If your skin is cut superficially, it heals within a few days. Many other organs in the body can also repair themselves: new cells are generated by cells that divide and reproduce in response to injury. Unfortunately, while brain cells do grow and specialize during infancy and childhood, by the time we become adults nearly all of them lose the capacity to divide and reproduce. And yet we know that our brains are constantly changing: we learn throughout our lives, we have a range of reactions that we can modulate in response to other people, places, and even time itself. So how do we explain this contradiction: the brain creates no new nerve cells but has great flexibility? The answer lies in the
revolutionary new finding of brain plasticity.
Dr. Eric Kandel, a Nobel Prize winner, works a few floors above my office in the same research institute. For several decades, Kandel has studied a species of snail called aplysia, which looks like a small black blob with ears. Aplysia has large nerve cells that lend themselves to experiments.
Kandel’s groundbreaking studies have shown that many nerve cells in aplysia, and in more complex species, retain the property of plasticity, which means that they can change their structure or function over time. The nerve cells do this by sprouting new branches called dendrites and forming contacts with other nerve cells to compensate for those that have been lost. Using a different approach, Bruce McEwen’s laboratory at Rockefeller University demonstrated what was once thought to be impossible: plasticity and regeneration of nerve cells in the hippocampus in animal studies.
As an analogy, we know that people who are born blind develop an exquisite sense of touch and hearing. For those who constantly use Braille and become expert at it, the brain region responsible for controlling the one finger used for reading physically grows in size. This type of compensation may also occur following memory loss, depending on the cause.
Taken From: The Memory Program How to Prevent Memory Loss
and Enhance Memory Power
