Longitudinal magnetic resonance imaging study of rhesus monkey brain development.
To examine early brain development, T1-weighted structural MRI scans of seven rhesus monkeys (Macaca mulatta) were obtained longitudinally between the ages of 1 week and 4 years at 12 age points. Total brain volume, calculated at each age point, increased significantly, by 56%, between 1 week and 4 years. The greatest increase of 22% occurred between 1 week and 1 month, followed by further significant increases between 1 and 2 months, and 3 and 4 months. Gradually smaller increases continued up to 3 years with no further significant changes thereafter. A robust maturation of white matter occurred between 1 week, at which the only easily identifiable fibre tracts were internal capsule and optic radiations, and 3 months, at which most large fibre tracts were visible; only at this age reproducible measurements were possible for all cases. White matter volume increased by 126% between 3 months and 4 years, with the biggest increase between 3 and 4 months (32%) followed by smaller but significant increases up to 4 years. The macaque brain development parallels that of humans by reaching the maximum in total brain volume around the age of sexual maturity (in macaques 3-4 years) and by the increases in white matter continuing beyond this age. The most rapid growth in both total brain volume and white matter from birth to approximately 4 months is consistent with the emergence of various cognitive abilities in macaques at that age.
Malkova
L
L
Department of Pharmacology, Georgetown University, 900 Reservoir Road, Washington, DC 20007, USA. malkoval@georgetown.edu
Heuer
E
E
Saunders
R C
RC
D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001921:Brain / Q000033:anatomy & histology* / Q000254:growth & development*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008253:Macaca mulatta / Q000033:anatomy & histology* / Q000254:growth & development*; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology / Q000648:ultrastructure; D009434:Neural Pathways / Q000033:anatomy & histology / Q000254:growth & development; D009929:Organ Size / Q000502:physiology; D013997:Time Factors