Louisville Magazine

AUG 2013

Louisville Magazine is Louisville's city magazine, covering Louisville people, lifestyles, politics, sports, restaurants, entertainment and homes. Includes a monthly calendar of events.

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rTMS administered, the better. About that, Matt Partin would certainly agree. He and his wife Benedicte are autism experts. Tey may lack Ph.D.'s, but their training is ongoing and a lot more handson than any doctoral candidate's. Tree of their four children have autism. Tere's Eli, a tall 12-year-old with a mop of lush brown curly hair, and his eight-year-old brothers, Charlie and Nick — identical twins in a set of triplets. Josie, the third party in the triplet trio, does not have autism, which hints at one feature of the condition: It's far more common in boys. For every girl with autism, four boys have the diagnosis. It's not uncommon for families to have more than one child with autism. A 2011 study showed that parents who have a child with autism have a one-in-fve chance of having a second child with the diagnosis. Again, the risk is greatest for boys, with 26 percent of male siblings diagnosed as autistic compared to only 9 percent of the females. Te risk of having another child with autism was higher yet — 32 percent — for families with two or more autistic children. Tis trend in families points directly to some genetic cause for autism. In fact, at least 50 gene variants have been linked to autism, and some experts speculate that as many as 400 genes could be involved. But environment also plays a role, working in concert with a child's genetic inheritance. Nailing down just which environmental factors are important is quite another subject. Among the things identifed as possible contributors to an autism diagnosis are: greater maternal age, greater paternal age, greater age of grandfather at the time his children were born, the mother's stress level, the mother's diet, the mother's antidepressant use in the frst three months of pregnancy, a host of environmental contaminants, toxic metals, maternal autoimmune disorders, a diagnosis of allergies during the second trimester, the mother's gestational diabetes, maternal obesity, closely spaced pregnancies, use of anti-epileptic drugs during pregnancy, infant low birth weight, maternal smoking and mothers who were abused as children. About the only thing conclusively and repeatedly ruled out as a cause of autism is the thing most often blamed — childhood vaccines. Eli chats away happily from the moment he arrives in Sokhadze's lab with his dad. His brown eyes slip away from eye contact as he talks — a fairly common behavior among many with autism — but in so many ways he's a diferent kid than the one who walked in here in January, 18 rTMS sessions ago, his father says. "We've seen his sense of humor develop, his social interactions. He teases," Partin says. "If someone had seen him a year ago, and spent a lot of time with him, and then saw him now, it would almost be like two diferent people." Eli's school performance also refects an improvement, his father says, with a trend line that made a sharp upturn in January and kept rising. M anuel Casanova thinks he knows why children like Eli improve. Te answer is the magnet's interaction with the particular arrangement of all those soldierly microprocessors — called minicolumns — across the top of your brain. Tere are hundreds of millions of these stacks of cells in the cortex — the brain layer that folds and corrugates as your intellect develops. Even in the brain's deepest valleys, minicolumns always point upwards, like pine trees on a hillside pointing to the noon sun. Another unique property of minicolumns is that all the cells in the core of the column fre together. If the top cell in the column is assigned to monitor touch on a tiny patch of skin on your left ring fnger, so is every other cell in the people with autism to those without, Casanova found more minicolumns in the autistic brain, all more densely packed. Sacrifced in this minicolumn population boom was the shower curtain. Tis inhibitory region of the minicolumn is consistently smaller in autistic brains — about 12 percent smaller, he found. As a consequence of this lost insulation, excitatory signals dominate and overlap in autism, Casanova says. Te fring of one minicolumn core sends static electricity to its neighbors. Individual, discrete signals are overwhelmed by the noise of other microprocessors. Tere is simply too much stimulus. "Stimulus overload is devastating to the brain," Casanova says. Someone overloaded with stimuli "is actually being traumatized by their own brain." Tat, he proposes, is the story of autism. When you think of the many feats your brain can execute, few are as mighty as its ability to not notice. In fact, you need to work hard to notice more than one thing at a time. If you direct your attention, you can feel the drape of your shirt on your shoulders, the rub of your pant leg at your knee, the squeeze of your running shoes where they meet your ankle, the way your hair lies on your scalp, the seat of your chair pushing "Stimulus overload is devastating to the brain," Casanova says. Someone overloaded with stimuli "is actually being traumatized by their own brain." Tat, he proposes, is the story of autism. column, and they respond to any stimulus there as a unit. Tese stacks of maybe 200 excitatory neurons are responsible for sending gogo signals, often to distant regions of the brain. But where things appear to go wrong in autism is in the periphery of the column, among smaller inhibitory neurons that surround the core. Unlike excitatory ones, inhibitory neurons work only in the neighborhood. Teir task is to keep the excitement from boiling over, like a kind of insulation. Believe it or not, the guy who discovered these inhibitory neurons in the minicolumn in the 1970s referred to this whole peripheral region in each column as the "shower curtain of inhibition." In autism, Casanova's research suggests, the bathroom foor is fooding. By comparing brain-tissue samples from at your hip bones, the whoosh of the ceiling fan, the monotonous whirr of your computer, several kinds of birds chirping outdoors, distant trafc and an airplane. Now, imagine your brain was not so skilled at ignoring. What if all these sensations came at you simultaneously, no single stimulus more important than the next — every sensation, all the time, competing with every other sensation, none with particular salience, all with similar urgency? Tat may be what it means to have shower-curtain issues. After fnding the same minicolumn oddities in more than 20 autistic brains, Casanova expanded his scope to see if minicolumns played a role in other brain problems such as Down syndrome, congenital rubella, tuberous sclerosis, Rett syndrome and schizophrenia, and found minicolumn anomalies of other descriptions. Other researchers 8.13 LOUISVILLE MAGAZINE 61

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