HDAC inhibition attenuates upregulation of class I HDAC isoforms. After 60 min of OGD, levels of HDAC 1–3 expression were upregulated in all glial cell nuclei (arrowheads) and processes of astrocytes (arrows) in MON. Note that OGD upregulated HDAC 3 most strongly (lower middle panel). HDAC inhibition with SAHA (1 µM), applied 30 min before, during, and 30 min after OGD, considerably attenuated HDAC 1–3 upregulation in MON