Preserved brain cells have been found in the remains of a young man who died in the eruption of Mount Vesuvius in 79 AD.
The structure of the brain cells is still visible in a black, glassy material that is in the man's skull. The new discovery of this structure, described October 2 in the journal PLOS One, adds to the accumulated evidence that this vitreous material is indeed part of the man's brain.
The transformation into glass took place through extreme heating and rapid cooling.
"The results of our study show that the vitrification process, unique in Herculaneum, has frozen the neural structures of this victim and has kept it intact to this day," study leader Pier Paolo Petrone, a forensic anthropologist at the Federico II University of Naples in Italy, said in a statement .
Above: A neuron can be seen along with its axons in this glazed segment of brain tissue that was covered in ash when Vesuvius exploded in 79.
Herculaneum was an ancient city at the foot of Mount Vesuvius that blew up its top in a spectacular eruption almost 2,000 years ago. A cloud of hot ash and gases known as the pyroclastic river buried Herculaneum and its famous neighbor Pompeii.
This hot ash simultaneously destroyed and buried the city and quickly heated organic materials. Oddly enough, the speed of burial meant that materials like wood and meat, even though they were carbonized or essentially converted to charcoal, were preserved as they were in the moments after they were suddenly heated to 500 degrees Celsius.
In rare cases, this preserved organic material appears to have contained brains. Petrone and his colleagues examined a glassy black material found in the cracked and charred skull of a 20-year-old man who was lying face down on a bed in the Herculaneum Collegium Augustalium or College of the Augustales.
Above: A view of the glazed spinal cord under the microscope.
This building near the main street of Herculaneum was the headquarters of the cult of Emperor Augustus, an organization that worshiped the emperor as a deity (a Roman religious tradition common at the time).
Petrone and his team previously analyzed the remains of Herculaneum victims, suggesting that their body tissues may have evaporated in the hot cloud of ash. Earlier this year, they reported in the Journal of the American Medical Association (JAMA) that they found the glassy remains of a brain in the body of the 20-year-old from the Collegium Augustalium.
Using scanning electron microscopy to see the smallest details of the sample, the researchers have now discovered tiny spherical structures and long tubular structures that look exactly like neurons and their projections, called axons.
With a diameter of only 550 to 830 nanometers, these protrusions are too small to be capillaries. The spherical structures appear to hold back cell membranes as well as internal filaments or structural proteins in the cell and tiny vesicles or internal sacs that help transport proteins to the cell surface.
The researchers also used a method called energy dispersive X-ray spectroscopy, which uses X-rays to determine the chemical composition of a material. They found the sample was rich in carbon and oxygen, which indicates that it was organic.
Building on previous research published in JAMA, which found a number of protein structures in the sample, the researchers compared these ancient proteins to a database of proteins found in the human brain.
They found that all of the proteins they discovered were present in brain tissue. For example, a protein called ATP6VIF is known to be involved in the transmission of chemicals known as neurotransmitters through synapses, the gaps between axons.
Based on the concentrations of these proteins and the location of the sample in the back of the skull, Petrone and his colleagues suspect that they discovered part of the man's spinal cord and cerebellum, a brain structure at the base of the skull that is affected in movement and coordination .
Finding preserved brain tissue is rare in archeology. But occasionally, brain tissue can survive for hundreds or thousands of years.
For example, a 2,600 year old skull found in a pit in northern England contains the shriveled remains of a brain with some proteins still intact. In this case, acidic chemicals from the surrounding clay may have stopped the decomposition. Thanks to extremely cold temperatures, it was also found that mammoth brains are preserved in permafrost.
This article was originally published by Live Science. Read the original article here.