OBJECTIVEThis study aimed to determine whether pentylenetetrazol-induced status epilepticus (SE) can induce dentate granule cell neurogenesis in the developing rat and the effect of MK-801, a noncompetitive antagonism of N-methyl-D-aspartate receptor (NMDAR), on neurogenesis.

METHODSTwo hundred and sixteen postnatal days 7, 14, 21 or 28 Sprague Dawley (SD) rats were involved in this study. Each age group consisted of 54 rats which were randomly assigned into a SE group, a SE + MK-801 group and a Normal control group (n=18 each). SE was induced by intraperitoneal injection of PTZ (80 mg/kg). The SE + MK-801 group was injected intraperitoneally with MK-801 (1 mg/kg) at 1 hr after SE episode. All rats were given 5-bromodeoxyuridene (BrdU) intraperitonealy to label newborn cells at 6, 13 and 27 days after seizures and then were sacrificed 24 hrs after BrdU injection. The immunohistochemistry method was used to measure the expression of BrdU, TuJl (betaIII tubulin), and glial fibrillary acidic protein (GFAP) in the dentate gyrus of hippocampus of rats.

RESULTSThe number of the BrdU positive cells in the SE group was significantly higher than in the age-matched normal controls at 7 and 14 days after SE episode (P <0.05 or 0.01). Approximately 82.5% and 80.3% of BrdU-labeled cells in the SE and the Control groups were co-expressed TuJ1 respectively. MK-801 treatment decreased the BrdU positive cells compared with the SE group at 7 and 14 days after SE seizures (P < 0.01). On the 28th day after SE episode there were no differences among the three groups for the BrdU positive cells.

CONCLUSIONSPTZ-induced SE can increase the dentate granule cell neurogenesis in the developing rat. NMDAR plays an important role in neurogenesis following seizures.