THE underground tunnel is narrow and eerie. I know what is at the other end, but that doesn鈥檛 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. 鈥淭here are over a thousand brains in this room,鈥� Jorge Tejada tells me. Human brains, to be precise, sliced up and preserved in formalin.
I鈥檓 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 world鈥檚 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 鈥� some of them famous, including mathematician John Nash and writer Sylvia Plath 鈥� 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 Alzheimer鈥檚 or schizophrenia. 鈥淲e鈥檝e 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,鈥� 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.
Tejada鈥檚 team often have to advise the pathologist on the procedure. 鈥淲e need to have the whole brain intact, with very little damage,鈥� says Tejada. The surgery must avoid the donor鈥檚 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. 鈥淵ou cut the spinal cord to detach it from the brain,鈥� says Tejada. 鈥淭hen you must remove the whole brain and cerebellum very slowly, because the tissue is very soft 鈥� you don鈥檛 want to destroy it.鈥� Meanwhile, the team back at the brain bank is preparing for the new arrival. 鈥淲e have a trained person on call 24/7,鈥� 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 掳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.
Tejada鈥檚 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.
鈥淗ow is it possible that these cells and tissues make such a wonderful machine?鈥�
Once prepared, the tissue goes into storage, ready for its next move. Some of the samples are used for research at the McLean Hospital鈥檚 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 鈥� seahorse-shaped structures that play a crucial role in memory. Anything left over eventually gets cremated. But there鈥檚 no great rush. Preserved brains don鈥檛 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. It鈥檚 hard to describe, he says. 鈥淲hen you have that brain in your hands you say: 鈥榦h 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? That鈥檚 an amazing part of my work, but I don鈥檛 have a way to explain that feeling.鈥�
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 鈥渃ontrol鈥� brains are especially in demand, says Tejada.
鈥淲e need to advance neuroscience, and to develop new cures and procedures for neurological diseases and psychiatric disorders,鈥� he says. 鈥淚鈥檓 convinced this will happen thanks to brain donations.鈥�
This article appeared in print under the headline 鈥淚 slice up human brains for a living鈥�
