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Objective To study the effects of different types of exercise training on learning and memory, as well as on the expression of synaptophysin (SYP) and on postsynaptic density protein 95 (PSD-95) in rats in which a model of vascular dementia had been created.Methods Forty male Wistar rats were divided randomly into a voluntary exercise group (V-EX) , a forced exercise group (F-EX) , an involuntary exercise group (I-EX) , a vascular dementia group (VD) and a sham-operation group (Sham) , with 8 rats in each group.Two-vessel occlusion (2-VO) of the arteria carotis communis was used to create a model of vascular dementia in all of the rats except those in the sham-operation group.Beginning one week after the surgery, the V-Ex rats were free to run in a running wheel.The F-EX rats were forced to run 270 m a day in an electric wheel.The I-EX rats were stimulated to imitate the gait pattern of their forelimbs running at 9 m/min three times a day for l0 minutes each time.No special training was given to the rats in the other 2 groups.Three weeks after the surgery, their learning and memory were tested using a novel object recognition test.Immediately after the test, their prefrontal cortex was sampled and the expression of SYP and PSD-95 was detected using western blotting.Results The average novel object recognition indices of the rats in the V-EX, F-EX and I-EX groups were all significantly higher than that of the VD group.Average PSD-95 expression was also significandy higher than in the VD group.Conclusion Exercise, whether voluntary, forced or induced by functional electrical stimulation can improve learning and memory in vascular dementia, at least in rats.The mechanism is possibly that the training can increase the expression of PSD-95 in the prefrontal cortex, though not SYP.
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Objective To investigate the effects of functional electrical stimulation (FES) on motor function and the expression of bromodeoxyuridine (Brdu) + and glial fibrillary acid protein (GFAP) + in the subventricular zone (SVZ) of rats with acute cerebral infarction,and to explore it's mechanism. Methods A rat model of cerebral infarction was established using Longa's technique for middle cerebral artery occlusion (MCAO) with an intraluminal filament.The rats were randomly divided into a FES group,a placebo stimulation group and a control group.In each group,rats were randomly allocated into 1 d,3 d,7 d and 14 d subgroups (6 rats/subgroup).Superficial electrodes were pasted on the paralyzed forelimbs of rats in the FES group for connecting with the FES instrument,and FES treatment was carried out with a current of 4-5 mA for 15 min on the third day after the MCAO operation to produce extension of the wrist and the digits of the paralyzed forelimb.The rats in the placebo stimulation group were pasted with electrodes,but no FES was administered and they received no other treatment.Neurological deficits were evaluated using the modified neurological severity score (mNSS) before treatment and on the 1 st,3rd,7th,and 14th day after treatment. BrdU and GFAP positive cells in the SVZ were detected by immunofluorescence techniques.Results After 7 or 14 days the motor function of rats in the FES group had improved significantly compared with the placebo stimulation and control groups.Compared with the other two groups,the expression levels of BrdU+ and GFAP+ cells in the ischemic SVZ in the FES group were significantly higher at the 3rd,7th and 14th day.Conclusion FES can improve motor function after acute cerebral infarction and also promote the proliferation and differentiation of neural stem cells in the SVZ.
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ObjectiveTo explore the relationship of body fat distribution with serum lipid and its potentially predictive value for dyslipidemia.MethodsA total of 784 Beijing rural residents were enrolled in this study using a cluster sampling method.The body height,weight,waist circumference (WC),hip circumference,body composition,high-density lipoprotein cholesterol ( HDL-C ),low-density lipoprotein cholesterol ( LDL-C),total cholesterol ( TC),and triglycerides (TG) were measured.The body mass index (BMI) and waist to hip ratio (WHR) were calculated.ResultsThe age-adjusted partial correlation analysis showed that WC had the best correlation with HDL-C ( r =- 0.310) and LDL-C ( r =0.204 ),while WHR with TC ( r =0.151 ) and TG ( r =0.271 ).Subgroup analysis with different BMI,WC,WHR,and trunk fat mass (TFM) showed that WC,WHR,and TFM sensitively reflected the changes of body lipids,whereas BMI,WC,WHR,and TFM sensitively reflected the low HDL,high TG,and risk of dyslipidemia.Receiver operating characteristic curve analysis showed that the predictive curves of WC,WHR,BMI,and TFM were above the reference line,and the areas under the receiver operating characteristic curves of WHR (0.684,0.630),WC (0.667,0.616),and TFM (0.661,0.604) showed high tendencies than BMI (0.629,0.597) for both male and female subjects,although no statistically significant differences were found ( all P ＞ 0.05 ).ConclusionsCompared with BMI,the body fat distribution indicators including WHR,WC,and TFM have higher predictive values in evaluating the risk of dyslipidemia.When the maximum Youden index for predicting the risk of dyslipidemia is applied,the ideal cutoff points was 24 kg/m2 for BMI,0.91 for WHR,85cm for WC,7.5kg for TFM in males,and 25 kg/m2,0.91,87cm,and 9.5 kg,respectively,in females.
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Objective To study the effects of functional electric stimulation(FES) on neural function recovery and expression of nestin around cerebral infract area of rats with acute stroke.Methods The model of middle cerebral artery occlusion(MCAO) of male adult SD rats was established with the method of modified intraluminal filament occlusion.Sixty successfully established model rats were randomly allocated into FES group, placebo group and control group(20/group).Three days after MCAO' s surgery, rats in FES group were treated with FES device while the ones in placebo stimulation group were treated with the same FES device but without electrical output.Rats in control group had no treatment.All groups were randomly assigned into 4 subgroups according to treatment time:1 d,3 d ,7 d and 14 d (5/subgroup).The modified neurological severity score(mNSS) was adopted to evaluate neural function recovery before and after treatment in 4 time points as mentioned above.Meanwhile,the nestin expression in various time points was detected by immunohistochemistry stain in distant area of ipsilateral cortex of infarction.Results The mNSS sours in FES group is lower than that in placebo simulation group and control group at the 7 thd and 14thd (P < 0.05 ) ;The expression of nestin-positive cells in distant area of ipsilateral cortex of infarction of rats in FES group is higher than that in placebo stimulation group and control group ( P < 0.05 ).Conclusions FES may improve the recovery of neural function in the earlier stage of cerebral infarction.FES treatment could improve the expression of nesitin around cerebral infarct area and it could be one of the mechanisms of FES' s effect.
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Objective To study the effects of low-frequency electrical stimulation(LFES)on motor function and the expression of glia fibrillary acidic protein(GFAP)around cerebral infarction sites in rats.Methods Fifty-four male adult Sprague-Dawley rats were randomly divided into a LFES group,a placebo group and a sham operation group(18/group).All groups were randomly divided into 3 treatment groups.A rat model of middle cerebral artery occlusion(MCAO)was established using intraluminal filament occlusion.Treatment was carried out 3 d after the operation.Rats in the LFES treatment groups were stimulated with LFES for 3,7 or 14 days (10 min/d);the placebo groups were treated in the same way without electric stimulation;the sham operation subgroups didn't receive any therapy.Scores on a beam-walking test,a rotating pole test and a screen test were assessed at each time point mentioned above.Expression of GFAP was also assessed using immunohistochemcal techniques.Results The paralysed limbs recovered motor function better in the LFES groups than in the control groups.GFAP-positive cells were more numerous at the margins of the infarction area in the treated groups than in the control groups.Conclusions LFES might increase the expression of GFAP,which might be an important mechanism in improving brain plasticity after cerebral ischemia,aiding the recovery of the central nervous system and rebuilding its functioning.
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Objective To study changes in synaptic plasticity in the contralesional mirror area of the cortexes of rats with cerebral infarction treated by low-frequency electrical stimulation(LFES)and to explore the therapeutic mechanism of LFES on the molecular level.Methods Forty-eight Sprague-Dawley rats were randomly allocated into a LFES group,a placebo group and a sham-operation group.Following middle cerebral artery occlusion(MCAO),rats in the LFES group were treated with LFES for 7 d(20 min/d),while the ones in placebo group were connected with the same LFES device but without electricity.Rats in the sham-operation group were subjected to a MCAO operation without occlusion and then received no special treatment.Synaptic ultra-structures and the expression levels of glia fibrillary acidic protein(CFAP)and synaptophysin in the contralesional mirror area of the cortexes of the rats in each group were measured with electron-microscopy and Western blotting.Results Compared with the placebo group or the rats before treatment,rats treated with LFES exhibited ultra-structural changes in the form of larger curvature of synaptic interfaces and narrower synaptic clefts.GFAP expression levels did not fluctuate significantly,but the expression of synaptophysin was significantly up-regulated.Conclusion LFES treatment can induce active changes in synaptic plasticity in the contralesional mirror area of the cortex of rats after cerebral infarction.