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Date Submitted
Spring 4-15-2015
Research Mentor and Department
Beau Ances, M.D., Ph.D
Restricted/Unrestricted
Dissertation/Thesis
Abstract
Human immunodeficiency virus (HIV) infection and high levels of early life stress (ELS) have independently been associated with alterations in brain function. Previous studies have implicated both processes with changes in functional connectivity measured using functional magnetic resonance imaging (fMRI) in the resting state, and one study has specifically demonstrated a significant interaction between HIV and ELS on brain volumetrics and cognition. However, the functional consequences of ELS in HIV+ individuals are unknown. This study served as a preliminary investigation of the impact of ELS on resting-state functional connectivity MRI (rs-fcMRI) at the brain network level in HIV+ individuals. One hundred and nine HIV+ individuals were assigned to a high (n=64) or low (n=45) ELS group based on responses to a validated self-report ELS questionnaire. All participants also underwent functional neuroimaging. Analyses of variance (ANOVA) were performed using the level of ELS and composite correlations within and between 13 resting-state brain networks. We hypothesized that individuals with high ELS would demonstrate significantly decreased connectivity with and within the default mode network (DMN), the network most active in the absence of tasks. In addition, we hypothesized that ELS would significantly impact connectivity with or within the frontoparietal task control, dorsal attention, and cingulo-opercular task control networks, all of which are associated with cognitive behaviors found to be affected by ELS in prior neuropsychological studies in otherwise healthy individuals. A significant difference in rs-fcMRI due to ELS was observed in 4 intra- and inter-network correlations, including correlations with and within the dorsal attention (DAN) and cingulo-opercular task control networks (CON). However, the DMN and frontoparietal task control network were not associated with any significant changes due to ELS. Our results indicate that ELS is associated with changes in functional connectivity in HIV+ individuals, but the mechanism remains unclear.