Scientists use nanotechnology to give mice a temporary "night vision"

A multidisciplinary team of researchers has just given the mice a "night vision" by inserting nanoparticles in their little eyes – and this could possibly be applied to humans one day.

Cue the music of superheroes.

A new article published in Cell describes this technology, which uses a simple injection containing nanoantennae – nanoscopic electromagnetic collectors designed to absorb specific wavelengths – to allow mice to see beyond their visible light spectrum. The whole process is temporary and disappears after about two weeks with no lingering effects. In addition, the injection works with structures already present in the eye and has no effect on the ability of rodents to see during the day.

In a nutshell, most mammals can only see a very small percentage of the electromagnetic spectrum, which corresponds to wavelengths of 400 to 700 nanometers or the colors of the rainbow. -sky. Our eyes are not equipped to see the longer wavelengths emitted at night, which includes light in the near infrared (NIR) and infrared (IR), both around we, like the heat released by people or reflective objects. infrared light.

"When light enters the eye and strikes the retina, rods and cones – or photoreceptor cells – absorb photons with visible light wavelengths and send corresponding electrical signals to the brain." , said the author of the study, Gang Han. "Because infrared wavelengths are too long to be absorbed by photoreceptors, we are not able to perceive them."

This is where "lectin-conjugated nanoparticles" come in. Delivered via droplets, these proteins guide the nanoantennae and "stick" them to the outside of the retinal photoreceptors in the eyes of mice. Once anchored in the photoreceptor cell, they convert the near infrared into visible green light which can then be observed by the retinal cell. The stem or cone then absorbs the shorter wavelengths and sends them to the brain for translation.

"Through this research, we have broadened the applications of our nanoparticle technology both in the lab and in translation," Han said. "These nanoantennae will allow scientists to explore a number of intriguing questions, ranging from how the brain interprets visual cues to the treatment of color blindness."

You may wonder how you can tell if a mouse sees the night or not. Simple: laboratory tests. The researchers noted that the mice injected with the nanoparticles exhibited subconscious reactions to infrared light, such as the constriction of their pupils. They were also able to distinguish different shapes, such as triangles and circles, that end up in a labyrinth in the same way as during the day.

The researchers claim that their work is not only superhuman abilities, but also an opportunity to explore neural networks in the brain and potentially help repair vision.

"We believe this research is a breakthrough in the field of biotechnology. This exciting study is expected to pave the way for many critical applications through the unique creation of the near-infrared mammal's visual capacity and its high translational potential, "said Han. "Moreover, it is very likely that the sky is very different at night and day. We can have the ability to see all the hidden information of NIR and IR radiation in the universe that is invisible to our bare eyes. "