Even old brains can make new neurons, study suggests
Your body is constantly generating new cells. In your digestive tract, the colon’s lining turns over every five to seven days. Your red blood cells replace themselves every few weeks, skin cells about once a month. But certain organs are a big exception. Contrary to popular belief, we are not biological Theseus’ ships, reconstructing ourselves entirely from fresh building blocks every seven years. Most of your neurons, the cells that fast-track information across the brain, spine, and sensory organs, have the same lifespan as you do. Until the late 20th century, the prevailing view in neuroscience was that, past childhood, humans stop making neurons, brain-wide. What we have in adolescence, is what we get, and all we can do is lose cells or reorganize them. However, the latest research adds to a mounting body of evidence finding that the timeline of neuron generation isn’t so clear-cut. In at least two parts...