Some proteins are specifically expressed in certain cellular compartments of neurons. So with the help of these proteins, we can state different compartment of neurons. For example, MAP2, this protein microtubule associated protein. This protein only expressed in the dendrites and soma region of neurons. So if we stain MAP2, then we can know where cell body, soma, and a dendrites are. The green stain is the dendrites and the soma and the blue stain is the dapi stain that we mentioned here. Dapi can find too DNA. So dapi stain for the nucleus identified cell population. So some other proteins can localize only in axons. So for example, tao protein is another microtubule associated protein. So tao only localizes in axons, so tao staining will tell us where the axons are. So we have more fancy, modern variations of applications of fluorescence protein. This technique came several years ago, called brainbow. It's like the word rainbow, they called this brainbow. So the principle of this brainbow staining is very simple. The purpose of this staining is to label different cells in our brain with different color. If you label two neighbor cell with one color sometime is very hard to distinguish this two cells because they are close to each other and then they label the same color right? So the ideas is to randomly label all cells in our brain region with different colors. So the principle of this stainy messes or this label new messes pretty straightforward. With four color, with the fluorescence protein was four different colors, one is blue color, one is yellow, one is red and one is green color. So this is for basic color, randomly expressed in the neurons at random dosage. Dosing at random level expression. So that you can make theoretically any color in this world. With just four basic colors. Four basic pixels. So this is the actual picture it the brain tissue, cortex region labeled with this technique, rainbow technique. You can see every neural labeled with different color. Sometimes dramatic difference, sometimes slight difference but different colors. And with this technique that we can study the connections of these neurons. We can trace this neuron for example this more green like neuron. Where he send his axon too and then which neurals are connected to this green like axons and then the next level of neural connected to rare. So we can study the connections of these neurals in the real tissue