Monday, April 15, 2013

Did you know: A new technique allows high resolution structural imaging of an intact brain

20X magnification of the somatosensory cortex of a mouse
brain slice. These little guys have green flourescent
protein (GFP) from a jelly-fish expressed in a subset of
their neurons. Layer V neuron cell bodies are
the teardrop shaped things at the bottom
 and then the dendrite reaches up like a tree to
then bifurcate near the top (pial surface).
by Robert Cudmore
A group from Stanford have developed a technique called CLARITY which allows intact tissues to be embedded in a hydrogel matrix. The result is a fully assembled but optically transparent tissue that can go through multiple rounds of staining and destaining to reveal the inner structure of the brain. This approach alleviates the painstaking process of sectioning the brain which also has detrimental effects of the structures within the brain.

The procedure involves suspending the brain, or other tissue, in the hydrogel matrix which then forms a hybrid with the proteins, nucleic acids and small molecules found in the organ. The fats are excluded and can be dissolved away in an electric field and the fine structures of the brain can then be observed. This technique will hopefully reveal how different diseases affect brain structure.