In short, cortical tissue was placed in 1 ml of cold nuclei extraction buffer (.32 M sucrose, 5 mM CaCl2, three mM Mg(Ac)2, .1 mM EDTA, ten mM Tris-HCl and .1% Triton X-100) with 10 μl of protease inhibitor cocktail (Sigma-Aldrich, P8340), 1 μl of 100 mM phenylmethylsulfonyl fluoride (PMSF Sigma-Aldrich, 78830), one μl of 1 M 1,4-dithiothreitol (DTT Sigma-Aldrich, D9779) and three μl of 40 U μl−1 mRNase inhibitor (Promega, N2611).