For the latest scientific autism few months, visit the Blog Autism Information Science
Original text
Scientists at the Albert Einstein College of Medicine Yeshiva University have proposed a new theory of autism enlarged suggesting that the brains of people with autism is structurally normal but deregulated, which means that symptoms of the disorder may be reversible. The central tenet of the theory, published in the March issue of the journal Brain Research Reviews ", is that autism is a developmental disorder caused by impaired regulation of the defective locus coeruleus , a set of neurons in the brain that processes sensory signals from all parts of the body.
The new theory stems from decades of anecdotal evidence about some autistic children who seem to improve when they have fever, but regress when the fever subsides. A 2007 study in the journal Pediatrics looked at more seriously about fever and autism, observing autistic children during and after episodes of fever and comparing their behavior with autistic children who have no fever . This study found that the experimental behavior of autistic children change during fever.
"On a positive note, we are talking about a brain region that is changed irrevocably. This gives us hope that with new therapies, we will be able to help people with autism, "says co-author Mark F. Mehler, MD, chairman of the chair of neurology and director of the Institute for Brain Disorders and Neural Regeneration "to Einstein.
Autism is a complex developmental disability that affects a person's ability to communicate and interact with others. It usually appears during the first three years of life. Autism is known as autism spectrum disorder "because it affects individuals differently and to varying degrees. An estimated one in 150 American children has some degree of autism.
Einstein Researchers conclude that the scientific evidence pointing directly to the locus coeruleus-noradrenergic (LC-NA) as a system involved in autism. "The LC-NA system is the only system of the brain involved in both production and fever in the control of behavior," says co-author Dominick P. Purpura, MD, dean emeritus and professor of neuroscience at Einstein. The locus coeruleus
has extensive connections to brain regions that process sensory information. It secretes the bulk of norepinephrine, a neurotransmitter that plays a key role in triggering defense mechanisms, such as "fight or flight". He is also involved in a variety of complex behaviors, such as focused attention (the ability to focus attention on environmental cues in relation to a manual task, or to shift its focus from one task to a other). Attention deficit is a characteristic of autism.
"What is unique is that the locus coeruleus activates almost all higher-order centers in the brain that are involved in complex cognitive tasks," says Dr Mehler.
The hypothesis of doctors and Purpura Mehler is that in Autism, the LC-NA interaction is deregulated by environmental or genetic factors or by epigenetic (chemicals that regulate gene expression both within and outside of the genome). They think that stress plays a central role in the deregulation of the LC-NA system, especially in the later stages of prenatal development when the fetal brain is particularly vulnerable.
As proof, researchers point to a 2008 study, published in the Journal of Autism and Developmental Disorders, found a higher incidence of autism in children mothers were exposed to hurricanes and tropical storms during pregnancy. Maternal exposure to severe storms in the middle of gestation resulted in the highest prevalence of autism.
The hypothesis of doctors and Mehler Purpura is that autistic children, fever stimulates the LC-NA and temporarily restores its normal regulatory function. "This could only happen if the autism was caused by an injury or a structural abnormality of the brain," said Dr. Purpura.
"This gives us hope that we will eventually be able to do something for people Autism " says he.
Researchers do not advocate therapy fever (fever caused by artificial means) to be too broad, and perhaps even a dangerous remedy. Instead, they say, the future of autism treatment is probably the drugs that selectively target certain types of noradrenergic receptors in the brain or, more probably, through epigenetic therapies targeting genes LC system -NA.
"If the locus coeruleus is altered in autism, it probably is because tens or hundreds or thousands of genes deregulation are subtle and complex, "says Dr Mehler." The only way to reverse this process through epigenetic therapies, which we begin to learn, have the ability to coordinate the integration of vast networks of genes ".
" The message here is one of hope but also caution, "said Dr. Mehler." You can not take a complex neuropsychiatric disease, which has eluded our understanding of 50 years and a once a treatment that goes to the reverse - it's madness. On the other hand, we now have clues to the neurobiology, genetics, Epigenetics and autism. To move forward, we must invest more money in the basic sciences to examine the genome and epigenome more focused. "Translation
Blog Autism Information Science
0 comments:
Post a Comment