HDAC activity in the amygdala and BNST tissues was measured, as described by us previously (Pandey et al., 2008 (link); Sakharkar et al., 2012 (link); 2014 (link)). In brief, cytosolic and nuclear protein fractions were prepared using a nuclear extraction kit (Sigma) and HDAC activity (HDAC class I and II) was assayed using the colorimetric HDAC activity assay kit (BioVision Research, Mountain View, CA). The enzymatic activity was calculated as O.D. /mg protein and then represented as the mean ± SEM.