Using a miniature electronic device implanted in the brain,
scientists have tapped into the internal reward system of mice, prodding
neurons to release dopamine, a chemical associated with pleasure.
The researchers, at Washington University School of Medicine
in St. Louis and the University of Illinois at Urbana-Champaign, developed tiny
devices, containing light emitting diodes (LEDs) the size of individual
neurons. The devices activate brain cells with light. The scientists report
their findings April 12 in the journal Science.