New research findings from the radical world of epigenetics:
Lab mice trained to fear a particular smell can transfer the impulse to their unborn sons and grandsons through a mechanism in their sperm, a study reveals.
The research claims to provide evidence for the concept of animals “inheriting” a memory of their ancestors’ traumas, and responding as if they had lived the events themselves.
It is the latest find in the study of epigenetics, in which environmental factors are said to cause genes to start behaving differently without any change to their underlying DNA encoding…
For the study, Dias and co-author Kerry Ressler trained mice, using foot shocks, to fear an odour that resembles cherry blossoms.
Later, they tested the extent to which the animals’ offspring startled when exposed to the same smell. The younger generation had not even been conceived when their fathers underwent the training, and had never smelt the odour before the experiment.
The offspring of trained mice were “able to detect and respond to far less amounts of odour… suggesting they are more sensitive” to it, says Ressler co-author of the study published in the journal Nature Neuroscience.
They did not react the same way to other odours, and compared to the offspring of non-trained mice, their reaction to the cherry blossom whiff was about 200 percent stronger, he says.
The scientists then looked at a gene (M71) that governs the functioning of an odour receptor in the nose that responds specifically to the cherry blossom smell.
The gene, inherited through the sperm of trained mice, had undergone no change to its DNA encoding, the team found.
But the gene did carry epigenetic marks that could alter its behaviour and cause it to be “expressed more” in descendants, says Dias.
This in turn caused a physical change in the brains of the trained mice, their sons and grandsons, who all had a larger glomerulus – a section in the olfactory (smell) unit of the brain…
“Such information transfer would be an efficient way for parents to ‘inform’ their offspring about the importance of specific environmental features that they are likely to encounter in their future environments,” says Ressler.
Regarding extrapolation to humans:
Commenting on the findings, British geneticist Marcus Pembrey says they could be useful in the study of phobias, anxiety and post-traumatic stress disorders.
“It is high time public health researchers took human transgenerational responses seriously,” he said in a statement issued by the Science Media Centre.
“I suspect we will not understand the rise in neuropsychiatric disorders or obesity, diabetes and metabolic disruptions generally without taking a multigenerational approach.”
The implications of this field of science for myth studies (e.g., Carl Jung’s theory of collective unconsciousness) are profound.
Will we eventually be able to discern, qualify, or at least make better sense of, the no doubt significant differences in ancient memories of, say, someone from Africa vs. someone from Scandinavia?