外源性催产素对shank3缺陷斑马鱼成鱼社交行为的影响

Effects of exogenous oxytocin on social behaviors in the shank3 deficient zebrafish

目的通过注射外源性催产素对shank3缺陷(shank3ab-/-)斑马鱼成鱼进行药物干预,检测不同疗程的催产素对shank3ab-/-斑马鱼社交偏好缺陷行为的影响。方法利用已构建成功的shank3ab-/-斑马鱼成鱼及野生型斑马鱼成鱼,在其尾鳍肌肉处注射外源性催产素或生理盐水,分别进行单次注射、短期给药疗程和长期给药疗程的实验。适应15 min后,通过30 min的社交偏好实验,检测斑马鱼的社交行为,进而评估外源性催产素的疗效。通过实时荧光定量PCR检测斑马鱼脑部催产素受体(oxytocin receptor,oxtr)的mRNA水平。结果外源性催产素单次注射给药的结果显示:注射催产素30 min后,shank3ab-/-催产素组在伙伴侧游动的平均距离比显著高于shank3ab-/-生理盐水组(0.96±0.015 vs.0.86±0.042,P=0.013);注射催产素45 min后,shank3ab-/-催产素组在伙伴侧游动的距离高于shank3ab-/-生理盐水组,但差异无统计学意义。催产素7天短期给药疗程的结果显示:shank3ab-/-催产素组在伙伴侧游动的距离比明显高于shank3ab-/-生理盐水组(0.94±0.015 vs.0.88±0.018,P=0.006),疗效可持续12 h;催产素长期给药疗程的结果显示:给药14天后间隔1个月对斑马鱼进行行为学检测,发现shank3ab-/-催产素组与shank3ab-/-生理盐水组的社交偏好差异无统计学意义。外源性催产素单次给药后,野生型催产素组和野生型生理盐水组相比,oxtr基因mRNA水平显著上升(P<0.001);相比于shank3ab-/-生理盐水组,shank3ab-/-催产素组的oxtr基因mRNA水平也有上升趋势,但差异无统计学意义。结论应用外源性催产素对shank3缺陷斑马鱼的社交偏好缺陷行为具有潜在的改善作用,改善的持续时间与给药疗程相关。

Objective To study the role of exogenous oxytocin on social behaviors of a shank3 deficient zebrafish model,and to observe the effects of exogenous oxytocin on adult shank3 ab-/-zebrafish through multiple pharmacologic means.Methods The shank3-deficient zebrafish model,carrying loss-offunction mutation in two shank3 paralogs(referred to shank3 ab-/-),was generated and maintained as previously described.The adult shank3 ab-/-zebrafish and wild-type(WT)zebrafish were used in this study.The exogenous oxytocin and 0.9%normal saline were administered by intramuscular(i.m.)injection in the zebrafish caudal fin.WT zebrafish and shank3 ab-/-zebrafish were treated through three kinds of pharmacologic means:an acute single dose,a single-round short-term administration,and a long-term treatment.Social preference test was performed to evaluate the curative effect of exogenous oxytocin 15 min after injection.The m RNA level of oxytocin receptor(oxtr)gene was examined by real-time q-PCR of the whole brain of zebrafish.Results Single dose treatment:shank3 ab-/-zebrafish,treated with exogenous oxytocin(an acute single dose),showed significant improvement in the social interaction(0.96±0.015 vs.0.86±0.042,P=0.013)within 30 min after administration.We assessed the timeliness of acute exogenous oxytocin effect on social preference with social preference test and observed that social behaviors in shank3 ab-/-zebrafish model was also improved after 45 min.Though the differences didn’t reach statistically significance.Short-term treatment(once daily for 7 days):The group of short-term treatment showed that the distance ratio in the conspecific sector in shank3 ab-/-zebrafish receiving daily OXT administration was significant higher than those receiving saline(0.94±0.015 vs.0.88±0.018,P=0.006).The effects lasted more than 12 h after cessation of treatment.Long-term treatment(i.m.,once daily for 2 weeks):The results of long-term treatment showed that the abnormal sociability in shank3 ab-/-zebrafish receiving daily oxytocin administration wasn’t changed significantly when tested one month later.The experiment of single-dose group showed that,compared to WT control(receiving saline),WT zebrafish receiving acute single dose of oxytocin showed a significant increase(P<0.001)in m RNA level of oxtr gene.In addition,there was a rising trend in shank3 ab-/-zebrafish receiving acute single dose of oxytocin.Conclusion Exogenous oxytocin rescues social preference deficits in the shank3-deficient zebrafish model.The timeliness for therapeutic efficacy of the abnormal sociability correlated with the courses of treatment.