Structural growth trajectories and rates of change in the first 3 months of infant brain development.

Fulfilling the researchers criteria were 87 neonates who underwent MRI scans while asleep without sedation. The assessment of multiple regions of interest (ROIs) (including, lateral ventricles, hippocampus, caudate, and putamen), sexual dimorphisms, lef-right asymmetries, growth rate as a function and sex-specific volume-byage percentage was performed. The researchers found a link between longer gestational age at birth and larger size of brain structures for all ROIs, excluding the pallidum and third ventricle. There was also a significant interaction between gestational age at birth and age, indicating “catching up” among those born earlier than average. Over the 90 days, the brains of the neonates grew from 33.5% to 54.9% of an adult size brain and during this time, the cerebellum exhibited the highest rate of growth and the hippocampus the slowest rate of growth than all the other structures. When comparing intergender differences, by 90 days, the males had larger whole-brain size, ventricles, putamen and cerebellum. The only significant differences between lef and right brain was the size of the lef lateral ventricle, which was larger than the right. The results for the rates of brain growth revealed a rate of 1% per day initially, and then tapered off as 3 months of age approached to 0.4% per day. Using longitudinal analysis of MRI images, the authors found brain development to be most rapid in the days immediately afer birth. They also found that longer gestation leads to larger brain size at birth and male infants showed greater increase in whole brain volume over time. The cerebellum grew at the highest rate and hippocampus at the slowest