Effects of enriched environment on immature neurons in piriform cortex of a rat model of vascular dementia / 中国组织工程研究

ABSTRACT

BACKGROUND:Researches showed that the enriched environment could improve the cognitive dysfunction of rats with vascular dementia. However, there are few reports regarding its mechanism of action. OBJECTIVE:To explore the effect of enriched environment on the cognitive dysfunction of rats with vascular dementia from the behavioral level. METHODS:Vascular dementia models weremade by permanent ligation of bilateral common carotid arteries and were divided into vascular dementia group (n=8) and enriched environment group (n=12). Vascular dementia group was taken care under conventional breeding environment for 30 days, while the enriched environment group was subjected to the enriched environment for 30 days. Morris water maze test was adapted to test the cognitive function of rats between two groups. Immunohistochemistry and immunoblotting were applied to observe the number ofDCX+cels and DCX protein level in both groups. The number of DCX-labeled cels co-expressing NeuN was observed using immunofluorescence technique. RESULTS AND CONCLUSION:(1) The escape latency in the vascular dementia group was longer than that in the enriched environment group (P< 0.05). The times across the platform was less in the vascular dementia group than that in the enriched environment group (P< 0.05). (2) In comparison with the enriched environment group, the number of DCX-positive cels andits protein level in the piriform cortex were significantly decreased in the vascular dementia group (P< 0.05). (3) The number of DCX/NeuN co-labeled cels in the piriform cortex was significantly less in the vascular dementia group than in the enriched environment group (P< 0.05). (4) These findings suggested that enriched environment could improve the cognitive dysfunction of rats with vascular dementia through promoting the expression and differentiation of the immature neurons.