目的：有研究表明甲状腺功能减退大鼠学习、记忆功能的损伤与神经元局部三碘甲状腺原氨酸（triiodothyronine,T3）缺乏有关。该研究探讨左旋三碘甲状腺原氨酸（L-T3）对新生小鼠兴奋毒性脑损伤后学习、记忆行为的影响。方法：5日龄ICR种小鼠71只，用鹅膏蕈氨酸（ibotenic acid，IA）建立兴奋毒性脑损伤模型，随机分为磷酸盐缓冲液（PBS）组（n=14,脑内及腹腔注射PBS 10 mL/kg）、IA组（n=14,脑内注射IA+腹腔注射PBS 10 mL/kg）、低剂量T3组（n=14,脑内注射IA+腹腔注射L-T3 0.2 μg/kg）、中剂量T3组（n=15,脑内注射IA+腹腔注射L-T3 0.5 μg/kg）、高剂量T3组（n=14,脑内注射IA+腹腔注射L-T3 1 μg/kg）。腹腔注射时间为小鼠脑内注射后1、24、48、72、96 h。小鼠于生后第33、34天进行Y-迷宫分辨学习实验。结果：PBS组、IA组、低、中、高剂量L-T3组小鼠学会所需次数分别为15.0±4.7、21.3±6.3、20.5±6.0、21.0±6.5、15.8±4.5，高剂量L-T3组小鼠“学会”所需次数明显低于IA组和中、低剂量L-T3组（P<0.05）；记忆正确率分别为(90.7±7.3)%、(79.3±10.0)%、(77.9±14.2)%、(80.7±12.2)%、(91.4±9.5)%，高剂量L-T3组小鼠记忆正确率明显高于IA组和中、低剂量L-T3（P<0.05）。结论：高剂量L-T3（1 μg/kg）能促进兴奋毒性脑损伤小鼠的学习记忆行为。［中国当代儿科杂志，2010，12（4）：284-286］

OBJECTIVE: Some research has shown that learning and memory function impairments in rats with hypothyroidism are associated with triiodothyronine (T3) deficiency in neurons. This study aimed to investigate the effects of L-T3 administration on learning and memory behaviors in neonatal mice with excitotoxic brain damage. METHODS: Seventy-one 5-day-old ICR neonatal mice were randomly assigned to five groups: controls that received intracerebral and intraperitoneal injections of phosphate buffered saline (PBS) (n=14); a group that received intracerebral injections of ibotenic acid (IA) and intraperitoneal injection of PBS (n=14); 3 groups that received intracerebral injections of IA and intraperitoneal injection of L-T3 at 0.2, 0.5, and 1 μg/kg, respectively (n=14-15). Intraperitoneal injections were done 1, 24, 48, 72 and 96 hrs after intracerebral injections. Learning and memory functions were evaluated by the Y-maze discrimination learning test on postnatal days 33-34. RESULTS: The learning and memory functions in the highest L-T3 dose group were significantly better than those in the IA, and the lower L-T3 dose groups, presenting with decreased number of trials to criterion ［15.8±4.5 vs 21.3±6.3 (IA group), 20.5±6.0 (0.2 μg/kg L-T3 group) or 21.0±6.5 (0.5 μg/kg L-T3 group); P<0.05］, and achieving a higher correct percentage ［91.4±9.5% vs 79.3±10.0% (IA group), 77.9±14.2% (0.2 μg/kg L-T3 group) or 80.7±12.2% (0.5μg/kg L-T3 group); P<0.05］. CONCLUSIONS: High-dose L-T3 (1 μg/kg) may improve learning and memory functions in mice following excitotoxic brain damage.［Chin J Contemp Pediatr, 2010, 12 (4):284-286］