Amygdala structure and function and its associations with social-emotional outcomes in a low-risk preterm sample

TL;DR

This study finds that low-risk preterm birth does not affect social-emotional outcomes or amygdala volume in young adults, but it does increase amygdala connectivity with the medial frontal cortex.

Contribution

The study reveals increased amygdala-medial frontal cortex connectivity in low-risk preterm individuals without structural or outcome differences.

Findings

No differences in social-emotional outcomes or amygdala volumes were found between low-risk preterm and full-term groups.

Low-risk preterm individuals showed increased amygdala-medial frontal cortex connectivity at the cluster level.

Increased connectivity was associated with better social-emotional outcomes only in low-risk preterm individuals.

Abstract

Amygdala atypical volume development and functional connectivity (FC) at small gestational ages (GA) have been found across childhood. This adult-oriented study assesses whether altered amygdala structure and function is present following low-risk preterm birth. T1-weighted and resting-state functional MRI images of 33 low-risk preterm (30–36 weeks’ GA) and 29 full-term (37–42 weeks’ GA) young adults of both sexes, aged between 20 and 32 years old, were analyzed using FreeSurfer (v6.0.0) and Coon Toolbox (v21.a). The social-emotional assessment included Happé’s Strange Stories Test, the Moral Judgment Test, Delay-Discounting Test, Adult Self Report, and Emotion Regulation Questionnaire. No differences were found in social-emotional outcomes or amygdala volumes between the groups. Low-risk preterm young adults showed increased FC between the left amygdala, right amygdala and medial frontal cortex (MedFC) (F = 9.89, p-FWE = 0.009) at cluster level compared to their full-term peers. However, significant results at connection level were not observed between left and right amygdala. Lastly, increased FC at cluster level between the right amygdala and MedFC, and left amygdala and MedFC, was related to better social-emotional outcomes only in low-risk preterm young adults (F = 6.60, p-FWE = 0.036) at cluster level. At connection level, in contrast, only right amygdala–MedFC increased FC was significantly associated with better social-emotional outcomes. This study reveals that low-risk prematurity does not have an effect on social-emotional outcomes or structural amygdala volumes during young adulthood. However, individuals who were considered to be at a lower risk of exhibiting neurodevelopmental alterations following preterm birth demonstrated increased FC between the left and right amygdala and MedFC.

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