You can grow new brain cells. Here's how

Can we, as adults, grow new nerve cells?

There's still some confusion
about that question,

as this is a fairly new field of research.

For example, I was talking
to one of my colleagues, Robert --

who is an oncologist --

and he was telling me,

"Sandrine, this is puzzling,

some of my patients that have been told
they are cured of their cancer,

still develop symptoms of depression."

And I responded to him,

"Well, from my point of view
that makes sense.

The drug you give to your patients
that stops the cancer cells multiplying,

also stops the newborn neurons
being generated in their brain."

And then Robert looked at me
like I was crazy and said,

"But Sandrine, these are adult patients,
adults do not grow new nerve cells."

And much to his surprise, I said,
"Well actually, we do."

And this is a phenomenon
that we call Neurogenesis.

[Neurogenesis]

Now, Robert is not a neuroscientist,
so when he went to medical school,

so when he went to medical school
he was not taught what we know now --

that the adult brain
can generate new nerve cells.

So, Robert, you know,
being a good doctor that he is,

wanted to come to my lab to understand
the topic a little bit better.

And I took him for a tour

of one the of most exciting
parts of the brain,

when it comes to Neurogenesis --

and this is the Hippocampus.

So this is this gray structure
in the center of the brain.

And what we've known for what
seems like already for very long,

is that this is important for learning,
memory, mood and emotion.

However, what we have learned
more recently,

is that this is one of the unique
structures of the adult brain

where new neurons can be generated.

And if we slide
through the Hippocampus

and zoom in,

what you actually see here in blue

is a newborn neuron
in an adult mouse brain.

So when it comes to the human brain,

my colleague Dr. Jonas Frisén
from the Karolinska Institute,

has estimated that we produce

700 new neurons per day
in the Hippocampus.

So you might think this is not much
according the to billions of neurons we have,

according to the billions
of neurons we have,

but by the time we will turn 50