I mentioned before that I work at the University of Miami as a postdoctoral research. My previous research focused on sharks and their sense of smell, but the research I do at UM is very different. Now I am looking at the taste system of mammals. The similarity, of course, is that I am still investigating how animals detect chemicals in their environment, but now my work is more applicable to humans.
In my experiments, I take living taste buds (which are made of several, individual taste cells), load them up with a calcium-sensitive dye, and place them in a little dish. In this dish, I can stimulate the taste buds with different “tastants” (i.e. bitter, sweet, sour tasting substances). If the taste cells detect the bitter substance, for instance, we know that one of the things that happens is that calcium rushes into the taste cells. Lots of other things also happen, which results in a signal getting sent to the brain and a person actually tasting something, but for me, the key is what happens with the calcium. Remember, I loaded the taste buds with a calcium sensitive dye earlier, so this mean that when the taste buds detect the bitter substance, calcium rushes into the cells, and the dye in there “sees” the calcium and basically lights up. The end result is that when I stimulate taste buds, they will glow when they respond. It is so cool!
Of course, taste buds are really small, so all of this happens under a microscope, which is connected to all sorts of other machines and a computer so I can look at the taste bud responses on the screen. This technique is called “calcium imaging”. Below you can see what my calcium imaging “rig” looks like and a zoomed in picture of the little dish containing the taste buds.
This technique is used by lots of different scientists, who research a wide variety of topics other than taste. It can be use with any cells that responds to any kind of stimulus with a change in intracellular calcium – including neurons. Yay science!