This episode of SciShow is brought to you by the Smithsonian
National Air and Space Museum’s Teacher Innovator Institute.
If you’re a 5th- through 8th-grade teacher in the US, you can visit s.si.edu/tii
to learn more about the program and fill out the application.
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When you think of a young kid, their incredible brainpower probably isn’t
the first thing that comes to mind.
But kids’ brains have a sort of superpower:
they are excellent at rewiring themselves.
That allows kids to be great learners, and in some cases,
they can even recover from brain injuries adults can’t.
Like, for years, there was a visual condition that doctors thought
could only be treated in kids, thanks to their adaptable brains.
The good news is, things definitely aren’t hopeless for adults.
And with more research, doctors may even be able to restore
some of the brain’s flexibility later in life.
When researchers are describing how adaptable kids’ brains are,
they say the brain has high neural plasticity.
It’s moldable, like warm plastic.
And that is huge for development.
In fact, a time of high plasticity that can affect how a skill develops
is called a critical period.
This is a time where a kid’s brain is super responsive to outside influences,
to the point where some skills are harder or even impossible
to learn after the critical period is over.
Now, your brain still has some plasticity as an adult.
Whenever you learn something,
you’re still physically forming or fine-tuning connections in your brain.
You might grow cells called neurons to carry signals around.
Or you might strengthen or change the number of connections between neurons.
But this happens way more easily for kids.
Scientists are still learning why, but it seems to be related
to the fact that our brains develop inhibitory circuits over time.
In other words, neurons develop that reduce communication
between other neurons.
And a chemical called GABA is often involved, but we’ll come back to that later.
Now, all this isn’t bad: Inhibition is an important part of brain function.
But as our brains develop, it means that the way we learn does, as well.
Now, not every brain region develops at the same time,
so there are different critical periods for different skills.
One that stood out to scientists was the critical period for vision.
Like, sometimes, a kid is born with or develops a weakness in one eye;
for instance, their vision in that eye might just be worse.
That can be treated with glasses, but if it isn’t caught in time,
the kid’s brain may try to compensate for the weaker eye.
Their brain’s visual cortex will start ignoring signals from that eye
and relying on input from the stronger one.
This condition is called amblyopia.
And it’s effectively vision loss or impairment in one eye driven by your brain.
In a way, it’s caused because kids’ brains are so adaptable.
In that time of high plasticity, the brain rewires itself.
But on the flip side, if amblyopia is caught while someone
is still in that critical period, it’s also straightforward to treat.
A doctor might have someone wear an eyepatch over their stronger eye,
essentially forcing their brain to use input from the weaker eye
while the visual cortex is still flexible.
In fact, you lose so much flexibility after the critical period closes
that many researchers used to think you couldn’t treat amblyopia
once someone was past around six to eight years old.
Now, at least one study has shown that the eyepatch method
did work in some people in their late teens.
And this method and other therapies have also been shown
to help adults with amblyopia.
That suggests the visual cortex has some plasticity later in life.
But scientists are also looking for ways
to just flat-out increase brain plasticity in adults.
That wouldn’t just help with amblyopia,
but could also help people recover from strokes and other brain injuries.
So far, these studies have been done on animals like rats,
and there’s a lot to learn before researchers start human trials.
But so far, experiments have found ways to increase plasticity
in adult rodents’ brains.
Some of them come back to those inhibitory neurons and chemicals like GABA.
The idea is that, if the development of inhibition in the brain is what closes
critical periods…well, maybe stopping inhibition would open them up again.
And studies have found evidence for that.
In a 2010 paper from The Journal of Neuroscience, researchers deprived rats
of vision in one eye — basically, trying to create something like amblyopia.
Then, they took four of the rats and used a drug
to reduce GABA activity in their visual cortices.
Another four rats got saline injections as a control.
After that, the team tested how much the rats’ brains had changed
in response to their simulated amblyopia.
And the results were encouraging!
In the rats that got saline, their brains didn’t change.
They were using both eyes equally.
But in rats where the scientists had reduced GABA,
their brains adapted and were favoring the stronger eye.
This suggested that reducing GABA made their visual cortices more plastic,
like what you’d find in a younger rat.
That said, there is a catch: Other research has found that
some chemicals that reduce GABA can also cause seizures.
So until we learn that this treatment would be safe, it isn’t ready to test in humans.
But research is ongoing!
And scientists are also exploring ways
to affect inhibition without messing with GABA.
Because on their own, the plasticity adult brains already have is amazing.
It allows us to keep learning, growing, and sometimes healing throughout our lives.
But if we could tap into the extra adaptability our brains had as kids…
that would mean some amazing things for medicine.
Now, if you’re a teacher who works with kids and their superpowered brains,
check out today’s sponsor, the Smithsonian National Air
and Space Museum’s Teacher Innovator Institute!
The Teacher Innovator Institute is an all-expense-paid development intensive
for 5th through 8th grade STEAM teachers from the United States.
For two consecutive summers, you would spend two weeks in Washington DC.
And there, you’d tour museums, gain expert knowledge from museum educators,
and work with other teachers, with the goal of using aerospace science,
history, and technology to shape your ideas about authentic learning
and ways to bring informal education techniques into your classrooms.
The 2022 cohort will welcome up to 10 teachers and will be focused
on early career teachers with less than 6 years in the classroom, as well as
educators of color, LGBTQ+ educators, and educators with disabilities.
Wondering if you or a teacher in your life might be a good fit?
You can click the link in the description
to see if you’re eligible and fill out the application.
Applications close February 15, 2022, so visit s.si.edu/tii or search the
National Air and Space Museum’s Teacher Innovator Institute to learn more today!
And as always, thanks for watching this episode of SciShow!
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