© LUCY READING-IKKANDA
Dan Berkowitz might never have noticed the phenomenon if not for the new lights. In 2012, Johns Hopkins University’s Berkowitz had just moved to a lab space where the lights were motion-activated, and his postdoc Gautam Sikka soon began to observe a curious response in the blood vessels he had isolated for study: whenever he walked in and the lights turned on, the vessels exerted less pressure on the force transducer the researchers had attached to constantly stream data.
A literature search revealed that the relaxation of blood vessels in response to light, called photorelaxation, had been described almost 50 years earlier, but the underlying mechanisms had never been fully elucidated. Berkowitz wondered if these effects were mediated by resident light-sensing pigments. If so, it ...