Of particular value to studying the transcriptional mechanisms involved in human brain functioning and development are such foundational resources as Atlases, which present data on gene expression in different anatomical structures of the brain at its different developmental stages; examples are the HUDSEN and BrainSpan Atlases. Both were created as ongoing systems to combine data on the anatomical regions of the brain and gene expression in those regions. The HUDSEN atlas particularly focuses on representing human embryonic brain development and currently provides information on the expression of 104 genes in different subdivisions of the brain through the12 Carnegie stages (CS 12–23, corresponding to 26–56 days post conception) of prenatal development (http://www.hudsen.org). The BrainSpan atlas (http://www.brainspan.org) represents spatiotemporal gene expression patterns in different anatomical structures of the human brain across all of the main stages of its development. The Atlas provides data on gene expression profiles by RNA sequencing and exon microarray in 8-16 cortical and subcortical structures of the brain across 13 developmental stages – from embryonic (5–7 post-conception weeks) to adult (20-40 years of age and older).
