ABSTRACT
Objective To investigate the correlations between the hippocampal acetylcholine (ACh) content and neuronal apoptosis in the hippocampal CA1 region as well as the spatial memory impairment in a rat model of vascular dementia (VaD).Methods Forty male healthy Sprague-Dawley rats were randomly divided into either a VaD group or a sham operation group (n =20 in each group).A VaD model was induced by intermittently clipping common carotid artery.Microdialysis was used to collect dialysis solutions in rat hippocampus.High-performance liquid chromatographic analysis was used to detect the ACh content in the dialysis fluid.Morris water maze test was used to test their learning and memory abilities.TUNEL staining was used to detect neuronal apoptosis in the hippocampal CA1 region.Results Microdialysis analysis showed that the ACh content in the hippocampus in the VaD group was significantly lower than that in the sham operation group (0.442 ± 0.028 μmmol/L vs.1.560 ± 0.092 μ mmol/L; t =51.697,P =0.000).TUNEL staining showed that the apoptosis rate in the hippocampal CA1 region in the VaD group was significantly higher than that in the sham operation group (55.652％ ±2.051％ vs.6.530％ ± 1.872％ ; t =79.114,P=0.000).The escape latencies at different detection time points were prolonged significantly (At day 3:49.713 ± 18.161 s vs.13.322 ± 2.454 s; t =-8.881,P =0.000; at day 4:34.368 ± 7.424 s vs.10.503±1.415 s; t=-14.121,P=0.000; at day 5:30.676± 6.669s vs.7.311± 1.534 s; t=-15.270,P =0.000),and the numbers of cross platform were reduced significantly (3.768 ± 1.072 vs.10.218 ± 1.165; t =18.224,P=0.000).Pearson correlation analysis showed that the ACh contents in the VaD group were negatively correlated with the escape latencies (at day 3:r =-0.476,P =0.034; at day 4:r=-0.700,P=0.001; at day 5:r=-0.693,P=0.001).They were positively correlated with the numbers of cross platform (r =0.689,P =0.001),and negatively correlated with the neuronal apoptosis rates in the hippocampal CA1 region (r =-0.271,P =0.031).Conclusions The decreased ACh content,the increased neuronal apoptosis rate in the rat hippocampal CA1 region in the VaD model may be one of the mechanisms of cognitive impairment in VaD rats.
ABSTRACT
ObjectiveTo explore the expression of hemopoietin(EPO) mRNA on cerebral ischemia-reperfusion injury in rats brain tissue and the effect of Tongxinluo on it.Methods The model of rat (MCAO) were perfused with Tongxinluo,the changes of neural stem cell proliferation and differentiation related cell factors of EPO mRNA were detected after ischemia-reperfusion injury 3、5、7、14 d by means of reverse transcriptase polymerase chain reaction(RT-PCR).ResultsEPO mRNA of ischemia-reperfusion models showed expression in different period,the expression enhanced in the third day,reached the highest in the fifth day; the ischemia side EPO mRNA expression enhanced in the third day after give Tongxinluo,in the 5,7 and 14 day,PCR expression gray values were higher than the model group.ConclusionEPO mRNA expression enhanced after cerebral ischemia,this expression can be strengthened by Tongxinluo,and may further induce neural stem cell proliferation and differentiation.