The brain arrives shortly after lunch.
It rests on the lab bench, in a Styrofoam box plastered with “Urgent Delivery” and “Fragile” stickers, while two research assistants prepare the dissection laboratory. One has tuned a small radio to a classical station. The sounds of bassoons and strings waft into the room. The opus is an allegro – upbeat and quick.
The technicians glide around the room with practised coordination. They are cloaked in knee-length blue plastic aprons, sleeves tucked into latex gloves. They tape absorbent mats to the bench tops and lay out scalpels and forceps.
Josée Prud’homme adjusts her face mask and eye shield, and nods to her colleague, Maâmar Bouchouka.
Bouchouka lifts the red biohazard bag from the box and slices it open with a scalpel.
“We’re starting. It’s 13:21,” he says.
He pats the brain down with paper cloths and sets it on a white cutting board. It slouches a bit. The tissue has started to break down. The brain is pink and a little shiny. Dark red blood vessels snake through the deep wrinkles and folds of the cerebral cortex, like rivers through weathered canyons.
It’s the brain of someone who took his life over the weekend, and was donated to the Quebec Brain Bank shortly thereafter.
“It’s very emotional, each time we receive a brain at the bank. We don’t get used to death,” says Prud’homme.
For 90 minutes, Bouchouka and Prud’homme will remove and freeze the brain’s key structures. They’ll separate the two hemispheres, preserving one in a rectangular clear plastic container filled with a formaldehyde solution, and cutting the other into one-centimetre-thick slices flash-frozen for storage at minus 80 degrees Celsius.
Now named S-252, this brain has become a critical resource for scientists interested in the biological and environmental underpinnings of mental illness.
* * *
For scientists interested in the origins of disease, mental illnesses have been difficult to untangle. Researchers have rummaged through the genome looking for common genetic disruptions to explain the cause of these overwhelming conditions.
Some scientists assume they’ll find the genetic roots of mental illnesses with more sophisticated technologies and approaches, and more powerful computers, says Arturas Petronis, a senior scientist in the Krembil Family Epigenetics Laboratory at the Centre for Addiction and Mental Health, and the Tapscott Chair in Schizophrenia Studies at the University of Toronto.
But genetics cannot explain all cases. Identical twins have nearly identical DNA, but if one twin develops schizophrenia, the other has only a 50 per cent chance of the same outcome.
“There’s another line of thinking that says, ‘There’s probably something wrong with the paradigm,’ ” Petronis says. “Maybe we’ve been barking up the wrong tree.”
A growing cadre of scientists is finding that life experience can be chemically “painted” onto DNA, creating a genetic on/off switch. This type of genetic regulation is called epigenetics, “epi” meaning above.
“Scientists have been studying epigenetics for years, but its application to the study of behaviour is relatively recent,” says Barry Lester, a professor of psychiatry and pediatrics at Brown University’s Center for the Study of Children at Risk.
The chemical traces of potent past experiences – such as famine or abuse – can change the way the brain works, and may be a source of addictions, depression and other mental illnesses.
>> Continue reading this story.
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“This is the heart of the brain bank,” Danielle Cecyre says, gesturing to the freezers and the pair of chrome wire shelving carts stacked with brains that have been donated to research. Each freezer is about the size of an old European elevator -just big enough to hold two adults. There are 17 of these freezers at the brain bank, each one closely monitored to ensure the temperature stays at minus 80C. >> more
Don’t forget to watch the video about the Quebec Brain Bank
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