Clues to addiction
Harvard scientists have developed the fullest picture yet of how neurons in the brain interact to reinforce behaviors ranging from learning to drug use, a finding that might open the door to new treatments for addiction. The finding is the result of a yearlong effort by a team of researchers led by Naoshige Uchida, associate professor of molecular and cellular biology, to examine a brain process known as reward prediction error. Thought to be a key component of learning, prediction error has long been considered the product of dopamine neurons firing in response to an unexpected “reward,” thus reinforcing the behavior that led to the reward. But Uchida and colleagues from Harvard and Beth Israel Deaconess Medical Center report in the Jan. 18 issue of Nature that reward prediction error is actually the product of a complex interplay between two classes of neurons — one that relies on dopamine and an inhibitory...