Elevated ALFF in Early Developing Brain Systems from Birth to Three Years
Poster No:
1278
Submission Type:
Abstract Submission
Authors:
Ashley Nielsen1, Alyssa Labonte2, Max Herzberg1, Deanna Barch3, Joan Luby2, Cynthia Rogers2, Chad Sylvester2, Christopher Smyser2
Institutions:
1Washington University in St. Louis, Saint Louis, MO, 2Washington University in St. Louis, St. Louis, MO, 3Washington University, Saint Louis, MO
First Author:
Co-Author(s):
Introduction:
The blood oxygen level dependent (BOLD) signal measured with functional magnetic resonance imaging (fMRI) indirectly reflects the synaptic activity of neural populations. Early in development, the maturation of inhibitory interneurons refines the synaptic activity of neural populations, shifting from synchronous, high amplitude activity to sparse, suppressed activity and marks the closing of sensitive periods. Thus, the amplitude of the low-frequency fluctuations (ALFF) in the BOLD signal has been proposed as a putative indicator of cortical maturity and neuroplasticity, illuminating changes in the balance of excitation and inhibition. Developmental patterns of ALFF during childhood and adolescence differ across the brain (Sydnor et al. 2023). In sensorimotor areas that develop early, ALFF decreases in childhood, while, in association areas that develop late, ALFF increases across adolescence and then decreases into adulthood. How ALFF emerges beginning at birth when neuroplasticity and developmental change are greatest has yet to be characterized. Here, we aimed to chart the developmental trajectory of ALFF during the first three years of life to potentially uncover how developmental neuroplasticity differs across the brain in humans.
Methods:
fMRI was acquired during natural sleep at birth (n=261), age 2 years (n=98), and age 3 years (n=80) as part of the Early Life Adversity and Biological Embedding Study. Functional data were mapped to individual surfaces. ALFF, the amplitude of low-frequency (0.01-0.08 Hz) fluctuations, was derived using the Fast Fourier transform for each vertex in the cortical surface and each voxel in the subcortex and cerebellum. Longitudinal change in ALFF from birth to age 2 years (n=75) and from age 2 years to age 3 years (n=39) was determined. We also examined how sub-millimeter head motion in the scanner impacts estimates of ALFF to avoid inflating or obfuscating true developmental change. Head motion was quantified as mean frame-wise displacement (meanFD) and de-noising strategies were applied to evaluate the relationship between head motion and ALFF.
Results:
Across all three timepoints (Figure 1 A-C), ALFF was highest in sensorimotor areas (somatosensory, visual, auditory) and the subcortex (thalamus, amygdala, hippocampus). The change in ALFF between birth and age 2 years was four times greater than between age 2 years and 3 years. ALFF increased the most in somatosensory and visual areas as well as parts of the thalamus and putamen (Figure 1 D-E). ALFF remained low in the majority of frontal cortex from birth to age 3 years. ALFF varied with head motion (meanFD) such that greater head motion was associated with greater ALFF, but the effect was reduced by applying de-noising strategies.
·Figure 1. ALFF across the first three years of life
Conclusions:
ALFF has been proposed as a marker of neuroplasticity and maturation. These findings demonstrate that, during the first three years of life, ALFF is highest in brain regions known to undergo the earliest maturation. The greatest change in ALFF occurred between birth and age 2 years, potentially indicating the opening of sensitive periods and/or the rapid developmental change occurring during this period. Later developing brain areas, like frontal cortex, did not exhibit increases in ALFF, consistent with the notion that the greatest developmental change in the balance of excitation and inhibition has not yet occurred for this region. During this developmental window decreases in ALFF were not observed (except for the cerebellum), potentially indicating that early developing sensorimotor systems are still sensitive to environmental exposures and have not yet completed maturation. Charting how ALFF varies across the brain during early development as a potential guide to when plasticity is greatest could greatly facilitate efforts to promote healthier brain development and prevent adverse exposures during sensitive developmental windows.
Lifespan Development:
Early life, Adolescence, Aging
Normal Brain Development: Fetus to Adolescence 1
Modeling and Analysis Methods:
Motion Correction and Preprocessing
Task-Independent and Resting-State Analysis 2
Neuroanatomy, Physiology, Metabolism and Neurotransmission:
Normal Development
Keywords:
Development
FUNCTIONAL MRI
Plasticity
Other - Amplitude of Low Frequency Fluctuations (ALFF)
1|2Indicates the priority used for review