Peng Shuang, Yang Bo, Duan Meng Yun, Liu Zi Wei, Wang Wei Feng, Zhang Xiang Zhi, Ren Bo Xu, Tang Feng Ru
Health Center of Yangtze University, Jingzhou, Hubei, China.
Department of Medical Imaging Center, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China.
Dose Response. 2019 Jan 7;17(1):1559325818822574. doi: 10.1177/1559325818822574. eCollection 2019 Jan-Mar.
The effect of acute X-ray irradiation with 2 Gy or fractionated exposure with 0.2 Gy continuously for 10 days (0.2 Gy × 10 = 2 Gy) was evaluated in the postnatal day 21 (P21) BALB/c mouse model. Both acute and fractionated irradiation induced impairment of cell proliferation and neurogenesis in the subgranular zone of the dentate gyrus labeled by Ki67 and doublecortin, respectively. Parvalbumin immunopositive interneurons in the subgranular zone were also reduced significantly. However, the 2 patterns of irradiation did not affect animal weight gain when measured at ages of P90 and P180 or 69 and 159 days after irradiation. Behavioral tests indicated that neither acute nor fractionated irradiation with a total dose of 2 Gy induced deficits in the contextual fear or spatial memory and memory for novel object recognition. Animal motor activity was also not affected in the open-field test. The disparity of the impairment of neurogenesis and unaffected cognition suggests that the severity of impairment of neurogenesis induced by acute or fractionated irradiation with a total dose of 2 Gy at P21 may not be worse enough to induce the deficit of cognition.
在出生后第21天（P21）的BALB/c小鼠模型中，评估了2 Gy的急性X射线照射或连续10天每天0.2 Gy（0.2 Gy×10 = 2 Gy）的分次照射的效果。急性照射和分次照射均分别导致齿状回颗粒下区中由Ki67和双皮质素标记的细胞增殖和神经发生受损。颗粒下区中帕瓦丁免疫阳性中间神经元也显著减少。然而，在P90和P180龄时（即照射后69和159天）测量动物体重增加时，这两种照射模式均未产生影响。行为测试表明，总剂量为2 Gy的急性照射或分次照射均未在情境恐惧、空间记忆或新物体识别记忆方面诱发缺陷。在旷场试验中，动物的运动活动也未受影响。神经发生受损与认知未受影响之间的差异表明，在P21时总剂量为2 Gy的急性或分次照射所诱发的神经发生受损严重程度可能不足以导致认知缺陷。
