Methods of study of neuron structural heterogeneity: Flow cytometry vs. laser interferometry

Neuronal cells are probably the less studied cells regarding their heterogeneity on a single cell or population levels. One of the main problems of studying of individual neurons is the presence of long processes (axons) on differentiated adult neurons that hamper their isolation without significant damage to the cells. Therefore, the most common method to study neuronal cells is immunofluorescent microscopy of sections of the brain, which remains poorly quantitative and allows analyzing a small number of fixed cells. Also, immunofluorescent microscopy has a number of staining artifacts since histology section has high level of autofluorescence and non-specific binding of fluorescent probes. Alternative methods that could overcome disadvantages of immunofluorescent histology include flow cytometry, scanning cytometry, and laser interferometry. Flow cytometry and, to some extent of degree, scanning cytometry allow performing analysis of multiple markers with a low level of non-specific background and very robust statistics. Laser interferometry allows studies intact, alive neurons without staining. Limitations and advantages of these methods are discussed in this chapter.