中年ICR小鼠学习记忆损害与血清甲状腺素的关系

研究中年ICR小鼠在新物体再认任务和六臂辐射状水迷宫(RAWM)中的学习记忆能力变化及其与血清甲状腺素(TH)的相关性。结果表明,新物体再认试验中12月龄与6月龄ICR小鼠间的成绩无显著性差异;RAWM中,12月龄小鼠较6月龄小鼠空间学习记忆能力减退;12月龄小鼠血清TH水平(FT3,FT4)低于6月龄小鼠,且FT3水平既与小鼠的空间性学习能力相关,又与记忆能力相关,而FT4仅与空间性学习能力相关。这些结果提示血清TH水平下降可能参与了中年ICR小鼠空间学习记忆能力减退。

Relationship between spatial cognitive impairment and the TH levels in middle-aged ICR mice

In the present study,age-related spatial cognitive ability of 41 ICR mices(12 mice aged 12 months,29 mice aged 6 months) was measured respectively in the novel-object recognition task and six-arm water maze(RAWM),followed by detection of the levels of free triiodothyronine(FT3) and free tetraiodothyronine(FT4).The results showed that in the novel-object recognition task,a non-spatial cognitive task,there was no difference between the two groups.In the RAWM,a spatial learning and memory task,the performance in the 6-month-old mice was better than that in the older mice.The levels of FT3 and FT4 in the 12-month-old mice were decreased compared with the 6-month-old mice.Interestingly,for all mice combined,the FT3 level was positively correlated with the spatial learning and memory ability in the RAWM,while the FT4 level was only related with spatial learning ability.These results suggested that decreased levels of thyroid hormones in middle-aged mice might be responsible for the impairment of spatial learning and memory.