Expression of neuronal migration-related factors and the spatial learning and memory of rats prenatally exposed to tritiated water / 中华放射医学与防护杂志

ABSTRACT

Objective@#To study the expression of neuronal migration-related factors and spatial learning and memory of rats exposed to tritiated water (HTO).@*Methods@#Hippocampal neural cells from newborn Sprague-Dawley(SD) rats at postnatal 24 h were primarily cultured in DMEM/F12 medium with 20% of fetal bovine serum for 6 days, followed by subjection to tritiated water(HTO) at concentrations of 3.7×102, 3.7×103, 3.7×104, 3.7×105, 3.7×106 Bq/ml for 24 h, respectively. Western blot and RT-qPCR were used to determine the expression levels of F-actin, α-tubulin, tau, AP2, BDNF mRNA and Reelin mRNA. 16 pregnant SD rats at embryonic (E) day 14 were randomly divided into the tested and control groups (8 rats/ each group). The tested rats were injected with body fluid of HTO (3.7×106 Bq/g) intraperitoneally, while the saline as the control. Morris water maze (MWM) was employed for the spatial learning and memory of rats.@*Results@#Compared to the control cells, HTO caused a significant downregulation of expressions of cytoskeletal proteins [F-actin (t=8.898-19.896, P<0.05), α-tubulin (t=3.261-7.900, P<0.05), tau (t=2.274-5.003, P<0.05), and MAP2 (t=2.274-5.003, P<0.05)] and mRNA of BDNF(t=3.580-19.792, P<0.05) and Reelin (t=3.240-39.692, P<0.05) in the tested neural cells in a dose-dependent manner. In addition, the escape latency of irradiated offsprings was significantly prolonged (t=-2.563, P<0.05), the time for offsprings to cross through target quadrant was markedly reduced (t=3.214, P<0.05), and the swimming time in the platform quadrant of irradiated offsprings were obviously shortened (t=3.874, P<0.05) in the MWM trial.@*Conclusions@#The results indicate that HTO irradiation in utero downregulates the expressions of neuron migration-related factors and induces brain dysfunction, which may shed a light on a mechanism of the radiation-induced brain impairment.