'Memories' pass between generations

[Solomon2]

HEALTH
1 December 2013 Last updated at 13:26 ET
'Memories' pass between generations
By James GallagherHealth and science reporter, BBC News

Continue reading the main story
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Behaviour can be affected by events in previous generations which have been passed on through a form of genetic memory, animal studies suggest.

Experiments showed that a traumatic event could affect the DNA in sperm and alter the brains and behaviour of subsequent generations.

A Nature Neuroscience study shows mice trained to avoid a smell passed their aversion on to their "grandchildren".

Experts said the results were important for phobia and anxiety research.

The animals were trained to fear a smell similar to cherry blossom.

The team at the Emory University School of Medicine, in the US, then looked at what was happening inside the sperm.

They showed a section of DNA responsible for sensitivity to the cherry blossom scent was made more active in the mice's sperm.

Both the mice's offspring, and their offspring, were "extremely sensitive" to cherry blossom and would avoid the scent, despite never having experiencing it in their lives.

Changes in brain structure were also found.

"The experiences of a parent, even before conceiving, markedly influence both structure and function in the nervous system of subsequent generations," the report concluded.

Family affair
The findings provide evidence of "transgenerational epigenetic inheritance" - that the environment can affect an individual's genetics, which can in turn be passed on.

One of the researchers Dr Brian Dias told the BBC: "This might be one mechanism that descendants show imprints of their ancestor.

"There is absolutely no doubt that what happens to the sperm and egg will affect subsequent generations."

Prof Marcus Pembrey, from University College London, said the findings were "highly relevant to phobias, anxiety and post-traumatic stress disorders" and provided "compelling evidence" that a form of memory could be passed between generations.

He commented: "It is high time public health researchers took human transgenerational responses seriously.

"I suspect we will not understand the rise in neuropsychiatric disorders or obesity, diabetes and metabolic disruptions generally without taking a multigenerational approach."

In the smell-aversion study, is it thought that either some of the odour ends up in the bloodstream which affected sperm production or that a signal from the brain was sent to the sperm to alter DNA.

Solomon2 comment: What does this imply for us humans?

 

[Levina]

Should we be surprised??
we already knew it.
This is a fascinating discovery though.
Nearly everything we do affects our DNA.(including the smoke of cigarettes ahem ahem)
That's what's so clever about evolution.
It seems logical that these changes..,or at least some of them will be passed on with reproduction.
Obviously we are born to 'know' lots of things,much of this knowledge has been passed down the generations from before they were even humans.
Just to make things even more interesting, it's now been found that pregnant women receive cells from the foetus(microchimerism.)
As well as inheriting from the mother...baby gives something back!
Subsequent babies as well as passing their own cells to the mother ,also receive a tiny amount of the cells 'donated' by their older siblings.
So there really is a little of each child in the mother, and a little of all the older siblings in each child
Evolution is much more complicated than we think it is.