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Tero Toivanen

Autism disorders might be reversible. | - I Teach Autism.com - - 0 views

  • Scientists at Albert Einstein College of Medicine of Yeshiva University have proposed a sweeping new theory of autism that suggests that the brains of people with autism are structurally normal but dysregulated, meaning symptoms of the disorder might be reversible.
  • The central tenet of the theory, published in the March issue of Brain Research Reviews, is that autism is a developmental disorder caused by impaired regulation of the locus coeruleus, a bundle of neurons in the brain stem that processes sensory signals from all areas of the body.
  • The new theory stems from decades of anecdotal observations that some autistic children seem to improve when they have a fever, only to regress when the fever ebbs.
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  • Einstein researchers contend that scientific evidence directly points to the locus coeruleus–noradrenergic (LC-NA) system as being involved in autism. “The LC-NA system is the only brain system involved both in producing fever and controlling behavior,” says co-author Dominick P. Purpura, M.D., dean emeritus and distinguished professor of neuroscience at Einstein.
  • The locus coeruleus has widespread connections to brain regions that process sensory information.
  • It is also involved in a variety of complex behaviors, such as attentional focusing (the ability to concentrate attention on environmental cues relevant to the task in hand, or to switch attention from one task to another).
  • “What is unique about the locus coeruleus is that it activates almost all higher-order brain centers that are involved in complex cognitive tasks,” says Dr. Mehler.
  • Drs. Purpura and Mehler hypothesize that in autism, the LC-NA system is dysregulated by the interplay of environment, genetic, and epigenetic factors (chemical substances both within as well as outside the genome that regulate the expression of genes). They believe that stress plays a central role in dysregulation of the LC-NA system, especially in the latter stages of prenatal development when the fetal brain is particularly vulnerable.
  • Drs. Purpura and Mehler believe that, in autistic children, fever stimulates the LC-NA system, temporarily restoring its normal regulatory function.
  • the future of autism treatment probably lies in drugs that selectively target certain types of noradrenergic brain receptors or, more likely, in epigenetic therapies targeting genes of the LC-NA system.
  • “You can’t take a complex neuropsychiatric disease that has escaped our understanding for 50 years and in one fell swoop have a therapy that is going to reverse it — that’s folly. On the other hand, we now have clues to the neurobiology, the genetics, and the epigenetics of autism. To move forward, we need to invest more money in basic science to look at the genome and the epigenome in a more focused way.”
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    Scientists at Albert Einstein College of Medicine of Yeshiva University have proposed a sweeping new theory of autism that suggests that the brains of people with autism are structurally normal but dysregulated, meaning symptoms of the disorder might be reversible.
Tero Toivanen

New Theory Of Autism Suggests Symptoms Or Disorder May Be Reversible - 0 views

  • the brains of people with autism are structurally normal but dysregulated, meaning symptoms of the disorder might be reversible.
  • autism is a developmental disorder caused by impaired regulation of the locus coeruleus, a bundle of neurons in the brain stem that processes sensory signals from all areas of the body.
  • The new theory stems from decades of anecdotal observations that some autistic children seem to improve when they have a fever, only to regress when the fever ebbs.
  • ...11 more annotations...
  • This study documented that autistic children experience behavior changes during fever.
  • Einstein researchers contend that scientific evidence directly points to the locus coeruleus–noradrenergic (LC-NA) system as being involved in autism. "The LC-NA system is the only brain system involved both in producing fever and controlling behavior," says co-author Dominick P. Purpura, M.D., dean emeritus and distinguished professor of neuroscience at Einstein.
  • The locus coeruleus has widespread connections to brain regions that process sensory information. It secretes most of the brain's noradrenaline, a neurotransmitter that plays a key role in arousal mechanisms, such as the "fight or flight" response. It is also involved in a variety of complex behaviors, such as attentional focusing (the ability to concentrate attention on environmental cues relevant to the task in hand, or to switch attention from one task to another). Poor attentional focusing is a defining characteristic of autism.
  • "What is unique about the locus coeruleus is that it activates almost all higher-order brain centers that are involved in complex cognitive tasks," says Dr. Mehler.
  • autism, the LC-NA system is dysregulated by the interplay of environment, genetic, and epigenetic factors
  • They believe that stress plays a central role in dysregulation of the LC-NA system, especially in the latter stages of prenatal development when the fetal brain is particularly vulnerable.
  • a higher incidence of autism among children whose mothers had been exposed to hurricanes and tropical storms during pregnancy.
  • autistic children, fever stimulates the LC-NA system, temporarily restoring its normal regulatory function. "This could not happen if autism was caused by a lesion or some structural abnormality of the brain," says Dr. Purpura.
  • future of autism treatment probably lies in drugs that selectively target certain types of noradrenergic brain receptors or, more likely, in epigenetic therapies targeting genes of the LC-NA system.
  • If the locus coeruleus is impaired in autism, it is probably because tens or hundreds, maybe even thousands, of genes are dysregulated in subtle and complex ways," says Dr. Mehler. "The only way you can reverse this process is with epigenetic therapies, which, we are beginning to learn, have the ability to coordinate very large integrated gene networks."
  • "You can't take a complex neuropsychiatric disease that has escaped our understanding for 50 years and in one fell swoop have a therapy that is going to reverse it — that's folly. On the other hand, we now have clues to the neurobiology, the genetics, and the epigenetics of autism. To move forward, we need to invest more money in basic science to look at the genome and the epigenome in a more focused way."
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    the brains of people with autism are structurally normal but dysregulated, meaning symptoms of the disorder might be reversible.
Tero Toivanen

New study confirms link between advanced maternal age and autism - 4 views

  • Advanced maternal age is linked to a significantly elevated risk of having a child with autism, regardless of the father's age, according to an exhaustive study of all births in California during the 1990s by UC Davis Health System researchers.
  • The researchers note that understanding the relationship between increased parental age and autism risk is critical to understanding its biological causes. Earlier studies have observed that advanced maternal age is a risk factor for a variety of other birth-related conditions, including infertility, early fetal loss, low birth-weight, chromosomal aberrations and congenital anomalies.
  • One possible clue comes from a 2008 UC Davis study that found some mothers of children with autism had antibodies to fetal brain protein, while none of the mothers of typical children did. Advancing age has been associated with an increase in autoantibody production.
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  • They added that some persistent environmental chemicals accumulate in the body and also may have a role to play in autism, possibly contributing to the apparent effect of parental age.
  • The study also suggests that epigenetic changes over time "may enable an older parent to transfer a multitude of molecular functional alterations to a child ... thus epigenetics may be involved in the risks contributed by advancing parental age as a result of changes induced by stresses from environmental chemicals, co-morbidity or assistive reproductive therapy."
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    Advanced maternal age is linked to a significantly elevated risk of having a child with autism, regardless of the father's age, according to an exhaustive study of all births in California during the 1990s by UC Davis Health System researchers.
Tero Toivanen

Genes implicated in twins' autism | The Autism News - 1 views

  • Researchers have known for years that when one identical twin has autism, the other is also likely to be diagnosed with it – evidence that autism likely has a genetic component.
  • Researchers at Kennedy Krieger Institute studied 277 pairs of twins and found that when one identical twin had the disorder, the other developed it 88 percent of the time; for fraternal twins, that figure was 31 percent.
  • Despite this progress in unlocking the mysteries of autism, scientists have simply confirmed that there are likely numerous genetic links to autism.
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  • Each discovery explains just a tiny fraction of autism’s causes. Researchers think the great majority – 90 percent – of autism cases have a genetic cause, but they’ve found fewer than 10 percent of the triggers.
  • researchers have found about 50 genes so far that might be tied to autism, which explain very few cases, he said.
  • Autism isn’t one disease; it’s too individual to locate just one genetic cause. It’s not like cystic fibrosis, a disorder for which researchers have identified one gene – and tests to diagnose it.
  • autism researchers envision that a wide variety of gene defects are responsible for the symptoms collectively known as autism spectrum disorders. The disabilities, different in each child, range from the mild Asperger syndrome to more severe impairments in social interaction and communication.
  • “It’s going to take some work before we understand the true causes of autism,” he said. “We need to make much more headway to ever have enough understanding so that patient management and therapies can be improved.”
  • None of the new findings explains why more children are being diagnosed with autism. Genes, said Goldstein, tell only part of the story.
  • “The idea is there is an environmental interaction with the genetic component,” he said.
  • Autism may be inherited to some degree, but even twin studies show that not all sets of identical twins have autism. And when they do, they don’t always have the same severity of the disorder
  • That connection between genes and the environment, called epigenetics, might explain these distinctions
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    Researchers have known for years that when one identical twin has autism, the other is also likely to be diagnosed with it - evidence that autism likely has a genetic component.
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