Study emotional trauma may change gene expression that last for generations

joeylittle

Administrator
From the article:
The limited data—Mansuy says her lab is now working on an expanded study—suggest life experience can be healing as well as hurtful at the molecular level. "Environmental enrichment at the right time could eventually help correct some of the alterations which are induced by trauma," Mansuy says.

This and a few other studies suggesting epigenetic change is reversible have the potential to change the narrative of doom around the topic, researchers say. "If it's epigenetic, it's responsive to the environment," says Feig, who more than a decade ago found similar effects on brain function across generations by giving mice play tubes, running wheels, toys, and larger cages. "That means negative environmental effects are likely reversible."
I appreciate the 'healing as well as hurtful' concept, re: life experience. Useful to remember.
 

StillPen

MyPTSD Pro
What remains puzzling to me is why a nonadaptive mechanism is selectable.
You lost me on your meaning, Agita. Where in the article are you referring to 'nonadaptive mechanism' being selectable? Or do you mind explaining in more depth your statement? All of this is so interesting to me, but I find some of it is 'over my head'...I don't understand it.
 

Agita Kaput

Policy Enforcement
Sponsor
You lost me on your meaning, Agita. Where in the article are you referring to 'nonadaptive mechanism' being selectable? Or do you mind explaining in more depth your statement? All of this is so interesting to me, but I find some of it is 'over my head'...I don't understand it.
I knew the study could be important for the group - I haven't finished it yet. Im new here and still preoccupied with adjusting to interacting with people who "speak my language." It's foreign to me and a little overwhelming.

What I mean is... Its my impression (assumption) that the cellular activity resulting from the exposed genes is not protective of the effects of trauma or providing protection against future trauma but actually makes the current experience MORE disturbing than it would otherwise be.

As you have spent more time with this article than I... can you confirm or disconfirm that assumption before I go on (which would be a waste of time if Im confused)?
 
I think people like Gabor Mate have said the stress of the parent obviously hormonally and biochemically affects development of the child, and that care giving shortens telomeres and ends in earlier death, without life style choices and parenting styles even taken in to consideration (behavioral). But it would be expected I think to be selected for genetically because the amygdala's role is threat protection. So I think it's predictable that there would be changes, perhaps in sensitivity or memory consolidation, or something else. (We sometimes forget that our DNA is constantly replicating, and we know the changes as they said from other influences, eg exposure to Mustard gas, radiation). There is a school of thought that reflects the impact of what they call Collective Trauma also, such as the effects of systemic racism, or what is currently happening with the war in Ukraine. It sounds a bit 'out there' but they now seem to believe in what I've seen elsewhere that for example a grandparent's trauma would indeed affect genetically potentially their grandchild, even if the parents were otherwise stable and non-traumatized. (Such as studies with Holocaust survivors and their children/ grandchildren).

Genetics is amazing, really. Such a new science.

PS, there is a geneticist on here, if I'm not mistaken? Maybe someone can help with the name.. I'm at a bit of a loss? Possibly @bellbird ? (Sorry if not.)
 
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OliveJewel

MyPTSD Pro
thought about that with respect to suicide
I studied evolution in college. We talked about maladaptive traits. One example, heart attacks. Certain personality types are more susceptible. Teacher gave the example of a police officer. Imagine a man who’s tough, played sports, seeks adrenaline, sees loads of crap in life. He’s also stressed, rude to his family, lonely and alcoholic. He passes relatively young from a heart attack, but already has kids and a wife. Why is this trait preserved?

Because many females are biased toward choosing males loaded with testosterone, which unfortunately has consequences, but not until after breeding years typically. Heart attack not a direct consequence of his personality but connected to a suite of behaviors and conditions.

As long as the individual pushes out kids who are likely to have more kids? Their genes are “adaptive” or successful, according to the theory of evolution by natural selection.

Same teacher studied depression, searching for how it could be adaptive. What he discovered is that the “goal” of depression is to secure support. Lack of self-care motivates others to step in and care for the individual in a tribe-like setting where all individuals are necessary for the survival of the group. Why does the person want to secure support? My professor’s theory was that the individual wants to change their social status.

Hard to know how natural selection operates on humans today versus in the past.
 

joeylittle

Administrator
From the article:
But today the hypothesis that an individual's experience might alter the cells and behavior of their children and grandchildren has become widely accepted. In animals, exposure to stress, cold, or high-fat diets has been shown to trigger metabolic changes in later generations. And small studies in humans exposed to traumatic conditions—among them the children of Holocaust survivors—suggest subtle biological and health changes in their children.
The hypothesis being posed is that gene expression - how an individual's genetic code is changed into a physical reality - alters as a result of exposure to extremes.

Take an individual whose ancestors have had zero exposure to any kind of stress. Then, expose that individual to significant trauma.

That individual then procreates

It's a huge oversimplification to say that the progeny will have altered genes....that's not really what it is. The factors that go into HOW those genes become proteins, which then become physical attributes - that's where the parental exposure to trauma may have the ability to influence which proteins form in the child.

Its my impression (assumption) that the cellular activity resulting from the exposed genes is not protective of the effects of trauma or providing protection against future trauma but actually makes the current experience MORE disturbing than it would otherwise be.
Not so much more disturbing, as: the individual becomes more vulnerable to the overall impact of trauma. And that may lead to the experience being more disturbing, or not. But there is a greater likelihood that they will be damaged by the trauma. It's always useful to remember that not everyone who experiences severe trauma ends up with the particular problems of sustained psychological damage.

This IS an adaptive process - not the way humans adapt behavior, but in the way evolution itself is adaptation.
 

OliveJewel

MyPTSD Pro
I will try. An adaptation is a physical or behavioral trait that an organism possesses which increases their chances of survival. Example: schooling behavior in some species of fish is an adaptation for avoiding predation.

Within a population of organisms of a given species (like white-tail deer for example) there is a variety of physical and behavioral traits. No two individuals have exactly the same look or actions. There is a finite amount of food, shelter, and mating opportunities. Those individuals who survive and produce offspring are said to be passing on traits which are adaptive for survival. Over time those traits which confer survival will change because the environment changes. This is called the process of evolution by natural selection. The physical and behavioral traits which are the hallmarks of different species are the adaptations which help them survive and reproduce in their environment.

Not all adaptations are helpful, but if they are good enough they will persist. Example: airway next to gullet means we can choke to death, but overall it works well enough.

And in modern society there are maladaptive traits which persist but might not if humans had to live without assistive technology. Example: all the congenital diseases that used to kill people at a young age.

So ptsd, depression, did—are these adaptations? Of course. They are behavioral suites which have the purpose of securing care from close relationships, or of surviving adverse experiences by closing off points of access, or other reasons.

It’s a fascinating thought experiment to try to imagine how all these mental disorders could be adaptive in certain situations. People who study Evolutionary Psychology are often thinking of adaptations from the point of view of how it would affect primitive humans living without modern society, which gets them in trouble from critics who argue that there is no agreed upon single account of primitive human life.

why a nonadaptive mechanism is selectable.
Selection happens through the reproduction of certain traits. When you use the word non adaptive it seems you are referring to the experience of the person having the ptsd symptoms. As in, “I’m struggling to adapt to life with PTSD.”

Selection of traits happens at a genetic level, however the mechanism of epigenetics is a way of changing not the genes but whether or not (or how much) a gene is expressed. So it’s not really selected for but rather effects selection, from my understanding.
 
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