 8.

Fig. 1

Selected acupoints on the mouse (ST36 and CV12).

Fig. 2

The Hadatomo TM Z WEL5200 photoacoustic imaging system (supported by the Advantest (China) Co., Ltd).

Fig. 3

Regions of interested selected on the mice (Left: the head region, Right: CV12 (Zhongwan) acupoint region, 6mm×6 mm).

Fig. 4

Results of hidden platform trial in the Morris water maze test. A) The changes of escape latency with the training days of each group. B) The differences of each group during each training days.

Fig. 5

Results of spatial probe trial in the Morris water maze test. A) The differences of the times of crossing the platform region of each group in the spatial probe trial. B) The search strategy of each group in the spatial probe trial.

Fig. 6

The top view of photoacoustic images of CV12 acupoint region of each group (6 mm×6 mm).

Fig. 7

Microcirculation differences at CV12 acupoint region of each group.

Fig. 8

The top view of photoacoustic images of the head region of each group (6 mm×6 mm).

Fig. 9

Microcirculation differences at the head region of each group.

Fig. 10

Relation of matriculation data between the head region and the CV12 acupoint region.