Abstract
Early-life psychological stress (ELPS) can cause anxiety, pessimism, and a decrease of cognitive ability in adult individuals. In this study, a psychological stress model (a terrified sound stress) was applied to new-born Sprague-Dawley rats for 21 days. And then, we separately evaluated the impact of ELPS on their spatial learning and memory abilities and hippocampal proteome from early-stage to the adult-stage. The Morris Water Maze (MWM) test was employed to evaluate their spatial learning and memory abilities after ELPS till to the adult-stage. Two-dimensional gel electrophoresis (2DE) as well as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) were used to uncover the protein expression profile of the hippocampus from both ELPS-young and ELPS-adult as well as their control groups. We found that the rats had a dysfunction of spatial learning and memory after the ELPS till to the adult-stage. The proteomic analysis revealed that 51 proteins were significant differentially expression, and 25 of them were down-regulated, while the other 26 proteins were up-regulated in the hippocampus of the ELPS-young rats compared with the controls. In the ELPS-adult rats, there were 56 significant differentially expression proteins, and 42 of them were down-regulated, the other 14 proteins were up-regulated in the hippocampus compared with their controls. Thirteen of the most significant differentially expressed proteins in ELPS-adult hippocampus were identified as SPTAN1, MYH4, HSPA8, HS90A, DYN1, DLDH, ARP3, GLNA, SAHH, HBB1, ACLY, TBB2A and GBB1, that demonstrated the greatest stress-induced changes. Furthermore, western blotting analyses consistently showed that the reduced expression of SPTAN1 and MYH4 whereas the expression of HSPA8 was up-regulated in the hippocampus after ELPS till to the adult-stage. The current study showed the impaired spatial learning and memory and changed hippocampal gene expressions induced by ELPS from early-stage to adult-stage in rats. This study shows that ELPS plays an important role in behavioral cognition and hippocampal protein expression in adult rats.
A novel trimeric peptide, Neuropep-1-stimulating brain-derived neurotrophic factor expression in rat brain improves spatial learning and memory as measured by the Y-maze and Morris water maze
