Pentetrazole Repeated Kindling Influences Hippocampal Neurogenesis In Developing Rats And Its Mechanisms

Objection Investigate the effect on neurogenesis of hippocampus and the role of NF-κB after pentetrazole repeated kindling in developing rats.Methods 10-day-old Wistar rats(n=72) were prepared for epilepsy model. They were divided into three groups at random. The PTZ(pentetrazole) group(n=24) were induced seizure by intraperitoneally inject pentetrazole repeatly. The PDTC+PTZ group(n=24) were intraperitoneally injected pyrrolidine dithiocarbamate (PDTC, an inhibitor of NF-κB) before kindling. The control group(n=24) received 0.9% NaCl. We used Bromodeoxyuridine(BrdU) labeling to investigate neurogenesis in dentate gyrus. Thionin stain was utilized to observe morphological changes and cell counts of hippocampus. NF-κB expression and BrdU positive cells was examined by immuno- histochemistry assay. Timm's method of silver sulfide staining was adopted to observe the mossy fiber sprouting.Result 1. 24 hours after the model completed in PTZ group, the NF-κB express in hippocampus are significantly higher than PDTC+PTZ group and control group(P<0.01); 2. Three days after the model completed in PTZ group, the CA3, CA1 and hilar cells count have no significant difference comparing with control group, the dentate gyrus cells count(63.13±5.44)/0.1mm2 is significantly higher than control group(50.25±6.34)/0.1mm2 (P<0.05);In PDTC+PTZ group hippocampus cells count is significantly lower than PTZ group(P<0.05), the dentate gyrus cells count have no significant difference comparing with control group. 3. The BrdU positive cells in dentate gyrus in PTZ group(175.86±9.20)and PDTC + PTZ group ( 150.75±12.97 ) are significantly higher than control group(131.50±13.33)(P<0.01), but in PDTC+PTZ group BrdU positive cells count is significantly lower than the PTZ group(P<0.01). 4. One month after the model completed, there are mossy fiber sprouting in both PTZ and PDTC+PTZ group, the degrees of sprouting have no significant differences between the two groups. The control group has no significant mossy fiber sprouting.Conclusion 1.Pentetrazole repeated kindling can promote neurogenesis in hippocampus of developing rats. 2. NF-κB is involved in the mechanism of neurogenesis in hippocampus. 3. NF-κB protects neurons.