早期环境干预对脑损伤仔鼠脑神经丝蛋白表达的影响

Effect of Early Environment Intervention on Expression of Neurofilament Protein in Brain of Filial Rats with Brain Injury

目的观察早期环境干预对宫内感染致脑损伤仔鼠脑组织神经丝蛋白(NFP)的表达及对其神经行为的影响。方法孕第17天的孕鼠腹腔注射脂多糖(LPS)450μg/(kg·d),连续2d,建立感染性脑损伤仔鼠模型(LPS组);对照组腹腔注射同等剂量的9g/L盐水。孕22d前分娩的仔鼠为早产鼠,二组均去除早产鼠。仔鼠出生后,立即取孕鼠子宫胎盘行HE染色观察宫内感染情况;仔鼠出生24h,随机选取对照组和LPS组仔鼠脑组织,常规HE染色,观察脑白质损伤情况。LPS组足月产仔鼠随机分为干预组与非干预组,干预组于仔鼠出生8d起进行早期抚触和丰富环境刺激;对照组和非干预组常规饲养。仔鼠出生21d采用悬吊试验进行神经行为学检测;应用免疫组织化学方法对各组仔鼠脑组织NFP阳性染色进行分析。结果LPS组胎盘病理检测可见腹腔注射LPS造成的宫内感染;1d仔鼠脑白质结构稀疏。对照组悬吊试验得分最高,干预组次之,非干预组最低,两两比较差异均有统计学意义(Pa<0.01)。NFP的阳性表达在对照组最高,干预组其次,非干预组最低;两两比较差异均有统计学意义(Pa<0.01)。结论早期环境干预可促进宫内感染致脑损伤的恢复,NFP表达增加是其可能的机制之一。

Objective To explore the effect of early enriched environment intervention on expression of neurofilament protein （NFP） in brain and the neurobehavior of filial rats with brain injury.Methods The pregnant Wistar rats of lipopolysaccharide （LPS） group were consecutively injected intraperitoneally with LPS on the 17th and 18th day of gestation while the control group only received an injection of same dose of 9 g/L saline.All premature rats,whose gestational age was less than 22 days,were removed from both groups;While the full-term newborn rats were chosen.After delivering,the uterus and placenta were taken out immediately to examine the infection situation by HE staining.Twenty-four hours after born,the brains of the newborn rats were taken out to observed the white matter damage by HE staining.LPS group was randomly divided into 2 groups：intervention group and non-intervention group.The intervention group was treated with neonatal handling and enriched environment from postnatal 8 days,while no management was performed in control group and non-intervention group.Ethological examination was tested with hanging test,and immunohistochemical technique was used to detect the expression of NFP,when the neonatal rats were 21 days old.Results There were a large amount of neutrophilic granulocyte in the uterus and placenta in LPS-treated group; In the 1-day-old rats in LPS group,brain tissue pathology test showed diffuse white matter lucencies.The scores of hanging test in control group was the highest,the ones in non-intervention group was the lowest among the 3 groups,and there was significant difference between them （Pa〈0.01）.NFP immunoreactivity in the white matter in control group was the most and the one in the non-intervention group was the lest among them,and the difference between them was also significant （Pa〈0.01）.Conclusion Early environment intervention may promote the recovery of the brain injury caused by intrauterine infection,which may result from its up-regulating the expression of NFP.