Nearly 2000 years ago, a cloud of scorching-ash from Mount Vesuvius buried a young man as he lay on a wooden bed. That burning ash quickly-cooled turning his brain to glass.
This confluence-of events during A.D. 79 in the town of Herculaneum, which lay at the western base of the volcano preserved usually delicate neural tissue during a durable glassy form. New scrutiny of this tissue has revealed signs of nerve cells which elaborate tendrils for sending and receiving messages, scientists report October 6 in PLOS ONE.
That young man once possessed these nerve cells or neurons is not any surprise; human brains are full of roughly 86 billion neurons But samples from ancient brains are sparse. People who do exist became a soaplike substance or mummified, says Pier Paolo Petrone, a biologist & forensic anthropologist at University of Naples Federico II in Italy. But while studying the Herculaneum site, Petrone noticed something dark & glossy inside this man’s skull. He realized that those glassy, black-fragments “had to be the remains of the brain”.
Petrone & colleagues used scanning microscopy to review glassy remains from both the man’s brain & medulla spinalis. The researchers saw tubular structures also as cell bodies that were the proper sizes & shapes to be neurons. In further-analyses, team found layers of tissue wrapped around tendrils in the brain tissue. This layering appears to be myelin, a fatty substance that speeds signals along nerve fibers.
The preserved tissue was “something really astonishing & incredible” Petrone says, because the conversion of objects to glass, a process called vitrification is comparatively rare in nature. “This is the first-ever discovery of ancient human brain remains vitrified by hot ash during a volcanic eruption.”