Biology subjects

Williams, L. Z.

Publications and source records attributed to Williams, L. Z..

2 recordsLinked to original sources

bioRxiv2026

Structural Brain Co-Maturation In The Neonatal Period

Background. The neonatal period is characterized by neurodevelopmental processes coinciding with rapid physiological transitions, however, spatial patterns of brain expansion in early life remain incompletely characterized. Here, we leverage grey matter structural covariance in term- and preterm-born neonates to study the interregional synchrony of neonatal brain maturation along principal brain organizational axes. Methods. We used structural MRI data from the developing Human Connectome Project (n=525; 435 term-born) scanned at 37-44 weeks postmenstrual age (PMA)), stratifying the sample by term status and PMA. Based on cortical thickness (CT) and surface area (SA) metrics, we computed age group- (CVg) and individual-level (CVi) structural covariance matrices. Applying surface-based linear models, we identified changes in interregional covariance with postmenstrual age (PMA) and gestational age at birth (GAB), and contextualized alterations to neonatal functional networks. Using gradient decomposition, we identified major trajectories of cortical expansion on individual and group levels, and determined their correlation to archetypal geometric, evolutionary, and functional axes. Results. We found age-related changes reflecting cortical expansion and an increased structural differentiation with age. Gradient decomposition of group-level covariance revealed that primary components followed both an posterior-anterior distribution, anchored in the visual cortex, and a sensorimotor-association gradient. Individual-level covariance gradients adhered most to geometric axes, and diverged from a sensorimotor-association pattern with increasing PMA. Term-born neonates exhibited a higher spatial correlation to functional and geometric axes than preterm-born neonates, overall pointing to different expansion patterns in neonates of the same PMA. Conclusion. We found trajectories of structural maturation in the neonatal period that appear coordinated along geometric and functional axes. On an age group level, term-born neonates appear to follow archetypal axes more than preterm-borns at term-equivalent age, underlining differential expansion patterns in preterm-born neonates.

neuroscience↗

bioRxiv2021

Preterm birth alters the development of cortical microstructure and morphology at term-equivalent age

IntroductionThe dynamic nature and complexity of the cellular events that take place during the last trimester of pregnancy make the developing cortex particularly vulnerable to perturbations. Abrupt interruption to normal gestation can lead to significant deviations to many of these processes, resulting in atypical trajectory of cortical maturation in preterm birth survivors. MethodsWe sought to first map typical cortical micro and macrostructure development using invivo MRI in a large sample of healthy term-born infants scanned after birth (n=270). Then we offer a comprehensive characterisation of the cortical consequences of preterm birth in 78 preterm infants scanned at term-equivalent age (37-44 weeks postmenstrual age). We describe the group-average atypicality, the heterogeneity across individual preterm infants, and relate individual deviations from normative development to age at birth and neurodevelopment at 18 months. ResultsIn the term-born neonatal brain, we observed regionally specific age-associated changes in cortical morphology and microstructure, including rapid surface expansion, cortical thickness increase, reduction in cortical anisotropy and increase in neurite orientation dispersion. By term-equivalent age, preterm infants had on average increased cortical tissue water content and reduced neurite density index in the posterior parts of the cortex, and greater cortical thickness anteriorly compared to term-born infants. While individual preterm infants were more likely to show extreme deviations (over 3.1 standard deviations) from normative cortical maturation compared to term-born infants, these extreme deviations were highly variable and showed very little spatial overlap between individuals. Measures of regional cortical development were associated with age at birth, but not with neurodevelopment at 18 months. ConclusionWe showed that preterm birth alters cortical micro and macrostructural maturation near the time of fullterm birth. Deviations from normative development were highly variable between individual preterm infants.

neuroscience↗