Laser-induced generation of singlet oxygen and its role in the cerebrovascular physiology

For over 55 years, laser technology has expanded from laboratory research to widespread fields, for example telecommunication and data storage amongst others. Recently application of lasers in biology and medicine presents itself as one of the emerging areas. In this review, we will outline the recent advances in using lasers for the generation of singlet oxygen, traditionally used to kill tumour cells or induce thrombotic stroke model due to damage vascular effects. Over the last two decade, completely new results on cerebrovascular effects of singlet oxygen generated during photodynamic therapy (PDT) have been shown alongside promising applications for delivery of drugs and nanoparticles into the brain for therapy of brain cancer. Furthermore, a "gold key” has been found to overcome the limitations of PDT, such as low light penetration and high toxicity of photosensitizers, by direct generation of singlet oxygen using quantum-dot laser diodes emitting in the near infrared (NIR) spectral range. It is our motivation to highlight these pioneering results in this review, to improve understanding of the biological role of singlet oxygen and to provide new perspectives for improving clinical application of laser based therapy in further research

Technology of the photobiostimulation of the brain’s drainage system during sleep for improvement of learning and memory in male mice

In this study on healthy male mice using confocal imaging of dye spreading in the brain and its further accumulation in the peripheral lymphatics, we demonstrate stronger effects of photobiomodulation (PBM) on the brain’s drainage system in sleeping vs. awake animals. Using the Pavlovian instrumental transfer probe and the 2-objects-location test, we found that the 10-day course of PBM during sleep vs. wakefulness promotes improved learning and spatial memory in mice. For the first time, we present the technology for PBM under electroencephalographic (EEG) control that incorporates modern state of the art facilities of optoelectronics and biopotential detection and that can be built of relatively cheap and commercially available components. These findings open a new niche in the development of smart technologies for phototherapy of brain diseases during sleep

Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd

Extended detrended cross-correlation analysis of electrocorticograms

An extension of detrended cross-correlation analysis (DCCA) for processing interrelated nonstationary time series is considered using electrocorticograms (ECoG) in mice as an example. The application of this approach to the case of wakefulness and 1-day sleep deprivation is discussed. It is shown that, although the DCCA method enables to detect changes in ECoG caused by sleep deprivation, its extension improves the separation of the dynamics and may reduce the amount of data required to identify the state of the brain electrical activity

Indices of cardiorespiratory synchronization from rat blood pressure data

A recently developed method for diagnostic of phase synchronization between several oscillatory processes from one-dimensional signals alone was extended and applied to the blood pressure signal of freely moving rats. Each rat examined has undergone four stages: 1) healthy not-influenced 2) healthy challenged by beta blocker 3) with stress-induced myocardial injuries 4) with stress-induced injuries challenged by beta-blocker. It is shown that cardiorespiratory synchronization plays an essential role at each of these stages

Multiresolution wavelet analysis of transients: numerical simulations and application to EEG

We explore the capabilities of multiresolution wavelet analysis (MWA) to characterize complex dynamics based on short data sets that can be applied for diagnosing inter-state transitions. Using the example of chaos–hyperchaos transitions in the model of two interacting Rössler systems, we establish the minimum amount of data necessary for reliable separation of chaotic and hyperchaotic oscillations and discuss how this amount changes depending on the length of the transient process. We then discuss transitions between wakefulness and artificial sleep in mice and estimate the duration of electroencephalograms (EEG) that provide separation between these states