Because these results implied a hypothalamic site of Aza action, we carried out a study to verify the ability of Aza to reduce DNA methylation in the hypothalamus. We measure global DNA methylation in the MBH and cerebral cortex at two intervals (one and seven days) after initiating the Aza treatment. At both time points DNA methylation was significantly reduced in the MBH, but not the cerebral cortex (Fig. 2d). This difference may be due to the lack of a fully functional blood brain barrier in the MBH, a feature that allows significant transfer of macromolecules from the bloodstream to the hypothalamic parenchyma 25, 26.
