Localized CT-guided irradiation inhibits neurogenesis in specific regions of the adult XXXX brain.

@entity1 @entity10081 @entity19 @entity5 @entity7079 @entity2006
Radiation is used in the study of neurogenesis in the adult @entity19 both as a model for @entity1 undergoing radiation therapy for CNS @entity5 and as a tool to interrupt neurogenesis. We describe the use of a dedicated CT-guided precision device to irradiate specific sub-regions of the adult @entity19 brain. Improved CT visualization was accomplished with intrathecal injection of iodinated contrast agent, which enhances the lateral ventricles. T2-weighted MRI images were also used for target localization. Visualization of delivered beams (10 Gy) in tissue was accomplished with immunohistochemical staining for the protein y- @entity2006 , a marker of DNA double-strand breaks. y- @entity2006 stains showed that the lateral ventricle wall could be targeted with an accuracy of 0.19 mm (n = 10). In the hippocampus, y- @entity2006 staining showed that the dentate gyrus can be irradiated unilaterally with a localized arc treatment. This resulted in a significant decrease of proliferative neural progenitor cells as measured by Ki-67 staining (P < 0.001) while leaving the contralateral side intact. Two months after localized irradiation, neurogenesis was significantly inhibited in the irradiated region as seen with @entity10081 / @entity7079 double labeling (P < 0.001). Localized radiation in the rodent brain is a promising new tool for the study of neurogenesis.
