New research by scientists at UC San Francisco shows that one of the brain's fundamental self-protection mechanisms depends on coordinated, finely calibrated teamwork among neurons and non-neural cells knows as glial cells, which until fairly recently were thought to be mere support cells for neurons. The study, which has implications for understanding neurodegenerative diseases, stroke, and other nervous system disorders, adds to a growing body of evidence that glial cells are integral to brain function.
Because this mechanism is localized at synapses, the sites where communication between neurons takes place, said Marta Margeta, MD, PhD, assistant professor of pathology and senior author of the new study, it ensures that protective measures will only be taken when and where they're most needed.
"The President needs more bodyguards than a Congressman, and with this system you can have your cake and eat it too: protection when you need it, without having to have it everywhere."
The brain is the body's hardest-working organ, consuming as much as 25 percent of our overall energy. This metabolic demand makes brain cells particularly vulnerable to damage from oxidative stress, in which reactive oxygen species (ROS), sometimes called free radicals, exert toxic effects on cellular components. ROS damage to neurons has been implicated in Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions.
The brain can also be severely damaged when disease or injuryespecially strokecauses neurons to repetitively fire, flooding brain tissue with toxic levels of the excitatory neurotransmitter glutamate, a condition known as excitotoxicity.
To counteract the potential damage arising from ROS, excitotoxicity, and other dangers, animals including humans have evolved sophisticated physiological defenses such as the Nrf2 pathway, a molecular network that triggers the expression of a suite of protective genes when cel
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University of California - San Francisco