Functional electrical stimulation improves cognitive deficits of an animal model of vascular dementia by upregulating expression of the BDNF-SYN-MAP2 pathway proteins / 中华物理医学与康复杂志

ABSTRACT

Objective:To explore the effect of functional electrical stimulation on cognition and on the expression of the brain-derived neurotrophic factor (BDNF), synaptophysin (SYN) and microtubule-associated protein 2 (MAP2) using a rat model of vascular dementia.Methods:Ninety pathogen-free male Wistar rats were randomly divided into a sham operation group, a placebo stimulation group and an electrical stimulation group. Both the placebo and electrical stimulation groups underwent bilateral occlusion of the common carotid artery to establish a model of vascular dementia. In the sham operation group the arteries were exposed without occlusion. Each group was then sub-divided into 3, 7 and 14 days subgroups with 10 rats in each subgroup. Beginning seven days after the surgery, the rats in the electrical stimulation group were given 30-minutes of stimulation every day while those in the sham operation group and the placebo stimulation group were given false electrical stimulation. After 3, 7 or 14 days the rats′ cognitive functioning was quantified using the Morris water maze test. The rats were then sacrificed and the expression of BDNF mRNA was measured using in situ hybridization. MAP2 and SYN levels were quantified immunohistochemically.Results:After 14 days the average latency in the placebo stimulation group was significantly longer than in the other groups. On the sixth day the average time in the target zone among the placebo stimulation group was significantly shorter than the other two groups′ averages. After only 3 days of simulation, the average expression of BDNF mRNA in the CA1 area of the hippocampus was significantly lower in the placebo stimulation group than among the others. After 7 days of stimulation the placebo group′s average was significantly lower than that of the sham operation group. The average expression of MAP2 had decreased significantly in the placebo stimulation group compared with the other two groups after 7 and 14 days of simulation. After 7 days the average expression of SYN in the placebo stimulation group was significantly lower than in the sham operation group, and after 14 days it was significantly lower than in the other two groups.Conclusions:Functional electrical stimulation may improve learning and memory in rats modelling vascular dementia through increasing BDNF, SYN and MAP2 expression levels.