Effects of Aging on Hippocampal Neurogenesis After Irradiation
- Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)
Purpose: To assess the influence of aging on hippocampal neuronal development after irradiation (IR). Methods and Materials: Male mice, 2, 4, 6, 12, and 18 months of age, were given a single dose of 0 or 5 Gy of IR. A bromodeoxyuridine (BrdU) incorporation study was used to label newborn cells. Neural progenitors, newborn neurons, and microglia in dentate gyrus (DG) were identified by phenotypic markers, and their numbers were quantified by nonbiased stereology 9 weeks after IR. Results: BrdU-positive or newborn cells in DG decreased with aging and after IR. The number of neuroblasts and newborn neurons decreased with aging, and a further significant reduction was observed after IR. Total type 1 cells (the putative neural stem cells), and newborn type 1 cells decreased with aging, and further reduction in total type 1 cells was observed after IR. Aging-associated activation of microglia in hippocampus was enhanced after IR. Conclusions: The aging-associated decline in hippocampal neurogenesis was further inhibited after IR. Ablation of neural progenitors and activation of microglia may contribute to the inhibition of neuronal development after IR across all ages.
- OSTI ID:
- 22645161
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 94; ISSN IOBPD3; ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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