Fig. 4

Neonatal ketamine exposure interfered with the functional integration of developmentally generated neurons into the hippocampal DG circuits during the adult stage. High magnification examples of c-Fos (blue), NeuN (Green) and BrdU (Red) immunofluorescences in the DG were captured by using a laser scanning confocal microscope, following the Morris Water Maze testing (a; magnification: a–h  × 40); the scale bar was 50 μm. The arrowheads point to the NeuN/BrdU double-positive cells. The filled arrows point to the c-Fos/NeuN/BrdU triple-positive cells. Ketamine could significantly decrease the density of triple-positive cells in the hippocampal DG (c), and the percentage of double labeled cells that were also triple labeled was reduced in the ketamine group (d). The percentage of NeuN/BrdU-positive cells that expressed c-Fos in the GCL was decreased in the ketamine group (e). Data are presented as the mean ± SD, 5 tissue sections per group. ^*P < 0.05, ^**P < 0.01 vs the control group. GCL granule cell layer, SGZ subgranular zone, ML molecular layer, PCL polymorphic cell layer