The brain inside your head right now is not the same one you woke up with. For most of the 20th century, neuroscientists held a bleak dogma: once you reach adulthood, the brain is finished, hardwired, in slow permanent decline. This episode shatters that idea, tracing neuroplasticity from the pioneers who were shouted down to the experiments that proved the brain is less a printed circuit board than a live-wiring city grid, constantly rerouting itself.

It walks through the landmark evidence, Merzenich's monkeys remapping a scrambled hand, London cabbies physically growing their hippocampi to hold 25,000 streets, seasonal brain growth in chickadees, and breaks down the mechanics: structural versus functional plasticity, the four rerouting workarounds, and adult neurogenesis. It ends at the clinical frontier, where psychoplastogens like ketam ...