Figure 1: The genomic approach used for uncovering transcriptional mechanisms underlying apoptosis of CGNs. Primary cultures of CGNs undergo rapid apoptotic cell death within 24 h after removal of serum and lowering of extracellular potassium [22]. Engagement of apoptosis requires transcription and protein synthesis and the process becomes irreversible during the first 6 hours following induction. Expression profiling by microarray analysis of CGNs during the pre-commitment period of apoptosis (3 and 6 h) was used to decipher the transcriptional changes underlying apoptosis [7]. The genomic approach starts with RNA extraction, moves through DNA microarray analysis, and ends with the identification of deregulated genes and pathways.