We report here a comparative (using chemical, electrical, and optical stimulation) study of the electrophysiological properties of cultured hippocampal neurons from transgenic animals expressing a mutant presenilin 1 protein. All three types of stimulation were found to elicit the following differences from the wild type: with overall more active electrophysiological behavior (especially at the beginning of stimulation), mutant cells differed from wild-type neurons by not maintaining consistent activity over time. However, only optogenetic stimulation increased the absolute number of action potentials and decreased their amplitude as compared with the corresponding values in wild-type neurons. The molecular-cellular mechanisms of this effect are suitable for further studies, both basic and applied (to identify regimes for controlling the electrical activity of neurons).

In this paper we gave a comparative study of the various physico-chemical properties of the hippocampal neurons in cell culture model of Alzheimer's Desease (Presenilin 1 mutations). It is shown that chemical, electrical and optical effects increase neuronal excitability differently for wild-type and KI (PS1-M146V neurons). In contrast to wild type KI neurons were more excitable, especially at the beginning of stimulation, but over time, this activity has been decreasing. At the same time, only in the case of optogenetic stimulation, exceeding the absolute values of their numbers has been registered, which made it possible to reduce their effect on the corresponding indices in wild type neurons. Molecular-cellular mechanisms of this phenomenon can serve as a material for further studies, both fundamental and practical (determination of the regimes of regulation of the electrical activity of neurons).

This review focuses on general optogenetics issues (in particular the choice of the necessary light exposure settings), as well as certain promising areas of research with optogenetics.

The paper deals with the currently available implants used in optogenetic experiments on laboratory animals in vivo. We present a brief description of the optogenetic investigation stages. Various types of implantable devices generating and recording signals in excitable tissues have been considered. The features of control signal transduction inside living tissues were analyzed. We discussed the possibility of medical and biological use of optical fibers for excitable tissues stimulation. Then we proposed a device of an implantable optical-electrode system for scanning and controlling the bioelectric parameters. The device can be used in medical diagnostics, prosthetics, myostimulation, neurostimulation and cardioacceleration, for instance, at neurological and rehabilitation medical institutions. With this in mind, an attempt will be made to make special combined microelectrode arrays to implant them into living tissue. The arrays should be able to change their profile according to the implantation-area contour and biophysical features of the substrate surface. It is necessary to provide a point generation and layer-by-layer scanning of excitation pulse through integration of individual microelectrode arrays into a single test-system.

The article is devoted to problems of realization and application of optogenetic methods used to identify reasons of various diseases, to monitor the biochemical processes of cell activity and to study various organisms. The problems of delivery, embedding and monitoring the expression of opsin genes into the cell genome of interest have been considered. In the article, the parameters and properties of various opsins and also the main ways of achievement of precise optical control over cell using opsins were presented. The rules for choosing the parameters of a light beam and the features of its putting were pointed out. The characteristic properties of the different measurement technique and recording the experimental quantities were analyzed and given.

A complex on-line procedure based on combined use of integral (spectroturbidimetry) and differential (nephelometry) light scattering methods was applied to studying the size and formation kinetics of dispersed particles in solutions containing a protein and synthetic cationic soluble polymers. The influence of pH of the medium and of the molecular weight and structural organization of polymers on the floccule size and flocculation kinetics was evaluated.