An undertaker turned academic, Alexandra Morton-Hayward became interested in brains — specifically how they decompose — during her former job.
Now a forensic anthropologist studying for a doctorate at the University of Oxford, Morton-Hayward has discovered that brains, while not as commonly found intact as bones, do preserve surprisingly well in the archaeological record.
To understand why, the anthropologist has compiled a unique archive of information about 4,405 brains unearthed by archaeologists. Brains have surfaced from northern European peat bogs, Andean mountaintops, shipwrecks, desert tombs and Victorian poorhouses. The earliest discovered were 12,000 years old.
Morton-Hayward is primarily working toward understanding how these brains survive the ravages of time, with at least four preservation mechanisms at play.
However, the database also will open whole new areas of study.
“This database will enable scientists to study brain tissue from ancient times and determine whether diseases known today were also present many years ago in civilizations completely different from the ones we currently live in,” said Martin Wirenfeldt Nielsen, a senior physician and pathologist at South Denmark University Hospital.
“Examining tissue from brains that have not been exposed to the environment and stimuli in modern society might help us understand whether some of the brain diseases we encounter today could be at least in part caused by the way we live now.”
Morton-Hayward scoured scientific literature going back three centuries and interviewed historians and archaeologists to catalog the brains. However, not all the corresponding physical specimens are still available for study.
The researchers have identified four preservation mechanisms: dehydration, tanning, freezing, and saponification.
Dry, hot conditions dehydrated the brains in a way that mimics embalming, while in acidic peat bogs, the body was essentially tanned. In cold places, the brain was frozen, while in a few cases, fats found in the brain transformed into “grave wax,” a process known as saponification.
In addition to these known preservation methods, there seems to be a fifth, unknown mechanism that Morton-Hayward hypothesizes could involve molecular crosslinking, possibly promoted by the presence of metals like iron.
The researchers don’t believe the skull’s protective shell is behind the preservation of the brain in the absence of other soft tissue because preserved brains had been found in damaged skulls.
It’s possible that ancient DNA and proteins could be extracted from these preserved brains, revealing information about the people they belonged to that bones and teeth cannot provide.
Overall, the research conducted by Morton-Hayward and her colleagues opens up exciting possibilities for studying brain tissue from ancient times and gaining insights into the prevalence of diseases and the biomolecular composition of the brain. It is a testament to the incredible preservation potential of this organ and its ability to reveal information about our past.
Alexandra L. Morton-Hayward
Fragments of brain from a person buried in a Victorian workhouse cemetery in Bristol, England, some 200 years ago. No other soft tissue survived amongst the bones, which were dredged from a heavily waterlogged grave.
Alexandra L. Morton-Hayward
Shown here is the 1,000-year-old brain of a person excavated from the c. 10th century churchyard of Sint-Maartenskerk, in Ypres, Belgium. The folds