Brainbow: Principle, Technique, and Applications

In the field of neuroscience, studying the intricate architecture of neuronal and glial cells forming a network in the nervous system can be extremely useful to understand the networking of neurons within the brain and other parts of the nervous system. However, this is an extremely arduous task due to the complexity of the brain and nerve tissue. To this end, optical techniques combined with genetic labeling techniques can be used to obtain a visual representation of the neurons in the tissue. Brainbow is one such strategy that uses Cre-lox recombination to stochastically express two to four fluorescent proteins in cells of the same tissue. This expression is combinatorial and depends on the copy number of the loxP sites present in each cell, thereby resulting in a myriad of colors and hues, which are unique to each cell, making it easier to visually distinguish each neuron within the complex arrangement of the tissue. This multicolor labeling technique otherwise referred to as the “Brainbow” technique is briefly discussed in the following chapter, along with the principle, techniques, and various applications in the field of neuroscience.