Hot Publication - Larsen & Luna
In Vivo Evidence of Neurophysiological Maturation of the Human Adolescent Striatum
Larsen B and Luna B
Developmental Cognitive Neuroscience, Published Online
Maturation of the striatum has been posited to play a primary role in observed increases in adolescent sensation-seeking. However, evidence of neurophysiological maturation in the human adolescent striatum is limited. In collaboration with his mentor in the Department of Psychiatry, Dr. Bea Luna, graduate student Bart Larsen applied T2*-weighted imaging, reflecting indices of tissue-iron concentration, to provide direct in vivo evidence of neurophysiological development of the human adolescent striatum.
In an article recently published online in the journal Developmental Cognitive Neuroscience, Dr. Luna and Mr. Larsen present evidence from T2*-weighted MRI signal suggesting dynamic changes in the physiology of the striatal dopamine system. Multivariate pattern analysis (MVPA) of striatal T2*-weighted signal generated age predictions that accounted for over 60% of the sample variance in 10-25 year olds, using both task-related and resting state fMRI. Dorsal and ventral striatum showed age-related increases and decreases, respectively, in neurophysiology measures, suggesting qualitative differences in the maturation of limbic and executive striatal systems. In particular, the ventral striatum, the primary system underlying motivation, was found to be the strongest age predictor.
Together, the results provide the first in vivo evidence in humans of protracted neurophysiological development of brain areas central to the mesolimbic and mesocortical dopamine reward pathways hypothesized to underlie the peaks in sensation-seeking behavior and striatal reward reactivity during adolescence. This study thus represents an important step forward in understanding the normative development of the human adolescent brain and can serve to inform models of psychopathology which emerge during the adolescent period and have been associated with striatal abnormalities.
Bart Larsen, BA (Department of Psychology, University of Pittsburgh)
Beatriz Luna, PhD (Department of Psychiatry, University of Pittsburgh)