Word: braine
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These are the neuron-packed gray matter of the cerebral cortex and white matter, which contains the fibrous connections projecting to and from the cerebral cortex and other areas of the brain, including the cerebellum. Perhaps, Courchesne speculates, it is the signal overload caused by this proliferation of connections that injures the Purkinje cells and ultimately kills them. "So now," says Courchesne, "a very interesting question is, What's driving this abnormal brain growth? If we could understand that, then we might be able to slow or stop...
...proliferation of connections between billions of neurons occurs in all children, of course. A child's brain, unlike a computer, does not come into the world with its circuitry hard-wired. It must set up its circuits in response to a sequence of experiences and then solder them together through repeated neurological activity. So if Courchesne is right, what leads to autism may be an otherwise normal process that switches on too early or too strongly and shuts off too late--and that process would be controlled by genes...
Currently Courchesne and his colleagues are looking very closely at specific genes that might be involved. Of particular interest are the genes encoding four brain-growth regulators that have been found in newborns who go on to develop mental retardation or autism. Among these compounds, as National Institutes of Health researcher Dr. Karin Nelson and her colleagues reported last year, is a potent molecule known as vasoactive intestinal peptide. VIP plays a role not only in brain development but in the immune system and gastrointestinal tract as well, a hint that other disorders that so frequently accompany autism...
Paradoxically, the very thing that is so terrible about autistic disorders--that they affect the very young--also suggests reason for hope. Since the neural connections of a child's brain are established through experience, well-targeted mental exercises have the potential to make a difference. One of the big unanswered questions, in fact, is why 25% of children with seemingly full-blown autism benefit enormously from intensive speech- and social-skills therapy--and why the other 75% do not. Is it because the brains of the latter are irreversibly damaged, wonders Geraldine Dawson, director of the University of Washington...
...mistake to dwell exclusively on the genetics of Asperger's; there must be other factors involved. Experts suspect that such variables as prenatal positioning in the womb, trauma experienced at birth or random variation in the process of brain development may also play a role...