(A–C) Representative actograms of wheel-running activity of C57Bl/6J mice which received an infusion of (A) a negative control antagomir (scrambled), (B) miR-132 antagomir (40 μM, 3 μl), or (C) miR-219 antagomir at CT 14. All subjects received a single light pulse (15 min, 20 lux) at CT 15. Periods of darkness are shaded in gray. Activity onsets are indicated by blue lines. Red asterisk denotes light pulse. The x-axis (top) indicates the Zeitgeber (ZT) time over a 24-hr cycle. The y-axis (left) indicates the nth day of the experiment. (D) Quantitation of the effects of miR-132 antagomir on CT 15 light-induced phase shifts. Values are presented as mean ± SEM phase shift (in min). n=8–12 per group. * p<0.01 (two-tailed Student’s t-test). (E) Knockdown of miR-132 expression. miR-132 antagomir (40 μM, 3 μl) was infused into the lateral ventricle at CT 14, and a brief light pulse (100 lux, 15 min) was administered at CT 15. SCN tissue was subsequently harvested at CT 17. Control subjects were infused with vehicle and/or did not receive a light treatment. Abundance of mature miR-132 was determined by RPA. Abundance of 5S rRNA was used as the loading control.