Abstract
The deposition of amyloid-β (Aβ) in the brain is a risk factor for Alzheimer’s disease (AD). Therefore, new strategies for the stimulation of Aβ clearance from the brain can be useful in preventing AD. Transcranial photostimulation (PS) is considered a promising method for AD therapy. In our previous studies, we clearly demonstrated the PS-mediated stimulation of lymphatic clearing functions, including Aβ removal from the brain. There is increasing evidence that sleep plays an important role in Aβ clearance. Here, we tested our hypothesis that PS at night can stimulate Aβ clearance from the brain more effectively than PS during the day. Our results on healthy mice show that Aβ clearance from the brain occurs faster at night than during wakefulness. The PS course at night improves memory and reduces Aβ accumulation in the brain of AD mice more effectively than the PS course during the day. Our results suggest that night PS is a more promising candidate as an effective method in preventing AD than daytime PS. These data are an important informative platform for the development of new noninvasive and nonpharmacological technologies for AD therapy as well as for preventing Aβ accumulation in the brain of people with disorder of Aβ metabolism, sleep deficit, elderly age, and jet lag.
Highlights
Amyloid-β (Aβ) is present in the brain’s interstitial fluid (ISF) and is considered a metabolic waste product [1]
In our previous animal experiments, we clearly showed that PS effectively stimulates the clearing function of the meningeal lymphatic vessels (MLVs), which play a crucial role in Aβ clearance [30,31,32,33]
Since the standard sleep staging rules for mice are not available currently, we developed our original approach based on a Fourier method for the recognition of wakefulness and rapid eye movement (REM) and nonrapid eye movement (NREM) sleep as well as for the analysis of the spectrum of the EEG signals [42]
Summary
Amyloid-β (Aβ) is present in the brain’s interstitial fluid (ISF) and is considered a metabolic waste product [1]. Positron emission tomography with 18F-florbetaben reveals that only one night of sleep deprivation is associated with an increase in the Aβ brain level by 5% [7]. Effective strategies that prevent Aβ accumulation in the brain can be a promising step in AD therapy and promote healthy brain aging. In this aspect, there is increasing evidence that sleep plays an important role in the protection from Aβ accumulation in the brain [4]. Clinical studies have shown that Aβ levels in the cerebrospinal fluid (CSF) are the highest before sleep and the lowest after wakening, while CSF Aβ clearance is conducted by sleep deprivation [15]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
