Glowing nanotubes have allowed researchers to peer through a mouse's skull and examine its living brain in real time.

Credit: Dai Lab and Kuo Lab, Stanford Univ.

Calvin Kuo and Hongjie Dai of Stanford University in California and their colleagues injected fluorescent molecules based on carbon nanotubes into the tails of mice. The nanotubes were then carried around in the animals' bloodstreams and when lasers were shone onto the rodents' skulls, the molecules gave off near-infrared light (pictured) that was visible through the bone. This allowed the researchers to image blood moving through the brain to a depth of more than 2 millimetres and to detect obstructed arteries. However, the method might not be usable in humans because of our thicker skulls.

Nature Photon. (2014)