This article was first published in the September 2015 issue of WIRED magazine. Be the first to read WIRED's articles in print before they're posted online, and get your hands on loads of additional content by subscribing online
It's tough to watch taste buds in action -- you can't clamp a microscope on to a subject's tongue. As a result, researchers typically study taste cells in a Petri dish. But for bioengineer Myunghwan Choi and his colleagues at Harvard, a disembodied taste bud is useless. "All the microarchitecture is destroyed," Choi says. And without the microarchitecture -- from taste pores to capillaries -scientists can't fully understand how mice (and people) receive the flavour of Camembert at a molecular level.
So, to examine a live mouse tongue under a microscope, Choi's team invented an apparatus that wouldn't look out of place in A Clockwork Orange. First, researchers stain the anaesthetised rodent's tongue with dye designed to glow under infrared light. Then they use a suction hose to pull its tongue out, and they steady it on a steel brace. The researcher then drips artificial sweetener on to the tongue and beams it with infrared laser light. When a taste pore absorbs the sweetener, the taste cells attuned to sweetness start to fluoresce. It's the first proof that taste cells specialise in the flavours they encounter.
The technique Choi uses to study tongue cells in action has already been used to observe neurons. So the next step is to use two laser microscope setups (and one mouse) to film the tongue and the brain at the same time, revealing the complete mechanism of taste. Perhaps science will finally discover why string cheese is so popular.
The rodent rig
**[1]**A small suction hose pulls out and holds the tongue of an [2] anesthetised mouse. It's kept steady on a [3] steel brace.
This article was originally published by WIRED UK
