Aquaporin 4 channels or AQP4 channels are water channels distributed heavily within the central nervous system. The AQP4 channel are of interest to scientists because they are known to cause or be involved in a few different types of brain disorders. The next question is what goes wrong in these channel and how to treat it. However, another important question must be answered before treatment. How does one know what areas of the brain are being affected my non-funcational AQP4 channels?
The answer to this question is 2-nicotinamido-1,3,4-thiadiazole (TGN-020), a recently developed AQP4 channel block which when synthesized with a carbon-11 isotope allows for PET scans to pick up on where functional AQP4 channels are located by blocking the functional ones. The development on TGN-020 has been proven affective in mice at locating AQP4 channels and will hopefully help shed light on the causes or the effects of certain human brain disorders.
I thought this article was interesting because of the methods used. The study took regular mice and gave them TGN-020 and took pictures, then they took mice with AQP4 knocked out and administered the same amount of the drug and took pictures. They compared the two results, but the interesting thing about this is that they took the extra step. Not only was it enough to prove TGN-020 had infinity to AQP4 (which they had done in prior experiments) they also wanted to prove how how much compared to baseline levels (that don't exist in nature).
One can take the amount of pick-up from non-AQP4 aquaporins, from the mice without AQP4 (these channels do resemble each other some, so while selective, nothing is 100% exclusive), and subtract it from the AQP4 mice's results. The subtraction would give accurate readings on how much and where was AQP4 activated in the mouse. The part that struck me as being neat here is how much time this is going to save someone who is trying to figure this same thing out in humans, because unlike mice we can't just knock out AQP4 channels but you can apply the results from mice, into people to give a lot better estimate.
Kudos The University of Niigata, you win. If you would like to read the article it can be found here.