Применение метода экспансионной микроскопии в нейробиологии

Many biological studies require the analysis of ultrastructural changes at the cellular organelles and molecular interaction.  Since the modern confocal microscope resolution is limited by the diffraction limit (200-300nm), it is impossible to study such small objects using standard fluorescence microscopy. Ultra-high resolution microscopy methods require expensive equipment and are technically difficult in use, which in turn limits their widespread practical application. However, recently appeared methods make it possible to increase the resolution of microscopy not by improving the image registration system, but by physically isotropic expansion of a biological sample using a controlled chemical process. Thereby to this method, called expansion or expansive microscopy (EM), it became possible to obtain three-dimensional images of samples with a resolution sufficient for studying individual cell organelles using a conventional confocal microscope. This review covers the history of this method, its basic principles and examples of use in various fields of biology and medicine, as well as reflects future directions for improving this technology. The article discusses the methodological features of the EM applying in the study of brain tissue samples and primary neuronal cell culture with an algorithm that can be used to adapt the standard protocol to the goals and objectives of a particular study.