Biology subjects

Rabinak, C. A.

Publications and source records attributed to Rabinak, C. A..

2 recordsLinked to original sources

bioRxiv2019

Adolescent substance use and functional connectivity between the ventral striatum and hippocampus

Neurodevelopmental explanations for adolescent substance use have focused on heightened sensitivity of the brains reward system, centered around the ventral striatum (VS). Recent evidence demonstrates increased functional connectivity between the VS and hippocampus in adolescents relative to adults, suggesting that the adolescent brain may learn from subsequent exposure to risks/rewards. However, a link between VS-hippocampal circuitry and adolescent substance use has yet to be established. Two separate longitudinal studies were conducted to evaluate whether variation in VS-hippocampal resting-state functional connectivity (rs-FC) predicts subsequent adolescent substance use. Study 1 consisted of 19 youth recruited from a high sociodemographic risk population (N = 19; 14 female; 47% Black Non-Hispanic, 32% White Non-Hispanic). To replicate results of Study 1, Study 2 utilized data from the National Consortium on Adolescent Neurodevelopment and Alcohol, an ongoing multi-site imaging study (N= 644; 339 female; 11% Black Non-Hispanic, 11% Hispanic/Latino, 66% White Non-Hispanic). Resting-state fMRI data were collected at a baseline time point and lifetime and past year self-reported substance use was collected at a follow up visit. Regression models tested whether baseline VS-hippocampal rs-FC predicted substance use at follow up. Across both studies, higher VS-hippocampal rs-FC at baseline predicted greater substance use at follow up. These data provide the first evidence linking increased VS-hippocampal connectivity with greater adolescent substance use. Results fit with the emerging idea that adolescent substance use is driven by not only a heightened sensitivity to reward, but also a stronger link between reinforcement learning and episodic memory for rewarding outcomes.

neuroscience↗

bioRxiv2017

Mindfulness and dynamic functional neural connectivity in children and adolescents

BackgroundMindfulness is a non-judgmental, present-centered awareness and acceptance of ones thoughts, feelings, and bodily sensations. Interventions that promote mindfulness consistently show salutatory effects on cognition and psychological wellbeing in adults, and more recently, in children. Understanding the neurobiological mechanisms underlying mindfulness in children may allow for more judicious application of these techniques in clinical and educational settings.\n\nMethodsUsing multi-echo/multi-band fMRI, we measured resting-state connectivity and tested the hypothesis that the association between mindfulness and anxiety in children (N=42) will relate to static and dynamic interactions between large-scale neural networks considered central to neurocognitive functioning and implicated in mindfulness in adults (default mode [DMN], salience and emotion [SEN], and central executive networks [CEN]).\n\nResultsMindfulness was related to dynamic but not static connectivity in children. Specifically, more mindful children transitioned more between brain states over the course of the scan, spent overall less time in a certain connectivity state (state 2), and showed a state-specific reduction in SEN-right CEN connectivity (state 4). Results of a separate measure of present-focused thought during the resting-state were consistent with these results, suggesting state-trait convergence. Finally, the number of state transitions mediated the link between higher mindfulness and lower anxiety, suggesting that flexibility in transitioning between neural states may bridge the well-established link between mindfulness and anxiety in children.\n\nConclusionsResults provide new insights into neural mechanisms underlying benefits of mindfulness on psychological health in children, and suggest that mindfulness relates to functional neural dynamics and interactions between neurocognitive networks, over time.

neuroscience↗