Figure 3.

Example of BDNF-mediated transcriptional activation, through epigenetic regulation of the homer1a synaptic plasticity gene in hippocampus and amygdala (Mahan et al., 2012). Fear conditioning rapidly increases BDNF-signaling in both the hippocampus and amygdala and results in activation of the TRKB pathway that activates MEK and ERK. ERK further phosphorylates CREB which is then translocated to the nucleus where it binds to CRE sites in the promoter region of homer1a. CREB subsequently recruits CBP which induces specific histone changes (A) increased acetylation in the hippocampus and (B) decreased methylation in the amygdala, both of which result in increased homer1a transcription (Figure courtesy of Amy Mahan, PhD).