Alzheimer's and TNF-Alpha
ScienceDaily summarizes a recent demonstration of the dynamic role TNF-alpha plays in Alzheimer's disease. The full PDF paper is available for those who care to dig deeper. "Normally, TNF finely regulates the transmission of neural impulses in the brain. The authors hypothesized that elevated levels of TNF in Alzheimer's disease interfere with this regulation. To reduce elevated TNF, the authors gave patients an injection of an anti-TNF therapeutic called etanercept. Excess TNF-alpha has been documented in the cerebrospinal fluid of patients with Alzheimer's. The new study documents a dramatic and unprecedented therapeutic effect in an Alzheimer's patient: improvement within minutes." From the abstract: "In addition to its pro-inflammatory functions, TNF-alpha has recently been recognized to be a gliotransmitter that regulates synaptic function in neural networks. TNF-alpha has also recently been shown to mediate the disruption in synaptic memory mechanisms, which is caused by beta-amyloid and beta-amyloid oligomers." You might recall demonstrations in 2006 and 2007 showing mice full of beta-amyloid, but suffering no symptoms of neurodegeneration due to key changes in the mechanisms by which amyloid affects the brain.
Link: http://www.sciencedaily.com/releases/2008/01/080109091102.htm