Poster B17, Sunday, March 26, 8:00 – 10:00 am, Pacific Concourse
Structural Connectivity between the Left Basal Ganglia and Left Insula Predicts Initiation of Substance Use in Adolescence
Kelly C. Martin1, Katherine O’Connell2, Valerie L. Darcey1,2, Emma J. Rose3, Diana H. Fishbein3, John W. VanMeter1; 1Georgetown University, Center for Functional and Molecular Imaging, Washington, DC, 2Georgetown University, Interdisciplinary Program in Neuroscience, Washington, DC, 3The Pennsylvania State University, University Park, PA
Adolescence is marked by dynamic changes in brain development and great inter-individual variability in initiation of substance use. We examined white matter connectivity between different parts of frontal cortex and the basal ganglia, a region implicated in reward processing. Substance-naïve pre-adolescents (age 11-13 yo; n=135) were recruited to the Adolescent Development Study, a prospective, longitudinal study of neurodevelopmental trajectories mediating risk for substance use. Results reported herein compared those initiating substance use 18 months later (Users; n=11) to those who remained substance-naïve (Nonusers; n=24; currently analyzed). Probabilistic tractography was performed using the diffusion tensor imaging (80 directions, 3T) collected at the baseline to derive streamline counts, a measure of “connectivity strength,” using the left and right basal ganglia as seed regions to 22 frontal cortex regions from the Find atlas (Shirer et al., 2012). Non-parametric statistics revealed that prior to use, Users had greater connectivity strength than Nonusers between the left basal ganglia and the left insula (p=.027). There were no significant differences for the right basal ganglia. These results indicate that differences in structural connectivity between the left basal ganglia and ipsilateral insula may predict subsequent initiation of use. Recently Fareri (2015) found that functional connectivity between the insula and striatum follows a parabolic trajectory with much higher connectivity during childhood than either adolescence or adulthood. The greater connectivity observed in the User group may indicate a developmental delay between two nodes of the salience network, which has been implicated in adult substance use disorders.
Topic Area: EMOTION & SOCIAL: Development & aging