Effect of environmental enrichment on cognitive function and the expressions of hypoxia inducible factor 1α and vascular endothelial growth factor in rats with chronic cerebral hypoperfusion
10.3760/cma.j.issn.0254-9026.2016.01.020
- VernacularTitle:丰富环境对慢性脑低灌注大鼠低氧诱导因子血管内皮生长因子的表达及其认知功能的影响
- Author:
Min DENG
;
Junjian ZHANG
;
Jun SHEN
;
Xi LIU
- Publication Type:Journal Article
- Keywords:
Brain ischemia;
Cognition;
Milieu therapy;
Hypoxia-inducible factor 1;
Vascular endothelial growth factor
- From:
Chinese Journal of Geriatrics
2016;35(1):79-84
- CountryChina
- Language:Chinese
-
Abstract:
Objective To observe effect of environmental enrichment on the learning and memory ability and the expressions of hypoxia inducible factor 1α (HIF-1a) and vascular endothelial growth factor (VEGF) in rats with chronic cerebral hypoperfusion.Methods A total of 40 rats were randomly divided into 3 groups: bilateral vascular occlusion (2VO) of the common carotid arteries group (n=14, 2VO group), 2VO + enriched environment (EE) group (n=14, 2VO+EE group) and sham group (n=12, SHAM group).Morris water maze, novel object recognition test, real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), immunohistochemistry methods and Western blotting were used to detect changes in learning and memory ability of rats and HIF-1α and VEGF expression levels in hippocampus.Results Morris water maze showed that the escape latency was longer in the 2VO group than in the SHAM group at 3, 4 and 5 day during the training (all P＜0.05), while the 2VO+EE group spent significantly less time in finding the platform as compared with the 2VO group at 4 and 5 day (both P＜0.05).The time for space exploration in target quadrant was less in 2VO group than in SHAM group (P＜0.05), while it was longer in 2VO +EE group than in 2VO group (P＜0.05).Novel object recognition test showed that the 2VO operation impaired the priority index (PI) of time spending at exploring the novel object (P＜0.05), and environmental enrichment could improve the PI in 2VO group (P＜0.05).The real-time RT-PCR and Western blotting showed that the HIF-1α mRNA expression was higher in 2VO group than in SHAM group (P＜0.05).The VEGF mRNA and protein expressions were higher in 2VO+EE group than in 2VO group (both P＜0.05).The expression of HIF-1α in hippocampal CA1 area was higher in 2VO group than in SHAM group (P＜0.05).Conclusions Environmental enrichment can alleviate the damages of spatial and non-spatial learning and memory ability which are caused by chronic cerebral hypoperfusion.And HIF-1α and its downstream gene VEGF may be involved in the restoration of cognitive function by enriched environment.
