外源性催产素对shank3缺陷斑马鱼成鱼社交行为的影响

 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。

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

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 shank3ab^-/- zebrafish through multiple pharmacologic means.Methods The shank3-deficient zebrafish model,carrying loss-of-function mutation in two shank3 paralogs (referred to shank3ab^-/-),was generated and maintained as previously described.The adult shank3ab^-/- 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 shank3ab^-/-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 mRNA level of oxytocin receptor (oxtr)gene was examined by real-time q-PCR of the whole brain of zebrafish.Results Single dose treatment:shank3ab^-/-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 shank3ab^-/- 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 shank3ab^-/- 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 shank3ab^-/- 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 mRNA level of oxtr gene.In addition,there was a rising trend in shank3ab^-/- 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.