The video is based on a new imaging technique called light-sheet imaging, which has allowed researchers to get an unprecedented glimpse into the neural mechanisms of a living zebrafish.
You’d be hard-pressed to find anything on Earth as complex as the brain – even if that brain happens to belong to a simple zebrafish – and these almost inscrutable organs pose a real challenge to those trying to study them. For decades researchers have had to resort to external devices that work by picking up signals in the brain, and often from just a few hundred neurons out of possibly billions, but what if you could see almost all of these neurons firing in real-time inside an active brain? That’s what researchers from the Howard Hughes Medical Institute in the US have been working on.
“There must be fundamental principles about how large populations of neurons represent information and guide behaviour,” one of the team, neuroscientist Jeremy Freeman, told Joshua Batson at Wired. “In this system where we record from the whole brain, we might start to understand what those rules are.”
The team genetically engineered zebrafish to have a chemical indicator in each of the neurons inside their brains. These chemical indicators are so efficient, they become fluorescent within a tenth of a second after a neuron fires. The new light-sheet imaging technology directs lasers to sweep across the wholly transparent bodies of the fish, which makes these indicators glow. A video camera hanging overhead is then able to capture extremely clear footage of the activity going on inside their brains. Via WATCH: 80,000 neurons fire in a zebrafish brain (Science Alert).