What sex ed doesn’t tell you about your brain - Shannon Odell

While we often talk about puberty’s effect on the body, what gets overlooked are the fascinating changes that happen in the brain. I’ve been sent here to talk to you about puberty. Any questions?

During puberty, your reproductive organs grow and mature. Any questions? This ripening allows you to become a sexually mature adult. There are so many other changes to your body that puberty can seem almost magical.

I think I'll take it from here. Puberty, in fact, begins in the brain. At some point, usually between the ages of 9 and 14, puberty is triggered when a region known as the hypothalamus releases waves of a specialized hormone. As convenient as it would be to go to sleep a child and wake up an adult, this maturation is slow, and puberty lasts as long as 4 to 5 years.

And during this extended process, the brain undergoes its own transformation, thanks to two of puberty’s key players—estrogen and testosterone. Produced in the developing testes and ovaries, these hormones hitch a ride to the brain via the bloodstream. Once there, they interact with receptors on neurons, changing the way the individual cells work and function by making them more or less excitable, altering their growth, or reshaping their connections. Cumulatively, this can change how you feel, think, and behave.

For example, hormones remodel and develop the limbic system, a collection of brain regions responsible for emotional behavior. Research in animal models suggests that the amygdala undergoes changes in size and connectivity during puberty. The amygdala’s function is wide-ranging, from detecting threats in your environment to helping you recognize emotions in your friend’s faces. Its development allows you to better connect with your peers while priming your brain for learning and discovery.

Likewise, puberty organizes and restructures the nucleus accumbens involved in reward and sensation-seeking. Activity in this dopamine hub is thought to drive the pleasurable sensations we feel when doing rewarding activities, like spending time with friends or having new experiences. Several studies have found that as hormone levels increase through puberty, so does the response of the nucleus accumbens. As a result, exploration and social engagement may feel that much more important during adolescence.

As these emotion and reward centers rapidly develop, their connections with higher cortical brain regions tend to do so on an extended timeline. These cortical regions, which help impose emotional regulation and impulse control, continue to grow well past puberty, into your 20s. While teens are often unfairly stereotyped as rash or impulsive, research reveals a more complex story.

Teens are just as capable as adults of making thoughtful decisions when given the time and space. It’s only during high stress or in the heat of the moment that teens may find it more difficult to manage emotions. Further, this lengthy cortical development allows adolescent brains to remain adaptable as they learn and grow in new situations, form their identities, and build the skill sets needed for adulthood.

For all we know about the effects of puberty on the brain, there remain many unanswered questions. What sets off the initial puberty signal in the brain? Why is the average onset of puberty shifting earlier? And, while hormones may seem powerful, they may not be the full story. Experiences you have during adolescence may be just as influential as hormones in shaping and maturing the developing brain.

So while all these physical and mental changes can make you feel as if puberty is in control, you have more power than you think. The everyday choices you make, from learning new skills to being a good friend to setting boundaries, ultimately steer the path of who you are and will become. Any questions?