SchaferAutismReport: Immune System May Target Some Brain Synapses, Researchers Find

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SAR "Healing Autism:Schafer Autism Report No Finer a Cause on the Planet"________________________________________________________________Monday, December 17, 2007 Reader Supported Vol. 11 No. 180pDEADLINE FOR JANUARY 2008 AUTISM EVENTS CALENDAR ISMONDAY - December 24 !Submit listing here: http://www.sarnet.org/frm/cal-frm.htmRESEARCH* Immune System May Target Some Brain Synapses, Researchers Find* Data on Autism In Children DescribedPUBLIC HEALTH* Possible PreventionTREATMENT* Hospital Breaks Ground On Neurological Center In HoustonEDUCATION* Despite Court Win, Parents Struggle To Pay TuitionPEOPLE* A Statesman To Be?* A Mother's Autism CampaignFORENSIC* Sex Offender's Medical Condition At Issue, Madison, WIMEDIA*

Responding to Autism Stories* The Google Top Ten Searches By English Users Around The WorldRESEARCHImmune System May Target Some Brain Synapses, Stanford Researchers Findhttp://tinyurl.com/ytnmcmA baby's brain has a lot of work to do, growing more neurons andconnections. Later, a growing child's brain begins to pare down theseconnections until it develops into the streamlined brain of an adult.Now researchers at the Stanford University School of Medicine havediscovered the sculptor behind that paring process: the immune system.The value of this discovery goes beyond understanding how connectionsare weeded out in a normal, developing brain. The finding could also helpexplain some neurodegenerative disorders - such as glaucoma, Alzheimer'sdisease and multiple sclerosis - that result from the loss of too manyneuronal connections, which are known as synapses.The advance, which has implications

for drugs that could halt orreverse such conditions, will be published in the Dec. 14 issue of thejournal Cell.It was widely known that synapse elimination occurs during normaldevelopment of a child's brain, but until now, no one knew how certainsynapses were flagged for removal. "We have identified the long-mysteriousmechanism by which excess synapses are sculpted away in the developingbrain," said the study's senior author, Ben Barres, MD, PhD, professor ofneurobiology.Barres' team found that the brain-sculpting process was controlled bya component of the immune system known as the classical complement cascade.The complement cascade is one part of the multipronged attack theimmune system launches throughout the body when it detects a foreigninvader. Consisting of more than 20 small proteins that normally circulatein the blood in their inactive forms, the complement system is triggeredinto action by an invading

parasite. The first activated protein activates asecond one, which in turn activates a third, continuing down the line in adomino effect, ultimately yielding a membrane-attack response that killscells.Barres' team produced the first proof that the complement system alsoplays a role in the brain by showing that complement proteins bind tounwanted synapses, targeting them for elimination. Future studies willdetermine how the synapses are marked for death.When children reach the age of 10, synapse elimination normally shutsdown. But the researchers found that this elimination process becomesreactivated very early in glaucoma, a neurodegenerative disease that is amajor cause of blindness. They found that the earliest known sign inglaucoma was the complement cascade becoming active at synapses, followed bymassive synapse loss. Only much later did the neurons die, which is thehallmark of neurodegenerative diseases."This

is interesting, as these complement proteins are known to bedrastically up-regulated in nearly every neurodegenerative disease processthat has been examined," said Barres. Up-regulation is the process by whicha cell increases the amount of a molecule, such as a protein, in response toa change in its environment. Alzheimer's disease, which involves massivesynapse loss, has a hundredfold up-regulation of complement proteins, hesaid.Read more: http://tinyurl.com/ytnmcmFor rest of today's SAR click here:http://www.sarnet.org/frm/forsar.htmFor missed editions see archive:http://health.groups.yahoo.com/group/-AuTeach/messages _______________________________________________SARnets mailing listSARnets@...http://lists.igc.org/mailman/listinfo/sarnetsYou can unsubscribe send email:http://www.sarnet.org/frm/unsub2.htm-- You are subscribed as:

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