title: Development of BOLD signal hemodynamic responses in the human brain.
abstract: In the rodent brain the hemodynamic response to a brief external stimulus changes significantly during development. Analogous changes in human infants would complicate the determination and use of the hemodynamic response function (HRF) for functional magnetic resonance imaging (fMRI) in developing populations. We aimed to characterize HRF in human infants before and after the normal time of birth using rapid sampling of the blood oxygen level dependent (BOLD) signal. A somatosensory stimulus and an event related experimental design were used to collect data from 10 healthy adults, 15 sedated infants at term corrected post menstrual age (PMA) (median 41+1 weeks), and 10 preterm infants (median PMA 34+4 weeks). A positive amplitude HRF waveform was identified across all subject groups, with a systematic maturational trend in terms of decreasing time-to-peak and increasing positive peak amplitude associated with increasing age. Application of the age-appropriate HRF models to fMRI data significantly improved the precision of the fMRI analysis. These findings support the notion of a structured development in the brain's response to stimuli across the last trimester of gestation and beyond.
authors: Centre for the Developing Brain, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, Du Cane Road, London, W12 0NN, UK.
authors: Tomoki
authors: T
authors: Arichi
authors: Gianlorenzo
authors: G
authors: Fagiolo
authors: Marta
authors: M
authors: Varela
authors: Alejandro
authors: A
authors: Melendez-Calderon
authors: Alessandro
authors: A
authors: Allievi
authors: Nazakat
authors: N
authors: Merchant
authors: Nora
authors: N
authors: Tusor
authors: Serena J
authors: SJ
authors: Counsell
authors: Etienne
authors: E
authors: Burdet
authors: Christian F
authors: CF
authors: Beckmann
authors: A David
authors: AD
authors: Edwards
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply / Q000254:growth & development*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D055815:Young Adult
chemical_list: D010100:Oxygen