transcriptional effects and can act as a transcriptional activator or repressor in the brain in vivo. This is also true for ΔFosB, which has been shown previously (Kumar et al., 2005; McClung and Nestler, 2003; Renthal et al., 2008) and observed in our ChIP-chip data to act as either a transcriptional activator or repressor depending on the gene promoter and conditions involved.
