The Potential Mechanism Of The Rats’ Abnormal Behavior Resulted From Maternal Separation In Neonatal Period

Objectives To detect the expression level of Caveolin-1, GFAP, BDNF and in rats’ hippocampal formation after maternal separation, and explore the potential mechanism of rats’ abnormal behavior resulted from maternal separation in neonatal period.Methods48Wistar neonatal rats were divided into maternal separation group and control group, equally and randomly. The rats of maternal separation group were separated from the dam for3h per day (8:00-11:00am) on postnatal days (PND)2-21, nothing was done to the rats in the control group. The brain tissues were taken out after being killed on PND7, PND14, and PND21. The expression of Caveolin-1, GFAP and BDNF in rat’s hippocampal formation were detected by immunohistochemistry. Image-Pro Plus software were used to semiquantitative assessment the immuneohistochemical images.Results (1)The expression and distribution of Caveolin-1, GFAP, BDNF in rat’s hippocampal formation:the appearances of claybank particles were used as a positive judgment standard. Caveolin-1was mainly expressed in the neuron and glias of hippocampus; GFAP was mostly expressed in the hippocampal astrocyte, and BDNF was mainly expressed in the hippocampal pyramidal cells and dentate gyrus. (2)The expression of Caveolin-1in hippocampal formation: the expression of Caveolin-1in the control group showed significantly increased on postnatal days7,14and21(P<0.01). The expression of Caveolin-1in the maternal separation group showed no significant difference between postnatal days7and14(P>0.05), but significantly increased on postnatal days21(P<0.05). Compared with the control groups (0.15±0.02), the expression of Caveolin-1in the maternal separation group(0.15±0.01) showed no significant difference on postnatal days7(P>0.05), decreased on postnatal days14(P<0.05), and significantly decreased on postnatal days21(P<0.01).(3)The expression of GFAP in hippocampal formation:the expression of GFAP in the control group showed significantly showed significantly increased on postnatal days7,14and21, with the increase of time (P<0.05). The expression of GFAP in the maternal separation group showed no significant difference on postnatal days7,14and21(P>0.05). Compared with the control groups, the expression of GFAP in the maternal separation group showed significantly increased on postnatal days7(P<0.05), decreased on postnatal days14(P<0.05), significantly decreased on postnatal days21(P<0.05).(4) The expression of BDNF in hippocampal formation:the expression of BDNF in the control group showed significantly increased on postnatal days7,14and21, with the increase of time (P<0.05). All of the expression of BDNF in the maternal separation group showed no significant difference on postnatal days7,14and21(P>0.05). Compared with the control groups, the expression of GFAP in the maternal separation group showed significantly increased on postnatal days7(P<0.05), decreased on postnatal days14(P<0.05), significantly decreased on postnatal days14and21(P<0.01).Conclusion The expression of Caveolin-1, GFAP, BDNF decreased in hippocampal formation after maternal separation, which are possibly related to the rats’abnormal behavior in the condiction of consecutive maternal separation in early life, and it may provide important clue for further exploring the mechanism.