It seems non-intuitive, but occasionally it takes science creating something bizarre to help us better understand our most basic abilities. Case in point: scientists have engineered a mouse that can "smell" light, according to PhysOrg.com. It's part of a project to understand the complicated neural circuits that underlie the olfactory sense.
According to researchers, studying the sense of smell is difficult because odors can be chemically complex, and isolating the neural pathways the brain uses to identify each scent is difficult.
"It is hard to trace [neural] patterns using olfactory stimuli, since odors are very diverse and often quite subtle. So we asked: What if we make the nose act like a retina?" said Venkatesh N. Murthy, professor of molecular and cellular biology at Harvard, who conducted the study.
To create a mouse that could smell light, Murthy and his colleagues applied the relatively new field of optogenetics to the problem. More specifically, they utilized optogenetic techniques that integrate light-reactive proteins into systems that usually sense things other than light.
The scientists integrated these special light-reactive proteins directly into the olfactory system of the mouse, causing the system to react to light rather than to smell.
Since light input can be easily controlled, the researchers were able to target specific sensory neurons in the nose and were able to follow the activation of those neurons all the way through the pathways into the olfactory bulb.
This breakthrough has revealed some key secrets to how the olfactory sense works. Most notably, researchers found that the timing of a sniff actually plays a large part in how odors are perceived. They hope that future work using this methodology can make possible further research into the neural circuitry of our perception systems.
As for answering the question of what light smells like, that's something you'll have to ask the mouse.