DNA and Changeability
Posted: Wednesday, January 06, 2010
by Tex Norman
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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Top-level comments on this article: (4 total)Interesting article. Especially your final questions. :) Someone should be investigating an answer to those.Thanks for reading and I agree, these questions need answers. Peace be with you, tex
Yay! Tex Norman's back in town.Fascinating subject. I recently completed a course in physiological psychology, so this was actually not over my head. However, I question McGowan's conclusion that the explanation must be chromosomal change. I think some physiological change, or even anatomical changes in the sense of neuroplasticity is responsible for the activation or inhibition of a gene.Depression, on the other hand, is known to have physiological antecedents, which is why medication has proven far more effective for the treatment of depression than counseling. As to the question of whether depression was hardwired prenatally, of course that's possible. So, it is thought, is schizophrenia. The fact of a prenatal disposition to a trait does not necessarily mean chromosomal change, but systemic change.
If depression is mapped to a genetic trait, then McGowan would do well to look at the history of the subject's ancestry, and rule out inheritance before claiming a gene was altered in the egg.Thanks. Thanks for noticing and thanks for reading.
Hi Tex.Missed ya! Great article! The bit ("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.") is particularly distressing. I mean, what mother isn't a bit depressed and anxious as her pregnancy is coming to term?Anyway, I found your article very interesting and will have to look into it further.Thanks for sharing and I hope that you are well.Hugs,DianneDear Dianne: I think you are right about all pregnant women being under a lot of stress. I can never really know, but I imagine even a relatively stress free life is still stressed by pregnancy and the anticipation of a life long commitment to the coming child.Thanks for reading. I hope your holidays were great and I wish you a peace filled, joy filled 2010.tex
I have always felt that abuse, whether during childhood or pregnancy, has a profound effect on the childs DNA. How could it not?Still, it may not be my fault, but it is my problem.Great article, Tex.Thanks. How right you are. No matter who steps on your toe. it is still YOUR toe that is throbbing."...has a profound effect on the childs DNA. How could it not?"A better question is, how could it? DNA is the product of inheritance. It might be possible to change an actual egg's DNA, but I would think that once the egg is formed and viable, its DNA is more or less fixated. And women at puberty, I am given to understand, have already made their eggs. So how could DNA be altered after the fact, especially immediately before fertilization, and most especially after differentiation?And what about men, where DNA alteration is even more likely, because we are constantly generating new sperm? Shouldn't researchers also look at the factors that result in potential genetic changes in the man's contributing DNA?I have thought and felt the same thing. How can DNA be changed. I think of my body from the whole all the way down to the gene as what it is. To say DNA can be changed by emotion would be like saying "My truck turned into a Smart Car because I was feeling so environmentally worried. That is what I think, or have thought. DNA is some fixed solid thing. But I'm not a scientist. I googled your question "HOW COULD IT" and there were lots of entries. The very first entry contained the following information:Negativity or positivity during pregnancy can alter neural development and affect genetic expression, according to some researchers in the field of epigenetics. By causing a chemical hormonal response, pregnancy perceptions affect physical development of babies, and may also alter fetal genetics.In “Biology of Belief,” Bruce Lipton, Ph.D. discusses how thoughts “perceived by their mothers before birth” allow the unborn infant to “optimize their genetic and physiologic development.”Dr. Thomas Verny, who founded the Association for Prenatal and Perinatal Psychology and Health (APPPAH), writes, “Scientists have come to recognize living organisms as ‘dynamic systems’ capable of actively reprogramming gene behaviors to accommodate environmental challenges.”Maybe the answer to HOW COULD IT is that we need more study before this hypothesis is proven, or proven wrong.I think you're on to something, Tex. Maybe the answer was so obvious that an egghead like myself couldn't see it. But now, in a different light, I actually see how Ken was able to comprehend the possibility. In fact, I think I might favor a reality where the offspring's genetic expression can be altered by emotion. Such foreknowledge could be used for us, instead of against us.- G
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