Structured Spontaneity: Building Circuits in the Human Prenatal Brain

Abstract

Early brain activity is crucial for neurogenesis and the development of brain networks. However, it has been challenging to localize regions in the developing human brain that contribute to spontaneous waves of neuronal activity. Recently, Arichi and colleagues reported that the temporal and heteromodal insular cortices have a central role in propagating these neural instructional signals.

Figure 1

Regions that are hubs of global brain connectivity in neonates and infants. Functional MRI data were obtained in a healthy pediatric sample of 51 neonates (panel A), 50 1-year-olds (panel B), and 46 2-year-olds (data not shown) during natural sleep. Colors on brain surfaces are used to visualize mean regional ‘betweenness centrality’ (BC) values. BC is a quantitative graph-theoretical measure that represents how connected a given region is to all other regions. Regions with the highest BC values included regions of bilateral insular cortices and temporal lobes, which based on new results by Arichi and colleagues [5] are regions involved in propagation of spontaneous activity transients that are important for network development in the antenatal period. Figure modified from Gao et al. [6].