After FDA approval you might think the work on a drug is done. Wrong. When will surveillance of a drug end? Never. Ritalin (methylphenidate) was introduced 50 years ago. In a recent study, University of Pittsburgh neuroscientists got a rare look at how Ritalin affects activity in the brains of animals. They gleaned a deeper understanding of how some brain cells govern attention, and ideas for additional uses of the stimulant.
About 10 percent of children in the U.S. are prescribed stimulants like methylphenidate, to improve attention and focus in kids with attention deficit hyperactivity disorder (ADHD). An estimated 20 percent of adults use the drug off-label.
“We really know very little about what these drugs do to the activity of groups of neurons,” explains Marlene Cohen, a professor of neuroscience in the Kenneth P. Dietrich School of Arts and Sciences, in a statement. “But basic scientists like us have been investigating what groups of neurons can tell us about behavior and cognition, and so understanding what these drugs do to groups of neurons can maybe give us hints about other things that they would be useful for.”
Previously, Pitt postdoctoral researcher Amy Ni, leading a team, showed a link between animals’ performance on a visual task and neurons in the visual cortex. Their current work also shows that animals given methylphenidate performed better on a visual task of attention. On days when they were given the drug, they spent longer on the task and performed better, but only when the required task occurred in a spot to which they were already attentive.
Along with learning more about how the drug works, the study provides a broader understanding of how patterns of firing neurons translate into behaviors.
“It’s an approach that hasn’t received much attention,” Cohen says. She attributes that, in part, to a lack of funding for research on how drugs change the activity of neurons. “That makes it difficult to look for ‘crossover treatments’ – novel uses for drugs that are already on the market.
“These stimulants might actually be useful for treating a lot of things, ranging from the cognitive changes associated with normal aging, to Alzheimer’s disease and others,” Cohen continues. “Though it’s currently just a well-informed hunch, it’s one the lab plans to pursue in future studies. It’s one test case, and I think there’s a lot more to be done. I hope that people will see that these approaches are important.”
The research is published in the journal Proceedings of the National Academy of Sciences.