Shortage Of Brain Tissue Hinders Autism Research
Research on autism is being hobbled by a shortage of brain tissue.
The brain tissue comes from people with autism who have died, and it has allowed researchers to make key discoveries about how the disorder affects brain development.
But there's not nearly enough tissue because most potential donors aren't identified, and their family members are never approached about the possibility of donation. The shortage has been especially bad since last summer, when a freezer at a Harvard brain bank failed, allowing dozens of autistic brains to thaw.
This is the story of three people who are grappling with the shortage: one is a man who has autism, one is a scientist who studies the disorder, and one runs a tissue bank.
The man with autism is Jonathan Mitchell. He's in his late 50s and describes his brain as "damaged."
Here's how Mitchell describes life with an autistic brain: "It's prevented me from making a living or ever having a girlfriend. It's given me bad fine motor coordination problems where I can hardly write. I have an impaired ability to relate to people. I can't concentrate or get things done." He adds that part of his day is spent engaging in a self-stimulatory behavior that involves shaking a pencil and some shoelaces at a certain frequency while he rocks back and forth.
Mitchell lives in Los Angeles. He has a degree in psychology and used to work, at times doing things like data entry. "But then I got fired from so many jobs, I ended up retiring and being supported by my parents," he says. Mitchell says he was fired because employers thought he was too loud, made too many mistakes and smelled bad.
Like a lot of people with autism, Mitchell is unflinchingly honest. When I say he sounds angry, he says "Yes, I'm very angry and very embittered." When I ask why he decided to talk to me, he responds that he's "a little self-centered and superficial and a little bit of a publicity hound."
What's the worst part about having an autistic brain? "The celibacy," he says. "The loneliness. The isolation."
Mitchell has spent a lot of his life trying to understand his own brain. In college, he took classes in neuroscience because he wanted to know which parts of his brain weren't working correctly. Later he volunteered for research studies that used MRI scans to look at the structures in his brain.
Mitchell eventually began to focus on research that examined brain tissue from people with autism. Scientists were finding some amazing things. But the research was going very slowly because there wasn't much brain tissue available for research.
So a few years ago, Mitchell decided to do something. He signed up for a program that will donate his brain to science when he dies.
His hope, he says, is that researchers will find something in his brain that leads to a treatment or cure for autism so that someday children "wouldn't have to go through the hell that I went through and still continue to go through in my life."
Mitchell wants bits of his brain to go to autism researchers like Eric Courchesne at the University of California, San Diego. Courchesne has already looked at Mitchell's brain once — as part of an MRI study more than 20 years ago.
But there's a lot that even the most advanced scanner doesn't show, Courchesne says.
"It doesn't show you brain cells. It doesn't show you axons. It doesn't show you synapses, and it can't show you the underlying sort of fine architecture that makes up the cortex," he says. "The only way to get that kind of detailed information is through the study of brain tissue."
So Courchesne has been studying slices of frozen brain tissue in order to understand what autism does to the brain. But a decade ago, his research ran smack into the brain tissue shortage.
He had published a paper showing that children with autism tended to have brains that grow unusually fast during the first year or so. And he suspected that this accelerated growth left these children with an abnormally large number of brain cells in areas of the brain including the prefrontal cortex.
To find out, though, he needed to obtain slices of brain tissue and actually count the cells. "It's an easy procedure to do if you have the tissue," he says. "But without the tissue, then it's a long, slow study."
It took Courchesne years to cobble together enough samples of prefrontal cortex from children with autism and from typical children, who served as controls. Finally, though, he was able to quantify what was happening in the prefrontal cortex.
"Sure enough, what we found was a tremendous increase, 67 percent more brain cells in that frontal region of the brain than what was true of the controls," he says.
That study was published in 2011. Last year, Courchesne published another study of brain tissue that seemed to explain the increase. It found that children with autism had abnormalities in genes controlling the number of brain cells.
"It was incredibly startling, and it was very exciting," he says. "For the first time in my 30 years of doing autism research ... I really understood the early steps that were leading to the problems that these little children had."
This sort of research should help identify autism early in life. And it could lead to a treatment that corrects the abnormal growth pattern, Courchesne says.
One reason Courchesne is so determined to find a treatment for autism is that his own childhood was drastically altered by another neurological problem: polio.
"By the time my fifth birthday rolled around, I wasn't able to stand or walk on my own," he says. "So from the earliest years I understood what it was like to be separated from the normal activities of other kids."
Even so, he was luckier than most kids with autism, he says. "Eventually I received the kind of help that may not have made me perfect again but made able to fully participate in society and with my peers," he says, adding, "I suspect that we will be able to do that with autism."
How long it takes, though, may depend on how much brain tissue is available for studies.
Courchesne and other autism researchers depend on a handful of facilities like the Brain and Tissue Bank for Developmental Disorders at the University of Maryland for tissue samples. The banks maintain dozens of freezers that keep the tissue at minus 85 degrees Celsius.
The bank at the University of Maryland is funded by the National Institutes of Health and has been operating for about two decades. But it has collected only about 50 autistic brains, says its director, Ron Zielke, who is also a professor of pediatrics.
"It's very frustrating because more could be done if we had more tissue," he says. "We have some researchers who would like to have a particular brain lobe for their study. Other researchers would like to have the whole amygdala, and we cannot supply them."
The greatest demand is for tissue from children because researchers are trying to understand how autism is altering the brain early in life. But this tissue is especially hard to get, Zielke says.
When children die, there is usually an autopsy. And sometimes, a medical examiner will learn whether the child had autism.
That's just the first step, though. The medical examiner has to alert a tissue bank. The bank has to contact the parents. The parents have to agree to a donation. And all of this has to happen within hours. It rarely does.
Zielke and others who run tissue banks have been trying to improve the odds by attending meetings of autism groups and getting the word out to medical examiners. The University of Maryland bank also has a website for families interested in donation.
People who want to donate brain tissue simply register with the program and keep a donor card in their wallet. And the program is open to anyone — not just people with autism and their families. That's because autism researchers need to compare tissue from autistic brains with tissue from typical brains — and both types are in short supply.
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