Consider a transparent brain. Where you can see any neuron you want, and its connections. And imagine seeing them in 3D. Did you think?
At the link below you can find the images of neurons in the mouse hippocampus with fluorescent staining using the CLARITY technique. On the basis of the technique, there is the chemical SDS. A detergent-derived substance called SDS-sodium dodecyl sulfate- makes the brain transparent by removing fat molecules that block the passage of light.
Various fat removal techniques, previously tried by different groups, also removed proteins and prevented the identification of different neuron types. However, this problem was also solved by binding proteins, nucleic acids and other biomolecules using acrylamide. When acrylamide is heated, it polymerizes to form a network that holds the molecules together and enables the process to take place with a relatively small loss of 8% (was 41% in previous methods). Then, the lipids in the tissue are attached to the SDS molecules and are carried out of the tissue with the help of electric current. Only the biomolecules remain attached to the acrylamide.
With the CLARITY method, it is possible to see neurons from outer layers to inner structures such as the thalamus. It has also been tested in autopsy preserved brains, and a single neuron extension can be visualized up to 0.5 mm. With this method, healthy brain connections, connectivity disorders and aging can be studied, and especially for sensitive and rare diseases, brain libraries can be created that researchers can retrieve, study and return when necessary.
