The plasticity of the brain is its lifelong ability to reorganize neural pathways based on new experience. Imagine making an impression of a coin in a lump of clay. In order for the impression of the coin to appear in the clay, the shape of the clay changes as the coin is pressed into it. Similarly, the neural circuitry in the brain must reorganize in response to experience or sensory stimulation. Neurologists all agree that memories are formed in the hippocampus, a bean-shaped area of the brain, involved in learning. But the mechanism had been an assumption for more than three decades.
credits Marco Nguyen
In 1949, Donald Hebb, a psychologist from Nova Scotia, had suggested that information in the nervous system was probably stored as changes in the connections between neurons. Twenty-four years later, two Norwegian researchers demonstrated a cellular phenomenon that mimicked exactly what Hebb had imagined. Between 1966 and 1973, in Per Anderson’s Laboratory in Oslo, Norway, Timothy Bliss and Terje Lømo were applying patterns of electrical frequencies to a rabbit’s hippocampus and found that when stimulating the rabbit’s brain with very specific electrical patterns, they were inducing changes in the connection between the neurons. Bliss and Lømo called this strengthening long-term potentiation (LTP). Those changes in the hippocampus proved that the brain had remarkable plastic capabilities.
It wasn’t until August 2006 that Jonathan Whitlock, researcher at the Picower Institute, added the missing piece to the puzzle. He showed that the types of changes, Bliss and Lømo could induce in the brain, actually happened naturally.
