In young children, psychostimulants relieve symptoms of Attention Deficit Disorder, yet in adolescents and adults, those same medications can cause euphoria and are often abused.
What is behind these differing drug responses?
Temple University scientists have identified a potential molecular mechanism, the neurotrophin system comprised of brain-derived neurotrophic factor (BDNF) and its receptor TrkB, as the cause of age differences in stimulant response. Their findings appear in the current issue of the Journal of Neuroscience.
"Our findings suggest that the rapidly developing young brain is able to adapt and protect itself against the rewarding effects of stimulants due to the input of the TrkB system," said Ellen Unterwald, PhD, lead investigator and professor of pharmacology at Temple University's School of Medicine and Center for Substance Abuse Research.
Most preclinical studies have found that susceptibility to the addictive properties of stimulants is age-dependent. This is the first study to link the TrkB neurotrophin system to those age-specific responses. The hope is that BDNF/TrkB might someday be used as a target for the development of new treatments for childhood neuropsychiatric disorders or addiction.
Unterwald and her research team specialize in the effects of drug use, abuse and withdrawal and are currently investigating neurobiological mechanisms involved in drug addiction.
Other authors on this study are Michelle Niculescu,1 Shane A. Perrine,1 Jonathan S. Miller,1 Michelle E. Ehrlich,2 1Deparment of Pharmacology and Center for Substance Abuse Research, Temple University School of Medicine, 2Farber Institute for Neurosciences and Department of Neurology, Thomas Jefferson University College of Medicine, and 3Laboratory of the Biology of Addictive Diseases, The Rockefeller University.
The author wishes to acknowledge the input of her collaborator on this project, Michelle Ehrlich, MD, currently at Mt. Sinai School of Medicine.
This work was supported in part by grants from the National Institutes of Health.