Folding drives cortical thickness variations.
Level 4 - case-series / case-control
Observational neuroimaging cohorts combined with computational biomechanical modeling (graded by design analogy)
PubMed 37275766 · doi:10.1140/epjst/e2020-000001-6
What was done
The authors used a computational biomechanical model (a growing layer on an elastic substrate) to simulate how physical forces during brain development influence cortical thickness over time. They tested the model's predictions against structural magnetic resonance imaging (MRI) data from three human cohorts: 9 healthy adults, 564 healthy individuals aged 7–64 years, and 73 infants scanned at birth, age 1, and age 2. They also compared the model against pattern development in growing cortical organoids.
What was found
The biophysical simulations demonstrated that developing gyri universally thicken and sulci thin during folding, even without regional genetic information. The authors reported that these naturally emerging thickness variations matched the cortical folding patterns across the adult (n = 9), cross-sectional (n = 564), and longitudinal infant (n = 73) MRI cohorts, as well as in cortical organoids. The abstract reports no numerical effect sizes, correlation values, or statistical test results.
Why it matters
This study provides evidence that variations in human cortical thickness (ranging from 1.5 to 4.5 mm) can emerge directly from mechanical folding forces rather than exclusively from regional genetic programming. This physical perspective offers a framework for understanding brain morphogenesis and interpreting thickness biomarkers in neurological disorders.
Limits
The abstract reports no quantitative correlation coefficients, error metrics, or statistical significance tests. The computational model relies on a simplified bilayer system that does not capture complex multi-laminar cytoarchitecture, axonal tension, or vascular dynamics. The relative contribution of mechanical forces versus genetic patterning in vivo cannot be isolated from observational imaging.
Cited by
- supports The human cerebral cortex is the outer layer of the brain measuring approximately 3 millimeters in thickness.