MADISON, Wis., June 26 (UPI) -- U.S. scientists say they've discovered the specific effects the drug Ritalin has on brain cells in treating attention deficit hyperactivity disorder.
University of Wisconsin-Madison psychology researchers David Devilbiss and Craig Berridge determined Ritalin affects neurons in the brain's prefrontal cortex, or PFC -- a region involved in attention, decision-making and impulse control -- while having few effects outside that area. Although Ritalin has been used for more than 50 years to treat the condition marked by hyperactivity, impulsivity and the inability to focus or shift concentration, Berridge said little has been known about how the drug achieves its therapeutic effects.
He and Develbiss studied PFC neurons in rats given Ritalin.
They found the PFC neurons' sensitivity to signals coming from the brain's hippocampus increased dramatically when the rats were given therapeutic doses of Ritalin. Ritalin strengthened dominant and important signals within the PFC, while lessening weaker signals that might act as distractors, said Berridge.
"These results show a new level of action for cognition-enhancing doses of Ritalin that couldn't have been predicted from single neuron analyses," he said.
The study appears in the online edition of Biological Psychiatry.
