Background: Controversial results were reported on the effect‌ of exercise on the histology of hippocampal dentate gyrus (DG) in pentyleneterazole-(PTZ) kindled animals. The purpose of this study was to examine the effect of physical exercise on the histology of hippocampal DG in kindled rats.

Materials and Methods: In this experimental study, 40 adult male Wistar rats were randomly divided into four equal groups: control without exercise, PTZ without exercise, control + exercise and PTZ + exercise groups. After a 6 week-period training, the rats were deeply anesthetized and sacrificed and then their brains dissected out and fixed in formalin (10%). After tissue processing and sectioning, the samples were stained. An immunohistochemical method was used to determine the rate of cell death in hippocampal neurons.

Results: Results showed that a 6 week-period training significantly increased the mean number of normal cells in DG in the PTZ + exercise group compared to the PTZ without exercise group. Moreover, the mean number of normal cells in DG in the control + exercise group was significantly increased compared to the control without exercise group. The rate of cell death of DG neurons in PTZ groups was increased significantly compared to the other groups.

Conclusion: Experimental seizure using PTZ-kindling method can decrease the number of normal cells in DG neurons of hippocampus, while exercise delays the morphological changes of DG cells.