(Great Neck, N.Y. - May 12, 2009) — NARSAD Young Investigator Tracie Paine, Ph.D., was the lead author of a study by Harvard neuroscientists that identified a new link between a brain enzyme and attention deficits and hyperactivity, two key symptoms of attention deficit/hyperactivity disorder (ADHD).
The research, performed at McLean Hospital and published online on April 22 by the journal Neuropsychopharmacology, suggests that an enzyme called protein kinase-A (PKA) plays an important role in keeping these symptoms in check.
When researchers selectively disrupted the function of PKA in the prefrontal cortex, a part of the brain associated with decision-making, rats became hyperactive and unable to pay attention to lights that provided hints about how to obtain food. Genetic disruption of a protein that is activated by PKA also produced inattention, identifying a chemical signaling pathway within the nerve cells of the prefrontal cortex that might be sluggish in individuals with attention disorders. Additional studies suggested that disruption of PKA did not change the rats’ desire for the food, only their ability to pay attention to information needed to obtain it.
“These studies point to a mechanism by which psychostimulant-like medications for the treatment of ADHD work. Such drugs have many effects on the brain - one of which is to increase the activity of PKA,” said Paine, who recently accepted a position as an assistant professor of neuroscience at Oberlin College.
“Problematically, these drugs also have undesirable side effects such as insomnia and a potential for abuse,” Paine said, adding that ”knowing the mechanism by which these drugs treat the symptoms of ADHD may lead to the development of new treatments that lack these side effects.”