Gruesome 12,000-year-old preserved brains could unlock answers about Alzheimer's disease

An archive full of old human brains could help scientists to better understand how soft tissue is preserved — and aid research around neurodegenerative conditions.

The brain is made up of about three to four pounds (1.3kg to 1.8kg) of soft tissue, an extremely delicate substance that floats in the fluid within the skull.

It connects and supports other tissues in the region, and acts as a sort of bridge to other vital parts of the body.

Now, a team led by Alexandra Morton-Hayward, a forensic anthropologist and doctoral candidate at the University of Oxford's Department of Earth Sciences is collecting a global record of more than 4,400 preserved human brains.

The work, it is hoped, will further understanding of the brain and even help to tackle some of the modern era most prevalent diseases like Alzheimer's.

"I think what's really intriguing about this research is that although we know the brain can liquefy really quickly, clearly, in some circumstances, it also preserves and on incredibly long timescales," Ms Morton-Hayward told Newsweek. "So, I would argue that we need to start thinking in greater depth about soft tissue preservation."

The brains come from 213 sources across the world, and include some specimens that are a staggering 12,000 years old.

The work, which has been published in the journal Proceedings of the Royal Society B, also has brains as young as coming from the 20th century. Detailed records used in the research stretch as far back as the 1600s.

Preserved soft tissues are valuable to archaeologists because they offer the chance to find a variety of biological information compared to the presence of only hard tissues — things like bone, cementum, dentin and enamel.

Despite this, fewer than 1 percent of preserved brains have been investigated for historical biomolecules, the substances trapped inside living organisms like carbohydrates, proteins and lipids.

The researchers working on the new study therefore say they are exploring an "untapped archive" that could not only unlock secrets about human evolution but help to look at diseases such as Alzheimer's in completely new ways.

Their database draws on source material from more than 10 different languages and encapsulates the biggest such study to date.

Such examples of preservation are rare. Only when human remains have been deliberately protected do they generally survive.

This is because organs are usually the first organs to decompose after death.

The new research, however, suggests that preserved brains may occur more often than previously believed.

Some of the key factors that helped the preservation process include natural dehydration, freezing, saponification, and tanning.

Examples come from the last Ice Age, the Stone Age, and a prehistoric cemetery in Upper Egypt.

Some of the brains also come from the Iron Age, the time of the Inca, as well as from the much more recent Spanish Civil War.