The mystery of brains that have been preserved for thousands of years naturally

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The mystery of brains that have been preserved for thousands of years naturally

Brain more than 1,000 years old — photo caption, This is one of the brains that is more than 1,000 years old.

Author, Drafting
Author’s title, BBC News World
April 9, 2024

The brain is perhaps the softest of the soft tissues in the body and, for this reason, it is an organ that tends to decompose quickly after death, transforming into a liquid that disappears to leave only the skull.

Hence the fascination of forensic anthropologist Alexandra Morton-Hayward in discovering thousands of cases of brains that have been preserved practically intact for hundreds of years, and even thousands in some cases.

The professor at the Department of Earth Sciences at the University of Oxford led research to refute the belief that the appearance of perfectly preserved brains are extremely strange archaeological discoveries.

In fact, thanks to his study, he was able to verify that nervous tissues persist in much greater abundance than previously assumed, helped by specific conditions that help prevent their putrefaction.

Published in the scientific journal of the Royal Society of London for the Advancement of Natural Science, the study compiled a sample of more than 4,000 human brains appearing in more than 200 records, including some dating back to the mid-17th century.

Alexandra Morton-Hayward with a 1,000-year-old brain. — photo caption, The research team believes that the study of brains preserved for more than 1,000 years could be useful for our future.

Among them is a 12,000-year-old brain that appeared near some mammoth teeth in present-day Russia.

In the records there are mentions of a wide variety of archaeological sites such as the shores of a lake bed in Stone Age Swedenthe depths of a iranian salt mine around the year 500 BC and the summit of the andean volcanoes at the height of the Inca Empire.

Morton-Hayward believes that these ancient brains could be an important source of information about our past that has not yet been exploited.

“In principle, we should find proteins and DNA in brains that are less degraded than those in bones. Once we have this material we can learn a lot about our ancestors from it,” he explained in an interview with Science magazine.

Fifth mechanism

Morton-Hayward first became interested in brain preservation while working in a funeral home.

“One of the things that intrigued me the most was decomposition. Just as we are all different in life, We all break down differently in death.. And a lot seems to depend on how you lived and what you die from,” he explained in the scientific community.

Each of the recorded brains was compared to historical climate data from the same area, to explore trends in when and where they were found.

Preserved brains — photo caption, The oldest brain is about 12,000 years old.

These analyzes revealed patterns in environmental conditions associated with different modes of preservation over time, including dehydration, freezing, saponification (the transformation of fats into a type of soapy substance known as “grave wax”) and that of a tanning process.

But these known processes preserve all soft tissues, not just brains. They do not explain the 1,300 cases in which the brain is the only soft tissue that survives.

According to the researchers, this is due to what they describe as a fifth conservation mechanism.

“This unknown mechanism is completely different“Morton-Hayward told the NewScientist portal. “The key feature is that we only have the brain and bones left. There is no skin, no muscles, no guts.”

The hypothesis is that, under certain circumstances, substances such as iron or copper can catalyze the formation of bonds between proteins and lipids, forming more stable molecules that resist degradation. And it is in the nature of the proteins and lipids found in the brains, or their ratio, where the key could lie.

“Whether those circumstances are environmental or related to the unique biochemistry of the brain is the focus of our current and future work,” Morton-Hayward explained.

For the researcher, it is relevant that these mechanisms “are similar to those we see in neurodegenerative diseases, such as dementia.”

“So if we can find out what is happening to brains after deathwe might shed some light on what’s happening in brain aging later in life as well,” he added.