Neuron 62, 42–52 (2009)

Neurodegenerative diseases do not sow destruction randomly in the brain, but progress along defined and predictable neuronal networks, according to new imaging work.

William Seeley of the University of California, San Francisco, and his colleagues imaged the brains of patients with five different clinical dementias — including Alzheimer's disease — which can arise from different molecular pathologies.

The researchers traced intrinsic connectivity networks — such as that involved in episodic memory — in the brains of healthy controls, and compared them with data from each patient group. They found that each type of dementia targets a different neural network.