Effects of environmental enrichment and stress paradigm experience on adolescent period alter behaviors and neurochemistry in rats

摘要

Effects of environmental enrichment and stress paradigm experience on adolescent period alter behaviors and neurochemistry in rats The purpose of this study behavioral alteration caused by envi- ronmental stress and enrichment were changed by glutamate receptor activity and synaptic strength in the rat brain. 8 weeks-old Sprague-Dawley male rats were subjected to the restraint-stressed (Stressed) and enriched environment (Enriched) paradigm for four hours of daily on seven consecutive days. The stressed group indicated lower body weight gain and growth compare with the control and the enriched groups. After the environmental stimu- lation session, rats have been trained a standard water maze task for their spatial learning abilities, the stressed group was marked the delayed acquisition than other groups. The exploratory behav- ior was measured for 5 min after exposure to a novel environment for 3 consecutive days, the only dramatically difference showed that the enriched group animals show higher locomotive behav- ior compare to other groups. In the neurochemical assessment of the hippocampus, the expression level of p-CREB is significantly increased in the enriched group than other groups. The subfam- ily of metabotropic glutamate receptors, mGluR-5 and mGluR-1a expression had upregulated in the hippocampus both the control and the enriched groups. These results suggested that the repeti- tive exposure to stressed or enriched environmental on adolescent period may alter explorative behavior and neurochemical chages in the hippocampus.