A team at the University of Medicine in Washington has figured out what makes lighting capable of stimulating photoreceptors and neurons that regulate circadian rhythms.
Their study published today in Current Biology identifies a cell in the retina, which plays an important role in signaling our brain centers that regulate circadian rhythms. It increases alert attention, memory and cognitive function, and improves mood. We are moving towards the development of a "circadian" light that influences our rhythms "on demand".
A beautiful sunny day in the middle of the night.
Circadian light, the role of a pigment
These effects have been attributed to a pigment in the eye called melanopsin which is sensitive to blue light, but researchers say cone photoreceptors are a thousand times more sensitive to light than melanopsin.
The impulses of the cone photoreceptors respond to short wavelength blue light, but they also respond strongly to long wavelength orange and yellow, coincidentally the colors that exist at sunrise and sunset.
At the head of the study on “circadian” light is Sara Patterson, a neuroscience student at the University of Washington.
The mechanisms that regulate our internal clock have been studied for a long time. In the study, for example, Patterson and colleagues identified a special cell. It is known as inhibitory interneuron o amacrine cell in the retina, which can send signals to the photosensitive cells connected to our brain centers that regulate the circadian cycle.
The researchers claimed that these cells are “The missing component of an ancient evolutionary circuit of vision of colors. A circuit that is able to set the circadian clock by encoding the spectral content of light ”.
“This research started out of our interest in the benefits of getting natural light to help regulate our lives. In particular our watch, our attention and our mood, " says Neitz.
The next goal is to make these lights hundreds of times brighter than normal lights, to stimulate melanopsin.
For this reason, the University of Washington has licensed the use of this technology to TUO, a lighting technology company. The company will develop LED bulbs that incorporate “circadian” wavelengths.