But even crazier, the mini brain attached itself to a spinal cord and muscle tissue

that twitched!

Granted, this tiny brain was about the size of a lentil, but this still holds incredible

promise for the future of how we study our brains.

Now, you might be wondering why would we grow brains in the first place.

Well in the past, scientists were confined to studying the brain during autopsies, but

observing a dead brain could only get us so far.

What neuroscientists really want to know is how the human brain and nervous system develop.

Yes, we have MRI’s, EEGs and CT scans etc., which capture brain activity and have taught

us a lot about what we know today.

But this new method brings us one step closer to trying to understand the cause and possibly

find treatments for neurological disorders.

Officially called, cerebral or brain organoids, these 3D tissues are generated from human

stem cells which allow modelling of brain development in vitro.

Essentially allowing scientists to monitor brain development in a petri dish.

Now, we’ve been able to grow these organoids for a number of years, but this is the first

time that we’ve been able to attach a spinal cord to the tissue and see muscles contract.

So how did they do it?

Well, it all begins with stem cells taken from skin samples.

The stem cells are placed into 3D culture, where they undergo the initial phases of embryonic

development.

Next, they’re implanted in droplets of Matrigel, a gel containing proteins that support the

cells growth.

The droplets were then placed into an orbital shaker to help stimulate the stem cells to

transform and grow into the ball-like clusters of neural tissue.

This is where researchers had been running into problems.

Previously, once the organoid reached a certain size, its center wouldn’t get as many nutrients

or oxygen, putting an end to its growth.

And This where the new research comes in.

The scientists used an “air-liquid interface culture”, allowing the tissue access to

the nutrient rich-liquid below and the oxygen above.

To demonstrate this, they used a tiny slice of organoids on a porous membrane, surrounded

by a nutritious solution.

This allowed for the mini-brain model to develop in the dish for up to a year, thus producing

more sophisticated and mature organoids.

The next step was to monitor the neural activity of the mini brain model.

In order to do that, the researchers placed a spinal cord and some back muscle from a

mouse’s embryo next to the mini brain to observe whether or not its neurons would grow

out to connect with them.

Over the next 2 to 3 weeks, the neurons did just that and connected with the spinal cord

to send out electrical impulses.

And guess what happened?!

THE MUSCLES TWITCHED!

It’s the first time cerebral organoids had demonstrated an ability to control muscle

movement.

This new discovery also furthers our knowledge into understanding how neurons connect up

inside the brain and with the spinal cord.

The models can also allow scientists to monitor the progression of certain neurological disorders

like schizophrenia and autism, conditions where neuronal connections are believed to

be damaged.

But growing mini brains hasn’t come without controversy.

Some believe that regulations must be drawn in order to address the future implications

of this type of research.

For example, could these brains develop consciousness?

Well, at their current size, no.

The mini-brain is still only pea-sized and contains about a couple of million neurons,

now I know that sounds small, but it’s actually twice the number of neurons in a cockroach’s

brain.

Which suffice to say, is still pretty far away from a fully developed human brain that

has over 80 BILLION neurons.

Which is why the researchers acknowledge that their mini brain is far from reaching consciousness.

But what happens when these mini-brains continue to grow in size and complexity, will it become

an issue then?

It’s a question that some ethicists are pushing to find the answer to especially as

the research is moving so quickly.

But as research progresses, these miniature brains can start helping us to better understand

the fundamental questions about our brains.

So what do you think?

Should we be growing brains in a petri dish?

Let us know in the comments below and don’t forget to subscribe to Seeker for more science

in your day and thanks for watching Seeker.