Environmental Enrichment Improves Spatial Learning and Memory in Vascular Dementia Rats with Activation of Wnt/β-Catenin Signal Pathway

Abstract

BackgroundEnvironmental enrichment (EE) has a beneficial effect on some neuropsychiatric disorders. In this study, we aimed to investigate whether environmental enrichment could improve the spatial learning and memory in rats with vascular dementia (VaD) and the mechanism underpinning it.Material/MethodsBilateral common carotid occlusion (2-vessel occlusion [2VO]) was used to develop the animal model of vascular dementia. Adult male Sprague-Dawley (SD) rats were used in the experiment and were randomly divided into 4 groups: sham group, 2VO group, sham+EE group, and 2VO+EE group (n=19/group). The 2VO group and 2VO+EE group underwent bilateral common carotid occlusion. Two different housing conditions were used in this experiment: standard environment (SE) and enriched environment (EE). Rats in the sham group and 2VO group were put into SE cages for 4 weeks, while rats in the sham+EE group and 2VO+EE group were put in EE cages for 4 weeks. The Morris water maze and Y-maze were used to assess spatial learning and memory. Apoptosis was detected by TUNEL. The damage of neurons in the hippocampus was assessed by Nissl staining. The level of wnt pathway proteins were detected by Western blot.ResultsCompared with the 2VO group, the rats in the 2VO+EE group had better behavioral performance, fewer apoptotic neurons, and more surviving neurons. Western blot analysis showed that the levels of wnt pathway proteins were higher in 2VO+EE rats than in the 2VO group.ConclusionsEnvironmental enrichment can improve the spatial learning and memory in rats with vascular dementia, and the mechanism may be related to activation of the wnt/β-catenin signal pathway.

Restoring Wnt6 signaling ameliorates behavioral deficits in MeCP2 T158A mouse model of Rett syndrome

“…Thus, we have provided novel molecular mechanisms of EE in the context of RTT. These results are also congruent with another report showing that EE improves memory function in vascular dementia rats associated with activation of Wnt3a signaling 29 . It is conceivable that EE activates many more genes other than Wnt6, yet EE could not completely rescue the behavioral deficits of MeCP2 T158A mice.…”

Effect of Environmental Factors on Depressive-like Behavior and Memory Function in Adolescent Rats

“…In previous studies using environmental enrichment, they have shown to improve spatial memory in the Morris water maze test [11,12];…”

“…In other words, environmentally enriched housing helped improve their stress-coping strategies [10]. Regarding spatial learning and memory, environmental enrichment showed positive effect by reducing the escape latencies in the Morris water maze test [11,12].…”

Heavy metals contaminating the environment of a progressive supranuclear palsy cluster induce tau accumulation and cell death in cultured neurons

“…Although more studies are needed to understand why RA treatment makes SH-SY5Y cells more sensitive to Ni and more resistant to Cr, these two heavy metals may induce neuronal death by different mechanisms. Cr and Ni have opposite effects in the regulation of the PI3K/AKT survival signaling pathway, Cr treatment inhibits PI3K/AKT activity 66 while Ni exposure activates the pathway 67 . RA treatment induces the activation of survival pathways including PI3K/AKT in SH-SY5Y cells 61 , thus we speculate that the addition of RA could be protecting the neuron-like differentiated SH-SY5Y cells from toxicity induced by Cr but sensitizing them to the cell death induced by Ni.…”