Photobiomodulation Under Electroencephalographic Controls of Sleep for Stimulation of Lymphatic Removal of Toxins from Mouse Brain

Summary

This study presents an original and portable tPBM technology under electroencephalographic (EEG) control of deep or non-rapid eye movement (NREM) sleep in non-anesthetized male C57BL/6 mice of different ages to stimulate lymphatic clearance of Aβ from the brain into the peripheral lymphatic system (the deep cervical lymph nodes, dcLNs).

Abstract

The meningeal lymphatic vessels (MLVs) play an important role in the removal of toxins from the brain. The development of innovative technologies for the stimulation of MLV functions is a promising direction in the progress of the treatment of various brain diseases associated with MLV abnormalities, including Alzheimer's and Parkinson's diseases, brain tumors, traumatic brain injuries, and intracranial hemorrhages. Sleep is a natural state when the brain's drainage processes are most active. Therefore, stimulation of the brain's drainage and MLVs during sleep may have the most pronounced therapeutic effects. However, such commercial technologies do not currently exist.

This study presents a new portable technology of transcranial photobiomodulation (tPBM) under electroencephalographic (EEG) control of sleep designed to photo-stimulate removal of toxins (e.g., soluble amyloid beta (Aβ)) from the brain of aged BALB/c mice with the ability to compare the therapeutic effectiveness of different optical resources. The technology can be used in the natural condition of a home cage without anesthesia, maintaining the motor activity of mice. These data open up new prospects for developing non-invasive and clinically promising photo-technologies for the correction of age-related changes in the MLV functions and brain's drainage processes and for effectively cleansing brain tissues from metabolites and toxins. This technology is intended both for preclinical studies of the functions of the sleeping brain and for developing clinically relevant treatments for sleep-related brain diseases.

Introduction

Meningeal lymphatic vessels (MLVs) play an important role in the removal of toxins and metabolites from brain tissues^1,2,3. Damage of MLVs in various brain diseases, including tumors, traumatic brain injuries, hemorrhages, and neurodegenerative processes, is accompanied by a decrease in the MLV functions leading to the progression of these pathologies^1,2,3,4,5,6. Therefore, the de....

Protocol

All procedures were performed in accordance with the "Guide for the Care and Use of Laboratory Animals", Directive 2010/63/EU on the Protection of Animals Used for Scientific Purposes, and the guidelines from the Ministry of Science and High Education of the Russian Federation (Nº 742 from 13.11.1984), which have been approved by the Bioethics Commission of the Saratov State University (Protocol No. 7, 22.09.2022).

1. Hardware assembly

1. Cut a piece of f.......

Discussion

MLVs are an important target for the development of innovative technologies for modulation of the brain's drainage and removal of cellular debris and wastes from the brain, especially in aged subjects whose MLV function declines^1,22. In a homeostatic state, deep sleep is associated with the natural activation of brain tissue cleansing^13,14. Therefore, it is obvious to expect that stimulation of MLVs d.......

Materials

Name	Company	Catalog Number	Comments
0.1% Tween20	Helicon,  Russia	SB-G2009-100ML
Catheter	Scientific Commodities Inc., USA	PE-10, 0.28 mm ID × 0.61 mm OD
CO2 chamber	Binder, Germany	CB-S 170
Confocal microscop	Nikon, Japan	A1R MP
Dental acrylic	Zermack, Poland-Russia	Villacryl S, V130V4Z05
Drill	Foredom, Russia	SR W-0016
Dumont forceps	Stoelting, USA	52100-07
Evans Blue dye	Sigma-Aldrich, St. Louis, MO, USA	206334
Hamilton	Hamilton Bonaduz AG, Switzerland	29 G needle
Ibuprofen	Sintez OJSC, Russia	N/A	Analgesic drug
Insulin needle	INSUPEN, Italy	31 G, 0.25 mm x 6 mm
Levomekol antibacterial ointment	Nizhpharm	D06C	For external use at a dose of 40 mg/g, 1 time per day
Micro forceps	Stoelting, USA	52102-02P
Microcentrifuge	Gyrozen, South Korea	GZ-1312
Microinjector	Stoelting, USA	53311
Non-sharp tweezer	Stoelting, USA	52108-83P
PINNACLE system	Pinnacle Technology, USA	8400-K3-SL	System for recording EEG (2 channels) and EMG (1 channel) of mice
Shaving machine	Braun	Series 3310s
Single and multi-channel pipettes	Eppendorf, Austria	Epp 3120 000.020, Epp 3122 000.019
Sodium chloride	Kraspharma, Russia	N/A
Soldering station	AOYUE, China	N/A
Stereotaxic frame	Stoelting, USA	51500
Straight dissecting scissors	Stoelting, USA	52132-10P
Tetracycline	JSC Tatkhimfarmpreparaty, Russia	N/A	Eye ointment
Tweezer	Stoelting, USA	52100-03
Ultrasonic cell disrupter	Biobase, China	USD-500
Wound retractor	Stoelting, USA	52125
Xylanit	Nita-Farm, Russia	N/A	Muscle relaxant
Zoletil 100	Virbac Sante Animale, France	N/A	General anesthesia