More than 4,400 preserved human brains found around the world, study findsExBulletin

SCOTT SIMON, HOST:

If you dig in ruins, who among us hasn't dug? – You may discover ancient human teeth and bones. But scientists are also discovering the brain. Unlike skin, muscle, and other soft tissues, the human brain appears to be durable. Alexandra Morton Hayward joins us. She's a paleontologist at the University of Oxford and joins us from Oxford. Thank you very much for joining us.

Alexandra Morton-Hayward: Thanks so much for having me, Scott.

SIMON: Your research paper says that more than 4,400 preserved human brains have been discovered around the world, right?

Morton Hayward: Yeah. That's it – all the continents of the world, except Antarctica. And the reports we found date back to his early 1600s.

SIMON: How were they preserved?

Morton Hayward: So we identified five different types of preservation. For example, dehydration, freezing to death, sunburn, etc. are familiar to most people. We also identified an unknown storage mechanism that appears to be unique to the brain. These brains are the only soft tissue preserved in the skeletal remains, so it's very strange to see the brains just rattling around inside the skull.

SIMON: Oh, have mercy.

Morton Hayward: That's amazing, isn't it?

SIMON: So to speak, yeah, it's interesting. What does a preserved brain look like?

Morton Hayward: Oh, they're amazing – they're shrinking so constantly, usually down to about a fifth of their lifetime volume. Therefore, it looks like a large walnut. It fits perfectly in the palm of your hand.

SIMON: Oh, sorry. It suggests that you have had it in the palm of your hand.

Morton Hayward: Oh, sure. Here at Oxford we have a collection of over 570 of his brains of this unknown type of preservation, which is very mysterious. We have four and a half refrigerators, and there's so much stuff in there that we're dealing with all the time. I always open the refrigerator and walk around the lab, checking on what's going on in the refrigerator and having small conversations. I often store them in jam jar sized containers and now I have so many that I have to tape them to a shelf so they don't shake when I open the door.

SIMON: What can we learn from ancient human brains?

Morton Hayward: That's my favorite question. As a result, archaeological science is experiencing an explosion in the amount of information that can be gleaned from biomolecules (such as ancient DNA, proteins, and lipids) recovered from ancient tissues. And these brains seem to be very rich stores of those molecules. And soft tissues are a richer source of these molecules in life because they are more metabolically active than hard tissues, such as bones. In other words, they are a very promising trove of archaeological information.

SIMON: What do you mean?

Morton Hayward: There's a lot of work in paleopathology looking at ancient proteins as markers of nutritional status, the richness or poverty of the diet. We can look at metabolic disorders, and there is even a possibility to look at neurological disorders in these specific brains. But all sorts of things can be studied, from past pandemics to whether an individual was infected with a dangerous ticker.

SIMON: (Laughter) Do you get a dangerous ticker in your brain?

Morton Hayward: That's right. It is possible to investigate using ancient proteins, such as at the population or individual level.

SIMON: Did you discover Julius Caesar's brain or…

Morton Hayward: Oh, that's a good question. So, there are some famous ancient royal families. Some are Egyptian royalty. But we also have the brains of fallen people. For example, there are 80 criminals who were thrown into a well in the Middle Ages. So this is a real cross-section of society.

Simon: By the way, they are my ancestors…

MORTON-HAYWARD: (Laughter).

SIMON: …Criminals thrown into a well. If you could read their brains, they'd probably say, “I'm Simon.” but…

MORTON-HAYWARD: (Laughter).

SIMON: …This is a fascinating job. How did you decide to go in this direction?

Morton Hayward: I think in a way that's what found me, rather than the other way around. I have worked as a mortician and embalmer for many years, so I have always worked with the deceased. And I was so fascinated by decomposition that I wanted to study it on a scientific level.

Simon: This is a fascinating job. What more do you think we can learn from it?

Morton Hayward: Yeah, I think this is just the beginning. My PhD researchers are focused on figuring out what this conservation mechanism is, which appears to be unique to the brain. Once we understand why the brain survives when other organs are destroyed, we will be able to perform all of the exciting tasks we talked about earlier.

SIMON: Alexandra Morton Hayward, paleontologist at Oxford University. Thank you very much for joining us.

Morton-Hayward: Thank you, Scott.

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