母爱剥夺对大鼠海马PP1Cγ表达与神经发育的影响

目的 探讨母爱剥夺(MD)对PP1Cγ的表达改变和神经发育的影响.方法 新生雄性仔鼠随机分为MD组(35只)和正常对照组(24只),MD组在出生后1～21 d每天接受3h的MD.通过早期神经行为实验观察神经发育情况,水迷宫实验观察学习记忆的影响,实时荧光定量PCR分析PP1Cγ的基因表达改变.结果 MD能改变大鼠体质量、上肢运动协调能力和大鼠痛觉敏感性[(26.23±2.81)g,(30.38±3.85)g;(19.37±11.89)s,(22.39±17.62)s;(4.36±1.76)s,(5.26±2.55)s;P＜0.05],对神经反射影响较小[(0.83±0.30)s,(0.83±0.34)s;(3.68±1.63)s,(5.61±3.01)s;(3.00±0.00),(3.00±0.00);P＞0.05],对学习记忆能力影响不明显(P＞0.05).在出生后第22天MD可致海马PP1Cγ表达下降[(2.19±0.62),(3.52±0.86);P＜0.05],在出生后60d大鼠PP1Cγ表达无明显改变[(1.73±0.78),(1.33±0.34);P＞0.05],而在出生后第90天海马PP1Cγ表达升高[(2.85±0.34),(1.34±0.93);P＜0.05].结论 MD可致大鼠早期神经行为和海马PP1Cγ的表达发生改变,但对学习记忆的影响却很小.同时PP1Cγ表达随生长发育时期的不同而改变.

Abstract：

Objective To investigate the effect of maternal deprivation (MD) on neurobehavior and PP1Cγgene expression in hippocampus. Methods Male pups were randomly divided into MD group(thirty-five)and control group(twenty-four). From PND 1 to PND 21 ,pups in the MD groups underwent daily maternal deprivation for 3 h ( Postnatal day). Neurobehavior was observed to investigate neurodevelopment, Morris water maze was used to measure spatial learning and memory,and Real-Time quantitative PCR was employed to analyze PP1Cγ gene expression. Results Several significant deficiencies were observed in bodyweight and grasping reflex while a great enhancement in hot-plate test in rat pups suffering from MD( (26.23 ± 2.81 )g vs. (30. 38 ± 3.85 )g;( 19.37 ± 11.89) s vs. (22.39 ± 17.62 ) s; (4.36 ± 1.76 ) s vs. ( 5.26 ± 2.55 ) s; P ＜ 0. 05 ), but deficiencies in neurological reflexes were subtle ( ( 0.83 ±- 0.30 ) s vs. ( 0. 83 ± 0. 34 ) s; ( 3.68 ± 1.63 ) s vs. ( 5.61 ± 3. 01 ) s;( 3.00 ± 0.00 ) vs. ( 3.00 ± 0. 00); P ＞ 0. 05 ). MD had a subtle influence on spatial learning and memory (P ＞0.05). Meanwhile,MD could lead to PP1Cγ expression down-regulation on PND 22 ( (2.19 ±0.62) vs. (3.52 ±0.86), P＜0. 05)which was in line with early neurobehavior results. No difference was found compared with MD group and control group on PND60 ( ( 1.73 ± 0. 78 ) vs. ( 1.33 ± 0. 34); P ＞ 0.05 ). However, there was the up-regulation of PP1Cγexpression on PND 90 ( (2.85 ± 0. 34) vs. ( 1.34 ± 0.93 ); P ＜ 0.05 ). Conclusion MD alters early neurobehavior and hippocampal PP1Cγgene expression in the Wistar rats,but has a subtle effect on learning and memory. At the same time,MD can make PP1Cγexpression in the hippocampus varying with the age.