THE underground tunnel is narrow and eerie. I know what is at the other end, but that doesnât make it any less creepy. I emerge into an old hospital building and then enter a square room stacked floor-to-ceiling with plastic boxes. âThere are over a thousand brains in this room,â Jorge Tejada tells me. Human brains, to be precise, sliced up and preserved in formalin.
Iâm visiting the Harvard Brain Tissue Resource Center at McLean Hospital in Massachusetts, where Tejada is assistant director of operations. Known informally as the , it houses the worldâs largest collection of human brains. Tejada, a pathologist, has worked here for 15 years. He is going to talk me through what happens when a fresh brain arrives at the facility.
The institution traces its history back to 1818, when Massachusetts General Hospital opened its Asylum for the Insane on a wooded hillside just outside Boston. In 1895, with the city encroaching, the asylum moved to its present location in Belmont. As well as treating patients â some of them famous, including mathematician John Nash and writer Sylvia Plath â the renamed McLean Hospital established itself as a world-leading research centre. The brain bank opened in 1978.
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Since then, it has received about 9000 brains, or four to five per week on average. Most were donated by people with brain conditions, such as Alzheimerâs or schizophrenia. âWeâve also launched a programme to collect brains from people who had post-traumatic stress disorder because it has become a major issue in the US,â says Tejada. Today, the brain bank houses around 2000 specimens. Tejada personally prepared several hundred of them.
As soon as a registered brain donor dies, Tejada and his team leap into action. A dead brain can deteriorate fast, so the team has a 24-hour window to obtain consent from the next of kin, find a pathologist who can remove the brain and put it on ice, and transport it from anywhere in the US to the brain bank.
Tejadaâs team often have to advise the pathologist on the procedure. âWe need to have the whole brain intact, with very little damage,â says Tejada. The surgery must avoid the donorâs face, he says, especially since many donors will have open-casket funerals.
Once the back of the skull has been removed, the next step is to ease the brain from the surrounding tissue. âYou cut the spinal cord to detach it from the brain,â says Tejada. âThen you must remove the whole brain and cerebellum very slowly, because the tissue is very soft â you donât want to destroy it.â Meanwhile, the team back at the brain bank is preparing for the new arrival. âWe have a trained person on call 24/7,â says Tejada.
A newly arrived brain is first weighed before being cut in half to separate the right and left hemispheres. One is further sliced by hand to dissect out regions required for research before being frozen and stored in a freezer at -80 °C. The other hemisphere is fixed in formalin. Tissue from the fixed hemisphere is used to study proteins and the shape of tissue, whereas frozen tissue is better suited to DNA analysis.
Tejadaâs team also diagnoses any disease that might have affected the brain, and runs tests on blood samples, to check for viruses like HIV and hepatitis.
âHow is it possible that these cells and tissues make such a wonderful machine?â
Once prepared, the tissue goes into storage, ready for its next move. Some of the samples are used for research at the McLean Hospitalâs labs, but the bank mainly serves as a repository of interesting tissue for others to use. Dissected sections are shipped on request to researchers around the world.
Some brain regions are more in demand than others. Right now there are a lot of requests for hippocampi â seahorse-shaped structures that play a crucial role in memory. Anything left over eventually gets cremated. But thereâs no great rush. Preserved brains donât have an expiry date, says Tejada.
I ask him what it is like to handle and prepare a brain that, 24 hours earlier, was inside a living person. Itâs hard to describe, he says. âWhen you have that brain in your hands you say: âoh my god! This is what makes a person think, jump, talk and do everything. How is it possible that these cells and tissues make such a wonderful machine? Thatâs an amazing part of my work, but I donât have a way to explain that feeling.â
Most people who donate have some kind of neurological disorder and hope their brain will speed the development of new treatments. For that reason, healthy âcontrolâ brains are especially in demand, says Tejada.
âWe need to advance neuroscience, and to develop new cures and procedures for neurological diseases and psychiatric disorders,â he says. âIâm convinced this will happen thanks to brain donations.â
This article appeared in print under the headline âI slice up human brains for a livingâ
