Venki Ramakrishnan

I think, well, there are a number of possibilities. I think to me, cellular reprogramming is perhaps, if it pays off, one of the most powerful ways of doing it. But I will tell you, you could reprogram many tissues perhaps, but reprogramming the brain is going to be a real challenge because the brain doesn't naturally regenerate.

I think, well, there are a number of possibilities. I think to me, cellular reprogramming is perhaps, if it pays off, one of the most powerful ways of doing it. But I will tell you, you could reprogram many tissues perhaps, but reprogramming the brain is going to be a real challenge because the brain doesn't naturally regenerate.

There's only a very small amount of new neurons being synthesized compared to things like skin or blood or even liver. And of course, when neurons decay, or become dysfunctional, how you would reprogram them or even replace them, it's not at all clear. And you would have to do this in a way that, you know,

There's only a very small amount of new neurons being synthesized compared to things like skin or blood or even liver. And of course, when neurons decay, or become dysfunctional, how you would reprogram them or even replace them, it's not at all clear. And you would have to do this in a way that, you know,

maintains the connections between neurons and their states, because that's after all what determines the workings of a brain. And I think that is going to be a huge challenge. And there is this worry that we're all getting older, we're staying healthy. Eventually, if it means that we're going to come down with dementia, And, you know, the incidence of dementia is growing tremendously.

maintains the connections between neurons and their states, because that's after all what determines the workings of a brain. And I think that is going to be a huge challenge. And there is this worry that we're all getting older, we're staying healthy. Eventually, if it means that we're going to come down with dementia, And, you know, the incidence of dementia is growing tremendously.

It's already the largest killer of an old age in the UK. You know, it surpassed other causes. That could be a ticking time bomb. And so I'm optimistic that we'll be able to improve health in many ways in old age. I'm not so optimistic about this, you know, eventual thing of extending life dramatically. I think that's going to be much harder than people think.

It's already the largest killer of an old age in the UK. You know, it surpassed other causes. That could be a ticking time bomb. And so I'm optimistic that we'll be able to improve health in many ways in old age. I'm not so optimistic about this, you know, eventual thing of extending life dramatically. I think that's going to be much harder than people think.

Well, cellular reprogramming is, you know, I mentioned how you start with a fertilized egg and it slowly develops. And as it develops, the cells become more and more differentiated into different types. And And eventually you still have stem cells, but then those stem cells are differentiating into the final tissue. Those final tissues can only divide a certain number of times and then they die.

Well, cellular reprogramming is, you know, I mentioned how you start with a fertilized egg and it slowly develops. And as it develops, the cells become more and more differentiated into different types. And And eventually you still have stem cells, but then those stem cells are differentiating into the final tissue. Those final tissues can only divide a certain number of times and then they die.

And then they have to be replaced by stem cells. And also those tissues can't be any other kind of cell, okay? So cellular reprogramming would be taking one of these final tissue cells, like a skin cell or an epithelial cell from your gut, and programming it to go backwards in that development process. And that means changing which genes it's expressing.

And then they have to be replaced by stem cells. And also those tissues can't be any other kind of cell, okay? So cellular reprogramming would be taking one of these final tissue cells, like a skin cell or an epithelial cell from your gut, and programming it to go backwards in that development process. And that means changing which genes it's expressing.

And what's amazing is that it, and this is why Yamanaka won the Nobel Prize, is that it only takes four factors to to take a final cell all the way back to that early pluripotent cell, which could create any type of cell, okay? The downside is that if you do that, you often end up getting cancers.

And what's amazing is that it, and this is why Yamanaka won the Nobel Prize, is that it only takes four factors to to take a final cell all the way back to that early pluripotent cell, which could create any type of cell, okay? The downside is that if you do that, you often end up getting cancers.

If you start developing those cells in a tissue culture, they often will develop tumor-like growths and so on. So I think, you know, That's both a promising and a challenging approach. And it's the one thing that actually reverses the process. And one reason that I am perhaps somewhat optimistic is, remember Dolly the Sheep? I do. Dolly the Sheep was cloned from something like a skin cell, okay?

If you start developing those cells in a tissue culture, they often will develop tumor-like growths and so on. So I think, you know, That's both a promising and a challenging approach. And it's the one thing that actually reverses the process. And one reason that I am perhaps somewhat optimistic is, remember Dolly the Sheep? I do. Dolly the Sheep was cloned from something like a skin cell, okay?

And It was a sick sheep and it had all sorts of problems. It had shorter telomeres than normal, and it died at about half the age of a normal sheep. And everybody went, aha, that's because you started with an adult cell, which is already old and damaged. And then you tried to grow a new animal out of it. And so of course you haven't reset the clock.

And It was a sick sheep and it had all sorts of problems. It had shorter telomeres than normal, and it died at about half the age of a normal sheep. And everybody went, aha, that's because you started with an adult cell, which is already old and damaged. And then you tried to grow a new animal out of it. And so of course you haven't reset the clock.

Well, it turns out Dolly was only one of a cohort. There were other sheep like Dorothy and Daisy and Debbie. They gave them all D names for some reason. Anyway, it turns out most of these sheep were normal. Of course, you have to realize that the frequency of success in a cloning experiment is very small. most of those experiments fail and don't grow into adult animals.

Well, it turns out Dolly was only one of a cohort. There were other sheep like Dorothy and Daisy and Debbie. They gave them all D names for some reason. Anyway, it turns out most of these sheep were normal. Of course, you have to realize that the frequency of success in a cloning experiment is very small. most of those experiments fail and don't grow into adult animals.