So it's unethical to do an experiment
with a healthy,
human, baby brain so for
several years scientists have relying on
animal models for example we try to
learn
what happens in a mouse or in a monkey
and we extrapolate to humans but as I
pointed out the human brain is so
different from other species so we need
to understand how the human brain is
formed
so here comes this new technology
which is a brain organoid in a brain
organoid
is just the recapitulation of the human
development
inside the lab using stem cells
to grow every single step at these very
early stages of neurodevelopment
let's explain what stem cells are so
this will make sense
all right stem cells are cells that are
immature they don't have
a fate defined yet for example
in in you have your skin cells you have
your blood cells you have your brain
cells
all these cells have names right now
because they already
acquire some kind of identity in the
early stages of
uh the embryogenesis you have stem cells
that
are not defined yet they are just
self-replicating
and they will give rise to progenitor
cells that later
will form all the tissues in the body so
these cells we call them pluripotent
stem cells because they can form any
tissues of the body
so if they're given the right
instructions or stimulus they could
become
liver or brain right you don't know so
you figured out how to
induce them to becoming brain yeah we
are brain makers
we develop uh protocols and recipes,
formulas
that we can uh add on these stem cells
uh and instruct them or or fool them
around to think that they are in the
right environment to become the cell
type that we want
and my lab has been optimizing these
protocols to create what we call a brain
organoid or a mini brain some people
call them
mini brains because they're just a very
miniaturized version of the human brain
so last year we learned how to grow
these organoids to create functional
neural networks so that's one step ahead
so now so now we have to explain what
the neural net the functional network is
right a functional network is when
neurons
start to talk to each other and in
and form
complex uh nets of information
so that's how our
beginning of our cognition appears or
or arises
in in the early stages of
neurodevelopment
um so so the baby doesn't have all those
connections
the baby already have them but they are
not mature enough
and in the organoid we never seen that
before because we thought that
it would be impossible to recreate that
in vitro
and a brain organoid has intrinsic
limitations it's not
vascularized not all cell types are
there we don't even know
if the conditions are the same condition
as
uh in uterus so we were quite skeptical
that the networks would appear in this
brain organoids
but so science has evolved to the point
where we
we could tweak this protocol and make
them actually form these networks
so now we open the possibility to study
conditions where the brain is intact
but the networks are not for example
conditions like autism or schizophrenia
so we don't see a major neuronal flaws or
a neurodegeneration
in autism or schizophrenia but the
network but the network is defective
so the question is can we use these
brain organoids to find
new drugs or eventual gene therapy
to help people with this kind of
neurological conditions so
understanding normal how it how it works
how it's supposed to work
helps you identify what to do in
situations where it didn't work the way
we want it to work exactly that's that's
that's how we do it we always compare
the disease condition with the
neurotypical
that's what we call disease modeling in
a dish so we're doing this right now
I remember years ago i met an indian
sitar player
and he gave me music to play for my
children and he
and I said why shouldn't I listen to it
he said that I
never developed the neural connections
to hear all the sounds
because those were not made when I was a
baby and when I can make those networks
you speak portuguese and the sounds
I have to concentrate very hard to hear
all of that but your neural network
was exposed to that and it was
reinforced and created so you're now
looking at these kinds of networks that
babies
that's how they learn and grow and being
able to develop them in a lab
so that's it's just to me amazing yeah
uh that that you're able to do that in a
laboratory and I think you now touch on
on on
other things which which might um uh
be a little bit more complex for example
uh we could use the same technology
to make the same human brain um
more plastic or more adaptable or have
more synapses
or be more protective against
neurodegeneration later in life
would be nice to have a brain that is
protected against alzheimer's
yes so we can ask those questions and
perhaps finding answers
and um and and some of these answers
might require early modulations of these
networks
at very early stages in development so
we as a society we have to discuss
the ethical implications of those um
alterations
you know as as a parent that's a that's
a tough question
to think about and in society that
that's a tough question
I don't think we'll answer that today
but but it's an important question
because
science is about to give us those
options right uh and and
sooner rather than later to decide that
I'm a pediatric ophthalmologist
we have children of amblyopia that
really can't be treated after you get
older because the neuroplasticity is
gone
right uh there are brain injuries that
we'd love to be able to repair I mean
there's so much that we'd want to be
able to do that you could see
you making a difference in
