ABSTRACT
Objective To investigate the effects of low dose radiation on dendritic growth of newborn neurons in the hippocampus of young rat.Methods One month-old male rats were randomized into radiation group aind sham control group.Radiation group received whole brain irradiation at a single dose of 2 Gy.Retrovirus expressing green fluorescent protein (GFP) was used to label newborn neurons in the hippocampus through stereotaxic intracranial infusion.Immunofluorescence assays were performed to detect dendritic architecture alterations induced by irradiation at different time points.Results Compared with control group,the lengths of total dendrite and the longest dendrite significantly decreased at 2 and 4 weeks after irradiation (t =3.10,2.07,2.94,4.02,P ＜ 0.05).The branching points of new born neurons were also decreased significantly at 2 weeks post irradiation (t =2.23,P ＜ 0.05).The number of new born neurons reduced at 4 weeks post irradiation (t =8.43,P ＜ 0.05).Conclusions Low dose radiation could inhibit newborn neuron growth in the hippocampus of young rat,which may be one of the most important mechanisms involved in radiation-induced cognitive impairment.