Developmental differences in haemodynamics drives temporal features of the cortical-depth-dependent BOLD response in neonates at 7T

Motivation: Many biophysical, neurovascular and physiological factors determining BOLD response characteristics are altered during the neonatal period. It is unclear how each factor affects the immature BOLD response. Goal(s): To understand whether altered physiology, neuronal activity or neurovascular coupling predict neonatal specific features of the neonatal BOLD response. Approach: Cortical-depth-dependent BOLD responses were defined in neonates and adults using GRE-EPI fMRI at 7T. Temporal and amplitude features were predicted with the laminar BOLD response model and infinite cylinder model. Results: Distinct cortical-depth-dependent neonatal BOLD response features can be largely accounted for by altered haemodynamics and baseline physiology in the developing brain. Impact: Developmental differences in haemodynamics and cerebral physiology significantly alter temporal and amplitude features of the cortical-depth-dependent BOLD response in neonates. This has clear implications for using fMRI to study the emergence of brain activity across this critical period.