Neural correlates of verbal memory in youth with heavy prenatal alcohol exposure

Abstract

Prenatal alcohol exposure can impact both brain development and neurobehavioral function, including verbal learning and recall, although the relation between verbal recall and brain structure in this population has not been examined fully. We aimed to determine the structural neural correlates of verbal learning and recall in youth with histories of heavy prenatal alcohol exposure using a region of interest (ROI) approach. As part of an ongoing multisite project, subjects (age 10-16 years) with prenatal alcohol exposure (AE, n = 81) and controls (CON, n = 81) were tested using the CVLT-C and measures of cortical volume, surface area, and thickness as well as hippocampal volume were derived from MRI. Group differences in brain and memory indices were tested with ANOVA. Multiple regression analyses tested whether brain ROIs significantly predicted memory performance. The AE group had lower scores than the CON group on all CVLT-C variables (ps ≤ .001) and volume and surface area (ps < .025), although results varied by ROI. No group differences in cortical thickness were found. The relations between cortical structure and memory performance differed between group among some ROIs, particularly those in the frontal cortex, generally with smaller surface area and/or thinner cortex predicting better performance in CON but worse performance in AE. Cortical surface area appears to be the most sensitive index to the effects of prenatal alcohol exposure, while cortical thickness appears to be the least sensitive. These findings also indicate that the neural correlates of verbal memory are altered in youth with heavy prenatal alcohol exposure compared to controls.

Alcohol use in pregnancy and its impact on the mother and child

“…Similar associations between neural imaging/function and academic performance have been noted by other studies, including an inverse relationship between frontal cortical thickness and memory [126], an association between spatial working memory impairment and aberrant fronto‐parietal network synchrony [127] and a relationship between right occipito‐temporal cortical thickness and IQ [128] and between anterior cingulate cortical surface area and behavioural inhibition [129].…”

Impact of adolescent stress on the expression of stress‐related receptors in the hippocampus of animals exposed to alcohol prenatally

“…stress) is a required property for the hippocampus to play its critical role in learning and memory as well as in emotional and stress regulation, all of which show some level of dysregulation following PAE. Clinical studies support this suggestion by demonstrating that PAE-induced disruptions in hippocampal development is directly associated with problems in memory and learning (Coles, et al, 2011; Gross et al, in press; Willoughby et al, 2008).…”

Academic Difficulties in Children with Prenatal Alcohol Exposure: Presence, Profile, and Neural Correlates

“…Reading, while impaired in alcohol-exposed children relative to controls, did not appear to have cortical surface area correlates and may relate to broader neural circuitry dysfunction or differential trajectories (Houston et al, 2014, Ashkenazi et al, 2013). Further, there were no differential associations with cortical thickness, suggesting it may not be as sensitive an indicator for prenatal alcohol exposure (Gross et al, 2016) or the use of an alcohol-exposure group may not be as sensitive in detecting cortical effects of thickness as other continuous measures of alcohol exposure (Meintjes et al, 2014, Roberston et al, 2016). …”

“…This approach also prevented potential signal dilution errors that occur in measuring their product (volume) (Migliorini et al, 2015). Furthermore, recent work from our laboratory suggests that surface area is a sensitive index to the teratogenicity of prenatal alcohol exposure (Gross et al, 2016). Cortical maps were spatially smoothed with a Gaussian kernel of 10 mm full width half max and averaged across subjects using a spherical aligning method for cortical folding patterns.…”