Effects of Low Level Radiation Exposure on Neurogenesis and Cognitive Function: Mechanisms and Prevention.

摘要

Studies were carried out to investigate the radiation response of neural precursor cells in vitro and in vivo, to determine the role of reactive oxygen species (ROS) in the reactions of those cells, and to determine if antioxidant treatment could modify those responses. Our data show that proliferating precursor cells and their progeny are extremely sensitive to low/moderate x-ray doses (2-10 Gy), and that ROS play a major role in the sensitivity on these cells and may act in concert with p53 and cell cycle- dependent processes. In addition, conditions of reduced cell density, such as that seen after radiation exposure of the dentate subgranular zone, are associated increased ROS, which may stimulate proliferation in surviving cells. Modulating ROS using antioxidant compounds may provide a means to control proliferation in damaged cells allowing for repair and recovery after radiation injury. We have begun to address specific mechanistic factors that are not only associated with oxidative processes, but that may provide additional targets for interventional treatment. The ability to ameliorate the radiation effects on neural precursor cells may provide a potential protective strategy for individuals exposed-to unplanned exposure to low/moderate doses of irradiation.