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The onset of puberty has potentially worrying consequences for young girls' learning

More research needs to be done to see if the male brain is affected in the same way as the female brain.
More research needs to be done to see if the male brain is affected in the same way as the female brain. More research needs to be done to see if the male brain is affected in the same way as the female brain.

The onset of puberty has been found to hit a “switch” in the part of the brain that is associated with learning, a University of California study has found.

The hormones associated with puberty were found to impede some aspects of “flexible learning” in young female mice, with the authors particularly worried about the impact this could have on young girls.

“Puberty onset is occurring earlier and earlier in girls in modern urban settings – driven by such factors as stress and the obesity epidemic – and has been associated with worse outcomes in terms of school and mental health,” said study senior author Linda Wilbrecht, an associate professor of psychology and neuroscience at UC Berkeley.

 children in a classroom
children in a classroom
(Dave Thompson/PA)

Wilbrecht and her team exposed the mice to pubertal hormones and discovered significant changes in the frontal cortex – a region of the brain associated with learning, attention and behavioural regulation.

Children have been found to have greater brain “plasticity” than adults, the thing that makes them more adept at learning multiple languages than older people.

But while learning continues into adolescence, the cognitive focus is often redirected towards relationships and social learning, which could be a problem if hormonal changes are happening at a young age when basic learning is still taking place, Wilbrecht said.

“We should be more thoughtful about aligning what we know about biology and education to accommodate the fact that many girls’ brains are shifting to this adolescent phase earlier than expected,” she said.

Lab mice
Lab mice
(unoL/Getty Images)

The study, published in the journal Current Biology, involved inducing puberty in some young female mice by injecting them with hormones, while removing the ovaries of others and thus blocking puberty in that group.

Significant changes in synaptic activity thought to regulate brain plasticity were observed through measuring the electrical activity in the frontal cortices of the post-pubertal mice – while an experiment with Cheerios found further changes in the hormone-injected mice.

By hiding the cereal under bowls scented with licorice, clove, thyme or lemon and allowing each mouse to figure out which scent was paired with the Cheerio before changing it, researchers found that the post-pubertal mice had a harder time adapting to the rule changes than their pre-pubertal counterparts.

“These data demonstrate that puberty itself, not just age, plays a role in frontal cortex maturation,” the study concluded.

The researchers noted that future studies on male mice will be needed to see if the same results apply to male brains.