It’s fascinating how resilient the brain is and how it can miraculously rewire and restore itself. There are so many stories about people who, after extensive injuries or having part of their brain taken out, have recovered the lost function as one part of the brain takes over the damaged or missing part. In this series of brain blogs, I will be exploring ways to change and improve our own brains – neuroplasticity.
Our brains want us to be healthy and functional. Likewise, if they have been injured, they are programmed to make themselves healthy and functional again.
When I first began studying the brain, the accepted theory was that after age 24 one’s brain stops growing. According to this theory the brain became fixed, no longer able to heal itself. Today’s science tells us this is far from the truth.
In the 1990s major new discoveries were made, and now the notion that the brain has the ability to act and react in ever-changing ways at all ages has become generally accepted. The brain-peoples’ jargon term for this is neuroplasticity – neuro meaning the nervous system, and plasticity meaning the ability to change and be changed.
To convey a good understanding how neuroplasticity works, I need to introduce another important concept: synaptic pruning. Synapses (see picture above) are the wires and gaps in the brain that connect one part to another. Our brain sends electrical impulses that begin in a brain cell. Then the electricity travels down the axon where it goes to the synaptic gap. At this point the electrical impulse gets turned into neurotransmitters in the synaptic gap at the end of the axon. The neurotransmitters travel across the synaptic gap and enter a “lock-and-key” structure on the opposite side of the synaptic gap to be turned into electricity again, which travels down the dendrites to the receiving brain cells.
As newborns we start out with many, many connections. Then, with age, we prune away (trim) the unused and useless or injured ones. So a baby’s learning process consists not just of making the connections (for example to walk), but by refining the number of connections to a more manageable number so that walking becomes more dedicated, targeted and better timed. At later age, these connections can also be recreated, or even rerouted, which is where “use it or lose it” comes in ... but more about that later.
How your brain is like a computer
One way to look at this is to compare it with how a computer works. When you Google “Debi Brain Blog,” Google will give you the answer within a second, but even for the powerful Googles of this world it is impossible to read all internet pages in a second. Instead, the Google robots that read Internet pages put the words of each page in an alphabetical index. Then when it is time to locate a word or combination of words, the connections between “Debi,” “Brain” and “Blog” have already been established. Google offers a useful service because it prunes the billions of useless connections, and presents us with the 10 best ones.
Synaptic pruning and growing is driven by experience – that is through practice, repetition, exercise and rehab. Individual connections within the brain are constantly being removed or recreated. Which connections are pruned or grown largely depends upon how they are used. This process is summed up in the catch phrase "neurons that fire together, wire together. And neurons that fire apart, wire apart.”
The meaning of this concept is well described in a 1993 experiment. A group of people with webbed fingers got their brain mapped. Then the fingers were surgically separated, and within weeks the one region in the brain that had been moving the fingers in unison before was now separating in “finger” areas. The reverse is also true. In a more gruesome experiment, a monkey had two fingers sewn together, and soon the brain merged the two separate finger areas.
Add the two basic concepts of pruning (neuron wiring) and exercise (use or firing), and we have neuroplasticity. It means that you have the right and the ability to change your brain!
Now comes your responsibility. What do you want to create in your life and how much are you willing to practice this?
In this first brain blog on neuroplasticity I have been talking mainly about physical functions: walking, moving fingers, dancing. But what about emotions? What about love? Can we grow and connect these, too? Can we lose the love connections? What about pain perception? Can we grow more pain connections in the brain just by “dealing with it”?
This is what I’ll be talking about in my next brain blog