Abstract
Sequencing of multiple mammalian genomes, together with the development of whole-transcriptome profiling technologies, have opened the door to an unprecedented ability to study gene expression in the brain. Transcriptomics refers to a class of high-throughput methods, such as microarray (gene chip), serial analysis of gene expression, and, more recently, whole-transcriptome sequencing (RNA-Seq), which enable measurement of the abundance of tens of thousands of transcribed RNAs in a given sample. Before the development of these technologies, studies of gene expression and function in the brain were restricted to targeted assay of a relatively small number of genes for any given study. Now it is possible to obtain a more panoramic view of gene expression, and potentially to understand the molecular underpinnings of brain function from the viewpoint of gene networks rather than from a viewpoint dominated by the effects of single genes.