In terms of computational power, the human brain
far surpasses any animal in the animal kingdom.
It's what makes us special, but we still
don't understand how it arises, and so that's
what me and my lab were trying to figure out.
The thing that makes our brains so special
is the number of connections and the number of neurons.
At about 80 to 100 billion neurons,
that's about three times more than our closest relatives,
the chimpanzees.
And so it's thought that during human brain development
neuron production really skyrockets.
But when and how this happens is completely unknown.
So to get the answers to these questions
we've turned to growing human brain tissues in the lab.
In the past 10 years there's been a revolution
in this field, allowing researchers
to generate 3D tissues that look just like actual organs.
And essentially, it involves taking stem cells, which
have this amazing capacity to develop
into any tissue of the body, including brain tissue,
if we give them the right conditions.
And those conditions include a three-dimensional gel,
which essentially mimics the surrounding
tissue of the developing brain.
And what's really amazing about this is that,
when these cells are kept in just the right conditions,
they will then follow their own natural developmental
programme, generating neurons with the same timing
and positioning as an actual human developing brain.
So because we have these 3D mini brain tissues in a dish,
we now have access to human developing brain
tissue in a way that was never before possible.
We can actually really get hands-on,
and start looking inside of them by taking cross-sections,
looking at different cell types, and comparing different time
points to see what changes over time.
We can also do live imaging and actually watch
as human neural stem cells do generate neurons,
and then watch those neurons position themselves.
And this is something that was never before possible.
And so at the moment, we can observe these processes
very well, but what we'd really like to do
is start to challenge the system and look
at what's controlling the skyrocketing neuron production
that we're so interested in, and get
at the root of the question of what
makes our brains so unique.