New growth in old, 7/26/12, a photo by altiemae on Flickr.
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Scientists are finding one of the ways your brain changes itself is by actually changing your genes - or more correctly, by the acting out (or not) of certain genes - in the process of epigenesis.
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Another layer of information, called the epigenome, is stored in the proteins and chemicals that surround and stick to the DNA. It's a kind of chemical switch that determines which genes are activated (or not): it tells your genes what to do and where and when.
Researchers have discovered that the epigenome can be affected by many things, from aging and diet to environmental toxins to even what you think and feel. This means that even your experiences can literally change your mind by chemically coating the DNA that controls a function. The coating doesn't alter the underlying genetic code; rather, it alters specific gene expression, shutting down or revving up the production of proteins that affect your mental state.
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Epigenetics can profoundly affect your health and, it seems, your happiness, changing not only your vulnerability to some diseases such as cancer but also your mental health. Scientists have found, for example, that a mother rat's nurturing, through licking and loving behaviour that boosts the expression of a gene that eases anxiety and stress, bolsters emotional resilience in her newborn pups. They've also found that distressing events can turn off the expression of genes for brain cell growth protein and therby trigger depression, and that epigenetic changes may also underlie the pathology of schizophrenia, suicide, depression, and drug addiction.
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So it turns out that your brain is a nursery: every day, it seems, new brain cells are born. But it seems that your brain doesn't always keep these newborn neurons. Just like all other babies, they need special care to survive. And it's not pampering: your newborn neurons, scientists are finding, need to be challenged , exercised, and run hard.
If you don't use those new cells, they will disappear ... unless that brain is challenged to learn something new and, preferably something hard that involves a great deal of effort. And new is key here as well: just repeating old activities won't support new brain cells.
The Scientific American Brave New Brain
Judith Horstman
2010
Wiley USA
