After demonstrating the accuracy and viability of using the dataset to profile human neurodevelopment, we manually curated lists of genes associated with over 80 categories, including various neurodevelopmental processes, neural cell types, and neurotransmitter systems (Supplementary Information 6.9; Supplementary Table 12). Interesting trajectories and notable differences in their onset, rates of incline and decline, and shapes were observed within and between brain regions for in the categories, including major neurodevelopmental processes (neural cell proliferation and migration, dendrite and synapse development, and myelination; Fig. 5d), cortical GABAergic inhibitory interneurons (CALB1, CALB2, NOS1, PVALB, and VIP), and glutamate receptors (Supplementary Figs 23 and 24). As expected, two major trends were observed in neurodevelopmental trajectories: changes in expression of cell proliferation genes preceded the increase in expression of DCX, both of which decreased during perinatal development while synapse development, dendrite development, and myelination trajectories increased. Interestingly, the NCX expression trajectory for synapse development (Fig. 5c, d) did not display a drastic decline during late childhood or adolescence as previously reported for synapse density42. We also identified network modules and additional genes that are
