The effects of cyclophosphamide on hippocampal cell proliferation and spatial working memory in rat.

Cyclophosphamide (CP) is a chemotherapy used in combinations that are associated with cognitive impairment. In the present study male Lister-hooded rats (n=12) were used to investigate the effects of chronic administration of CP (30mg/ kg, 7 i.v. doses, or an equivalent volume of saline) on performance in the novel location recognition (NLR) task and on the proliferation and survival of hippocampal cells. The survival of hippocampal cells dividing at the beginning of treatment was significantly reduced by CP. However, no difference was seen between CP treated and control groups for the number of cells proliferating 7 days after the final injection and both groups performed equally well in the NLR task. These results indicate that the given dose of CP acutely reduces the survival of newly born hippocampal cells. However, it does not have a longer term effect on spatial working memory or hippocampal proliferation, suggesting that CP is less neurotoxic than other chemotherapies with which it is used in combination.