For the very first time, Japanese researchers have recorded brain activity as thoughts are being formed, publishing their findings via Current Biology and uploading a video of their discovery to YouTube on Thursday night. The seven-second video clip is embedded at the bottom of the page.
“Our work is the first to show brain activities in real time in an intact animal during that animal’s natural behavior,” Koichi Kawakami, a co-author on the study, said in a press release. “We can make the invisible visible; that’s what is most important.”
The video shows the brain of a baby zebrafish lighting up in its response to seeing food appear in its eyesight.
“The zebrafish is a suitable model animal for fluorescence imaging studies to visualize neuronal activity, because its body is transparent through the embryonic and larval stages,” the study said.
To pull off this incredible video, researchers embedded a double-transgenic larva in agarose -- a porous gel used to measure microorganism motility and mobility -- and presented a spot on an LCD display directly in front of the zebrafish’s right eye. When the fish spotted the food, researchers detected calcium signals on the left tectum -- located in the roof of the midbrain, or mesencephalon -- which disappeared when the spot was removed from view; in the video, you can see regions of the brain light up and then dim when the prey appears and disappears from view.
For comparison, researchers analyzed a swimming paramecium and analyzed its tectal activity during perception of a natural object, comparing it to the tectal response of its free-swimming larval fish. Scientists were able to correlate that these same dynamic brain activities correlated between the paramecium and the fish, particularly regarding prey-capture behavior.
Most people don’t care what zebrafish are thinking, but this new report shows a great deal of promise: Perhaps some day soon, we can utilize similar techniques to gain better insight into how the brain works in other animals, particularly humans and other mammals.
“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 said. “This has the potential to shorten the long processes for the development of new psychiatric medications.”
Watch the seven-second video of the zebrafish’s brain spotting its prey below: