Dr. Sergiu Pașcă

But for us and in primates, it's as simple as this.

So what we did was we essentially made an organoid that resembles the cortex and has some of those neurons.

And then we made an organoid that resembles the spinal cord.

and has some motor neurons in it.

And then we made a ball of human muscle that you can make from a biopsy.

You can literally biopsy a muscle.

You get the myoblast, you grow them, and you get a nice ball of muscle.

And then, of course, the challenge was that the reality is that we don't know how those cells find each other.

Like in development, we know some of the molecular cues that they use, but we're far from having a comprehensive understanding of how they find each other.

And I remember we were sitting down in the lab and kind of like thinking, I resisted actually doing this as the first assembloid in the lab for a while because the probability was like against us.

Like those cells in the cortical organoid that are less than 5%, the motor neurons are less than 10%.

The probability that they find each other perfectly and in enough numbers to trigger muscle contraction was close to zero.

And yet you do it, you put the three parts together, you let them assemble.

And within a few weeks, you can actually now stimulate the cortex.

with whatever you want to use, with an electrode, with light, and then the muscle starts to contract.

And in fact, the more you do it, the more reliable the process is.

And then, of course, we went on, so like reverse engineering it and figure out that indeed the cells have connected in that precise way.

So I think what we started actually to realize was that, of course, a lot of stem cell biology was, you know, I think a lot of biology was based on chemical and physical factors that we were leveraging.

But we've never truly leveraged this kind of like next level of law or power in biology, which is self-organization.

the ability of a biological system, of build it itself.