Fig. 5. Effect of a single systemic injection of NMDA on the number of BrdU⁺ cells in the subgranular zone of the dentate gyrus 3 days and 28 days after administration. Diagrams show the way animals were treated (see Materials and Methods); arrows indicate drug application; arrowheads indicate BrdU detection. (A,B) Stereoscopic 3D-counting revealed that treatment with NMDA (100 mg/kg) decreased the number of BrdU⁺ cells (red) when analyzed 3 days after treatment, whereas MK801 (50 mg/kg) increased it (saline, 8758±883 cells/mm³; NMDA, 5720±510 cells/mm³; MK801, 11,503±456 cells/mm³, n=11 animals in each group). (C,D) Twenty-eight days after treatment, NMDA application resulted in an increase in the number of BrdU⁺ cells, whereas MK801 produced a decrease (saline, 3048±417 cells/mm³; NMDA, 4669±455 cells/mm³, MK801, 1657±124 cells/mm³, n=12 animals in each group). All cells were counterstained with DAPI (blue). Bar, 100 µm. Data are presented as the mean ± s.e.m. ^*P<0.05, ^**P<0.01.