PROJECT SUMMARY/ABSTRACT
The hippocampus is composed of cytoarchitecturally-distinct subfields that support specific memory and learning
functions. Evidence suggests distinct developmental trajectories in hippocampal subfields throughout childhood
and adolescence, periods in which environmental factors exact strong influence on brain development. However,
evidence is largely from cross-sectional samples, is based on inconsistent practices for delineations of subfields,
and is limited by the power and diversity within single studies. Thus, developmental trajectories of hippocampal
subfields remain unclear, prohibiting the systematic study of the influence of environmental factors on
hippocampal development. Variations in total hippocampal volume across development have been linked to
socioeconomic status, a proxy for access to material resources, medical care, and quality education in one’s
environment. Low household socioeconomic status in childhood is associated with worse cognitive abilities later
in adulthood, and low neighborhood socioeconomic status (an additional index of social capital and
connectedness) further predicts poor behavioral outcomes beyond the household, especially in adolescence.
The proposed study examines differential vulnerability of hippocampal subfield structures to variations in
household and neighborhood socioeconomic across development. Understanding of normative developmental
changes in subfield structure and vulnerability to low socioeconomic environments can have significant
implications for individual and community interventions. However, testing these questions requires a large
sample size, adequate coverage of age, specialized ultra-high-resolution scans, and sufficient representation of
the diverse United States population. The proposed study will achieve this using integrative data analysis, an
advanced latent modeling approach that directly addresses differences in methodologies while allowing new
hypotheses to be tested in existing data. Hypotheses will be tested using a novel integrated longitudinal dataset
of 678 typically developing subjects covering the span of 4- to- 25-years from four geographically- and
demographically-diverse sites across the United States by pursuing these specific aims: Aim 1) Characterize
typical developmental trajectories of hippocampal subfields in a diverse multi-site study pediatric sample; and
Aim 2) Elucidate the link between variations in socioeconomic status and the development of hippocampal
subfields. The hippocampus is implicated in neurodevelopmental disorders such as depression, schizophrenia,
and low SES also confers risk for neurodevelopmental disorders. Thus, obtaining accurate characterization of
hippocampal subfield development trajectories and identifying the effects of household and neighborhood SES
in a large sample will pave the way for early identification of neurodevelopmental disorders and targeted
intervention for specific factors associated with socioeconomic disparity. Further, the successful application of
integrative data analysis to neuroimaging data from multiple studies will demonstrate a means to leverage
existing data to answer critical questions otherwise not feasible in individual studies.
