RNA samples (1–2 µg) from frontal cortex (BA9; 33 control and 31 BD samples), anterior cingulate cortex (29 control and 29 BD samples) and cerebellum (lateral cerebellar hemisphere; 34 control and 29 BD samples) were obtained from the Stanley Medical Research Institute (Chevy Chase, MD, USA) Array Collection. Quality and concentration of total RNA was measured using a NanoDrop ND-1000 spectrophometer (Thermo Fisher Scientific, Waltham, MA) and each sample was processed in triplicate for quantification of miR-34a and miR-34a target expression by quantitative real time PCR (qRT-PCR). miR-708 levels were measured in cerebellar samples only. The research met the criteria for Exemption 4 in terms of Human Subjects Research and was approved by the Institutional Review Board of the Massachusetts General Hospital.
