Scrambling eggs like a neuroscientist

DSC_9764 (425x640)One of the more exciting parts of science is that you get to improvise every once in a while. When you are developing a method, or getting used to new equipment for example. We had been using a train/delay generator and a stimulus isolator to electroplate our platinum tetrodes, but we felt these instruments were slightly overqualified for the job and just as underused. At the same time we tried to find out what the best way was to make tetrode tracks (and more specifically the end points) in the histology of the rat brain visible. We thought that the electroplating equipment could be useful for that, but to find out, we had to bring a box of eggs into the lab.

A well established method to find the end point of electrodes in brain tissue, is to run a short current through the electrode. The brain matter heats up around the tip of the electrode and the proteins in it denature, which is visible as a denser spot during histological evaluation. Of course we went through the literature to see what duration and current other neuroscientists use (higher current and longer duration denature more tissue, we aimed for a spot with a diameter not much bigger than 50 micrometer). Once we had some references, we had to try iDSC_9763 (640x424)t ourselves. On eggs.

Apparently psychologists who performed lesion studies over half a century ago, did pilot studies on egg whites first. Since egg whites behave the same way as brain tissue when exposed to heat, this is the perfect method to see the size of the lesions as a result of current and duration, which can then be applied to the real lesion study. So on a smaller scale we did the same, connecting the train generator and stimulus isolator to one of our precious microdrives that had a tetrode dipped into egg white.

For more, see this excellent post.