Radiation effects on neurogenic regions in the mammalian forebrain

Radiotherapy is a major treatment modality for intracranial tumors, and while it is effective, it can cause serious normal tissue injury. Such injury can involve tissue destruction but can also manifest as cognitive impairments. The pathogenesis of radiation-induced cognitive injury is not well-understood but may involve forebrain neurogenesis. Neurogenic cells are very sensitive to irradiation and undergo apoptosis after clinically relevant doses. While the overall effect of irradiation on neurogenesis is based partly on the intrinsic radiation sensitivity of neural precursor cells, it also involves changes in the microenvironment in which they exist. This review summarizes what is known about ionizing irradiation and neurogenesis and provides insight into some approaches that may be effective in mitigating this particular adverse effect of radiation treatment.