Effects of maternal deprivation on hippocampal PP1Cγ gene expression and neurobehavior of rats

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. Key words: Maternal deprivation; Hippocampus; Neurobehavior; PP1Cγ