Table 1.
Chronology and selected major findings on the neurobiological impact of high dose ionising radiation.
| Year | IR type | Location | Total dose | Dose rate | Impact | Reference |
|---|---|---|---|---|---|---|
| 1896 | X-radiation | – | – | – | X-rays and radioactivity are first described, X-rays are first utilised medically in cancer treatment | H. Becquerel [13] W.C. Röntgen [14] |
| 1934 | X-radiation | Cranial | – | – | Fractionated cancer treatments utilising X-radiation, effective in head and neck cancer | H. Coutard [12] |
| 1964 | Alpha particles | Cranial | 60 Gy | 10 Gy/min | Activation of microglia present in the cortex 48 h post-irradiation, degeneration of myelin. Suggested the peroxidation of lipids after irradiation | Estable-Puig et al. [15] |
| 1994 | X-ray | Cranial | 10 Gy | 0.2 Gy/min | Mn-SOD activity reduced by 30% in cerebral cortex | Yamaoka et al. [119] |
| 2003 | X-ray, single | Cranial | 10 Gy | – | Neuroinflammation by activated microglia (CD68+/CD11b+) inhibits HC neurogenesis | Monje et al. [98] |
| 2007 | X-ray, single | Cranial | 4 Gy | 0.275 Gy/min | No microglial activation (Iba-1) and reversed proliferative capacity of HC progenitor cells after 1 week (Ki67) | Ben Abdallah et al. [97] |
| 2012 | γ-ray, single | In vitro | 10 Gy | 3.56 Gy/min | Alleviation of radiation-induced neuroinflammation via NF-κB and decreased ROS by application of PPARδ | Schnegg et al. [108] |
| γ-ray, single dose | In vitro | 10 Gy | 3.7 Gy/min | MEK/ERK/1/2 signalling cascade activated c-Jun, increases ROS and pro-inflammatory cytokines via NADPH | Deng et al. [49] | |
| γ-ray, single | Cranial | 2 Gy | 1.079 Gy/min | Upregulation of apoptosis inducible genes caspase-3 and caspase-7 | Otani et al. [138] | |
| 2013 | γ-ray, single 56Fe heavy ion, single | Whole body | 2 Gy | 1 Gy/min | Lipid peroxidation (MDA), oxidative stress, DNA DSBs, decreased DNA repair proteins, apoptosis and reduced cortical thickness | Suman et al. [114] |
| 2015 | γ-ray, single dose | Cranial | 2, 3, 5 Gy | – | Reduced Cu/Zn/MnSOD in HC and cortex | Todorović et al. [80] |
| 2016 | γ-ray, single | Whole body | 6 Gy | 0.456 Gy/min | Increased DNA DSBs, lipid peroxidation (MDA), reduced GSH and SOD activity. Ameliorated with pre-treatment of antioxidant agent | Ismail et al. [113] |
Abbreviations: Mn-SOD= Manganese superoxide dismutase, HC=hippocampus, ROS=reactive oxygen species, PPARδ=peroxisome proliferator-activated receptor delta, MDA=malondialdehyde, DSBs=double strand breaks, Cu/Zn-SOD= Copper/Zinc superoxide dismutase, GSH=glutathione