Another Novel View of Alzheimer's Disease
It is good that more new theories on the mechanisms of Alzheimer's disease are emerging, such as this, via EurekAlert! One thing you don't want to see in an advancing field of science is a monoculture of ideas. "For years we thought that A-beta was just metabolic garbage produced as a byproduct of other processes within the brain, but these data suggest it is a normal component of the brain's innate immune system. It looks like factors that trigger hyperactivity of the innate immune system - not only infection but also traumatic brain injury and stroke, which are already known to increase the risk for Alzheimer's - could cause excessive deposition of A-beta. ... The researchers suggest that chronic activation of the innate immune system in response to either a persistent or transient infection of the central nervous system might lead to excess production and accumulation of A-beta. Known Alzheimer's risk factors – such as stroke, head injury and exposure to certain anesthetics – could also trigger the innate immune system and increase A-beta production, leading to an excessive and dangerous inflammatory response within the brain. ... Now we need to figure out what is triggering the innate immune system, particularly as we age, and what genes control A-beta's role in the innate response. If we can identify which pathogens are more likely to trigger A-beta plaque aggregation, we might develop ways to prevent or control that response, for example by immunization."
Link: http://www.eurekalert.org/pub_releases/2010-03/mgh-apm022510.php