NewScientist Cornect IT'S NOT ROCKET SCIENCE BUT IT CAN BE HARD TO FIND LOVE search New Scientist Opinion   TV   Galleries   Topic Guides   Last Word Home Subscribe Dating News   In-Depth Articles   Blogs PHYSICS&MATH SCIENCE IN SOCIETY SPACE TECH ENVIRONMENT HEALTH LIFE Look for Science Jobs Cookies & Privacy Home | Life | News Fluorescent protein lets us read a fish's thoughts 17:00 31 January 2013 by Douglas Heaven Video: Glowing protein lets us see into a fish's brain The zebrafish spots its lunch. What goes through its brain? Now, for the first time, we can see exactly what it is thinking, thanks to a new way of studying single neurons that lets researchers track patterns of brain activity in a live animal. A standard way to achieve detailed imaging of cellular activity is by genetically altering cells to express green fluorescent proteins (GFPs) which light up when calcium concentrations rise – such as occurs when neurons are activated. To try to see activity in individual neurons, Koichi Kawakami at the National Institute of Genetics in Shizuoka, Japan, and colleagues created a super- sensitive GFP and tested it in zebrafish larvae between four and seven days old, when they are transparent. The researchers focused on capturing activity in the zebrafish's tectum – a region of the brain that processes vision. They set up an LCD screen that displayed a blinking dot to one side of an immobilised zebrafish larva. As the dot appeared and disappeared, they saw corresponding flashes of light from the tectum, reflecting neural activity. When the team moved the dot from left to right and top to bottom, they saw horizontal and vertical movement of brain signals in the tectum, revealing what is known as the visuotopic map. Visual information from each eye is processed in the opposite hemisphere of the brain, so movement seen by the right eye was replicated in the left side of the tectum and vice versa. Magnification factor The difference in scale between the brain map and the actual movement showed that the magnification factor was larger in the vertical direction than the horizontal, but why this should be is unclear. "I think fish eyes and our eyes could be better at finding differences in height rather than those in the horizontal direction," says Kawakami. "It's an interesting question." The team then introduced a live paramecium – a tiny single-celled organism eaten by zebrafish – near the larva's head. There was no response when the paramecium was motionless, but when it started swimming, signals in the zebrafish brain matched the movement of its prey. Kawakami Group/NIG) More
Latest news
Why we're building a €1 billion model 08:00 11 February 2013 The Human Brain Project has just won a €1 billion research prize. Its director Henry Markram says the initiative will unify our understanding of the brain In a rare sighting, a black snub-nosed monkey has Sleep and dreaming: Why can't we stay 16:25 08 February 2013 From fruit flies to dolphins, every creature needs its shut-eye. Why we sleep is one of the biogest mysteries in biology, NewSdentist Connect ADVERTISEMENT http://www.newscientist.com/article/dn23123-fluorescent-protein-lets-us-read-a-fishs-thoughts.html This week's issue Finally, the team observed brain signals while the zebrafish larva and prey both swam freely. Just before the larva caught its prey, the signals converged in the front of the tectum, suggesting that activation of this area could be connected with subsequent activation of the larva's motor pathways. "This is very exciting work," says Martha Constantine-Paton, who studies brain development at the Massachusetts Institute of Technology. She hopes that it will soon be possible to watch how neural circuits grow as a zebrafish matures. That will be the next big hurdle, she says, and since the fish are only transparent as larvae, it would require a cranial window or especially sensitive optical reagents. But we might not be far off. "The sensitivity resolution of this new green fluorescent protein is amazing," she says. Kawakami and colleagues are now attempting to observe activity across the whole brain. "We will explore neurons that work while the fish learns and thinks," he says. "This will lead to an understanding of the fundamental neuronal circuits at work during human thought." Journal reference: Current Biology , DOI: 10.1016/j.cub.2012.12.040 If you would like to reuse any content from New Scientist, either in print or online, please contact the syndication department first for permission. New Scientist does not oan rights to photos, but there are a variety of licensing options available for use of articles and graphics we own the copyright to.
Have your say
Only subscribers may leave comments on this article. Please log in.
Only personal subscribers may leave comments on this article Subscribe now to comment. All comments should respect the New Scientist House Rules. If you think a particular comment breaks these rules then please use the "Report" link in that comment to report it to us. If you are having a technical problem posting a comment, please contact technical support. search New Scientist
© Copyright Reed Business Information Ltd. Go
been seen helping another monkey give birth in south-west China Robot inquisition keeps witnesses on 20:00 07 February 2013. Interviewers are likely to lead witnesses astray. It's time for the machines to start asking the questions see all related stories Most read
Most commented
Grounded: Where the Boeing Dreamliner went wrong Liver cancer survival time tripled by virus Why we're building a €1 billion model of a human brain New map pinpoints cities to avoid as sea levels rise Webcam and CCTV security flaw shows us to prying eyes TWITTER Get the latest from New Scientist: sign up to our Reed Scientific: Life Science Partnership Manager Life Technologies: Scientist III Molecular Biology Life Technologies: Scientist III Molecular Biology Life Technologies: Scientist II Molecular Biology Life Technologies: Scientist II Molecular Biology Back to too Login Science Jobs
LATEST JOBS