When a baby is born, the now-useless umbilical cord is usually thrown away. But sometimes, it finds renewed purpose. Parents can decide to donate the blood from the cord to blood banks, which freeze the stem cells within so they can eventually be used to treat people with various cancers and genetic disorders. In the process, plasma—the liquid portion of blood—is usually ignored. But neuroscientist Tony Wyss-Coray thinks this liquid has a purpose, too.
His team at Stanford University School of Medicine has found that plasma from human umbilical cords can rejuvenate the brains of old mice—specifically in an area called the hippocampus that’s vital for learning and memory. Using actual cord plasma “is not something you’d ever want to develop as a treatment,” he says. “It’s very cumbersome and difficult to collect.” But he hopes that by identifying specific beneficial molecules in the fluid, he can develop treatments for conditions like Alzheimer’s. Already, his team has identified a possible candidate—a protein called TIMP2 that seems to underlie many of the improvements in their experiments.
This is the latest in a line of provocative studies involving lab rodents. Collectively, they suggest that it may be possible to revitalize several aging organs—the brain included—by injecting individuals with molecules that are abundant in young blood, but that decline as we age. “The mounting evidence is incredibly exciting,” says Sara Burke, a neuroscientist at the University of Florida who studies age-related memory loss. She wants to know if this approach could enhance the function of other brain areas that become vulnerable in old age, like the prefrontal cortex which governs planning, decision-making and other complex skills.
But Leigh Turner, a bioethicist at the University of Minnesota, adds a word of caution. “It’s not difficult to find innovative findings in mice,” he says. “Any time we’re talking about preliminary research in mouse models, we want to be careful about assuming that we’ll see the same outcomes in human diseases that have historically been very hard to treat.” Wyss-Coray agrees. “It will be important to know if plasma is indeed beneficial in any form in humans and whether TIMP2 could be produced synthetically to mimic beneficial effects.”
He’s also the first to admit that it sounds “creepy” to revive old organs with young blood—an act with echoes of vampirism, supervillainy, and historical apocrypha. The non-fictitious version of this practice has equally macabre roots. In 1863, French physiologist Paul Bert surgically stitched together the blood supplies of two mice, with a technique called parabiosis that has since been used to study cancer, the immune system, organ transplants—and aging. And in 1956, researchers at Cornell…