WEBVTT

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Imagine the brain could reboot,

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updating its withered and damaged cells
with new, improved units.

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That may sound like science fiction,

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but it's a potential reality
scientists are investigating right now.

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Will our brains one day 
be able to self-repair?

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It's well known that embryonic cells
in our young developing brains

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produce new neurons,

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the microscopic units 
that make up the brain's tissue.

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Those newly generated neurons migrate
to various parts of the developing brain,

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making it self-organize 
into different structures.

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But until recently,

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scientists thought cell production came to
an abrupt halt soon after this initial growth,

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leading them to conclude 
that neurological diseases,

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like Alzheimer's and Parkinson's,

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and damaging events, like strokes,
are irreversible.

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But a series of recent discoveries

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has revealed that adult brains 
actually do continue to produce new cells

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in at least three specialized locations.

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This process, known as neurogenesis,

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involves dedicated brain cells,
called neural stem cells

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and progenitor cells,

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which manufacture new neurons
or replace the old ones.

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The three regions where neurogenesis
has been discovered

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are the dentate gyrus,
associated with learning and memory,

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the subventricular zone, which may
supply neurons to the olfactory bulb

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for communication 
between the nose and brain,

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and the striatum, 
which helps manage movement.

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Scientists don't yet have a good grasp
on exactly what role

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neurogenesis plays 
in any of these regions,

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or why they have this ability 
that's absent from the rest of the brain,

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but the mere presence of a mechanism
to grown new neurons in the adult brain

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opens up an amazing possibility.

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Could we harness that mechanism
to get the brain to heal its scars

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similar to how new skin
grows to patch up a wound,

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or a broken bone 
stitches itself back together?

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So here's where we stand.

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Certain proteins and other small molecules
that mimick those proteins

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can be administered to the brain

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to make neural stem cells 
and progenitor cells

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produce more neurons 
in those three locations.

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This technique still needs improvement

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so that the cells 
reproduce more efficiently

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and more cells survive.

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But research shows that progenitor cells
from these areas

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can actually migrate to places where
injury has occurred

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and give rise to new neurons there.

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And another promising possible approach

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is to transplant healthy 
human neural stem cells,

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which are cultured in a laboratory,
to injured tissue,

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like we can do with skin.

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Scientists are currently experimenting

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to determine whether transplanted
donor cells can divide, differentiate

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and successfully give rise 
to new neurons in a damaged brain.

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They've also discovered

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that we might be able to teach
other kinds of brain cells,

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such as astrocytes
or oligodendrocytes

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to behave like neural stem cells
and start generating neurons, too.

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So, a couple of decades from now
will our brains be able to self-repair?

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We can't say for sure,

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but that has become one of the major 
goals of regenerative medicine.

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The human brain has 100 billion neurons

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and we're still figuring out the wiring
behind this huge biological motherboard.

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But everyday, research on neurogenesis
brings us closer to that reboot switch.