BARONESS SUSAN GREENFIELD: OK, so, the huge question, and one that I'm working on - and I should stress, this is my own view - is, we start with the idea that Alzheimer's and Parkinson's can co-occur. And I'll just remind people what Parkinson's is - that's a disorder of movement, presenting with one of three, or any of three, possible symptoms: rigidity, tremor, and a poverty of movement. Alzheimer's is characterised by confusion, disorientation, loss of understanding, and so on. Now, if you look in the brain, at the primary sites of where it all starts, you'll find that there's a hub of brain cells deep down, in the very basic part of the brain. And the two areas are next to each other. So, what we imagine happens is that if one area, let's call it Area A, is damaged, you'll have Alzheimer's. If it's the adjacent area, Area B, Parkinson's. But if the damage is extensive you would have both. Now, why are these cells so special, why are they different? What we think happens is that because they come from a different part of the embryo, they have very different features. And we know they come from a different part of the embryo, and we know that one of these very distinctive features they have is that they have retained their ability to grow again, unlike other cells in the brain. Now, surely, you would say, that's fantastic. Cos if they can grow again, if they're damaged, they'll grow again. The problem is that the mechanisms, the underlying chemistry by which cells grow again, is fantastic in an embryo. But, out of context, in a different situation of the adult brain, it actually becomes toxic. Your brains are unique. They're the very essence of you.My grandfather had Parkinson's Disease and it was heartbreaking. My grandmother on the other side had dementia.
BARONESS SUSAN GREENFIELD IN VOICEOVER: In the early '90s, after I'd give the Royal Institution Christmas Lectures, I got approached to write a book encapsulating the lectures. And I did, and it was called The Human Brain: A Guided Tour. And, amazingly, this went into the bestseller list. And as a result of that, I got approached by the BBC to turn that into a TV series.
Read more about Baroness Susan Greenfield in the Talking Heads interview.