One of the problems those who work looking inside the body encounter every day is that there is just too much “flesh” around and finding the tree you’re looking for is difficult in such a dense forest. But, what if we could make all trees in the forest other than those we are interested in, say the willow tress, disappear? This would make our life much easier for we could know exactly where do their branches go, where do they converge or simply quantify better the total number of willow trees in the whole forest.
Well, for the second time in the last five years there’s been a publication that promises to make the forest fade away. First, it was a japanese group from the Riken Institute who developed a method to fade body structures almost to invisibility so that only exogenously labeled ones (by fluorescent proteins, for instance) would keep their coloration and would stand above the “nothingness” of the rest of the tissue. Now, an american group lead by Karl Deisseroth publishes in Nature that they’ve taken this approach one step further, because in contrast with the japanese method, theirs allows for a better recovery of the native proteins of the sample, which is pretty important to maintain structures as similar as possible as the biological template, so to say.
However, even though this method has countless advantages to better describe and characterize biological systems never before exposed to the human eye, it simply cannot allow to see these systems in action since these magician methods can only be applied to fixated tissue, that is dead samples. So functionality is out of the question. Sadly for me…
But! It is going to be a great advantage to many scientists, specially to those working in the Human Connectome Project, which tries to describe the whole set of connections of the human brain. Something like the europe roadmap, only more complex because it changes all of the time (everytime we learn or forget we are creating or destroying some of those connections. The same happens during aging, during a human lifetime there are periods of higher gain or loss of connections among neurons…)
Let me end with a video, in it the researchers present and nicely explain their method. The most impressive to me is the beauty of the images they achieve. However, the full extent of its power still remains to be seen.