Japanese scientists have harnessed the power of bioluminescence to create animals with vibrantly glowing brain cells so bright they can be seen from outside the body.
Why so, Frankenstein? You might ask. Well, it’s not just a cool demonstration of bioluminescence, it could be used to non-invasively check out cells inside animals, including tracking cancers or visualizing changes in neurons (brain cells) related to learning and behavior.
As described in Science, a team of researchers led by the RIKEN Brain Science Institute in Japan managed to create mice with brains that contain glowing neurons in the hippocampus. This allowed them to see how the mouse brains were changing as they began learning about a new environment.
"This is the first time such a small ensemble of a few dozen deep neurons related to a specific learning behavior can be visualized non-invasively," lead researcher Atsushi Miyawaki noted in a statement.
In another part of the experiment, they used a similar technique on marmoset monkeys, allowing them to track neurons in the striatum, a deep brain area, for more than a year. The light was so bright, in both of these animals, that the team even managed to image the light from outside of their bodies, as it passed through their skulls.
In animals such as fireflies and jellyfish, bioluminescence is naturally caused by luciferins, a class of substances that are broken down by an enzyme called luciferase to produce light. For this research, the team modified luciferase to produce a bioengineered substance called AkaBLI that glows almost 1,000 times stronger than the typical luciferin-luciferase reaction. This substance was then introduced to the creatures simply by adding it to their water. After drinking the water, hey presto, they were given the power of bioluminescence.
“This technology will allow a range of in vivo applications, including monitoring neuronal-activity–dependent gene expression, following tumor growth and metastasis, tracking immune cell migration, monitoring stem cell fate, and assessing the efficiency of gene delivery and editing technologies,” Yusuke Nasu and Robert E. Campbell wrote in an accompanying article, adding that the research was a “substantial leap forward.”
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