Alzheimer's Disease and Microglia Triggered Inflammation

A recent posting at Developing Intelligence blog discussed the vital role of glial cells in the activity of neurons, including the effect of inflammation triggered by glia. Now U Penn Medical School researchers have shown that microglial activation leads to formation of neural tangles of tau protein. These tangles cause more inflammation and so on . . .

Researchers at the University of Pennsylvania School of Medicine have shown that impaired function and loss of synapses in the hippocampus of a mouse form of Alzheimer’s disease (AD) is related to the activation of immune cells called microglia, which cause inflammation. These events precede the formation of tangles – twisted fibers of tau protein that build up inside nerve cells – a hallmark of advanced AD. The researchers report their findings in the February 1 issue of Neuron.

“Abolishing the inflammation caused by the accumulation of the tau protein might be a new therapy for treating neurodegenerative disorders,” says senior author Virginia Lee, PhD, Director of the Center for Neurodegenerative Disease Research. “This work points the way to a new class of drugs for these diseases.”

In addition, the immunosuppressant FK506 diminishes neuron loss and extends the life span of the transgenic Alzheimer’s mice. Normally only 20 percent of these mice survive by one year. With FK506, 60 percent of the mice were alive by one year.

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Glial cells perform housekeeping functions for neurons, but in some situations can trigger inflammation that leads to neuron death. Learning how to intervene in such situations before irreversible damage is done to neurons may postpone the loss of mental function in senescent individuals.