Emergence of resting state networks in the preterm human brain

TLDR

The functions of resting state networks (RSNs) revealed by fMRI remain unclear, but they may develop in parallel with related cognitive functions. We tested whether the full repertoire of resting state dynamics emerges during the rapid neural growth period before term birth (~40 wk gestation). We mapped RSN development in 70 infants aged 29–43 wk postmenstrual age using multiple independent analytical techniques. RSNs progressed from fragmentary elements at 30 wk PMA to full adult‑like patterns by term, with visual, auditory, somatosensory, motor, default mode, frontoparietal, and executive control networks developing at varying rates but all present and integrated with thalamic activity by term, indicating that RSNs largely emerge during the third trimester before later cognitive competencies.

Abstract

The functions of the resting state networks (RSNs) revealed by functional MRI remain unclear, but it has seemed possible that networks emerge in parallel with the development of related cognitive functions. We tested the alternative hypothesis: that the full repertoire of resting state dynamics emerges during the period of rapid neural growth before the normal time of birth at term (around 40 wk of gestation). We used a series of independent analytical techniques to map in detail the development of different networks in 70 infants born between 29 and 43 wk of postmenstrual age (PMA). We characterized and charted the development of RSNs from recognizable but often fragmentary elements at 30 wk of PMA to full facsimiles of adult patterns at term. Visual, auditory, somatosensory, motor, default mode, frontoparietal, and executive control networks developed at different rates; however, by term, complete networks were present, several of which were integrated with thalamic activity. These results place the emergence of RSNs largely during the period of rapid neural growth in the third trimester of gestation, suggesting that they are formed before the acquisition of cognitive competencies in later childhood.