Fluorescent methods are widely used in studies of the physiology of the brain in general, and in the analysis of the degree of permeability of the blood-brain barrier (BBB) in particular. As recent experimental data show, the spatial patterns of the BBB opening, on the one hand, observed for the whole brain, and on the other, they can be highly localized if one track their from the very beginning. We consider the issues related to image analysis from the point of view of the classification of flowrescent objects, and also propose a technology for simulating BBB leakage based on layer-by-layer modeling of the diffusion process in a heterogeneous spatial template created directly from experimental data.
Spreading vascular reactions are mediated by electrical signals that are transmitted through the endothelial layer of blood vessels. The contraction of a vessel as a whole is impossible without the coordinated work of the smooth muscle cells of its wall, the study of the mechanisms and characteristics of their interconnection is important for understanding how their synchronized behavior is formed. In our work, we propose and investigate a mathematical model that focuses on taking into account the peculiarities of the interposition of endothelial cells and smooth muscle cells.
Endothelial cells are cells lining the inner surface of the blood and lymphatic vessels, they separate the bloodstream from the deeper layers of the vascular wall. Earlier endothelium was considered only as a passive barrier between blood and tissues. However, it has now become apparent that endothelial cells, specifically reacting to different molecular signals generated locally and remotely, perform a variety of functions. Simulation of large vascular networks requires the development of specialized models of autoregulation of vascular tone. On the one hand, such models should have a strong support for cellular dynamics, on the other - be as computationally efficient as possible. A model of a two-dimensional cylindrical array of endothelial cells is proposed on the basis of the integral description by means of the whole-cell CVC. The process of propagation of hyperpolarizing and depolarizing pulses is investigated depending on the statistics of cell distribution between the two main types. Endothelial cells are considered as a dynamic system possessing bistability. Based on the articles, the results of the distribution of the resting-potential values were repeated, the propagation of the hyperpolarizing pulse was observed, the endothelial cell chain supported the propagation of the wave switching to a hyperpolarized state, and then the return wave returned to its original state.
Photoplethysmography is an optical technique that can be used to detect blood volume changes and to measure important physiological parameters. This is low cost and non-invasive technique. However, one has to apply sensor directly to the skin. In this regard, the development on remote mothods receives the growing attention, such as imaging photoplethysmography (iPPG). Note, most of public-available iPPG systems are based on smartphone-embedded cameras, and thus have a sample frequency about 30-60 frames per second, which is enough for heart rate measurements, but may be too low for some more advanced usages of this technique. In our work, we describe the attempt to use smartphone-based iPPG technique aimed to measure the tiny mismatch in RR interval data series recorded from left and right arms. We use the transmission mode iPPG, in which the light transmitted through the medium of finger is detected by a web-camera opposite the LED source. The computational scheme by processing and analysis of the received signal was implemented using MATLAB language (MathWork Inc. in the United States). We believe that further development of our approach may lead to fast and low cost method to access the state of the sympathetic nervous system.