Identifying changes in gene expression in the nervous system: mRNA differential display.

The majority of cellular and developmental processes are characterized by changes in gene expression. Recently, several polymerase chain reaction-based methods have been introduced for detecting genes whose expressions differ between cells or tissues. It is now possible to investigate whether novel gene expression occurs within many systems as a response to extracellular signals, and to identify systematically those genes. The characterization of cell-, tissue- or stage-specific gene expression will broaden our understanding of many complex biological processes.