Our present study also proves that stress causes pathological and morphological changes in the hippocampus, which is consistent with prior studies that show that several brain related issues, such as stress, seizure, ischemia, and hypoglycemia, alter BDNF expression in the central nervous system (Yan et al., 1997; Tapia-Arancibia et al., 2004). This evidence concerns the gene BDNF and ischemia.