Memory formation is a complex process that requires several processes within nerve cells. Here a question arises: Is it possible to inherit memories from parents to children?
In memory formation, processes occur that transform neurons from a pre-learning state, which is characterized by high levels of memory-suppressing genes, to a state characterized by high levels of memory-enhancing genes.
A study published in the journal Nature Neuroscience in 2014 explains the way in which a person’s behavior is influenced by the experiences of his or her ancestors.
The study conducted at Emory University, in the US state of Georgia, benefited from the mice’s love of cherries, according to an article published in the British newspaper The Guardian on June 17.
In this study, scientists first exposed a group of mice to a cherry-like scent, then immediately exposed them to a mild electric shock. The mice quickly learned to freeze in anticipation every time they smelled cherries for fear of being shocked.
The mice had newborns, and their babies were left to live happy lives without electric shocks or the smell of cherries. The youngsters grew up and had children (third generation) and at this point, the scientists conducted the experiment again.
The scientists found that the association between the sweet smell and shock was passed on to the third generation, meaning that the mice would freeze in anticipation every time they smelled cherries for fear of shock.
The research team discovered that the shape of the DNA in the sperm of the grandfather mouse had changed. This in turn changed the way the neural circuitry was laid out in his brood and young ones, redirecting some neurons from the nose away from pleasure and reward circuits and connecting them to the amygdala, which is responsible for fear.
Through a combination of changes, traumatic memories cascade down the generations to ensure that the young mice will acquire the hard-won wisdom of their early ancestors that the smell of cherries may be delicious, but they are associated with bad things.
tradition
The study’s authors wanted to rule out the possibility that imitation learning might have played a role. So they took some of the offspring of the mice, raised them away from their fathers and mothers, and used the sperm of some of these mice to give birth to mice away from their biological parents.
The results showed that the young mice incubated and born via artificial insemination still had increased sensitivity and different neural circuits to perceive that particular odor.
The researchers wanted to investigate whether it was possible to reverse this effect and spare grandchildren memories of the biological trauma. So they took the grandparents and re-exposed them to the smell without any accompanying trauma. After a certain period of repeating the pain-free experience, the mice stopped being afraid of the smell.
Anatomically, their neural circuits returned to their original form. Most importantly, the traumatic memory is no longer transmitted in the behavior and brain structure of new generations.