Figure 2.

Treatment schemes for evaluation of okadaic acid and melatonin effects on dendritic arbors in rat hippocampal organotypic slice cultures. Hippocampal slices (400 µm) were stabilized for one week after mechanical injury due to slicing procedure. The upper inserts depict the treatments applied at the 8th day in culture. A gray discontinuous line represents the stabilization period, whereas continuous lines indicate the different treatments (5 slices/treatment). Vehicle is shown in black (VEH, 0.00004% ethanol), 45 nM okadaic acid (OKA) in blue, and 100 nM melatonin (MEL) in pink. After the incubation time (6 or 8 h), slices were fixed as described in the methods section and 50 µm cryosections were either processed for fluorometric terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and DAPI nuclei counterstaining or for MAP2 staining by immunohistochemistry.