Sunday, December 20, 2009

DNA and Changeability



There is this guy, Patrick McGowan who believes he has evidence that childhood trauma actually changes the DNA. Mr. McGowan studied the brains of suicide victims, found indicators that child abuse actually modifies a gene called NR3C1. (It’s not the catchiest name for a gene is it). Apparently, the NR3C1 affects a person's ability to deal with stress. Scientist call these sorts of changes "epigenetic", and that word means that the gene's DNA sequence wasn't altered but it's structure was modified to make it less active and these MODIFICATIONS of the gene are often permanent.

The hypothalamus gland, the pituitary gland and the adrenal glands work together to shape your “nature.” Since glands ooze hormones and hormones make us feel stuff, or it makes body processes function properly then altering the hypothalamic-pituitary-adrenal axis alters our reactions to stressful situations, and it triggers a number of physiological changes that prime our bodies for action. The NR3C1 produces a protein called the glucocorticoid receptor, which sticks to a stress hormone called cortisol. Cortisol usually helps to deactivate those glands that make us all fight or flighty. Sometimes our body puts out these hormones, and we get upset, but if our brain figures out that the reaction is inappropriate, then your NR2C1 can turn off, or at least dial down the body’s reaction to stress. But if your NR3C1 is messed up, then you can’t properly deactivate those natural, but uncalled for reactions to stressful situations.

If you have a shortage of glucocorticoid receptors, your self-control goes out of control.

What does all this mean? Well, maybe it means that childhood trauma alters the way the body reacts to stress, which affects a person's mood, it has links to a risk of suicide, and it plays a role in mental disorders we experience later in life.

Mr. McGowan’s group of scientists did one experiment where they looked at 24 samples of brain tissue taken from autopsies of male suicide victims. I don’t know how they knew this, but they believed that half of those suicide people (12 of them) had been abused as children and the other 12 suicide victims had not been abused as children. In the next part of their study these scientists compared these 24 people to people who died from accidents, but had never been abused. In all cases they found that the activity of the NR3C1 gene was much lower in abuse victims who took their own lives, than in either of the other groups.

The implication is that childhood trauma changes this HPA trinity so that it can't turn itself down properly. These people then are constantly, continuously, unendingly on high-alert. If you had a bunch of childhood trauma you’ll be at a higher risk of anxiety, depression and suicide.

In other experiments the McGowan’s group found that it was possible, to actually change the HPA trinity in mice BEFORE they were born. This means that Mothers could affect the fates of their children even before they are born. If the mother was depressed or anxious during her third trimester it may change the child’s gene allowing these kiddos to be born with a vulnerability to depression.

So, if this is true, and IF my childhood had trauma, or IF my mother was stressed and depressed during the third trimester prior to my birth, then all my depression is NOT MY FAULT. This would mean that I was, in some sense, hardwired to be depressed. But what if that IS true? Am I suppose to just be depressed from now on because depression for me is as fixed as the color of my eyes? What am I suppose to do about my screwed up NR3C1?

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