Their work has been so fruitful that it could provide them with a lifetime worth of projects.But she and her collaborators can’t waste any time.By 2050, Frisén and Spalding estimate, the bomb pulse will have completely dissipated.The premise of bomb pulse dating is fairly straightforward.Standing outside the low, gray industrial building, she watched as horses went in one side and, about 15 minutes later, a worker appeared on the other end, holding a head, neurons and all.“It was precisely as revolting as it sounds,” she says.Our bodies are prolific artists, creating new cells throughout the body.Some cells, like those found in skin, hair, and the lining of the gut, are produced and discarded on a regular basis, like doodles on scrap paper. Kirsty Spalding was one of the scientists who doubted that assessment.
The only time neuron numbers could increase was thought to be during fetal development and early childhood.“We found stem cells in the hippocampus of adult mice and rats that could create new neurons,” Gage says.It was groundbreaking work, but at the time not everyone was convinced of its importance.Once the peak number was reached—usually around age four—it was all downhill.
But by the late 1960s and early 1970s, rodent studies led some experts like Fred Gage, a neuroscientist at the Salk Institute in La Jolla, California, to question this notion.
To our bodies, one type of carbon is as good as any other, so C in DNA because, while other molecules are frequently refreshed throughout a cell’s life, DNA remains constant.