Odd Men Out

Of autism’s many mysteries, one that is particularly intriguing is the sex bias: Four times as many boys are affected as girls.

If rodents were perfect disease models, we’d have an ironclad hypothesis for this bias.

Scads of studies on mice and rats have shown that males, because of testosterone surging through their brains, are more sensitive to stress during early development than females are. Their brains are primed to express fear and social anxiety, which, in turn, lead to social avoidance — a characteristic feature of autism.

But obviously mice aren’t people, and we know very little about whether testosterone acts in a similar way in the human brain. Considering the robust evidence in animals, however, this area deserves much more attention from autism researchers, argues a review published earlier this month in Autism Research.

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SFARI, April 2011.

Mice Lacking MET Have Strong Brain Connections

Mice missing the autism candidate gene MET have connections in the cortex that are twice as strong as those in controls.

The findings, published 13 April in the Journal of Neuroscience, agree with the ‘connectivity theory‘ of autism, which holds that individuals with the disorder have abnormally robust short-range neuronal connections and weak long-range connections.

MET has several important roles, including in the immune system, the gut and the brain. In the brain, MET is needed for the proper development of dendrites — thin neuronal branches — and the nubs that receive electrical messages on their ends.

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SFARI, April 2011.

Analysis Finds Weak Evidence for Most Autism Treatments

Only a small fraction of autism therapies are supported by robust scientific evidence, according to three reviews published in the May issue of Pediatrics.

Whether through doctors, teachers or the grapevine, parents of children with autism encounter an overwhelming array of potential treatments for the disorder, ranging from antipsychotic medications and dietary supplements to intensive behavioral interventions, music or animal therapies.

The new reviews — on drug treatments, behavioral interventions and the gut hormone secretin, respectively — summarize the findings of a 900-page analysis commissioned by the federal Agency for Healthcare Research and Quality.

Of the 159 studies included in the large analysis, the researchers deemed 90 to be of poor quality, 56 fair and 13 good, based on their precision, consistency with the wider literature and risk of bias.

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SFARI, April 2011.

Meth and Milkshakes

Pam is a former methamphetamine user. On a website for recovering addicts, she posted an entryfrom a journal she kept at the height of her problem, when she was 19 years old. It’s an engrossing story about how meth — snorted throughout the day, but always at lunch time, in a parking lot — has ravaged her body and personal relationships. Here’s the part I want to talk about:

…I stopped and got a milkshake to try to make myself feel better. The guy in line was flirting with me. I couldn’t smile at him, it was too hard. I answered all of his questions in between grinding my teeth. I sat in my car and forced the disgusting milkshake down my throat. I didn’t feel better until I did another one. I couldn’t get the whole Chick-fil-A biscuit down this morning, but I managed to eat the hash browns. The bad part is, I drove 30 minutes out of my way to go to Chick-fil-A house because I was craving a sweet tea. So, I was late to work… I’m just here killing time until my lunch break. The lunch break I take daily. When I say I’m going to Brittany’s to eat. Then I drive to the Wal-Mart and park.

From television, books and the popular press, I thought I’d already heard about all of the nasty effects of crank: paranoia, stroke, heart problems, acne, loss of appetite, loss of teeth. But what about these carb cravings?

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The Last Word on Nothing, April 2011.

Researchers Make Neurons from People with Schizophrenia

Researchers have taken skin cells from individuals with schizophrenia, bathed them in chemical cocktails and coaxed them to develop into neurons, according to a paper published 13 April in Nature.

The cultured neurons, called induced pluripotent stem (iPS) cells, show dampened signaling and altered gene expression similar to those seen in postmortem brains of people with the disease. Exposing the cells to a schizophrenia drug, loxapine, reverses the abnormal connections between the neurons.

The findings suggest that iPS cells can be used to study other complex brain disorders, including autism.

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SFARI, April 2011.

Researchers Track Down Autism Rates Across the Globe

In urban areas of South Korea, some families of children with developmental delays will go to great lengths to avoid a diagnosis of chapae, or autism. They think of it as a genetic mark of shame on the entire family, and a major obstacle to all of their children’s chances of finding suitable spouses.

The stigma is so intense that many Korean clinicians intentionally misdiagnose these children with aechak changae, or reactive detachment disorder — social withdrawal that is caused by extreme parental abuse or neglect.

“The parents prefer this [diagnosis] because the mother can take the bullet and protect everybody else,” says Roy Richard Grinker, professor of anthropology at George Washington University in Washington, D.C., who has screened some 38,000 children in South Korea for the country’s first study of autism prevalence.

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SFARI, April 2011.

Seeking Counsel

Many parents of children with autism are eager to volunteer for studies aimed at discovering genetic risk factors for the disorder.

Unfortunately, the vast majority of people who initially show interest in participating in a clinical trial don’t follow through. Daunted by logistic, economic and privacy concerns, not to mention notoriously long and confusing consent forms, most of them eventually drop out of the process.

These hurdles could be overcome if clinical researchers were to add genetic counselors to their teams, argues a commentary published in March in Science Translational Medicine.

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SFARI, April 2011.

My Coffee Problem

On Friday I woke up too early with a splitting headache and chest pain. This was alarming. In the shower, I tried to come up with a list of plausible explanations, but my mind found only one: the four cups of coffee I drank the day before. I wondered, is this how a heart attack begins? For the first time in eight years, I sat down at my desk to work without a mug of jolt.

The rational part of my brain knew why I had jumped to the worst-case scenario. I recently bought a genetic testing kit from 23andMe. After the initial shock about my melanoma risk variants, I calmed down and started digging into the rest of the data. Turns out I carry a variant for a condition that is, in some ways, more unnerving than skin cancer: slow caffeine metabolism.

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The Last Word on Nothing, April 2011.

Brain Activity Explains Keen Visual Skills in Autism, Group Claims

Individuals with autism use more brainpower in regions linked to visual perception, and less in those related to planning thoughts and actions, compared with healthy controls, according to a multi-study analysis published today in Human Brain Mapping.

The report is getting mixed reviews from other experts, however, who say it presents an oversimplified interpretation of the data. Some also take issue with how the researchers chose which studies to include in their analysis.

The analysis is based on data from 26 functional magnetic resonance imaging (fMRI) studies from many independent laboratories over the past 15 years.

Autism is often defined as a social disorder. Instead, “we may define autism as a condition characterized by a brain reorganization in favor of perceptual experience,” says lead investigator Laurent Mottron, professor of psychiatry at the University of Montreal.

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SFARI, April 2011.