桃叶珊瑚苷改善孕期艾司氯胺酮暴露诱发子代小鼠注意缺陷多动障碍的机制:缰核GABA能神经元

Mechanism of aucubin improving attention deficit hyperactivity disorder induced by maternal exposure to S-ketamine in offspring mice:GABAergic neurons in habenular nucleus

目的评价桃叶珊瑚苷改善孕期艾司氯胺酮暴露诱发子代小鼠注意缺陷多动障碍(ADHD)的机制与缰核GABA能神经元的关系。方法SPF级健康C57BL/6野生型孕鼠,于孕中晚期腹腔注射艾司氯胺酮建立子代小鼠ADHD模型。取艾司氯胺酮暴露孕鼠的子代小鼠24只,于出生后14 d时,采用随机数字表法分为2组(n=12):ADHD+生理盐水组(AN组)和ADHD+桃叶珊瑚苷组(AA组)。取非艾司氯胺酮暴露孕鼠的子代小鼠24只,于出生后14 d时,采用随机数字表法分为2组(n=12):对照+生理盐水组(CN组)和对照+桃叶珊瑚苷组(CA组)。CA组和AA组腹腔注射桃叶珊瑚苷40 mg/kg,1次/d,连续7 d;CN组和AN组以等容量生理盐水替代。出生后14 d时,于缰核区置入16通道微丝阵列电极,记录小鼠在埋珠实验中掩埋珠子时缰核兴奋性神经元/抑制性神经元数量比值。于出生后21 d(腹腔给药结束后)时,行O形高架迷宫实验和埋珠实验分别评估子代小鼠冲动及刻板样行为,随后采用免疫荧光法检测缰核谷氨酸脱羧酶2(GAD2)的表达。结果与CN组比较,AN组缰核兴奋性神经元/抑制性神经元数量比值升高,GAD2表达下调,开放臂停留时间延长,进入开放臂次数和掩埋珠子数量增多(P<0.05),CA组上述指标差异无统计学意义(P>0.05);与AN组比较,AA组缰核兴奋性神经元/抑制性神经元数量比值降低,GAD2表达上调,开放臂停留时间缩短,进入开放臂次数和掩埋珠子数量减少(P<0.05)。结论桃叶珊瑚苷改善孕期艾司氯胺酮暴露诱发子代小鼠ADHD的机制,可能与增加缰核GABA能神经元数量有关。

ObjectiveTo evaluate the relationship between the mechanism by which aucubin improved attention deficit hyperactivity disorder(ADHD)induced by maternal exposure to S-ketamine and GABAergic neurons in the habenular nucleus of offspring mice.MethodsSPF healthy C57BL/6 wild-type pregnant mice were used in this study,and an ADHD model in offspring mice was established by intraperitoneally injecting S-ketamine in the middle and late pregnancy.Twenty-four offspring of pregnant mice exposed to S-ketamine were divided into 2 groups(n=12 each)at 14 days after birth using a random number table method:ADHD+normal saline group(AN group)and ADHD+aucubin group(AA group).Twenty-four offspring of pregnant mice exposed to normal saline were divided into 2 groups(n=12 each)at 14 days after birth by a random number table method:control+normal saline group(CN group)and control+aucubin group(CA group).Aucubin 40 mg/kg was intraperitoneally injected once a day for 7 consecutive days in CA group and AA group,and the equal volume of normal saline was given instead in CN group and AN group.At 14 days after birth,the 16-channel microfilament array electrode was placed in the habenular nucleus,and the ratio of excitatory neurons to inhibitory neurons in the habenular nucleus was recorded when the mice buried beads in the marble burying test.At 21 days after birth(after the end of peritoneal administration),the impulsive and stereotypical behaviors of offspring mice were evaluated by elevated zero maze and marble burying test,respectively,and then the expression of glutamate decarboxylase 2(GAD2)in habenular nucleus was detected by the immunofluorescence method.ResultsCompared with CN group,the ratio of excitatory neurons to inhibitory neurons in the habenular nucleus was significantly increased,the expression of GAD2 was down-regulated,the time spent in the open arm was prolonged,the number of entries into the open arm and the number of buried beads were increased in AN group(P<0.05),and no statistically significant differences were found in the above indexes in CA group(P>0.05).Compared with AN group,the ratio of excitatory neurons to inhibitory neurons in the habenular nucleus was significantly decreased,the expression of GAD2 was up-regulated,the time spent in the open arm was shortened,and the number of entries into the open arm and the number of buried beads were decreased in AA group(P<0.05).ConclusionsThe mechanism by which aucubin alleviates prenatal S-ketamine exposure-induced ADHD may be related to increasing the number of GABAergic neurons in the habenular nucleus of offspring mice.