The drug has been available for more than 50 years and recognized for its effectiveness in the treatment of ADHD, however its mode of action was not fully understood. These Pitt neuroscientists offer rare insight into how Ritalin affects activity in the brain – here in animals – improving understanding of which groups of brain cells control attention. These findings suggest new indications for the stimulant.
While 1 in 11 children in wealthy countries are prescribed a stimulant like MPH to improve attention and concentration in ADHD, and many adults also use these off-label medications, it is essential to fully understand their functioning. Indeed, if there have been more studies on the possible side effects of these long-term treatments, their prescriptions have exploded in recent years in children, adolescents, but also in adults.
“We really know very little regarding the effect of these drugs on the activity of different groups of neurons,” says lead author Dr. Marlene Cohen, professor of neuroscience at the Kenneth P. Dietrich School of Arts and Sciences. Science: “Understanding what these drugs do to specific groups of neurons can give us clues to other useful indications.”
MPH, visual cortex neuron activation and concentration
Previous studies by the same team had already suggested a link between the performance of animals on a visual task and a particular measure of neurons in the visual cortex – specifically, the likelihood that these neurons would fire independently of each other, as opposed to to stay in sync. The new research reveals that animals treated with MPH perform better on a visual attention task, and that this improvement occurs at exactly the same time as this neural activity triggering specific neurons. Specifically, the researchers observe that:
- on days when animal models receive MPH, they spend more time on a test task, perform better at it, but only when the required task involves an object on which they are already focusing their attention;
- certain groups of neurons then fire independently of each other;
- the drug thus alters the activity of these specific neurons, suggesting new uses for the drug. Because research reveals similarities between neural patterns related to attention and certain types of learning, suggesting that MPH may also be effective for the treatment of certain learning disabilities.
“These stimulants might actually be useful for treating many disorders, ranging from the cognitive impairment associated with normal aging, to Alzheimer’s disease and other dementias.”.
At this stage, these data constitute a first step to better understand how these drugs, by acting on the activation of specific groups of neurons, affect our behavior.
