For years, the first line in Jerome M. Siegel's research-grant applications simply stated that the cause of narcolepsy is unknown. Time for a new opening line.
Following up on last year's discovery of gene mutations that cause forms of narcolepsy in dogs and mice (SN: 8/14/99, p. 100: http://www.sciencenews.org/sn_arc99/8_14_99/fob1.htm), Siegel and other investigators have now found that the human brand of this puzzling sleep disorder likely stems from the destruction of a small group of brain cells.
"I don't think this degeneration is the cause of all human narcolepsy, but I'll bet it [accounts for] 90 percent plus, maybe even 99 percent plus," says Siegel of the University of California, Los Angeles. His research team is one of two that identified the cell loss in the preserved brains of people who had narcolepsy when they were alive.