How a team of scientists turned ordinary rodents into 'mighty mice' - New York Post

Scientists transformed ordinary rodents into “super mice” by giving them the ability to see infrared light — a technique they say could one day be used on humans.

The mice’s vision was enhanced by tiny nanoparticles which were injected into their eyes by two researchers from Tian Xue of the University of Science and Technology of China and Gang Han from the University of Massachusetts Medical School.

These injectable photoreceptor-binding particles allow mice to develop infrared vision without compromising their normal vision and associated behavioral responses.Ma et al./Current Biology

The mice were able to detect near-infrared light (NIR), as well as normal light, for about 10 weeks without any long-term side effects, the study published Thursday in the science journal Cell found.

Humans and mice can only see about 380 to 740 nanometers within the visible spectrum, meaning longer wavelengths like near-infrared and shorter ones like ultraviolet are invisible.

“This is a physical limit on our visible spectrum,” said Xue.

The mice were injected with photon “up-conversion” nanoparticles that converted low-energy, invisible protons, like near-infrared light, to high-energy ones that are visible.

The particles clung on to photoreceptor cells in the mice’s eyes, allowing them to turn near-infrared light into visible rays.

To prove their findings, the scientists dilated the modified mice’s pupils and exposed them to near-infrared light and then measured their electrical brain activity. The findings showed that their eyes were functioning as though they were seeing visible light.

The mice were also tested in a Y-shaped water maze to see if they could tell between different light patterns. They were trained to escape using a hidden platform illuminated by infrared light.

The modified mice were able to detect the hidden platform, while the non-injected ones “made such choices in a random manner,” the study said.

The scientific breakthrough might mean that one day humans, too, will be able to detect near-infrared.

“In our study, we have shown that both rods and cones bind these nanoparticles and were activated by the near-infrared light,” said Xue. “So we believe this technology will also work in human eyes, not only for generating supervision but also for therapeutic solutions in human red color vision deficits.”