Bad Influence on Nerve Cells

Amyloid plaque (red) causes a break (yellow) in a dendrite (green).

The effects of amyloid plaques—implicated in Alzheimer’s disease—on nerve cells in the brain have been directly observed and documented for the first time, according to a study published recently in the journal Nature Neuroscience
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Using a sophisticated optical imaging technique called two-photon microscopy to peer deep inside the brains of living mice, Wenbiao Gan, Ph.D., Assistant Professor of Physiology and Neuroscience, and his colleagues observed over a period of weeks several effects seemingly caused by amyloid deposits in the mouse brain. Pockets formed in the nerve cells’ long, cable-like arms, called axons, that send messages to other nerve cells. Breaks occurred in the cells’ finger-like extensions, called dendrites, that receive information from other cells.

This kind of damage disrupts vital communication between nerve cells, eventually contributing to large-scale damage in the brains of Alzheimer’s patients, says Dr. Gan. But the news isn’t all bad. The scientists also found that nerve cells were less affected by newly formed amyloid plaque. Thus it is hoped that treatments that clear away young plaque could protect nerve cells and thereby prevent Alzheimer’s.