Brain adds cells in puberty to navigate adult world

March 4, 2013, Michigan State University

The brain adds new cells during puberty to help navigate the complex social world of adulthood, two Michigan State University neuroscientists report in the current issue of the Proceedings of the National Academy of Sciences.

Scientists used to think the brain cells you're born with are all you get. After studies revealed the birth of new brain cells in adults, conventional wisdom held that such growth was limited to two associated with memory and smell.

But in the past few years, researchers in MSU's neuroscience program have shown that mammalian brains also add cells during puberty in the amygdala and interconnected regions where it was thought no new growth occurred. The amygdala plays an important role in helping the brain make sense of social cues. For hamsters, it picks up signals transmitted by smell through pheromones; in humans, the amygdala evaluates and body language.

"These regions are important for social behaviors, particularly ," said lead author Maggie Mohr, a doctoral student in neuroscience. "So, we thought maybe cells that are added to those during puberty could be important for adult reproductive function."

To test that idea, Mohr and Cheryl Sisk, MSU professor of psychology, injected male hamsters with a to show cell birth during puberty. When the hamsters matured into adults, the researchers allowed them to interact and mate with females.

Examining the brains immediately after that rendezvous, the researchers found new cells born during puberty had been added to the amygdala and associated regions. Some of the new cells contained a protein that indicates cell activation, which told Mohr and Sisk those cells had become part of the neural networks involved in social and sexual behavior.

"Before this study it was unclear if cells born during puberty even survived into adulthood," Mohr said. "We've shown that they can mature to become part of the that underlies adult behavior."

Their results also showed that more of the new survived and became functional in males raised in an enriched environment – a larger cage with a running wheel, nesting materials and other features – than in those with a plain cage.

While people act in more complicated ways than rodents, the researchers said they hope their work ultimately sheds light on human behavior.

"We don't know if cells are added to the human amygdala during puberty," Sisk said, "but we know the amygdala plays a similar role in people as in hamsters. We hope to learn whether similar mechanisms are at play as people's brains undergo the metamorphosis that occurs during puberty."

Explore further: Adolescent sex linked to adult body, mood troubles, in animal study

Related Stories

Adolescent sex linked to adult body, mood troubles, in animal study

November 15, 2011
A new study suggests that sex during adolescence can have lasting negative effects on the body and mood well into adulthood, most likely because the activity occurs when the nervous system is still developing.

Sociability may depend upon brain cells generated in adolescence

October 4, 2011
Mice become profoundly anti-social when the creation of new brain cells is interrupted in adolescence, a surprising finding that may help researchers understand schizophrenia and other mental disorders, Yale researchers report.

Recommended for you

Neuroscientists suggest a model for how we gain volitional control of what we hold in our minds

January 16, 2018
Working memory is a sort of "mental sketchpad" that allows you to accomplish everyday tasks such as calling in your hungry family's takeout order and finding the bathroom you were just told "will be the third door on the ...

New study reveals why some people are more creative than others

January 16, 2018
Creativity is often defined as the ability to come up with new and useful ideas. Like intelligence, it can be considered a trait that everyone – not just creative "geniuses" like Picasso and Steve Jobs – possesses in ...

Even without nudging blood pressure up, high-salt diet hobbles the brain

January 16, 2018
A high-salt diet may spell trouble for the brain—and for mental performance—even if it doesn't push blood pressure into dangerous territory, new research has found.

Brain imaging predicts language learning in deaf children

January 15, 2018
In a new international collaborative study between The Chinese University of Hong Kong and Ann & Robert H. Lurie Children's Hospital of Chicago, researchers created a machine learning algorithm that uses brain scans to predict ...

Preterm babies may suffer setbacks in auditory brain development, speech

January 15, 2018
Preterm babies born early in the third trimester of pregnancy are likely to experience delays in the development of the auditory cortex, a brain region essential to hearing and understanding sound, a new study reveals. Such ...

BOLD view of white matter

January 15, 2018
The brain consists of gray matter, which contains the nerve cell bodies (neurons), and white matter, bundles of long nerve fibers (axons) that until recently were considered passive transmitters of signals between different ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
1 / 5 (1) Mar 05, 2013
In all mammals with an amygdala it is the microRNA/messenger RNA balance that makes sense of social cues, which in humans are indirectly associated with evaluations of facial expressions and body language. For an accurate representation of how this occurs in humans see: MicroRNA-182 Regulates Amygdala-Dependent Memory Formation.http://www.ncbi.n...23345246
JVK
1 / 5 (1) Mar 05, 2013
MicroRNA-182 Regulates Amygdala-Dependent Memory Formation.
http://www.jneuro...abstract

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.