Have you ever wondered what your pet fish was thinking? Researchers from Japan's Graduate University for Advanced Studies, National Institute of Genetics and Saitama University can help you find out. For the first time, they were able to see a thought swim across the brain of a zebrafish, and the findings could have implications for psychiatric treatment in humans.
The researchers developed an extremely sensitive fluorescent probe that could detect activity in the animal's neurons. Simultaneously, researchers developed a genetic method that allowed them to place the probe around the neurons of interest. Using this two-fold method, researchers were able to view the zebrafish's thoughts on a cellular basis. Because zebrafish larvae have transparent bodies, as The Telegraph explains, researchers were able to view exactly which neurons lit up when zebrafish saw their tasty prey - in their case a paramecium.
"Our work is the first to show brain activities in real time in an intact animal during that animal's natural behavior," study author Koichi Kawakami, from Japan's National Institute of Genetics, said in a statement. "We can make the invisible visible; that's what is most important."
The tool allows researchers to view exactly which neurons light up during various brain processes, like decision making, movement and perception. They could even see where the image of the fish's prey was sent in the brain. The results would hold important findings for humans as well, because the brains of zebrafish are very similar to our own. In the future, the researchers may be able to screen chemicals' impact on neuronal activity, cutting down on the lengthy process currently used to screen psychiatric drugs.
"In the future, we can interpret an animal's behavior, including learning and memory, fear, joy, or anger, based on the activity of particular combinations of neurons," Kawakami explained.
The study was published in the journal Current Biology.