Earlier today I wrote about a breakthrough method called CLARITY, pioneered by Stanford psychiatrist/bioengineer Karl Deisseroth, MD, PhD, for rendering intact tissue samples transparent. Above is a video clip showing off the new method's capabilities. First you'll witness a "fly-through" of a complete mouse brain using fluorescent imaging. The immediately following clip - it's spectacular! - provides a three-dimensional view of a mouse hippocampus (the brain's brain's memory hub), with projecting neurons depicted in green, connecting interneurons in red, and layers of support cells, or glia, in blue.
Note that in both cases, there was no need to slice the tissue into ultra-thin sections, analyze them chemically and/or optically and then laboriously "sew" them back together via computer algorithms in order to reconstruct a 3-D virtual image of the biological sample. All that was required, after performing the necessary hocus-pocus, was to "send in the stain" (i.e., use histochemical means to paint different cell types different colors) and move the sample or camera lens or shift the latter's focal length. Nice trick. With big implications for biomedical research.
Previously: Lightning strikes twice: Optogenetics pioneer Karl Deisseroth's newest technique renders tissues transparent, yet structurally intact, Visualizing the brain as a Universe of synapses and A federal push to further brain research