Xstrahl in action: Behavioural Effects of Focal Irradiation in a Juvenile Murine Model
Chemotherapy has been successfully used to reduce radiation dose and volume for most paediatric patients. However, because of the failure of chemotherapeutic agents to cross the blood-brain barrier and the lack of response of some brain tumours to these agents, radiation therapy is still used to treat many childhood cancers with CNS involvement.
In their study “Behavioural Effects of Focal Irradiation in a Juvenile Murine Model” Alexander TC, Butcher H, Krager K, Kiffer F, Groves T, Wang J, Carter G and Allen AR investigate the radiation effects on cognition and dendritic structure in the hippocampus in juvenile male mice.
Twenty-one-day-old male C57BL/6 mice were irradiated using the small animal radiation research platform (SARRP). Animals were exposed to either a 10 Gy single dose or 10 Gy × 2 fractionated doses of X-ray cranial radiation. Five weeks after irradiation, animals were tested for hippocampus-dependent cognitive performance in the Morris water maze.
Significant impairment in spatial memory retention was observed in the probe trial after the first day of hidden-platform training (first probe trial) in animals that received either 10 Gy single-dose or 10 Gy × 2 fractionated doses. However, by day 5, mice that received a 10 Gy single dose showed spatial memory retention in the probe trials, whereas mice that received the 20 Gy fractionated doses remained impaired. During Y-maze testing, animals exposed to radiation were impaired; the irradiated mice were not able to distinguish among the three Y-maze arms and spent approximately the same amount of time in all three arms during the retention trial.
It was concluded that radiation significantly compromised the dendritic architecture and reduced spine density throughout the hippocampal trisynaptic network.