Mice Inherit the Fears of Their Fathers
2013 11 21
By Virginia Hughes | Phenomena
There’s no question that trauma gets handed down from one generation to the next.
In one highly publicized example, researchers in New York studied several dozen women who were pregnant on September 11, 2001, and had been in the vicinity of the terrorist attacks. Some of these women developed post-traumatic stress disorder (PTSD), and this group shows lower levels of the stress hormone cortisol in their saliva than do those who did not develop PTSD. But here’s the rub: At 9 months old, the babies of the women with PTSD have significantly lower cortisol levels than babies of healthy mothers.
In earlier work, the same researchers had reported low cortisol levels in adult children of Holocaust survivors with PTSD. And in yet another study, Kerry Ressler’s group at Emory University showed that the so-called “startle response” to a sudden stimulus — a marker of anxiety — is more pronounced in kids whose mothers were physically abused as children then in those whose mothers were not abused. I could go on.
But how, exactly, does a parent’s stress leave such a deep impression on its progeny?
Part of it is nurture. A parent’s sadness and stress naturally affects how they interact with other people, including their children. The Holocaust study, in fact, found that the survivors with PTSD tended to emotionally abuse or neglect their children. And we know from some remarkable experiments in rats that parental care affects the offspring’s genes: Rat pups that get a lot of licking and grooming from their mothers show distinct changes in their epigenome, the chemical markers that attach to DNA and can turn genes on and off. Neglected pups, in contrast, don’t show these epigenetic tweaks.
Now a fascinating new study reveals that it’s not just nurture. Traumatic experiences can actually work themselves into the germ line. When a male mouse becomes afraid of a specific smell, this fear is somehow transmitted into his sperm, the study found. His pups will also be afraid of the odor, and will pass that fear down to their pups.
“Parents transfer information to their offspring, and they do so even before the offspring are conceived,” said Brian Dias, a postdoctoral fellow in Ressler’s lab, at an engaging talk about this unpublished data on Tuesday at the Society for Neuroscience meeting in San Diego.
And why, evolutionarily, would a parent pass down such specific information? “So that when the offspring, or descending generations, encounter that environment later in life, they’ll know how to behave appropriately,” Dias said.
The researchers made the mice afraid of certain odors by pairing them with a mild shock to the foot. In a study published a few years ago, Ressler had shown that this type of fear learning is specific: Mice trained to fear one particular smell show an increased startle to that odor but not others. What’s more, this fear learning changes the organization of neurons in the animal’s nose, leading to more cells that are sensitive to that particular smell.
Dias trained mice to fear acetophenone — which, according to this chemist, smells “like orange blossom with a bit of artificial cherry” — over three days, then waited 10 days and allowed the animals to mate. The offspring (known as the F1 generation) show an increased startle to acetophenone (with no shock) even though they have never encountered the smell before. And their reaction is specific: They do not startle to a different odor, propanol (which smells like alcohol). What’s more, the researchers found the same thing in the F1 generation’s offspring (known as F2).
Read the full article at: phenomena.nationalgeographic.com
Your Stress Response can become a Genetic Legacy
First Genetic Evidence That Humans Choose Friends With Similar DNA
DARPA to Genetically Engineer Humans by Adding a 47th Chromosome
Catastrophic Events: New archaeogenetic research refutes earlier findings
Are genes our destiny? ’Hidden’ code in DNA evolves more rapidly than genetic code
Are People Getting Dumber? One Geneticist Thinks So
PTSD Survivor’s Children May Have Genetic Scars
Latest News from our Front Page
Google’s New Computer With Human-Like Learning Abilities Will Program Itself
2014 10 30
In college, it wasn’t rare to hear a verbal battle regarding artificial intelligence erupt between my friends studying neuroscience and my friends studying computer science.
One rather outrageous fellow would mention the possibility of a computer takeover, and off they went. The neuroscience-savvy would awe at the potential of such hybrid technology as the CS majors argued we have nothing to ...
Former Cop Headed to Trial for Raping a Child While Other Officers Watched
2014 10 30
Pharr, TX — Trial is set to begin December 1, in the case of former Pharr police officer Erasmo Mata, Jr., accused of repeated first-degree felony sexual assaults of a child.
A federal civil lawsuit filed with Texas Southern District Court back in May accused Mata of assaulting the minor five times, on five separate occasions, all while on duty. ...
It Has Been Decided; Jeb Bush vs Hillary Clinton in ’16
2014 10 28
NY Times: The Bushes, Led by W., Rally to Make Jeb ‘45 ’
As Jeb Bush nears a decision to become the third member of his storied family to seek the presidency, the extended Bush clan and its attendant network are largely rallying behind the prospect and pulling the old machine out of the closet.
Rebuttal by The Anti-New York ...
Putin at Valdai - World Order: New Rules or a Game without Rules
2014 10 28
From Youtube: Russian President Vladimir Putin is delivering a speech at the plenary session of Valdai International Discussion Club, a forum involving the world leading experts at foreign and domestic policy.
Hillary – Says Business does NOT Create Jobs – Washington Does?
2014 10 28
We have a very serious problem with Hillary. I was asked years ago to review Hillary’s Commodity Trading to explain what went on. Effectively, they did trades and simply put winners in her account and the losers in her lawyer’s. This way she gets money that is laundered through the markets – something that would get her 25 years today.
|More News » |